Publications by authors named "Muhammad Jahangir"

29 Publications

  • Page 1 of 1

Identification of differentially expressed genes and pathways in isonuclear kenaf genotypes under salt stress.

Physiol Plant 2020 Nov 2. Epub 2020 Nov 2.

Key Laboratory of Plant Genetics and Breeding, College of Agriculture, Guangxi University, Nanning, 530005, China.

Salinity is a potential abiotic stress and globally threatens crop productivity. However, the molecular mechanisms underlying salt stress tolerance with respect to cytoplasmic effect, gene expression, and metabolism pathway under salt stress have not yet been reported in isonuclear kenaf genotypes. To fill this knowledge gap, growth, physiological, biochemical, transcriptome, and cytoplasm changes in kenaf cytoplasmic male sterile (CMS) line (P3A) and its iso-nuclear maintainer line (P3B) under 200 mM sodium chloride (NaCl) stress and control conditions were analyzed. Salt stress significantly reduced leaf soluble protein, soluble sugars, proline, chlorophyll content, antioxidant enzymatic activity, and induced oxidative damage in terms of higher MDA contents in both genotypes. The reduction of these parameters resulted in a reduced plant growth compared with control. However, P3A was relatively more tolerant to salt stress than P3B. This tolerance of P3A was further confirmed by improved physio-biochemical traits under salt stress conditions. Transcriptome analysis showed that 4256 differentially expressed genes (DEGs) between the two genotypes under salt stress were identified. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that photosynthesis, photosynthesis antenna-protein, and plant hormone signal transduction pathways might be associated with the improved NaCl stress tolerance in P3A. Conclusively, P3A cytoplasmic male sterile could be a potential salt-tolerant material for future breeding program of kenaf and can be used for phytoremediation of salt-affected soils. These data provide a valuable resource on the cytoplasmic effect of salt-responsive genes in kenaf and salt stress tolerance in kenaf.
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http://dx.doi.org/10.1111/ppl.13253DOI Listing
November 2020

Rosa brunonii Lindely fruit as a new protective agent evaluated against Rif/INH induced toxicity in rats.

Pak J Pharm Sci 2020 Mar;33(2(Supplementary)):805-814

Punjab University College of Pharmacy, University of Punjab, Lahore, Pakistan.

Rosa brunonii L., a less investigated plant contains flavonoid glycosides and is used to treat stomach ailments, heart problems, and diabetes in folk. The crude extract of the plant possesses antioxidant activity. The current work was aimed to investigate the presence of phytochemicals, antioxidative stress and protective potential of chloroform extract of the Rosa brunonii L. fruits (RBFCE) against liver and kidney toxicity induced by anti-tuberculosis drugs, rifampicin/isoniazid (Rif/INH) in Wistar albino rats. Animals were divided into six groups, each comprising 6 rats and fed with a standard pelleted diet. Normal control group was given only a standard pelleted diet. The vehicle control group received 0.5% carboxymethylcellulose (CMC) aqueous solution (vehicle). Negative and positive control groups were given Rif/INH (50+50 mg/kg, p.o) and silymarin (SILM) (200 mg/kg, p.o) in 0.5% vehicle for 30 days, respectively. Extract treated groups received low and high doses of RBFCE (500 mg/kg, p.o and 1000 mg/kg, p.o respectively) in 0.5% vehicle for 30 days. At a higher dose, animals showed significantly reduced Rif/INH induced toxicity in liver and kidney tissues as indicated by the normalized serum biochemical markers and histopathological investigations. The present exploration reveals the presence of strong antioxidant phytochemical constituents, antioxidative stress and protective potential of RBFCE against Rif/INH induced hepatic and renal damage.
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March 2020

Development of an Efficient Analytical Method for the Extraction and Analysis of Biocide Contents from the Textile Test Specimens on LC-DAD.

J Anal Methods Chem 2020 30;2020:3047961. Epub 2020 Mar 30.

Department of Chemistry, Government College University, Lahore, Pakistan.

Biocides are frequently used in the manufacturing of textiles that are in direct contact with human skin. Recently regulated biocides do not have validated methods for testing; so, their presence cannot be estimated in the consumer products. Hence a rapid method was developed for the separation and quantitative analysis of biocide contents (2-methyl-4-isothaizolin (MIT), 5-chloro-2-methyl-4-isothaizolin-3-one (CIT), 2-octo-4-isothaizolin-3-one (OIT), and 5-chloro-2-(2,4-dichlorophenxy) phenol (triclosan)) from the textile test specimens. Test specimens were extracted with methanolic sonication and purified by centrifugation and filtration. Biocide contents were separated at C18 column with 0.4% acetic acid: methanol (1 : 1 v/v) under isocratic mode and detected at 280 nm wavelength. Pretreatment factors such as extraction solvent, extraction method, dilution ratio, and extraction time were optimized initially and plotted calibration curve showed regression ( ≥ 0.9995) in the range of 1.0-5.0 mg L. Recoveries were between 95% and 108% with the relative standard deviation ≤ 4%. Limits of detection (LODs) were between 0.06 mg L and 0.12 mg L and limits of quantification (LOQs) were between 0.21 mg L and 0.38 mg L. From the results, conclusion was made that the method can achieve the purpose of quantitative detection and the analysis of real test specimens verified the reliability of this method.
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http://dx.doi.org/10.1155/2020/3047961DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7149327PMC
March 2020

