Publications by authors named "Xiao-Long Hu"

56 Publications

Field Test of Twin-Field Quantum Key Distribution through Sending-or-Not-Sending over 428 km.

Phys Rev Lett 2021 Jun;126(25):250502

Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology ofChina, Hefei, Anhui 230026, People's Republic of China.

Quantum key distribution endows people with information-theoretical security in communications. Twin-field quantum key distribution (TF-QKD) has attracted considerable attention because of its outstanding key rates over long distances. Recently, several demonstrations of TF-QKD have been realized. Nevertheless, those experiments are implemented in the laboratory, and therefore a critical question remains about whether the TF-QKD is feasible in real-world circumstances. Here, by adopting the sending-or-not-sending twin-field QKD (SNS-TF-QKD) with the method of actively odd parity pairing (AOPP), we demonstrate a field-test QKD over 428 km of deployed commercial fiber and two users are physically separated by about 300 km in a straight line. To this end, we explicitly measure the relevant properties of the deployed fiber and develop a carefully designed system with high stability. The secure key rate we achieved breaks the absolute key rate limit of repeaterless QKD. The result provides a new distance record for the field test of both TF-QKD and all types of fiber-based QKD systems. Our work bridges the gap of QKD between laboratory demonstrations and practical applications and paves the way for an intercity QKD network with measurement-device-independent security.
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http://dx.doi.org/10.1103/PhysRevLett.126.250502DOI Listing
June 2021

Synthesis and Biological Evaluation of Celastrol Derivatives with Improved Cytotoxic Selectivity and Antitumor Activities.

J Nat Prod 2021 Jul 25;84(7):1954-1966. Epub 2021 Jun 25.

State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, People's Republic of China.

Cdc37 associates kinase clients to Hsp90 and promotes the development of cancers. Celastrol, a natural friedelane triterpenoid, can disrupt the Hsp90-Cdc37 interaction to provide antitumor effects. In this study, 31 new celastrol derivatives, -, -, and -, were designed and synthesized, and their Hsp90-Cdc37 disruption activities and antiproliferative activities against cancer cells were evaluated. Among these compounds, , with the highest tumor cell selectivity (15.4-fold), potent Hsp90-Cdc37 disruption activity (IC = 1.9 μM), and antiproliferative activity against MDA-MB-231 cells (IC = 0.2 μM), was selected as the lead compound. Further studies demonstrated has strong antitumor activities both in vitro and in vivo through disrupting the Hsp90-Cdc37 interaction and inhibiting angiogenesis. In addition, exhibited less toxicity than celastrol and showed a good pharmacokinetics profile in vivo. These findings suggest that may be a promising candidate for development of new cancer therapies.
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http://dx.doi.org/10.1021/acs.jnatprod.1c00262DOI Listing
July 2021

Cynaroside protects the blue light-induced retinal degeneration through alleviating apoptosis and inducing autophagy in vitro and in vivo.

Phytomedicine 2021 Jul 24;88:153604. Epub 2021 May 24.

State Key Laboratory of Natural Medicines, Department of TCMs Pharmaceuticals, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 210009, People's Republic of China. Electronic address:

Background: Blue light can directly penetrate the lens and reach the retina to induce retinal damage, causing dry age-related macular degeneration (dAMD). Cynaroside (Cyn), a flavonoid glycoside, was proved to alleviate the oxidative damage of retinal cells in vitro. However, whether or not Cyn also exerts protective effect on blue light-induced retinal degeneration and its mechanisms of action are unclear.

Purpose: This study aims to evaluate the protective effects of Cyn against blue-light induced retinal degeneration and its underlying mechanisms in vitro and in vivo.

Study Design/methods: Blue light-induced N-retinylidene-N-retinylethanolamine (A2E)-laden adult retinal pigment epithelial-19 (ARPE-19) cell damage and retinal damage in SD rats were respectively used to evaluate the protective effects of Cyn on retinal degeneration in vitro and in vivo. MTT assay and AnnexinV-PI double staining assay were used to evaluate the in vitro efficacy. Histological analysis, TUNEL assay, and fundus imaging were conducted to evaluate the in vivo efficacy. ELISA assay, western blot, and immunostaining were performed to investigate the mechanisms of action of Cyn.

Results: Cyn decreased the blue light-induced A2E-laden ARPE-19 cell damage and oxidative stress. Intravitreal injection of Cyn (2, 4 μg/eye) reversed the retinal degeneration induced by blue light in SD rats. Furthermore, Cyn inhibited the nuclear translocation of NF-κB and induced autophagy, which led to the clearance of overactivated pyrin domain containing 3 (NLRP3) inflammasome in vitro and in vivo.

