Publications by authors named "Ali A El-Gamal"

37 Publications

Insecticidal Activity and Free Radical Scavenging Properties of Isolated Phytoconstituents from the Saudi Plant (Hochst.).

Molecules 2021 Feb 9;26(4). Epub 2021 Feb 9.

USDA, ARS, Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, FL 32608, USA.

Chromatographic purification of the alcoholic extract from the aerial parts of the Saudi plant (Hochst.), Benth., resulted in five isolated phenolic compounds. Two flavones, hispidulin () and jaceosidin (), and the phenylethanoid glycosides, verbascoside (), isoverbascoside (), and conandroside (), were identified and their chemical structures were determined by spectroscopic analyses. The insecticidal activity of compounds and in addition to 11 compounds isolated in a previous research (-), was evaluated against the Yellow Fever mosquito, . Four compounds displayed adulticidal activity with LD values of 2-2.3 μg/mosquito. Free radical scavenging properties of the plant extracts and compounds (-) were evaluated by measuring the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonate radical cation (ABTS) scavenging activity. All compounds exhibited notable activity, compared with the positive control, l-Ascorbic acid. This study suggests that could be a promising source of secondary metabolites, some with lethal adulticidal effect against .
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http://dx.doi.org/10.3390/molecules26040914DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7915531PMC
February 2021

Sterols and Triterpenes from Growing in Saudi Arabia and Their Cytotoxic Activity.

Plants (Basel) 2021 Jan 8;10(1). Epub 2021 Jan 8.

Department of Pharmacognosy, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia.

A new lupane caffeoyl ester, lup-20(29)-ene 3β-caffeate-30-al (), and a new oleanane-type triterpene, 3-hydroxyolean-13(18)-en-12-one (), were isolated from the aerial parts of (Forssk), along with ten known triterpenes, including seven lupane-type lupeol (), 30-nor-lup-3-ol-20-one (), ∆-lupenone (), lup-20(29)-en-3,30-diol (), lupeol caffeate (), 30-hydroxy lup-20(29)-ene 3-caffeate (), and betunaldehyde (); three oleanane-type compounds were also identified, comprising -amyrone (), -amyrin (), and 11-oxo--amyrin (); together with six sterols, comprising -sitosterol (), stigmasterol (), 7-hydroxy--sitosterol (), 7-hydroxy-stigmasterol (), 7-keto--sitosterol (), and 7-keto-stigmasterol (). Their structures were elucidated using a variety of spectroscopic techniques, including 1D (H, C, and DEPT-135 C) and 2D (H-H COSY, H-C HSQC, and H-C HMBC) nuclear magnetic resonance (NMR) and accurate mass spectroscopy. Subsequently, the different plant extracts and some of the isolated compounds (, and ) were investigated for their possible cytotoxic activity in comparison to cisplatin against a wide array of aggressive cancer cell lines, such as colorectal cancer (HCT-116), hepatocellular carcinoma (HepG-2), and prostate cancer (PC-3) cell lines. Compound displayed broad cytotoxicity against all of the tested cell lines (IC ≅ 8 µg/mL in all cases), and a high safety margin against normal cells (IC = 70 µg/mL), suggesting that may be a highly selective and effective anticancer agent candidate. Notably, the evidence indicated that the mode of action of compound could possibly consist of the inhibition of phosphodiesterase I (80.2% enzyme inhibition observed at 2 µM compound concentration).
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http://dx.doi.org/10.3390/plants10010119DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7827382PMC
January 2021

Vacillantins A and B, New Anthrone -glycosides, and a New Dihydroisocoumarin Glucoside from and Its Antioxidant Activities.

Plants (Basel) 2020 Nov 24;9(12). Epub 2020 Nov 24.

Department of Pharmacognosy, College of Pharmacy, King Saud University, PO. Box 2457, Riyadh 11451, Saudi Arabia.

A new dihydroisocoumarin glucoside, vacillanoside (), and two new anthrone -glycosides microdantin derivatives; vacillantin A () and B (), together with nine known compounds belonging to the anthraquinone, anthrone and isocoumarin groups were isolated from the leaves of . The structures were determined based on spectroscopic evidence including 1D and 2D nuclear magnetic resonance (NMR) spectroscopy and high resolution mass spectrometry (HRESIMS) data, along with comparisons to reported data. The leaves were used to extract compounds with different solvents. The extracts were tested for antioxidant activity with a variety of in vitro tests including 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonate (ABTS), ferric reducing antioxidant power assay (FRAP), superoxide, and nitric oxide radical scavenging assays. The dichloromethane fraction was most active, displaying significant free radical scavenging activity. The -butanol fraction also showed notable activity in all assays. Therefore, these findings support the potential use of leaves as an antioxidant medication due to the presence of polyphenolic compounds.
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http://dx.doi.org/10.3390/plants9121632DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7761211PMC
November 2020

Siphonocholin isolated from red sea sponge attenuates quorum sensing controlled virulence and biofilm formation.

Saudi Pharm J 2020 Nov 12;28(11):1383-1391. Epub 2020 Sep 12.

National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, India.