Young Yum pill inhibits inflammatory mediators and nuclear factor-kappa B signaling in lipopolysaccharide-stimulated RAW 264.7 macrophages.

J Tradit Chin Med 2019 10;39(5):624-631

Research and Development Centre for Natural Health Products, Hong Kong Baptist University Shenzhen Research Institute and Continuing Education, Shenzhen 518057, China.

Objective: To investigate the effect of Young Yum pill (YYP) on inflammatory mediators in cultured RAW 264.7 cells and elucidate the nuclear factor-kappa B (NF-κB)-related mechanism behind the action.

Methods: YYP was extracted with 95% ethanol Lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages were used to evaluate the effect of YYP on inflammatory mediators. Production of nitric oxide (NO) and prostaglandin E2 (PGE2) were measured by Griess test and enzyme-linked immunosorbent assay, respectively. The levels of genes and proteins involved in the generation of inflammatory mediators were examined using real-time polymerase chain reaction and Western blotting, respectively.

Results: YYP dose-dependently suppressed LPS-induced production of NO, PGE2 and tumor necrosis factor-α (TNF-α), and elevation of mRNA and protein levels of inducible NO synthase and cyclooxygenase-2 in RAW 264.7 macrophages. These observations were associated with decreased NF-κB p65 phosphorylation and nuclear localization, enhanced Akt (protein kinase B) phosphorylation, as well as reduced inhibitor of κB (IκB) α degradation and IκB kinase α/β phosphorylation.

Conclusion: The present study demonstrated an inhibitory effect of YYP on the NF-κB-regulated inflammatory mediators NO, PGE2 and TNF-α in LPS-stimulated RAW 264.7 macrophages, providing a pharmacological basis for the use of YYP in treating inflammatory disorders.
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October 2019

Quinoxaline-Based Linear HCV NS3/4A Protease Inhibitors Exhibit Potent Activity against Drug Resistant Variants.

ACS Med Chem Lett 2018 Jul 17;9(7):691-696. Epub 2018 May 17.

Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States.

A series of linear HCV NS3/4A protease inhibitors was designed by eliminating the P2-P4 macrocyclic linker in grazoprevir, which, in addition to conferring conformational flexibility, allowed structure-activity relationship (SAR) exploration of diverse quinoxalines at the P2 position. Biochemical and replicon data indicated preference for small hydrophobic groups at the 3-position of P2 quinoxaline for maintaining potency against resistant variants R155K, A156T, and D168A/V. The linear inhibitors, though generally less potent than the corresponding macrocyclic analogues, were relatively easier to synthesize and less susceptible to drug resistance. Three inhibitor cocrystal structures bound to wild-type NS3/4A protease revealed a conformation with subtle changes in the binding of P2 quinoxaline, depending on the 3-position substituent, likely impacting both inhibitor potency and resistance profile. The SAR and structural analysis highlight inhibitor features that strengthen interactions of the P2 moiety with the catalytic triad residues, providing valuable insights to improve potency against resistant variants.
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http://dx.doi.org/10.1021/acsmedchemlett.8b00150DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6047049PMC
July 2018

Synthesis and Characterization of New Photoresponsive, Ortho and Para Oriented Azomethine Polymers.

Acta Chim Slov 2018 sept;65(3):718-729

Five new azomethine polymers having aliphatic-aromatic moieties were synthesized by polycondensation reaction of dialdehydes and diamines. The dialdehyde monomers differ only in the orientation of the aromatic ring (ortho or para) and were synthesized by condensation reaction between aromatic aldehyde and 1,6-dibromohexane. The molecular mass of the monomers was recorded through E.I mass spectrum. The polymers structures were confirmed by elemental microanalysis, FT-IR, 1HNMR and UV-Vis Spectroscopy. The morphology of monomers and polymers was evaluated by scanning electron microscopy (SEM). All the polymers were soluble in DMSO (on heating) and somewhat in other solvents. Thermal stability of polymers was analyzed by thermogravimetry (TG) and differential thermal analysis (DTA), all the polymers showed good thermal stability higher than their corresponding monomers. The TG of polymers indicated maximum rate of weight loss (Tmax) within 412-708 °C. Fluorescence emission spectra of polymers were recorded and the results indicated that all the polymers were photo-responsive and indicated 1 to 4 emission bands with maximum within 349-606 nm. The limit of detection of polymers was within 0.625-1.25 ∆g/ml. The polymers were also examined for their antimicrobial activities against bacteria and fungi.
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February 2021

Report: Potential of nano-emulsions as phytochemical delivery system for food preservation.