Conclusion: Cyn protects against blue light-induced retinal degeneration by modulating autophagy and decreasing the NLRP3 inflammasome.
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http://dx.doi.org/10.1016/j.phymed.2021.153604DOI Listing
July 2021

Optimization of -Phenylpropenoyl-l-amino Acids as Potent and Selective Inducible Nitric Oxide Synthase Inhibitors for Parkinson's Disease.

J Med Chem 2021 06 21;64(11):7760-7777. Epub 2021 May 21.

State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, People's Republic of China.

-Phenylpropenoyl-l-amino acids (NPAs) are inducible nitric oxide synthase (iNOS) inhibitors possessing preventive effects for Parkinson's disease (PD). Here, structural modifications for improving the iNOS inhibitory activity and blood-brain barrier (BBB) permeability of NPAs were conducted, leading to 20 optimized NPA derivatives (). Compound , with the most potent activity (IC = 74 nM), high BBB permeability ( = 19.1 × 10 cm/s), and high selectivity over other NOS isoforms, was selected as the lead compound. Further studies demonstrated that directly binds to iNOS. In the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced acute PD model, the oral administration of (1 and 2 mg/kg) exerted preventive effects by alleviating the loss of dopaminergic (DAergic) neurons. Notably, in the MPTP-/probenecid-induced chronic PD model, the same dose of also displayed a therapeutic effect by repairing the damaged DAergic neurons. Finally, good pharmacokinetic properties and low toxicity made a promising candidate for the treatment of PD.
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http://dx.doi.org/10.1021/acs.jmedchem.1c00578DOI Listing
June 2021

[Adsorption of BS-18 Amphoterically Modified Bentonite to Tetracycline and Norfloxacin Combined Pollutants].

Huan Jing Ke Xue 2021 May;42(5):2334-2342

College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China.

Antibiotic pollution in the environment has become a hot topic. The amphoteric surfactant octadecyl dimethyl betaine (BS-18) was adopted to modify bentonite to investigate the effects and mechanisms of the composite adsorption of different types of antibiotics. Under the different modification ratios, temperatures, pH values, and ionic strength conditions, the adsorption of tetracycline (TC) and norfloxacin (NOR) by bentonite was studied under single and compound conditions, and the adsorption mechanism was analyzed and discussed in combination with the surface properties of amphoterically modified bentonite. The results showed that compared with those of CK, the CEC and specific surface area of the soil samples modified by BS-18 decreased, whereas the total carbon and total nitrogen contents increased. The adsorption order of BS-18 amphoterically modified bentonite to TC was CK > 100BS > 25BS > 50BS, which was in accordance with the Langmuir model; the adsorption order of NOR was 25BS > 50BS > CK > 100BS, which was consistent with the Henry model. The adsorption capacity of TC and NOR in the TC and NOR composite system was higher than that in the single system. With the increase in temperature, the adsorption of amphoterically modified bentonite to TC showed a positive warming effect, whereas the adsorption of NOR declined as the temperature increased. When the ionic strength increased from 0.001 mol·L to 0.500 mol·L, the adsorption of TC and NOR on each soil sample was inhibited. The pH of the solution can affect the existing forms of TC and NOR, and the adsorption capacity showed different trends as the pH increased. The adsorption of TC by BS-18-modified bentonite was mainly caused by electric charge attraction, whereas the adsorption of NOR was mainly caused by the combination of electric charge attraction and the hydrophobic effect. The different values of the octanol/water partition coefficient and the difference in structure resulted in different adsorption modes. In the TC and NOR composite system, a TC+NOR mixture was formed to promote the adsorption of soil samples.
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http://dx.doi.org/10.13227/j.hjkx.202009048DOI Listing
May 2021

Long-Distance Free-Space Measurement-Device-Independent Quantum Key Distribution.

Phys Rev Lett 2020 Dec;125(26):260503

Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China.

Measurement-device-independent quantum key distribution (MDI-QKD), based on two-photon interference, is immune to all attacks against the detection system and allows a QKD network with untrusted relays. Since the MDI-QKD protocol was proposed, fiber-based implementations aimed at longer distance, higher key rates, and network verification have been rapidly developed. However, owing to the effect of atmospheric turbulence, MDI-QKD over a free-space channel remains experimentally challenging. Herein, by developing a robust adaptive optics system, high-precision time synchronization and frequency locking between independent photon sources located far apart, we realized the first free-space MDI-QKD over a 19.2-km urban atmospheric channel, which well exceeds the effective atmospheric thickness. Our experiment takes the first step toward satellite-based MDI-QKD. Moreover, the technology developed herein opens the way to quantum experiments in free space involving long-distance interference of independent single photons.
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http://dx.doi.org/10.1103/PhysRevLett.125.260503DOI Listing
December 2020

Synthesis and Biological Evaluation of Celastrol Derivatives as Potential Immunosuppressive Agents.