Increasing incidence of multi-drug resistant bacterial pathogens, especially in clinical settings, has been developed into a grave health situation. The drug resistance problem demands the necessity for alternative unique therapeutic policies. One such tactic is targeting the quorum sensing (QS) controlled virulence and biofilm production. In this study, we evaluated a marine steroid Siphonocholin (Syph-1) isolated from siphonella against (CV) 12472, (PAO1), Methicillin-resistant (MRSA) and (BAA) for biofilm and pellicle formation inhibition, and anti-QS property. MIC of Syph-1 against MRSA, CV, PAO1 was found as 64 µg/mL and 256 µg/mL against BAA. At selected sub-MICs, Syph-1 significantly (P ≤ 0.05) decreased the production of QS regulated virulence functions of CV12472 (violacein) and PAO1 [elastase, total protease, pyocyanin, chitinase, exopolysaccharides, and swarming motility]. The Syph-1 significantly decreased (p = 0.005) biofilm formation ability of tested bacterial pathogens, at sub-MIC level (PAO1 > MRSA > CV > BAA) and pellicle formation in A. baumannii (at 128 µg/mL). Molecular docking and simulation results indicated that Siph-1 was bound at the active site of BfmR N-terminal domain with high affinity. This study highlights the anti-QS and anti-biofilm activity of Syph-1 against bacterial pathogens reflecting its broad spectrum anti-infective potential.
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http://dx.doi.org/10.1016/j.jsps.2020.09.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7679466PMC
November 2020

Evaluation of cytotoxicity, cell cycle arrest and apoptosis induced by L essential oil in human hepatocellular carcinoma cell line.

Saudi Pharm J 2019 Nov 25;27(7):1053-1060. Epub 2019 Sep 25.

Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia.

L. () commonly known as , is an essential oil bearing plant extensively being used in traditional system of medicine. However, the reports on the components and biological responses of essential oil (AG-EO) from Saudi Arabia are scarce. The present study was designed to explore the presence of basic constituents and apoptosis induced by AG-EO in HepG2 cells. The constituents in AG-EO was analyzed by Gas chromatography-Mass spectroscopy (GC-MS). Cytotoxicity of AG-EO was measured by MTT assay and cell cycle arrest and apoptosis assays were conducted by using flow cytometer. Based on GC-MS analysis, the main constituents present in AG-EO were carvone (53.130%), dillapole (25.420%), dihydrocarvone 2 (11.350%) and dihydrocarvone 1 (6.260%). A few other minor components were also identified -dihydrocarveol (0.690%), limonene (0.580%), isodihydrocarveol (0.370%), myristicin (0.210%) and -arsone (0.190%). The cytotoxicity results showed that AG-EO decrease the cell viability and inhibit the cell growth of HepG2 cells in a concentration-dependent manner. The inhibitory activity of AG-EO was found with IC = 59.6  5.64. The cell cycle arrest results showed that HepG2 cells exposed to AG-EO exhibited an increase in G2/M and pre-G1 cell population after 24 h exposure. Furthermore, the flow cytometry data revealed the primarily activation of cell death by apoptosis manners in HepG2 cells exposed to AG-EO. Overall, results from this study highlighted the anticancer potential of AG-EO, which could be considered as a new agent for the management of hepatocellular carcinoma.
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http://dx.doi.org/10.1016/j.jsps.2019.09.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6978617PMC
November 2019

Molluscicidal activity of cardiac glycosides isolated from Adenium obesum.

Pest Manag Sci 2019 Oct 1;75(10):2770-2775. Epub 2019 Apr 1.

Department of Plant Protection, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia.

Background: Terrestrial mollusks are one of most important agricultural pests worldwide. Natural phytochemicals have an extended history as a source of pesticides. This study was planned to isolate molluscicidal active compounds from the stems of Adenium obesum.

Results: The benzene-soluble fraction of the hydroethanolic extract displayed the most potent molluscicidal activity against Monacha obstructa among different solvent fractions with a median lethal dose (LD ) of 4.91 µg g body weight (bw). The bioactivity-guided chemical exploration of the benzene-soluble fraction led to the isolation of two known cardiac glycosides, cerberin and neriifolin which showed significant molluscicidal activity with LD values of 5.39 and 4.3 µg g bw, respectively.

Conclusion: Isolation of the cardiac glycoside neriifolin from A. obesum and the molluscicidal activity of cerberin and neriifolin against terrestrial snails are reported for the first time. © 2019 Society of Chemical Industry.
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http://dx.doi.org/10.1002/ps.5388DOI Listing
October 2019

Comparative evaluation of cytotoxic, antimicrobial and antioxidant activities of the crude extracts of three species grown in Saudi Arabia.

Saudi Pharm J 2019 Feb 25;27(2):162-170. Epub 2018 Sep 25.

Department of Pharmacognosy, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia.

Natural products from medicinal plants represent major resource of novel therapeutic substances for combating serious diseases including cancers and microbial infections. The genus (Family: Labiatae) represents a large and widespread group of species with a diversity of traditional uses in treatment of various ailments. Therefore, this research study aimed to evaluate the cytotoxic, antimicrobial and antioxidant activities of three species growing in Saudi Arabia namely Hocst. ex Benth. JRI Wood and Andrews Moreover, this work focused on the isolation of the active constituents responsible for the activities from the most active species. The extracts were tested for their cytotoxic activity against three cancer cell lines (Hela, HepG2 and HT-29), using MTT-test, antimicrobial activity against Gram positive, Gram negative bacterial and fungal strains using broth micro-dilution assay for minimum inhibitory and bactericidal concentrations (MIC and MBC) and antioxidant activity using scavenging activity of DPPH radical and β-carotene-linoleic acid methods. The ethanolic extracts of the species showed remarkable cytotoxic activity against all cancer cell lines with IC values ranging between 10.1 ± 0.33 to 102.6 ± 8.66 μg/mL and a great and antimicrobial activity with MIC values between 62.5 and 250 µg/mL. In addition, the three species showed almost moderate antioxidant activity. The most interesting cytotoxic and antimicrobial results were observed with the extract of Consequently, this extract was partitioned between water and hexane, chloroform and butanol and tested. The cytotoxic activity resided predominantly in the hexane and chloroform fractions. The analysis of the chloroform fraction led to the isolation of four diterpenoid compounds, two of labdane- and two of abietane-type, which were identified as coleonol B, forskolin, sugiol and 5,6-dehydrosugiol. Purification of the -hexane fraction led to isolation of a major abietane-type diterpene, which was identified as ferruginol. Sugiol, 5,6-dehydrosugiol and ferruginol were isolated for the first time from in this study. The isolated diterpenoids showed variable cytotoxic effects with IC values between 15.1 ± 2.03 and 242 ± 13.3 µg/mL, a great antimicrobial activity with MIC values between 15.6 and 129 µg/mL and a total antioxidant activity ranging from 23.1 ± 2.9 to 69.2 ± 3.8%.
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http://dx.doi.org/10.1016/j.jsps.2018.09.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6362157PMC
February 2019