Pak J Pharm Sci 2017 Nov;30(6):2259-2263

School of Agriculture and Food Science, The University of Queensland, Australia.

Nature is a rich source of bioactive phytochemicals. These plant based compounds have rich scope as antioxidants, antimicrobial compounds and food preservatives and so for long time to be used in meat, fruits, vegetables and processed food items, either as added preservative or as coating material in various food applications, but the major limitation is their limited solubility in a food grade medium. Nano-emulsion is a best choice as a medium having vast area of application. The major advantage of nano-emulsion would be the solubility of a vast group of compounds, due to the presence of water and lipid phases. In this way, nano-emulsions can be proved to be the most suitable candidate as phytochemical delivery system for food preservation. In present article, the use of phytochemicals as potent food preservatives has been reviewed, in context of solubility of phytochemicals in nano-emulsion and applications of food grade nano-emulsions to food systems.
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November 2017

Volatile terpenoids: multiple functions, biosynthesis, modulation and manipulation by genetic engineering.

Planta 2017 Nov 12;246(5):803-816. Epub 2017 Aug 12.

The Research Center for Ornamental Plants, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, 510642, China.

Main Conclusion: Terpenoids play several physiological and ecological functions in plant life through direct and indirect plant defenses and also in human society because of their enormous applications in the pharmaceutical, food and cosmetics industries. Through the aid of genetic engineering its role can by magnified to broad spectrum by improving genetic ability of crop plants, enhancing the aroma quality of fruits and flowers and the production of pharmaceutical terpenoids contents in medicinal plants. Terpenoids are structurally diverse and the most abundant plant secondary metabolites, playing an important role in plant life through direct and indirect plant defenses, by attracting pollinators and through different interactions between the plants and their environment. Terpenoids are also significant because of their enormous applications in the pharmaceutical, food and cosmetics industries. Due to their broad distribution and functional versatility, efforts are being made to decode the biosynthetic pathways and comprehend the regulatory mechanisms of terpenoids. This review summarizes the recent advances in biosynthetic pathways, including the spatiotemporal, transcriptional and post-transcriptional regulatory mechanisms. Moreover, we discuss the multiple functions of the terpene synthase genes (TPS), their interaction with the surrounding environment and the use of genetic engineering for terpenoid production in model plants. Here, we also provide an overview of the significance of terpenoid metabolic engineering in crop protection, plant reproduction and plant metabolic engineering approaches for pharmaceutical terpenoids production and future scenarios in agriculture, which call for sustainable production platforms by improving different plant traits.
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http://dx.doi.org/10.1007/s00425-017-2749-xDOI Listing
November 2017

Biology-Oriented Synthesis (BIOS) of Piperine Derivatives and their Comparative Analgesic and Antiinflammatory Activities.

Med Chem 2018 ;14(3):269-280

H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan.

Background: Serious side effects such as gastric intestinal ulcer, bleeding etc. are associated with most of the antiinflammatory and analgesic drugs. So, there is a need to search novel, potent, and safer antiinflammatory and analgesic drug.

Method: Based on "biology-oriented synthesis approach", piperine alkaloid was isolated from Piper nigrum L. and some derivatives of piperine having azomethine, sulfamoyl, propanoyl, acetamoyl and heterocyclic oxadiazole were synthesized. The structures of synthetic derivatives were confirmed by using different spectroscopic techniques such as 1H-, 13C-NMR, EI-MS, and IR. Melting points were also determined for all compounds. Piperine and its all the synthetic derivatives were subjected to comparative in vivo evaluation of analgesic and antiinflammatory activities at the oral dose of 6 mg/kg/day. Analgesic activity was evaluated by tail immersion, hot plate and acetic acid writhing methods. While, antiinflammatory activity was evaluated by carrageenan-induced paw inflammation. In silico studies of all synthetic compounds was also conducted on COX-2 and adenosine kinase enzymes.

Results: A number of derivatives showed enhanced antiinflammatory and analgesic activities as compared to piperine and standard drug diclofenac.

Conclusion: The newly identified molecules may serve as lead for the future research in connection of potent and safer antiinflammatory and analgesic drug candidate.
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http://dx.doi.org/10.2174/1573406413666170623083810DOI Listing
August 2018

Hepatitis C Virus NS3/4A Protease Inhibitors Incorporating Flexible P2 Quinoxalines Target Drug Resistant Viral Variants.

J Med Chem 2017 07 19;60(13):5699-5716. Epub 2017 Jun 19.

Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School , Worcester, Massachusetts 01605, United States.

A substrate envelope-guided design strategy is reported for improving the resistance profile of HCV NS3/4A protease inhibitors. Analogues of 5172-mcP1P3 were designed by incorporating diverse quinoxalines at the P2 position that predominantly interact with the invariant catalytic triad of the protease. Exploration of structure-activity relationships showed that inhibitors with small hydrophobic substituents at the 3-position of P2 quinoxaline maintain better potency against drug resistant variants, likely due to reduced interactions with residues in the S2 subsite. In contrast, inhibitors with larger groups at this position were highly susceptible to mutations at Arg155, Ala156, and Asp168. Excitingly, several inhibitors exhibited exceptional potency profiles with EC values ≤5 nM against major drug resistant HCV variants. These findings support that inhibitors designed to interact with evolutionarily constrained regions of the protease, while avoiding interactions with residues not essential for substrate recognition, are less likely to be susceptible to drug resistance.
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http://dx.doi.org/10.1021/acs.jmedchem.7b00426DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5748155PMC
July 2017

Metal II complexes of ethambutol as good enzyme inhibitor and promising antioxidant.

Pak J Pharm Sci 2016 Sep;29(5):1601-1608

Department of Chemistry, GC University, Lahore, Pakistan.

Ethambutoldihydrogenchloride (EMB) with chemical formula C10H24N2O2.2HCl is ethane-1,2-diamine in which one hydrogen attached to each of the nitrogen is substituted by a 1-hydroxybutan-2-yl group (S,S-configuration). It is an FDA approved drug and has been used for treatment of tuberculosis since 1960's. Prolong use of EMB has a side effect of visual impairment and in literature it is related with the depletion of Zn metal from the body. As it is a good chelating agent, many metal II complexes have been synthesized with anti-tubercular activity. The purpose of this work was to synthesize metal II complexes of EMB and to evaluate their antioxidant activity along with enzyme inhibition activity (acetylcholine esterase and protease). The metals used for complex formation were Co, Zn, Fe, Cu and Ni. IR spectral data and physical parameters supported the complex formation. The obtained results showed the synthesized complexes as notable antioxidants and enzyme inhibitors.
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September 2016

Tissue specific metal characterization of selected fish species in Pakistan.

Environ Monit Assess 2016 Apr 7;188(4):212. Epub 2016 Mar 7.

Section of Food Science and Technology, Department of Agricultural Sciences, University of Haripur, Haripur, Pakistan.

Concentration of various metals, i.e., zinc (Zn), copper (Cu), lead (Pb), nickel (Ni), iron (Fe), manganese (Mn), chromium (Cr), and silver (Ag), was evaluated in five indigenous fish species (namely, silver carp, common carp, mahseer, thela fish, and rainbow trout), by using atomic absorption spectrophotometer. It is proved from this study that, overall, mahseer and rainbow trout had high amount of zinc, whereas thela fish and silver carp had high concentration of copper, chromium, silver, nickel, and lead, while common carp had highest amount of iron contents. Furthermore, a tissue-specific discrimination among various fish species was observed, where higher metal concentrations were noticed in fish liver, with decreasing concentration in other organs like skin, gills, and finally the least contents in fish muscle. Multivariate data analysis showed not only a variation in heavy metals among the tissues but also discrimination among the selected fish species.
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http://dx.doi.org/10.1007/s10661-016-5214-6DOI Listing
April 2016

Storage Stability of Kinnow Fruit (Citrus reticulata) as Affected by CMC and Guar Gum-Based Silver Nanoparticle Coatings.

Molecules 2015 Dec 18;20(12):22645-61. Epub 2015 Dec 18.

Section of Food Science and Technology, Department of Agricultural Sciences, University of Haripur, Haripur 22620, KPK, Pakistan.

The influence of carboxy methyl cellulose (CMC) and guargum-based coatings containing silver nanoparticles was studied on the postharvest storage stability of the kinnow mandarin (Citrus reticulata cv. Blanco) for a period of 120 days (85%-90% relative humidity) at 4 °C and 10 °C. Physicochemical and microbiological qualities were monitored after every 15 days of storage. Overall results revealed an increase in total soluble solid (TSS), total sugars, reducing sugars and weight loss but this increase was comparatively less significant in coated fruits stored at 4 °C. Ascorbic acid, total phenolics, and antioxidant activity was significantly enhanced in coated fruits stored at 4 °C. Titratable acidity significantly decreased during storage except for coated kinnow stored at 4 °C. In control samples stored at 10 °C, high intensity of fruit rotting and no chilling injury was observed. Total aerobic psychrotrophic bacteria and yeast and molds were noticed in all treatments during storage but the growth was not significant in coated fruits at 4 °C. Kinnow fruit can be kept in good quality after coating for four months at 4 °C and for 2 months at 10 °C.
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http://dx.doi.org/10.3390/molecules201219870DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6332021PMC
December 2015

Assessment of different washing treatments to mitigate imidacloprid and acetamaprid residues in spinach.