J Nat Prod 2020 09 21;83(9):2578-2586. Epub 2020 Aug 21.

State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, People's Republic of China.

Celastrol, a friedelane-type triterpenoid isolated from the genus , possesses antitumor, anti-inflammatory, and immunosuppressive activities. A total of 42 celastrol derivatives (-, -, and -) were synthesized and evaluated for their immunosuppressive activities. Compounds - showed immunosuppressive effects, with IC values ranging from 25 to 83 nM, and weak cytotoxicity (CC > 1 μM). Compound , with a selectivity index value 31 times higher than that of celastrol, was selected as a lead compound. Further research showed that exerted its immunosuppressive effects by inducing apoptosis and inhibiting cytokine secretion via Lck- and ZAP-70-mediated signaling pathways.
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http://dx.doi.org/10.1021/acs.jnatprod.0c00067DOI Listing
September 2020

Hybrid protocol for sending-or-not-sending twin-field quantum key distribution.

Opt Lett 2020 Aug;45(15):4120-4123

We propose a hybrid protocol for sending-or-not-sending (SNS) twin-field quantum key distribution: replacing the signal source by heralded single-photon source (HSPS) in the original SNS protocol, while decoy sources are still unchanged. Numerical simulation shows that after adopting this HSPS, the performance in key rate and secure distance is much improved.
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http://dx.doi.org/10.1364/OL.399137DOI Listing
August 2020

Effects of methyl oleate and microparticle-enhanced cultivation on echinocandin B fermentation titer.

Bioprocess Biosyst Eng 2020 Nov 17;43(11):2009-2015. Epub 2020 Jun 17.

The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, 310014, People's Republic of China.

Echinocandin B (ECB) is a key precursor of antifungal agent Anidulafungin, which has demonstrated clinical efficacy in patients with invasive candidiasis. In this study, the effects of microparticle-enhanced cultivation and methyl oleate on echinocandin B fermentation titer were investigated. The results showed that the titer was significantly influenced by the morphological type of mycelium, and mycelium pellet was beneficial to improve the titer of this secondary metabolism. First, different carbon sources were chosen for the fermentation, and methyl oleate achieved the highest echinocandin B titer of 2133 ± 50 mg/L, which was two times higher than that of the mannitol. The study further investigated the metabolic process of the fermentation, and the results showed that L-threonine concentration inside the cell could reach 275 mg/L at 168 h with methyl oleate, about 2.5 times higher than that of the mannitol. Therefore, L-threonine may be a key precursor of echinocandin B. In the end, a new method of adding microparticles for improving the mycelial morphology was used, and the addition of talcum powder (20 g/L, diameter of 45 µm) could make the maximum titer of echinocandin B reach 3148 ± 100 mg/L.
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http://dx.doi.org/10.1007/s00449-020-02389-3DOI Listing
November 2020

Neuroprotective Effects of Lindleyin on Hydrogen Peroxide-Induced Cell Injury and MPTP-Induced Parkinson's Disease in C57BL/6 Mice.

Evid Based Complement Alternat Med 2020 28;2020:2938432. Epub 2020 Feb 28.

State Key Laboratory of Natural Medicines, Department of TCMs Pharmaceuticals, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, China.

Oxidative stress (OS) is a crucial factor influencing the development of Parkinson's disease (PD). Here we first reported that Lindleyin (), one of the major components of rhubarb, possessed neuroprotective effects against HO-induced SH-SY5Y cell injury and MPTP-induced PD of C57BL/6 mice. The results showed that can decrease cell death and apoptotic rate induced by HO through inhibiting mitochondrial apoptotic pathway and increasing the activities of SOD, GSH-Px, and CAT as well as decreasing the level of MDA. In addition, in vivo studies showed that oral administration of (5 or 20 mg/kg) showed significant change in motor function deficits, antioxidant enzyme activities, apoptotic pathway, and tyrosine hydroxylase expression. Our results reveal that might be a promising anti-PD agent by reducing OS and apoptosis.
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http://dx.doi.org/10.1155/2020/2938432DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7064860PMC
February 2020

Sending-or-Not-Sending with Independent Lasers: Secure Twin-Field Quantum Key Distribution over 509 km.

Phys Rev Lett 2020 Feb;124(7):070501

Shanghai Branch, National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Shanghai 201315, People's Republic of China.