The Phytochemical and Biological Investigation of Root Native to the Kingdom of Saudi Arabia.

Molecules 2018 Jul 28;23(8). Epub 2018 Jul 28.

Department of Pharmacognosy, Faculty of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia.

Extensive phytochemical analysis of different root fractions of Courb. (Euphorbiaceae) has resulted in the isolation and identification of 22 secondary metabolites. 6-hydroxy-8-methoxycoumarin-7--β-d-glycopyranoside () and 2-hydroxymethyl -methyltryptamine () were isolated and identified as new compounds along with the known diterpenoid (, , , and ), triterpenoid ( and ), flavonoid (, , , , and ), coumarinolignan (⁻), coumarin (), pyrimidine (), indole (, ), and tyramine-derived molecules (⁻). The anti-inflammatory, analgesic, and antipyretic activities were evaluated for fifteen of the adequately available isolated compounds (⁻, ⁻, , , , , and ). Seven (, , , , , and of the tested compounds showed a significant analgesic effect ranging from 40% to 80% at 10 mg/kg in two in vivo models. Compound could also prove its analgesic property (67.21%) when it was evaluated on a third in vivo model at the same dose. The in vitro anti-inflammatory activity was also recorded where all compounds showed the ability to scavenge nitric oxide (NO) radical in a dose-dependent manner. However, eight compounds (, , , , , , , and ) out of the fifteen tested compounds exhibited considerable in vivo anti-inflammatory activity which reached 64.91% for compound at a dose of 10 mg/kg. Moreover, the tested compounds exhibited an antipyretic effect in a yeast-induced hyperthermia in mice. The activity was found to be highly pronounced with compounds , , , , , and which decreased the rectal temperature to about 37 °C after 2 h of the induced hyperthermia (~39 °C) at a dose of 10 mg/kg. This study could provide scientific evidence for the traditional use of as an anti-inflammatory, analgesic, and antipyretic.
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http://dx.doi.org/10.3390/molecules23081892DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6222854PMC
July 2018

X-ray crystallographic and validated HPTLC analysis of the biomarker chromone glucoside (schumanniofioside A) isolated from growing in Saudi Arabia.

Saudi Pharm J 2017 Nov 27;25(7):955-960. Epub 2017 Feb 27.

Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia.

A chromone glucoside 2-methyl-5,7-dihydroxychromone 5--β-D-glucopyranoside (schumanniofioside A, compound 1) was isolated from the methanol extract of . The structure of compound 1 was fully assigned based on nuclear magnetic resonance (NMR) (H, C and 2D) spectra and electrospray ionization mass spectrum (ESI-MS) in addition to X-ray Crystallography. The molecules were packed in the crystal structure by eight intermolecular O-H⋯O and C-H⋯O interactions. The structure of compound 1 belongs to monoclinic, 2,  = 9.1989 (4) Å,  = 4.6651 (2) Å,  = 20.4042 (7) Å, β = 97.862 (3)°,  = 867.31 (6) Å,  = 2,  = 0.101,  = 100 K. Thus, the bond angles, bond lengths and absolute structure of compound 1 were confirmed by its X-ray structure. A validated HPTLC method was developed for the quantitative analysis of compound 1 in chloroform and methanol extracts of . It was found to furnish a compact and sharp band of compound 1 at R = 0.13 ± 0.005 using chloroform, methanol and glacial acetic acid [17:3:0.5 (v/v/v)] as mobile phase. The LOD and LOQ for compound 1 were found to be 17.86 and 54.13 ng/band, respectively. Compound 1 was found in both chloroform and methanol extracts of the plant (0.03% w/w and 0.31% w/w, respectively). The proposed HPTLC method can be used for the further analysis of schumanniofioside A in different plant extracts, herbal formulations and biological samples as well as in process quality control.
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http://dx.doi.org/10.1016/j.jsps.2017.02.011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5681304PMC
November 2017

Isolation, biological evaluation and validated HPTLC-quantification of the marker constituent of the edible Saudi plant L.

Saudi Pharm J 2017 Jul 12;25(5):750-759. Epub 2016 Nov 12.

Pharmacognosy Department, Faculty of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia.