J Sci Food Agric 2016 Aug 21;96(11):3749-54. Epub 2016 Jan 21.

National Institute of Food Science and Technology, University of Agriculture Faisalabad, Faisalabad, Pakistan.

Background: Agricultural crops treated with pesticides retain toxic residues that can cause various health disorders upon consumption. The present research project was designed to assess pesticide residues in contaminated spinach (Spinacia oleracea). The efficiency of chemical solutions (acetic acid, citric acid, hydrogen peroxide, sodium chloride and sodium carbonate) of different concentrations (% w/v) along with tap water for the dissolution of pesticide residues in spinach was studied. After various dipping treatments (T0 -T22 ) of treated spinach, imidacloprid and acetamaprid residues were determined by high-performance liquid chromatography (HPLC).

Results: Among the solutions tested, the highest reductions in imidacloprid and acetamaprid residues respectively were 0.92 ± 0.04 mg kg(-1) (83%) and 1.42 ± 0.53 mg kg(-1) (87%) in treatment T6 (10% acetic acid), followed by 0.79 ± 0.01 mg kg(-1) (69%) and 0.86 ± 0.05 mg kg(-1) (71%) in treatment T11 (10% citric acid), while the lowest were 0.30 ± 0.02 mg kg(-1) (27%) and 0.35 ± 0.02 mg kg(-1) (29%) in treatment T20 (4% sodium carbonate). Moreover, treatment T1 (tap water) caused 0.27 ± 0.00 mg kg(-1) (23%) and 0.38 ± 05 mg kg(-1) (27%) elimination of imidacloprid and acetamaprid residues respectively.

Conclusion: From these findings it is inferred that acetic acid and citric acid washing treatments can be used along with tap water to minimize pesticide residues in treated vegetables. © 2015 Society of Chemical Industry.
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http://dx.doi.org/10.1002/jsfa.7563DOI Listing
August 2016

Potent AChE enzyme inhibition activity of Zizyphus oxyphylla: A new source of antioxidant compounds.

Pak J Pharm Sci 2015 Nov;28(6):2053-9

Department of Chemistry, GC University, Katchehry Road, Lahore, Pakistan.

The purpose of this study was to assess the antioxidant potential and enzyme inhibition of various fractions of Zizyphus oxyphylla. The plant metabolites were extracted in methanol and partitioned with n-hexane, chloroform, ethyl acetate and n-butanol successively. Phytochemical screening showed presence of alkaloids, terpenoids and flavonoids in ethyl acetate and n-butanol fractions. The antioxidant potential and acetylcholine esterase assay of all these fractions and remaining aqueous fraction was evaluated by using reported methods. The results revealed that chloroform soluble fraction exhibited highest percent inhibition of DPPH radical as compared to other fractions. It showed 95.01 ± 0.37% inhibition of DPPH radical at a concentration of 120 μg/mL. The IC₅₀ of this fraction was 13.20 ± 0.27 μg/mL, relative to butylated hydroxytoluene (BHT, a reference standard), having IC₅₀ of 12.10 ± 0.29 μg/mL. It also showed highest total antioxidant activity i.e. 1.723 ± 0.34 as well as highest FRAP value (339.5 ± 0.57 TE μm/mL) and highest total phenolic contents (142.65 ± 1.20 GAE mg/g) as compared to the other studied fractions. The fractions were also studied for Acetylcholine esterase enzyme (AChE) enzyme inhibition activity and n-butanol soluble fraction exhibited maximum inhibition (95.5 ± 0.13 mg/mL with IC50 =9.58 ± 0.08 mg/mL relative to galanthamine (13.26 ± 0.73 mg/mL), while n- hexane soluble fraction (165.15 ± 0.94 mg/mL) showed non-significant. We are still working to isolate pure compounds for active fractions targeting potent inhibition responsible for some activities.
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November 2015

Alleviation of chilling injury in postharvest tomato fruit by preconditioning with ultraviolet irradiation.

J Sci Food Agric 2012 Dec 2;92(15):3016-22. Epub 2012 May 2.

Department of Food Science and Nutrition, Zhejiang University, Hangzhou 310058, PR China.

Background: Tomato fruit is usually stored at low temperatures for delayed ripening and extended shelf life. However, tomato fruit is susceptible to chilling injury when exposed to low temperatures. In this study, the potential effects of preconditioning with UV-C or UV-B irradiation on chilling injury of postharvest tomato fruit were investigated.