Twin-field (TF) quantum key distribution (QKD) promises high key rates over long distances to beat the rate-distance limit. Here, applying the sending-or-not-sending TF QKD protocol, we experimentally demonstrate a secure key distribution that breaks the absolute key-rate limit of repeaterless QKD over a 509-km-long ultralow loss optical fiber. Two independent lasers are used as sources with remote-frequency-locking technique over the 500-km fiber distance. Practical optical fibers are used as the optical path with appropriate noise filtering; and finite-key effects are considered in the key-rate analysis. The secure key rate obtained at 509 km is more than seven times higher than the relative bound of repeaterless QKD for the same detection loss. The achieved secure key rate is also higher than that of a traditional QKD protocol running with a perfect repeaterless QKD device, even for an infinite number of sent pulses. Our result shows that the protocol and technologies applied in this experiment enable TF QKD to achieve a high secure key rate over a long distribution distance, and is therefore practically useful for field implementation of intercity QKD.
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http://dx.doi.org/10.1103/PhysRevLett.124.070501DOI Listing
February 2020

Purcell effect and light extraction of Tamm-plasmon-cavity green light-emitting diodes.

Opt Express 2019 Oct;27(21):30852-30863

Tamm plasmons (TPs), whose plasmon modes are confined at the Bragg reflector/metal interface due to the photonic stopband of the reflector and the negative dielectric constant of the metal, exhibit many advantages over the conventional surface plasmons (SPs) and potential applications in sensors, filters, optical circuits and light-emitting devices. In this paper, a TP-cavity structure has been proposed for accelerating the light emission and alleviating the large metal loss, which is hopeful for solving the efficiency droop and "green gap" problems in InGaN green light-emitting diodes (LEDs). The light emission performance of TP-cavity LEDs was systematically investigated based on transfer matrix and finite-difference time domain methods. Purcell factor (F) and light extraction efficiency (LEE) were both remarkably enhanced, which would be attributed to the presence of the TP and/or SP modes induced by the TP-cavity structure. In addition, two important factors including the thicknesses of the top Ag film and medium layer were investigated in detail and taken into account for the balance between the F and the LEE. Finally, light emission intensity was significantly enhanced for the TP-cavity green LEDs after the structure optimization as compared to the conventional green LEDs.
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http://dx.doi.org/10.1364/OE.27.030852DOI Listing
October 2019

Experimental Twin-Field Quantum Key Distribution through Sending or Not Sending.

Phys Rev Lett 2019 Sep;123(10):100505

Shanghai Branch, National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Shanghai 201315, People's Republic of China.

Channel loss seems to be the most severe limitation on the practical application of long distance quantum key distribution. The idea of twin-field quantum key distribution can improve the key rate from the linear scale of channel loss in the traditional decoy-state method to the square root scale of the channel transmittance. However, the technical demands are rather tough because they require single photon level interference of two remote independent lasers. Here, we adopt the technology developed in the frequency and time transfer to lock two independent laser wavelengths and utilize additional phase reference light to estimate and compensate the fiber fluctuation. Further, with a single photon detector with a high detection rate, we demonstrate twin field quantum key distribution through the sending-or-not-sending protocol with a realistic phase drift over 300 km optical fiber spools. We calculate the secure key rates with the finite size effect. The secure key rate at 300 km (1.96×10^{-6}) is higher than that of the repeaterless secret key capacity (8.64×10^{-7}).
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http://dx.doi.org/10.1103/PhysRevLett.123.100505DOI Listing
September 2019

Erratum: Neuroprotective Effects of Dammarane-Type Saponins from Panax notoginseng on Glutamate-Induced Cell Damage in PC12 Cells.

Planta Med 2019 07 20;85(9-10):e2. Epub 2019 May 20.

State Key Laboratory of Natural Medicines, Department of TCMs Pharmaceuticals, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, People's Republic of China.

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http://dx.doi.org/10.1055/a-0916-3473DOI Listing
July 2019

Preventive Effects of Total Flavonoid C-Glycosides from Abrus mollis on Nonalcoholic Fatty Liver Disease through Activating the PPARα Signaling Pathway.

Planta Med 2019 May 26;85(8):678-688. Epub 2019 Apr 26.

State Key Laboratory of Natural Medicines, Department of TCMs Pharmaceuticals, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, People's Republic of China.

subsp (Hance) Verdc. (Leguminosae) is a well-known edible plant usually added to soups and beverages. In this study, vicenin-2 (1: ), isoschaftoside (2: ), schaftoside (3: ), and their enrichment fraction, total flavonoid -glycosides, derived from the extracts of , were firstly found to prevent nonalcoholic fatty liver disease both and . In the study, total flavonoid -glycosides decreased the lipid accumulation in oleic acid-treated HepG2 cells. The mechanisms of total flavonoid -glycosides are involved in the regulation of peroxisome proliferator-activated receptor and its downstream, and the reduction of proinflammatory cytokines. In high-fat diet-induced fatty liver rats, total flavonoid -glycosides decreased the levels of glutamic-oxalacetic transaminease and glutamic-pyruvic transaminase, and decreased the lipid accumulation both in the liver and blood without affecting food intake. In addition, total flavonoid -glycosides also increased the activities of the antioxidant enzyme system . In conclusion, total flavonoid -glycosides are active components of on nonalcoholic fatty liver disease, and can be used in functional food and supplements for nonalcoholic fatty liver disease prevention and treatment.
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http://dx.doi.org/10.1055/a-0895-5838DOI Listing
May 2019

Phloroglucinols with Immunosuppressive Activities from the Fruits of Eucalyptus globulus.