Phytochemical investigation and chromatographic purification of the -hexane fraction of the aerial parts of the edible Saudi plant led to the isolation of β-sitosterol (), stigmasterol () and β-sitosterol-β-d-glucoside (). The cytotoxic effects of the -hexane, dichloromethane, ethyl acetate and -butanol fractions were tested against three cancer cell lines viz., MCF-7, HCT-116 and HepG2, using the crystal violet staining (CVS) method, while the antibacterial activity against a number of pathogenic bacterial strains, was also estimated using the broth microdilution assay. The -hexane fraction showed potent cytotoxic activities against all tested human cancer cell lines (IC: 11.7-13.4 μg/mL), while the dichloromethane fraction was particularly potent against HCT-116 cells (IC: 5.42 μg/mL). On the other hand, the -hexane and EtOAc fractions demonstrated significant inhibitory activities against the Gram positive bacteria and ; and the Gram negative bacterium . Our results warrant the therapeutic potential of as nutritional supplement to reduce the risk of contemporary diseases. Additionally, a validated high performance thin-layer chromatography (HPTLC) method was developed for the quantitative analysis of biomarker β-sitosterol glucoside (isolated in high quantity) from the -hexane fraction. The system was found to furnish a compact, sharp, symmetrical and high resolution band for β-sitosterol glucoside (  = 0.43 ± 0.002). The limit of detection (LOD) and limit of quantification (LOQ) for β-sitosterol glucoside was found to be 21.84 and 66.18 ng band, respectively. β-sitosterol glucoside was found to be present only in -hexane fraction (2.10 μg/mg of dried fraction) while it was absent in the other fractions of . which validated the high cytotoxic and antibacterial activity of -hexane fraction of .
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http://dx.doi.org/10.1016/j.jsps.2016.10.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5506741PMC
July 2017

Prenylated flavonoids from Commiphora opobalsamum stem bark.

Phytochemistry 2017 Sep 3;141:80-85. Epub 2017 Jun 3.

Department of Pharmacognosy, Sattam Bin Abdulaziz University, College of Pharmacy, 11942, Al-kharj, Saudi Arabia.

A phytochemical study on the stem bark of Commiphora opobalsamum looking for cytotoxic compounds afforded eleven flavonoids, including six previously undescribed prenylated congeners, comophorin A-E, and comophoroside A. The structures of the isolated compounds were elucidated on the basis of spectroscopic evidences and correlated with known compounds. Isolated compounds were biologically evaluated using in vitro cytotoxicity MTT-based assay against two cancer cell lines; namely human hepato-cellular carcinoma (HepG-2) and human breast adenocarcinoma (MCF-7). Comophoroside A revealed to retain the strongest cytotoxic activity against MCF-7 and HepG-2 cell lines with IC values of 8 and 12 μg/mL, respectively.
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http://dx.doi.org/10.1016/j.phytochem.2017.05.014DOI Listing
September 2017

New Cytotoxic Seco-Type Triterpene and Labdane-Type Diterpenes from Nuxia oppositifolia.

Molecules 2017 Mar 2;22(3). Epub 2017 Mar 2.

Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia.

Chromatographic purification of the -hexane and dichloromethane extracts of aerial parts, growing in Saudi Arabia, resulted in the isolation and characterization of three new labdane-type diterpene acids, 2β-acetoxy-labda-7-en-15-oic acid (), 2β-acetoxy-7-oxolabda-8-en-15-oic acid (), 2β-acetoxy-6-oxolabda-7-en-15-oic acid (), and one new seco-triterpene, 3,4-seco olean-12-en-3,30 dioic acid (), together with 10 known lupane, oleanane and ursane-type triterpenes, as well as the common phytosterols, β-sitosterol and stigmasterol (-). Their structures have been assigned on the basis of different spectroscopic techniques including 1D and 2D NMR. Moreover, 13 of the isolated compounds were tested on the human cancer cell lines HeLa (cervical), A549 (lung) and MDA (breast), and most of the compounds showed potent cytotoxic activities in vitro.
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http://dx.doi.org/10.3390/molecules22030389DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6155346PMC
March 2017

New acyclic secondary metabolites from the biologically active fraction of flowers.

Saudi Pharm J 2017 Jan 24;25(1):110-119. Epub 2016 May 24.

Pharmacognosy Department, Faculty of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia.

The total extract of flowers was examined for its possible hepatoprotective activity in comparison with the standard drug silymarin at two doses. The higher dose expressed promising activity especially in reducing the levels of AST, ALT and bilirubin. Fractionation via liquid-liquid partition and reexamination of the fractions revealed that the -butanol fraction was the best in improving liver biochemical parameters followed by the -hexane fraction. However, serum lipid parameters were best improved with CHCl fraction. The promising biological activity results initiated an intensive chromatographic purification of flowers fractions. Two compounds were identified from natural source for the first time, the acyclic farnesyl sesquiterpene glycoside1-O-[6-O--l-arabinopyranosyl--d-glucopyranoside]-(2,6-)-farnesol () and the squalene derivative 2,3-dihydroxy-2,3-dihydrosqualene (), in addition to eight compounds reported here for the first time from the genus ; two benzyl glycosides, benzyl 1-O--d-glucopyranoside () and benzyl 6-O--l-arabinopyranosyl -d-glucopyranoside (); three acyclic monoterpene glycosides, linalyl -d-glucopyranoside () and linalyl 6-O--l-arabinopyranosyl--d-glucopyranoside (); (2)-3,7-dimethylocta-2,6-dienoate-6-O--l arabinopyranosyl--d-glucopyranoside (), two oligoglycosides, -hexyl--l arabinopyranosyl-(1 → 6)--d-glucopyranoside (creoside) () and -octyl -l-arabinopyranosyl-(1 → 6)--d-glucopyranoside (rhodiooctanoside) (); and ethyl fructofuranoside (). The structures of the isolated compounds were elucidated based on extensive examination of their spectroscopic 1D and 2D-NMR, MS, UV, and IR data. It is worth mentioning that, some of the isolated linalol glycoside derivatives were reported as aroma precursors.
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http://dx.doi.org/10.1016/j.jsps.2016.05.006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5310161PMC
January 2017

Cytotoxic Compounds from the Saudi Red Sea Sponge Xestospongia testudinaria.

Mar Drugs 2016 Apr 26;14(5). Epub 2016 Apr 26.

Department of Natural Products, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia.