Results: Mature-green tomato fruit were exposed to 4 kJ m(-2) UV-C or 20 kJ m(-2) UV-B irradiation and stored for 20 days at 2 °C and subsequently 10 days at 20 °C. UV irradiation was effective in reducing chilling injury index and delaying ethylene peak. Furthermore, UV irradiation preserved storage quality as manifested by reduced weight loss, better retention of firmness, and higher contents of total soluble solids, soluble protein and soluble sugar during subsequent storage at 20 °C. UV-C irradiation significantly delayed the development of the red colour after 10 days of storage at 20 °C. On the other hand, UV irradiation decreased total phenolics content and antioxidant capacity, suggesting possibly reduced stress response to low temperature resulted from enhanced physiological adaptation by UV preconditioning.

Conclusion: Our results suggest that preconditioning with UV-C or UV-B irradiation in appropriate doses had a positive effect on alleviating chilling injury in postharvest tomato fruit.
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http://dx.doi.org/10.1002/jsfa.5717DOI Listing
December 2012

Alleviation of aluminum toxicity by hydrogen sulfide is related to elevated ATPase, and suppressed aluminum uptake and oxidative stress in barley.

J Hazard Mater 2012 Mar 9;209-210:121-8. Epub 2012 Jan 9.

Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, PR China.

Greenhouse hydroponic experiments were performed to evaluate potential role of H(2)S on Al toxicity in barley seedlings. Seedlings pretreated with 200 μM NaHS as a donor of H(2)S for 24h and subsequently exposed to 100 μM AlCl(3) for 24h had significantly longer roots than those without NaHS. The promoted root elongation was correlated with a substantial decrease in Al-induced overproduction of lipid peroxidation, electrolyte leakage and Al accumulation in roots, and a marked increase in Al-induced depress activities of Na(+)K(+)-ATPase and H(+)-ATPase. The alleviating role of H(2)S on Al-induced toxicity was also found in a time- and dose-dependent experiment. Addition of 200 and 400 μM NaHS to 100 μM AlCl(3) effectively alleviated Al-toxicity, markedly diminished Al-induced MDA accumulation, and increased chlorophyll content, net photosynthetic rate (Pn) and maximal photochemical efficiency (Fv/Fm) compared with Al alone. Exogenous H(2)S significantly elevated depressed CAT activities, and further improved root POD activity. Moreover, NaHS decreased Al accumulation, but elevated concentrations of S, P, Ca, Mg and Fe in plants. These data suggest that H(2)S-induced alleviation in Al toxicity is attributed to reduced Al uptake and MDA accumulation, improved uptake of P, Ca, Mg and Fe, and elevated ATPase and photosynthetic performance.
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http://dx.doi.org/10.1016/j.jhazmat.2011.12.076DOI Listing
March 2012

Screening of selected Asian spices for anti obesity-related bioactivities.

Food Chem 2011 Jun 17;126(4):1724-9. Epub 2010 Dec 17.

Dept. Pharmacognosy, Sect. Metabolomics, Institute of Biology, Leiden University, Einsteinweg 55 2300 RA, Leiden, The Netherlands.

The potential health effects of 30 spices, commonly used for daily consumption, were submitted to bioactivity screening with several anti-obesity related bioassays: adenosine A1 receptor binding, cannabinoid CB1 receptor binding, TNF-α and 3T3-L1 adipocytes differentiation induction. Sesame seed and red chilli exhibited high binding activity to the adenosine A1 receptor and nutmeg, mace, black pepper and turmeric to the cannabinoid CB1 receptor, while piment and turmeric showed high inhibition of TNF-α accumulation. Black onion seed proved to be the only spice with high 3T3-L1 adipocyte differentiation induction activity. Several well known major compounds found in these active spices were tested with the respective bioassays but did not show activity. Thus, it appears that other minor compounds or the synergistic effects of different constituents are responsible for the observed activity.
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http://dx.doi.org/10.1016/j.foodchem.2010.12.066DOI Listing
June 2011

Accumulation of lignin and malondialdehyde in relation to quality changes of button mushrooms (Agaricus bisporus) stored in modified atmosphere.

Food Sci Technol Int 2010 Jun 18;16(3):217-24. Epub 2010 Aug 18.

Department of Food Science and Nutrition, Zhejiang University, Hangzhou 310029, PR China.