J Nat Prod 2019 04 8;82(4):859-869. Epub 2019 Mar 8.

State Key Laboratory of Natural Medicines, Department of TCM Pharmaceuticals, School of Traditional Chinese Pharmacy , China Pharmaceutical University , Nanjing 210009 , People's Republic of China.

Five new phloroglucinol derivatives, eucalyptins C-G (1-5), together with 13 known analogues (6-18) were isolated from the fruits of Eucalyptus globulus. The structures and absolute configurations of 1-5 were established by means of spectroscopic data analysis, computational calculation methods, and single-crystal X-ray diffraction. Compounds 1-18 were investigated for their immunosuppressive effects in vitro, and 1, 2, 6, and 7 displayed moderate inhibitory activities with IC values of 11.8, 10.2, 18.2, and 19.1 μM, respectively. The stimulation index (SI) of 1 was 64.2 and was compared to that of cyclosporine A (SI = 149.57). Further study demonstrated that 1 exhibited an immunosuppressive effect through inducing apoptosis and inhibiting cytokine secretion.
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http://dx.doi.org/10.1021/acs.jnatprod.8b00920DOI Listing
April 2019

Sending-or-not-sending twin-field quantum key distribution in practice.

Sci Rep 2019 Feb 28;9(1):3080. Epub 2019 Feb 28.

State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing, 100084, People's Republic of China.

Recently, the twin field quantum key distribution (TF-QKD) protocols have been investigated extensively. In particular, an efficient protocol for TF-QKD with sending or not sending the coherent state has been given in. Here in this paper, we present results of practical sending-or-not-sending (SNS) twin field quantum key distribution. In real-life implementations, we need consider the following three requirements, a few different intensities rather than infinite number of different intensities, a phase slice of appropriate size rather than infinitely small size and the statistical fluctuations. We first show the decoy-state method with only a few different intensities and a phase slice of appropriate size. We then give a statistical fluctuation analysis for the decoy-state method. Numerical simulation shows that, the performance of our method is comparable to the asymptotic case for which the key size is large enough. Our method can beat the PLOB bound on secret key capacity. Our results show that practical implementations of the SNS quantum key distribution can be both secure and efficient.
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http://dx.doi.org/10.1038/s41598-019-39225-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6395628PMC
February 2019

Neuroprotective Effects of Dammarane-Type Saponins from Panax notoginseng on Glutamate-Induced Cell Damage in PC12 Cells.

Planta Med 2019 Jul 21;85(9-10):692-700. Epub 2019 Feb 21.

State Key Laboratory of Natural Medicines, Department of TCMs Pharmaceuticals, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, People's Republic of China.

Dammarane-type saponins, the main active ingredients of , have substantial neuroprotective effects in different animal models of neurodegenerative diseases. However, because these compounds have different structures, the level of protection provided by individual compounds varies, and highly active compounds can be selected based on structure-activity relationships. Glutamate is a major excitatory neurotransmitter that plays an important role in synaptic response development. However, excessive extracellular glutamate levels lead to neuronal dysfunctions in the central nervous system. Herein, we investigated the neuroprotective effects of nine saponins (compounds 1:  - 9: ) on glutamate-treated PC12 cells in the concentration range of 0.1 - 10 µM. The MTT assay revealed that these compounds increased cell viability to 65.6, 69.8, 76.9, 91.7, 74.4, 63.3, 59.9, 64.7, and 59.9%, respectively, compared with the glutamate-treated cells (44.6%). Protopanaxatriol (compound 4: ) was the most neuroprotective compound, and subsequent experiments revealed that pretreatment with compound 4: significantly reverses mitochondrial membrane potential collapse, increases superoxide dismutase activity, and decreases lactate dehydrogenase leakage, malondiadehyde levels, reactive oxygen species generation, and cell apoptosis. Compound 4: also decreased the Bax/Bcl-2 ratio, cleaved caspase-3, -methyl-D-aspartic receptor 1, and Ca-/calmodulin-dependent protein kinase II expression, and inhibited glutamate-induced cytochrome C release and phosphorylation of apoptosis signal-regulating kinase 1, c-Jun N-terminal kinase, and p38. Overall, the results indicate that protopanaxatriol has significant neuroprotective effects, and might be a promising neuroprotective agent for preventing and treating neurodegenerative diseases.
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http://dx.doi.org/10.1055/a-0853-7754DOI Listing
July 2019

[Spatial Variability in Soil Respiration Under Different Land Use Patterns in Maocun Village, Guilin].