Bioassay-guided fractionation of the organic extract of the Red Sea sponge Xestospongia testudinaria led to the isolation of 13 compounds including two new sterol esters, xestosterol palmitate (2) and xestosterol ester of l6'-bromo-(7'E,11'E,l5'E)-hexadeca-7',11',l5'-triene-5',13'-diynoic acid (4), together with eleven known compounds: xestosterol (1), xestosterol ester of 18'-bromooctadeca-7'E,9'E-diene-7',15'-diynoic acid (3), and the brominated acetylenic fatty acid derivatives, (5E,11E,15E,19E)-20-bromoeicosa-5,11,15,19-tetraene-9,17-diynoic acid (5), 18,18-dibromo-(9E)-octadeca-9,17-diene-5,7-diynoic acid (6), 18-bromooctadeca-(9E,17E)-diene-7,15-diynoic acid (7), 18-bromooctadeca-(9E,13E,17E)-triene-7,15-diynoic acid (8), l6-bromo (7E,11E,l5E)hexadeca-7,11,l5-triene-5,13-diynoic acid (9), 2-methylmaleimide-5-oxime (10), maleimide-5-oxime (11), tetillapyrone (12), and nortetillapyrone (13). The chemical structures of the isolated compounds were accomplished using one- and two-dimensional NMR, infrared and high-resolution electron impact mass spectroscopy (1D, 2D NMR, IR and HREIMS), and by comparison with the data of the known compounds. The total alcoholic and n-hexane extracts showed remarkable cytotoxic activity against human cervical cancer (HeLa), human hepatocellular carcinoma (HepG-2), and human medulloblastoma (Daoy) cancer cell lines. Interestingly, the dibrominated C18-acetylenic fatty acid (6) exhibited the most potent growth inhibitory activity against these cancer cell lines followed by Compounds 7 and 9. Apparently, the dibromination of the terminal olefinic moiety has an enhanced effect on the cytotoxic activity.
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http://dx.doi.org/10.3390/md14050082DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4882556PMC
April 2016

Noncyanogenic Cyanoglucoside Cyclooxygenase Inhibitors from Simmondsia chinensis.

Org Lett 2016 Apr 1;18(8):1728-31. Epub 2016 Apr 1.

Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences , Datun Road, Chaoyang District, Beijing 100080, China.

Two new noncyanogenic cyanoglucoside dimers, simmonosides A and B (1 and 2), were identified from the aqueous extract of jojoba (Simmondsia chinensis) leaves. Compounds 1 and 2 are the first examples of noncyanogenic cyanoglucoside dimers containing a unique four-membered ring, representing novel dimerization patterns at α,β-unsaturated carbons of a nitrile group in 1 and γ,δ-unsaturated carbons in 2. Their structures were elucidated based on spectroscopic evidence and electronic circular dichroism (ECD) calculations. Compounds 1 and 2 exhibit promising COX-2 inhibition activity, with IC50 values of 13.5 and 11.4 μM, respectively.
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http://dx.doi.org/10.1021/acs.orglett.6b00206DOI Listing
April 2016

Lipoxygenase inhibitors from the latex of Calotropis Procera.

Arch Pharm Res 2016 Mar 9. Epub 2016 Mar 9.

Department of Botany and Microbiology, Faculty of Science, Assiut University, Assiut, Egypt.

A radical-scavenging, guided phytochemical study of the latex of Calotropis Procera afforded five lignans (1-5), including a new one (4). The structural determination was accomplished using 1D- and 2D-NMR, high-resolution electrospray ionization mass spectrometry (HRESIMS), and correlation with known compounds. Among the isolated compounds, acylated lignans (3-5) showed stronger antioxidant activity than non-acylated derivatives (1,2). Anti-inflammatory activity was evaluated by determining the inhibitory potential against 5- and 15-lipoxygenase enzymes. The highest anti-inflammatory activity was observed in compound 4, with IC values of 7.6 µM and 2.7 µM against 5-LOX and 15-LOX, respectively.
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http://dx.doi.org/10.1007/s12272-016-0725-9DOI Listing
March 2016

Antidiarrheal and Antispasmodic Activities of Buddleja polystachya are Mediated Through Dual Inhibition of Ca(++) Influx and Phosphodiesterase Enzyme.

Phytother Res 2015 Aug 14;29(8):1211-8. Epub 2015 May 14.

Department of Pharmacognosy, College of Pharmacy, Salman Bin Abdulaziz University, Alkharj, Saudi Arabia.

This study describes the antidiarrheal and antispasmodic activities of the hydro-alcoholic extract of Buddleja polystachya (Bp.Cr) with possible mode of action explored along with activity-directed fractionation. Bp.Cr and its aqueous (Bp.Aq) and organic fractions, petroleum ether (Bp.Pet), dichloromethane (Bp.DCM), ethylacetate (Bp.EtAc) and butanol (Bp.But), were tested using the in-vivo and in-vitro assays. The crude extract (100-300 mg/kg) showed 20 and 60% protection of castor oil-induced diarrhea in mice. In isolated rabbit jejunum, Bp.Cr like papaverine inhibited spontaneous and high K(+) (80 mM)-induced contractions equi-potently. In guinea-pig ileum, Bp.Cr showed a moderate spasmogenic effect. The activity-directed fractionation revealed that the spasmolytic activity was concentrated in the organic fractions and spasmogenic component in the aqueous fraction. Amongst the organic fractions, BP.DCM and Bp.Pet inhibited spontaneous and high K(+) -induced contractions equi-potently, while Bp.But, like verapamil was more potent against high K(+) . The crude extract and its organic fractions caused rightward shift in the Ca(++) -concentration response curves (CRCs), similar to verapamil, and all except Bp.But potentiated the isoprenaline-inhibitory CRCs to the left, similar to papaverine. The results of this study indicate that the crude extract of B. polystachya possesses antidiarrheal and antispasmodic activities, mediated possibly through dual inhibition of Ca(++) influx and phospodiesterase enzyme.
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http://dx.doi.org/10.1002/ptr.5367DOI Listing
August 2015

Beetroot (Beta vulgaris L.) extract ameliorates gentamicin-induced nephrotoxicity associated oxidative stress, inflammation, and apoptosis in rodent model.