Whole fresh button mushrooms (Agaricus bisporus) were stored in unsealed bags in two types of modified atmosphere packaging (MAP), namely, active and passive, at 4 °C. The packaging film was 0.04 mm low-density polyethylene and the gas composition of the active MAP was 12% O(2), 2.5% CO(2) and 85.5% N(2). Firmness of Mushroom showed a positive correlation with the accumulation of lignin in the tissue. On the other hand, changes of malondialdehyde content with storage time were proportional to the evolution of browning. The button mushrooms in control treatment developed severe browning at the end of the 15-day storage, while the mushrooms of both active and passive MAP treatments browned slightly. MAP treatments could not inhibit phenylalanine ammonia lyase activity; however, it can reduce the lignification process by the inhibition of peroxidase (POD) activity and the accumulation of lignin. Correlation between the cinnamyl alcohol dehydrogenase activity and lignin accumulation was not obvious. Our results suggested that an increase in the firmness of mushrooms during senescence may be a consequence of tissue lignification, a process associated with increase in POD activity. Both active and passive MAPs were useful for the conservation of tenderness and whiteness in button mushrooms.
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http://dx.doi.org/10.1177/1082013209353840DOI Listing
June 2010

Structure and composition changes in the cell wall in relation to texture of shiitake mushrooms (Lentinula edodes) stored in modified atmosphere packaging.

J Sci Food Agric 2010 Apr;90(5):742-9

Department of Food Science and Nutrition, Zhejiang University, Hangzhou 310029, P. R. China.

Background: Firmness in shiitake mushroom (Lentinula edodes) is an important textural attribute affecting consumer attitudes toward freshness and quality. In this study, the effects of modified atmosphere packaging (MAP) treatments on structure and composition changes in cell walls in relation to the texture of mushrooms were investigated.

Results: Shiitake mushrooms were packaged in low density polyethylene bags with no holes (M(0)), two microholes (M(1)), four macroholes (M(2)), stored at 4 degrees C for 16 days with non-wrapped mushrooms as control. Control mushrooms showed the highest firmness value due to significant increase of cellulose and chitin. All three MAP treatments reduced losses of protein and polysaccharides; the M(2) treatment can best preserve the original texture while mushrooms in M(0) became soft and deteriorated, possibly due to higher CO(2) accumulation, lower cellulose and chitin content. Transmission electron microscopy performed on caps at harvest and after 16 days indicated that disintegration of plasmalemma had been alleviated by M(2) treatment, leading to better preservation of the cell wall.

Conclusion: Our results suggest that differences in firmness of shiitake mushrooms during storage may be due to differences in cellulose and chitin concentrations. M(2) treatment may be a useful way of maintaining shiitake mushrooms texture during storage at 4 degrees C.
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http://dx.doi.org/10.1002/jsfa.3876DOI Listing
April 2010

Ammonium [(1S)-(endo,anti)]-(-)-3-bromo-camphor-8-sulfonate.

Acta Crystallogr Sect E Struct Rep Online 2010 Jun 18;66(Pt 7):o1707-8. Epub 2010 Jun 18.

In the title mol-ecular salt, NH(4) (+)·C(10)H(14)BrO(4)S(-), the norbornane skeleton of the anion is composed of two five-membered rings in envelope conformations and a six-membered ring with one Br atom, one carbonyl O atom and a methyl group held in a boat conformation by a bridging methyl-ene group. Short intra-molecular C-H⋯O and C-H⋯Br inter-actions occur. In the crystal, the component ions are linked by inter-molecular N-H⋯O and C-H⋯O hydrogen bonds.
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http://dx.doi.org/10.1107/S1600536810022804DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3006721PMC
June 2010

N-(3-Eth-oxy-phen-yl)-4-methyl-benzene-sulfonamide.

Acta Crystallogr Sect E Struct Rep Online 2010 Jun 16;66(Pt 7):o1682. Epub 2010 Jun 16.

In the title compound, C(15)H(17)NO(3)S, the two aromatic rings make a dihedral angle of 69.42 (9)° with each other and the bridging C-N-S-C torsion angle is 65.76 (16)°. Weak intra-molecular C-H⋯O inter-actions may affect the mol-ecular conformation. Two neighbouring mol-ecules generate a hydrogen-bonded dimer about a center of inversion through a pair of inter-molecular N-H⋯O inter-actions, forming an R(2) (2)(8) ring motif. Furthermore, two inter-molecular C-H⋯π inter-actions contribute to the stability of the crystal packing.
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http://dx.doi.org/10.1107/S1600536810022427DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3006737PMC
June 2010

1-Chloro-methyl-4-nitro-benzene.

Acta Crystallogr Sect E Struct Rep Online 2010 Jun 16;66(Pt 7):o1667. Epub 2010 Jun 16.

In the title compound, C(7)H(6)ClNO(2), the nitro group is almost coplanar with the aromatic ring [dihedral angle = 2.9 (2)°], but the Cl atom deviates from the ring plane by 1.129 (1) Å. In the crystal, mol-ecules are linked by weak C-H⋯O inter-actions to generate chains.
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http://dx.doi.org/10.1107/S1600536810022191DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3006927PMC
June 2010

1-Chloro-meth-yl-3-nitro-benzene.

Acta Crystallogr Sect E Struct Rep Online 2010 Feb 13;66(Pt 3):o608. Epub 2010 Feb 13.