Huan Jing Ke Xue 2019 Feb;40(2):924-933

Key Laboratory of Karst Dynamics, Ministry of Natural Resources/Guangxi, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin 541004, China.

To investigate the factors influencing the spatial variability in soil respiration among different land use patterns in a karst non-karst interactive distribution area, field experiments were conducted in Maocun Village, Guilin. Soil respiration, C-CO value, and relevant environment, vegetation, and soil factors were measured. The spatial variability in soil respiration and the relationship between soil respiration and these measured factors were examined. The results indicated that soil respiration rates ranged from 1.39 μmol·(m·s) to 5.31 μmol·(m·s), with the highest value being approximately 3.8 times the minimum. Soil respiration varied significantly among different land use patterns under different lithology zones. The soil respiration rate of the G2 pines in the same lithology area was 2.3 times higher than that in the orchard G1 point after the destruction of the forest. The soil respiration caused an increase in CO concentration in the atmosphere and a decrease in the C-CO value; the relationship between the two could be described by an inverse proportional function. The study found that in mid-April, the average water heat condition was close to that of the entire year. The difference in soil organic carbon content caused by land use was a driving factor of the spatial variability in soil respiration. In all ecosystems studied, the relationship between soil respiration and soil organic carbon content and total nitrogen content could be described by a two-element linear regression equation and explained 92.8% of the spatial variability in soil respiration.
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http://dx.doi.org/10.13227/j.hjkx.201805251DOI Listing
February 2019

Measurement-Device-Independent Quantum Key Distribution over asymmetric channel and unstable channel.

Sci Rep 2018 Dec 5;8(1):17634. Epub 2018 Dec 5.

State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing, 100084, People's Republic of China.

We show that a high key rate of Measurement-Device-Independent Quantum Key Distribution (MDIQKD) over asymmetric and unstable quantum channel can be obtained by full optimization and compensation. Employing a gradient optimization method, we make the full optimization taking both the global optimization for the 12 independent parameters and the joint constraints for statistical fluctuations. We present a loss-compensation method by monitoring the channel loss for an unstable channel. The numerical simulation shows that the method can produce high key rate for both the asymmetric channel and the unstable channel. Compared with the existing results of independent constraints, our result here improves the key rate by 1 to tens of times in typical experimental conditions.
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http://dx.doi.org/10.1038/s41598-018-35507-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6281621PMC
December 2018

Synthesis and biological evaluation of clovamide analogues with catechol functionality as potent Parkinson's disease agents in vitro and in vivo.

Bioorg Med Chem Lett 2019 01 15;29(2):302-312. Epub 2018 Nov 15.

State Key Laboratory of Natural Medicines, Department of TCMs Pharmaceuticals, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, People's Republic of China. Electronic address:

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http://dx.doi.org/10.1016/j.bmcl.2018.11.030DOI Listing
January 2019

Identification of amentoflavone as a potent highly selective PARP-1 inhibitor and its potentiation on carboplatin in human non-small cell lung cancer.

Phytomedicine 2018 Nov 5;50:88-98. Epub 2018 Sep 5.

State Key Laboratory of Natural Medicines, Department of TCMs Pharmaceuticals, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 210009, People's Republic of China. Electronic address:

Background: Nuclear protein poly (ADP-ribose) polymerase-1 (PARP-1) is a key enzyme in the repair of DNA and is a promising target in the development of chemosensitizers. This study first investigated the inhibitory effects of amentoflavone (AMF) and its derivatives on PARP-1 and the potentiation of AMF on carboplatin (CBP) in non-small cell lung cancer (NSCLC).

Purpose: This study aims to evaluate the inhibitory effect of AMF against PARP-1 and its potentiation on CBP in lung cancer both in vitro and in vivo.

Study Design: The inhibitory effect of AMF on PARP-1 was investigated using molecular docking and cell-free model of PARP-1 assay. Its potentiation on CBP in lung cancer was also evaluated.

Methods: Fluorescence resonance energy transfer assay was used to detect the inhibitory effects of AMF and its analogues on PARP-1. Molecular docking was employed to predict the binding mode of AMF and PARP-1. MTT assay, isobologram analysis, Hoechst staining, and Annexin V-PI double staining were used to confirm the potentiation of AMF on CBP in vitro. siRNA (PARP-1)-A549 cells were used to reveal the action target of AMF. Western blot analysis, immunohistochemistry, and Tunnel assay were employed to evaluate the potentiation of AMF on CBP in A549 xenograft mice.