Mediators Inflamm 2014 22;2014:983952. Epub 2014 Oct 22.

Department of Pharmacognosy and Medicinal, Aromatic & Poisonous Plants Research Center (MAPPRC), College of Pharmacy, P.O. Box 2457, King Saud University, Riyadh 11451, Saudi Arabia.

The present investigation was designed to investigate the protective effect of (Beta vulgaris L.) beat root ethanolic extract (BVEE) on gentamicin-induced nephrotoxicity and to elucidate the potential mechanism. Serum specific kidney function parameters (urea, uric acid, total protein, creatinine, and histopathology of kidney tissue) were evaluated to access gentamicin-induced nephrotoxicity. The oxidative/nitrosative stress (Lipid peroxidation, MDA, NP-SH, Catalase, and nitric oxide levels) was assessed. The inflammatory response (TNF-α, IL-6, MPO, NF-κB (p65), and NF-κB (p65) DNA binding) and apoptotic marker (Caspase-3, Bax, and Bcl-2) were also evaluated. BVEE (250 and 500 mg/kg) treatment along with gentamicin restored/increased the renal endogenous antioxidant status. Gentamicin-induced increased renal inflammatory cytokines (TNF-α and IL-6), nuclear protein expression of NF-κB (p65), NF-κB-DNA binding activity, myeloperoxidase (MPO) activity, and nitric oxide level were significantly down regulated upon BVEE treatment. In addition, BVEE treatment significantly reduced the amount of cleaved caspase 3 and Bax, protein expression and increased the Bcl-2 protein expression. BVEE treatment also ameliorated the extent of histologic injury and reduced inflammatory infiltration in renal tubules. These findings suggest that BVEE treatment attenuates renal dysfunction and structural damage through the reduction of oxidative stress, inflammation, and apoptosis in the kidney.
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http://dx.doi.org/10.1155/2014/983952DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4221885PMC
July 2015

Klodorone A and klodorol A: new triterpenes from Kleinia odora.

Nat Prod Res 2014 15;28(15):1142-6. Epub 2014 May 15.

a Department of Pharmacognosy , College of Pharmacy, King Saud University , Riyadh 11451 , Saudi Arabia.

Re-investigation of the EtOH extract of the aerial parts of Kleinia odora led to the isolation of two new triterpenes; klodorone A (3) and klodorol A (4), together with two known compounds: β-amyrin (1) and germanicol (2), which were reported from this plant for the first time. Their structures were determined by using extensive 1D ((1)H, (13)C and DEPT) and 2D ((1)H-(1)H COSY, HMQC and HMBC) NMR and mass spectral measurements in addition to comparison of their data with the literature.
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http://dx.doi.org/10.1080/14786419.2014.915831DOI Listing
November 2014

In vitro antiprotozoal activity of abietane diterpenoids isolated from Plectranthus barbatus Andr.

Int J Mol Sci 2014 May 12;15(5):8360-71. Epub 2014 May 12.

Laboratory for Microbiology, Parasitology and Hygiene (LMPH), Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, Antwerp University, Universiteitsplein 1, B-2610 Antwerp, Belgium.

Chromatographic separation of the n-hexane extract of the aerial part of Plectranthus barbatus led to the isolation of five abietane-type diterpenes: dehydroabietane (1); 5,6-didehydro-7-hydroxy-taxodone (2); taxodione (3); 20-deoxocarnosol (4) and 6α,11,12,-trihydroxy-7β,20-epoxy-8,11,13-abietatriene (5). The structures were determined using spectroscopic methods including one- and two-dimensional NMR methods. Compounds (1)-(3) and (5) are isolated here for the first time from the genus Plectranthus. The isolated abietane-type diterpenes tested in vitro for their antiprotozoal activity against erythrocytic schizonts of Plasmodium falciparum, intracellular amastigotes of Leishmania infantum and Trypanosoma cruzi and free trypomastigotes of T. brucei. Cytotoxicity was determined against fibroblast cell line MRC-5. Compound (2) 5,6-didehydro-7-hydroxy-taxodone showed remarkable activity with acceptable selectivity against P. falciparum (IC50 9.2 µM, SI 10.4) and T. brucei (IC50 1.9 µM, SI 50.5). Compounds (3)-(5) exhibited non-specific antiprotozoal activity due to high cytotoxicity. Compound (1) dehydroabietane showed no antiprotozoal potential.
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http://dx.doi.org/10.3390/ijms15058360DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4057736PMC
May 2014

Phytochemical, antimicrobial and antiprotozoal evaluation of Garcinia mangostana pericarp and α-mangostin, its major xanthone derivative.

Molecules 2013 Sep 2;18(9):10599-608. Epub 2013 Sep 2.

Department of Pharmacognosy, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia.