In the title mol-ecule, C(7)H(6)ClNO(2), the plane of the nitro group and the direction of the chloro-methyl group are twisted away from the benzene ring, forming dihedral angles of 8.2 (3) and 67.55 (12)°, respectively. In the crystal structure, weak inter-molecular C-H⋯O inter-actions link the mol-ecules into corrugated sheets parallel to the bc plane.
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http://dx.doi.org/10.1107/S1600536810005076DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2983641PMC
February 2010

Metal ion-inducing metabolite accumulation in Brassica rapa.

J Plant Physiol 2008 Sep 9;165(14):1429-37. Epub 2008 Jun 9.

Division of Pharmacognosy, Section of Metabolomics, Institute of Biology, Leiden University, Leiden RA, The Netherlands.

Plants face a number of biotic and abiotic environmental stress factors during growth. Among the abiotic factors, in particular, a great deal of attention has been paid to metals not only because of their increasing amounts in the environment due to rapid industrial development but also because of the variation of metal composition in soil. Cultivation of crops close to industrial areas or irrigation with contaminated water may result in both growth inhibition and tissue accumulation of metals. Brassica species are well known as metal accumulators and are being used for phytoremediation of contaminated soils. However, the metal tolerance mechanism in the plant still remains unclear. In order to investigate the metabolomic changes induced by metal ions in Brassica, plants were subjected to concentrations 50, 100, 250 and 500 mmol of copper (Cu), iron (Fe) and manganese (Mn) in separate treatments. (1)H NMR and two-dimensional NMR spectra coupled with principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA) were applied to investigate the metabolic change in Brassica rapa (var. Raapstelen). The (1)H-NMR analysis followed by the application of chemometric methods revealed a number of metabolic consequences. Among the metabolites that showed variation, glucosinolates and hydroxycinnamic acids conjugated with malates were found to be the discriminating metabolites as were primary metabolites like carbohydrates and amino acids. This study shows that the effects of Cu and Fe on plant metabolism were larger than those of Mn and that the metabolomic changes varied not only according to the type of metal but also according to its concentration.
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http://dx.doi.org/10.1016/j.jplph.2008.04.011DOI Listing
September 2008

Structural distinction between sabandins A and B from Artemisia scoparia waldst. (Asteraceae).

Nat Prod Res 2003 Jan;17(1):1-4

H.E.J. Research Institute of Chemistry, University of Karachi, Karachi 75270, Pakistan.

The three possible isomeric structures of the sabandin coumarin were published by Reyes and Gonzalez in 1970. We have isolated two of these isomers sabandins A and B from Artemisia scoparia (Asteraceae) and distinguished by NOE difference NMR measurements.
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http://dx.doi.org/10.1080/10575630290020640DOI Listing
January 2003

A bis-bithiophene from Tridax procumbens L. (Asteraceae).

Nat Prod Lett 2002 Aug;16(4):217-21

H.E.J. Research Institute of Chemistry, University of Karachi, Pakistan.

The ethyl acetate soluble part of hexane extract of Tridax procumbens yielded a new bis-bithiophene named tridbisbithiophene along with four known terpenoids: taraxasteryl acetate, beta-amyrenone, lupeol and oleanolic acid, which have never been reported so far from Tridax procumbens. The structures of all the isolated constituents were elucidated with the aid of 1D-NMR spectroscopy whereas, the structure of new constituent tridbisbithiophene was confirmed via COSY and HMBC interactions.
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http://dx.doi.org/10.1080/10575630290020451DOI Listing
August 2002

Gnapholide: a new guaiac-dimer from Pulicaria gnaphalodes (Asteraceae).

Nat Prod Lett 2002 Jun;16(3):179-86

H.E.J. Research Institute of Chemistry, University of Karachi, Pakistan.

The ethyl acetate soluble part of the chloroform extract of Pulicaria gnaphalodes belonging to the family Asteraceae afforded a new sesquiterpene-dimer of guaiane class named as gnapholide and anabsinthin of the same skeleton. The structures of both the compounds were elucidated with the aid of spectroscopic techniques including 2D NMR.
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http://dx.doi.org/10.1080/10575630290004260DOI Listing
June 2002

Inhibition of alpha-glucosidase by oleanolic acid and its synthetic derivatives.

Phytochemistry 2002 Jun;60(3):295-9

H.E.J. Research Institute of Chemistry, University of Karachi, Pakistan.

Oleanolic acid (1) and five synthetic derivatives (2-6) were tested spectrophotometrically for inhibition of urease, beta-lactamase, acetyl cholinesterase and alpha-glucosidase. All products showed a positive response only against alpha-glucosidase but not against the other enzymes; IC(50) calculations showed that the dihydroxy-olide derivative (4) was the most potent among all tested samples.
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http://dx.doi.org/10.1016/s0031-9422(02)00104-8DOI Listing
June 2002