Results: AMF and its analogues exerted excellent inhibitory effects on PARP-1 with IC values ranging from 0.198  μM to 0.409  μM. Docking experiment showed that AMF can stably bind to PARP-1 with a comparable binding energy to olaparib. AMF can decrease the expression of PAR induced by HOin vitro. AMF synergistically increased the CBP anti-proliferative effect in A549. However, its potentiation nearly disappeared when the cells were transfected with siRNAs against PARP-1. Oral administration of AMF (100  mg/kg), combined with CBP, remarkably inhibited A549 tumor growth and ki67 expression, and increased apoptosis compared with CBP-alone group.

Conclusion: All results suggest that AMF can be a potential PARP-1 inhibitor and a candidate adjuvant agent to boost the anticancer effect of CBP in NSCLC.
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http://dx.doi.org/10.1016/j.phymed.2018.09.012DOI Listing
November 2018

Stereoisomers of Schisandrin B Are Potent ATP Competitive GSK-3β Inhibitors with Neuroprotective Effects against Alzheimer's Disease: Stereochemistry and Biological Activity.

ACS Chem Neurosci 2019 02 6;10(2):996-1007. Epub 2018 Jul 6.

State Key Laboratory of Natural Medicines, Department of TCMs Pharmaceuticals, School of Traditional Chinese Pharmacy . China Pharmaceutical University , Nanjing 210009 , People's Republic of China.

Glycogen synthase kinase-3β (GSK-3β) is a key enzyme in hyperphosphorylation of tau proteins and is a promising therapeutic target in Alzheimer's disease (AD). Here, we reported, for the first time, that the stereoisomers of Schisandrin B (Sch B), (+)-1, (-)-1, (+)-2, and (-)-2, were potent GSK-3β inhibitors. They were demonstrated to selectively target GSK-3β in an orthosteric binding mode, with IC values of 340, 290, 80, and 70 nM, respectively. Further study showed that these stereoisomers can significantly increase the expression of p-GSK-3β (Ser9) and decrease the expressions of p-GSK-3β (Tyr216) and p-GSK-3β (Tyr279). Finally, these compounds can alleviate the cell injury induced by Aβ, and the cognitive disorders in AD mice, especially (+)-2 and (-)-2. Collectively, the stereoisomers of Sch B, especially (+)-2 and (-)-2, were found to be potential selective ATP-competitive GSK-3β inhibitors, which further affected their anti-AD effects. These promising findings explained the biological target of Sch B in AD, and bring a new understanding in the stereochemistry and bioactivities of Sch B.
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http://dx.doi.org/10.1021/acschemneuro.8b00252DOI Listing
February 2019

Turnover of Glycerolipid Metabolite Pool and Seed Viability.

Int J Mol Sci 2018 May 9;19(5). Epub 2018 May 9.

Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China.

Hydration⁻dehydration cycles can frequently cause stress to seeds, but can also be used to improve germination. However, the molecular basis of the stress caused is poorly understood. Herein, we examine the effects of hydration⁻dehydration cycles on seed viability and profile the membrane glycerolipid molecular species. We find that seed viability was not affected during the first two cycles, but significantly decreased as further cycles were applied, until all viability was lost. The abundances of seven glycerolipid classes increased and decreased through hydration and dehydration, respectively, but the phosphatidic acid and diacylglycerol abundances changed in the opposite sense, while total glycerolipid contents remained constant. This suggests that during hydration⁻dehydration cycles, turnover of glycerolipid metabolite pools take place, while no significant lipid synthesis or degradation is involved. As further hydration⁻dehydration cycles occurred, lipid unsaturation increased, plastidic lipids decreased, and phosphatidylserine acyl chains lengthened. The latter two could be lethal for seeds. Our findings reveal a novel model of membrane lipid changes, and provide new insights into the responses of seeds to hydration⁻dehydration cycles.
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http://dx.doi.org/10.3390/ijms19051417DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5983817PMC
May 2018

Phloroglucinol Derivatives from the Fruits of Eucalyptus globulus and Their Cytotoxic Activities.

Chem Biodivers 2018 Jun 21;15(6):e1800052. Epub 2018 May 21.

State Key Laboratory of Natural Medicines, Department of TCMs Pharmaceuticals, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 210009, P. R. China.