Five xanthone derivatives and one flavanol were isolated from the dichloromethane extract of Garcinia mangostana. Dichloromethane, ethyl acetate extract and the major xanthone (α-mangostin) were evaluated in vitro against erythrocytic schizonts of Plasmodium falciparum, intracellular amastigotes of Leishmania infantum and Trypanosoma cruzi and free trypomastigotes of T. brucei. The major constituent α-mangostin was also checked for antimicrobial potential against Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Bacillius subtilis, Staphylococcus aureus, Mycobacterium smegmatis, M. cheleneoi, M. xenopi and M. intracellulare. Activity against P. falciparum (IC₅₀ 2.7 μg/mL) and T. brucei (IC₅₀ 0.5 μg/mL) were observed for the dichloromethane extract, however, with only moderate selectivity was seen based on a parallel cytotoxicity evaluation on MRC-5 cells (IC₅₀ 9.4 μg/mL). The ethyl acetate extract was inactive (IC₅₀ > 30 µg/mL). The major constituent α-mangostin showed rather high cytotoxicity (IC₅₀ 7.5 µM) and a broad but non-selective antiprotozoal and antimicrobial activity profile. This in vitro study endorses that the antiprotozoal and antimicrobial potential of prenylated xanthones is non-conclusive in view of the low level of selectivity.
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http://dx.doi.org/10.3390/molecules180910599DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6270423PMC
September 2013

In vitro antiprotozoal activity of triterpenoid constituents of Kleinia odora growing in Saudi Arabia.

Molecules 2013 Jul 31;18(8):9207-18. Epub 2013 Jul 31.

Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia.

Two lupane and four ursane triterpenes, namely epilupeol (1), lupeol acetate (2), ursolic acid (3), brein (4), 3β 11α-dihydroxy urs-12-ene (5) and ursolic acid lactone (6) were isolated from aerial parts of Kleinia odora and identified. Compounds 1 and 3-6 were isolated for the first time from K. odora. The triterpene constituents were investigated for antiprotozoal potential against erythrocytic schizonts of Plasmodium falciparum, intracellular amastigotes of Leishmania infantum and Trypanosoma cruzi and free trypomastigotes of T. brucei. Cytotoxicity was determined against MRC-5 fibroblasts to assess selectivity. The ursane triterpenes were found to be active against more than one type of the tested parasites, with the exception of compound 6. This is also the first report on the occurrence of ursane type triterpenes in the genus Kleinia and their antiprotozoal potential against P. falciparum, L. infantum, T. cruzi, and T. brucei.
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http://dx.doi.org/10.3390/molecules18089207DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6269755PMC
July 2013

Chemical composition and biological evaluation of essential oils of Pulicaria jaubertii.

Pharmacogn Mag 2013 Jan;9(33):28-32

Department of Pharmacognosy, College of Pharmacy, King Saud University. P.O. Box 22452, Riyadh 11495, KSA ; Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt.

Background: The present study reports and compares the results of Gas Chromatographic-Mass analyses of Pulicaria jaubertii leaf (P-1) and root (P-2) essential oils, as well as their in vitro antimicrobial and cytotoxic activities.

Materials And Methods: The chemical composition of P-1 and P-2 essential oils of P. jaubertii, was investigated by GC-MS. Moreover, the essential oils were evaluated for their antimicrobial activity using the broth micro-dilution assay for minimum inhibitory concentrations (MIC). The crystal violet staining method (CVS) was used for evaluation of their cytotoxic activity on HEPG-2 and MCF-7 human cell lines.

Results: This investigation led to the identification of 16 constituents in P-1, and 23 constituents in P-2, representing 99.92% and 94.74% of the oils respectively. Oxygenated monoterpenes were found to be the major group in both P-1 (99.47%) and P-2 (89.88%). P-1 consists almost entirely of p-Menth-6-en-2-one (Carvotanacetone, 98.59%). P-2 is characterized by high contents of each of Dimethoxydurene (38.48%), Durenol (26.89%) and 2',4'-Dimethoxy-3'-methylacetophenone (20.52%). Both oils showed moderate antimicrobial activity against the Gram-positive strains and C. albicans. However, no activity was shown against Gram-negative bacteria. P-1 showed a significant cytotoxic activity against both MCF-7 and HEPG-2 (IC50 = 3.8 and 5.1 μg/ml, respectively), while P-2 showed selective cytotoxic activity against MCF-7 cell line (IC50 = 9.3 μg/ml).

Conclusion: The potent cytotoxic and moderate antimicrobial activities of P-1 may be attributed to its high content of Carvotanacetone.
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http://dx.doi.org/10.4103/0973-1296.108133DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3647390PMC
January 2013

Biological importance of marine algae.

Authors:
Ali A El Gamal

Saudi Pharm J 2010 Jan;18(1):1-25

Dept. of Pharmacognosy, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia.

Marine organisms are potentially prolific sources of highly bioactive secondary metabolites that might represent useful leads in the development of new pharmaceutical agents. Algae can be classified into two main groups; first one is the microalgae, which includes blue green algae, dinoflagellates, bacillariophyta (diatoms)… etc., and second one is macroalgae (seaweeds) which includes green, brown and red algae. The microalgae phyla have been recognized to provide chemical and pharmacological novelty and diversity. Moreover, microalgae are considered as the actual producers of some highly bioactive compounds found in marine resources. Red algae are considered as the most important source of many biologically active metabolites in comparison to other algal classes. Seaweeds are used for great number of application by man. The principal use of seaweeds as a source of human food and as a source of gums (phycocollides). Phycocolloides like agar agar, alginic acid and carrageenan are primarily constituents of brown and red algal cell walls and are widely used in industry.
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http://dx.doi.org/10.1016/j.jsps.2009.12.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3731014PMC
January 2010

Revision of the absolute configuration at C(23) of lanostanoids and isolation of secondary metabolites from formosan soft coral Nephthea erecta.

Chem Biodivers 2009 Jan;6(1):86-95

Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 804, Taiwan.

Three new oxygenated ergostanoids, 1-3, one known ergostanoid, 4, one new trinoreudesmadienone, 5, one new calamenene type sesquiterpene, 6, and one known aristolane-type sesquiterpene, (-)-aristolone (7), have been isolated from the AcOEt extract of the soft coral Nephthea erecta. The structures of these compounds were determined by extensive spectroscopic and X-ray crystallographic analysis, as well as Mosher's method. We revised the absolute configuration at C(23) in the side chain of some lanostanoids as a result of the Mosher's products of 1 (i.e., 1a and 1b). The cytotoxicities against selected cancer cells and the anti-inflammatory effects of these tested metabolites 1-7 were determined in vitro.
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http://dx.doi.org/10.1002/cbdv.200800015DOI Listing
January 2009

Cytotoxic lupane-, secolupane-, and oleanane-type triterpenes from Viburnum awabuki.

Authors:
Ali A El-Gamal

Nat Prod Res 2008 Feb;22(3):191-7

Faculty of Pharmacy, Department of Pharmacognosy, Mansoura University, Mansoura 35516, Egypt.

Bioassay-guided fractionation of the methanolic extract of Viburnum awabuki afforded two new lupane triterpene derivatives; 6 beta-hydroxyl-3,20-dioxo-30 norlupane-28-oic acid (1) and 3,4-secolup-4,20-dihydroxy-3,28-dioic acid-3-oic acid methyl ester (2), along with seven known lupane and oleanane-type triterpenes (3-9). The structure of the isolated compounds was assigned using different spectroscopic techniques including 1D and 2D NMR. The 13CNMR data of compounds 5 and 9 is reported for the first time. Triterpenes 1, 2, and 7-9 showed in vitro cytotoxic activity against several tumor cell lines.
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http://dx.doi.org/10.1080/14786410701761019DOI Listing
February 2008

Cytotoxic xenia diterpenoids from the soft coral Xenia umbellata.

J Nat Prod 2006 Mar;69(3):338-41

Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan, Republic of China.

Eleven new xenia diterpenoids, umbellacins A-G (1-7), 14,15-epoxy-xeniolide H (8), 3-acetyl-14,15-epoxy-xeniolide H (9), and umbellacins H and I (10, 11), were isolated from a methylene chloride-soluble fraction of the soft coral Xenia umbellata. The structures were elucidated by extensive spectroscopic analysis, and their cytotoxicity against selected cancer cells was measured in vitro.
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http://dx.doi.org/10.1021/np058093rDOI Listing
March 2006

Sesquiterpenoids and norsesquiterpenoids from the Formosan soft coral Lemnalia laevis.

J Nat Prod 2005 Dec;68(12):1749-53

Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan, Republic of China.

Eight new nornardosinane sequiterpenoids, laevinols A-H (1-8), a new neolemnane sesquiterpenoid, laevinone A (9), and the previously known 6beta-acetyl-4beta,5beta-dimethyl-1(10)alpha-epoxy-2beta-hydroxy-7-oxodecalin (10) and 11,12-dihydroxy-6,10-eremophiladiene (11) were isolated from the methylene chloride solubles of the Formosan soft coral Lemnalia laevis. Their structures were elucidated by extensive spectroscopic analysis, and their cytotoxicity against selected cancer cells was measured in vitro.
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http://dx.doi.org/10.1021/np050326rDOI Listing
December 2005

Xenia diterpenoids from the formosan soft coral Xenia blumi.

J Nat Prod 2005 Sep;68(9):1336-40

Department of Marine Resources, National Sun Yat-sen University, Kaohsiung, Taiwan, Republic of China.

Eight new xenia diterpenoids, blumiolide-A (1) (novel carbon skeleton), blumiolide-B (2), 9-deoxy-isoxeniolide-A (3), 9-deoxy-7,8-epoxy-isoxeniolide-A (4), 9-deacetoxy-7,8-epoxy-13-epi-xenicin (5), 9-deoxy-7,8-epoxy-xeniolide-A (6), blumiolide-C (7), and blumicin-A (8), were isolated from the methylene chloride solubles of the Formosan soft coral Xenia blumi. Their structures were elucidated by extensive spectroscopic analysis, and their cytotoxicity against selected cancer cells was measured in vitro.
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http://dx.doi.org/10.1021/np058047rDOI Listing
September 2005

Sulfur-containing polybromoindoles from the Formosan red alga Laurencia brongniartii.

J Nat Prod 2005 May;68(5):815-7

Department of Marine Resources, National Sun Yat-Sen University, Kaohsiung, Taiwan.

Five new sulfur-containing polybromoindoles, 2-methylsulfinyl-3-methylthio-4,5,6-tribromoindole (1), 3-methylsulfinyl-2,4,6-tribromoindole (2), 4,6-dibromo-2,3-di(methylsulfinyl)indole (3), 3,3'-bis(2'-methylsulfinyl-2-methylthio-4,6,4',6'-tetrabromo)indole (4), and 3,3-bis(4,6-dibromo-2-methylsulfinyl)indole (5), as well as seven known sulfur-containing polybromoindoles, 3-methylthio-2,4,6-tribromoindole (6), 3-methylthio-2,4,5,6-tetrabromoindole (7), 4,6-dibromo-2,3-di(methylthio)indole (8), 2,3-di(methylthio)-4,5,6-tribromoindole (9), 4,6-dibromo-2-methylsulfinyl-3-(methylthio)indole (10), 4,6-dibromo-2-(methylthio)indole (11), and 3,3-bis(4,6-dibromo-2-methylthio)indole (12), have been isolated from the Formosan red alga Laurencia brongniartii. The structures were elucidated by extensive spectral analysis, and their cytotoxicity against selected cancer cells was measured in vitro.
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http://dx.doi.org/10.1021/np058001yDOI Listing
May 2005
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