A new phloroglucinol derivative, named eucalyptin B (1), along with five related known compounds (2 - 6), was isolated from the fruits of Eucalyptus globulus. Their structures were elucidated by means of 1D- and 2D-NMR spectroscopy, with the absolute configuration of 1 determined by electronic circular dichroism (ECD) calculations. All isolated compounds (1 - 6) were evaluated for their cytotoxic activities against lung (A549), breast (4T1), and skin (B16F10) cancer cell lines. On the basis of cell viability assay, the cytotoxic activity of eucalyptin B (1) was further confirmed by apoptosis assay. Additionally, after treatment with eucalyptin B (1), the apoptosis factor proteins (Bcl2 and Bax) and caspase-3 levels in A549 cells were also determined by Western-blot analysis. By cytotoxic assay, eucalyptin B (1) exhibited potent cytotoxicity against A549 cells with an IC value of 1.51 μm and induced concentration dependent apoptosis of up to 49%. Additionally, eucalyptin B (1) inhibited 5-fold and increased 10-folds in the level of Bcl2 and Bax, respectively. Furthermore, the 11-fold increase in the level of caspase-3 confirmed eucalyptin B (1) activated caspase dependent apoptosis pathway. In conclusion, the isolated compound eucalyptin B (1) has promising cytotoxic activity in tumor cells, especially in A549.
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http://dx.doi.org/10.1002/cbdv.201800052DOI Listing
June 2018

Synthesis and biological evaluation of clovamide analogues as potent anti-neuroinflammatory agents in vitro and in vivo.

Eur J Med Chem 2018 May 1;151:261-271. Epub 2018 Apr 1.

Institute of Traditional Chinese Medicine & Natural Products, Jinan University, Guangzhou, 510632, People's Republic of China.

A series of clovamide analogues, namely, 1a-13a and 1b-13b, was synthesized and evaluated for their anti-neuroinflammatory activities using BV-2 microglia cells. Among these compounds, six (1b, 4b-8b) showed NO inhibition with no or weak cytotoxicity (CC > 100 μM), especially 4b, and showed an IC value of 2.67 μM. Enzyme activity and docking assay revealed that the six compounds, especially 4b, target inducible NO synthase (iNOS) and exhibit potent inhibitory effects on iNOS with IC values ranging from 1.01 μM to 29.23 μM 4b significantly suppressed the expression of pro-inflammatory cytokines in lipopolysaccharide-stimulated cells. Notably, the oral administration of 4b remarkably improved dyskinesia, reduced the expression of glial fibrillary acidic protein (GFAP)-a marker of neuroinflammation, and increased tyrosine hydroxylase-positive cells in 1-methyl-4-phenyl-1,2,3,6-tetrahydro-pyridine-induced Parkinson's disease (PD) mouse models. These observations demonstrated that 4b is an effective and promising candidate for PD therapy.
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http://dx.doi.org/10.1016/j.ejmech.2018.03.081DOI Listing
May 2018

Measurement-device-independent quantum key distribution via quantum blockade.

Sci Rep 2018 Mar 7;8(1):4115. Epub 2018 Mar 7.

Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing, 100084, People's Republic of China.

Efficiency in measurement-device-independent quantum key distribution(MDI-QKD) can be improved not only by the protocol, but also single-photon sources. We study the behavior of MDI-QKD with statistical fluctuation using quantum blockade source. Numerical simulation for a type of 4-intensity protocol shows that, after parameter optimization, this source can improve the final key rate by 100 times compared with traditional weak coherent state sources.
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http://dx.doi.org/10.1038/s41598-018-21576-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5841283PMC
March 2018

Regional and seasonal effects on the gastrointestinal parasitism of captive forest musk deer.

Acta Trop 2018 Jan 28;177:1-8. Epub 2017 Sep 28.

Laboratory of Non-invasive Research Technology for Endangered Species, College of Nature Conservation, Beijing Forestry University, No. 35 Tsinghua East Road, Haidian District, Beijing 100083, China. Electronic address:

Parasite infections can cause adverse effects on health, survival and welfare of forest musk deer. However, few studies have quantified the parasite infection status and evaluated the parasite temporal dynamics and differences between breeding centers for captive forest musk deer. The purpose of this study was to assess seasonal and regional effects on the parasite prevalence, shedding capacity, diversity, aggregation and infracommunity to establish baseline data on captive forest musk deer. The McMaster technique was applied to count parasite eggs or oocysts in 990 fecal samples collected at three breeding centers located in Qinling Mountains and Tibetan Plateau during spring, summer, and winter. Five gastrointestinal parasite groups were found in musk deer, and Eimeria spp. were dominant (mean oocysts per gram=1273.7±256.3). A positive correlation between Eimeria spp. and Strongyloides spp. (r=0.336, p<0.001) based on shedding capacity data was found, as well as a negative correlation between Eimeria spp. and Moniezia spp. (r=-0.375, p=0.003). Both seasonal and regional differences in diversity, prevalence, shedding capacity, aggregation and infracommunity were observed for five parasite groups. The low level of aggregation and high shedding capacity of Eimeria spp. and Strongyloides spp. might reflect the contaminated environment, and indicate that host-parasite relationships are unstable. The high degree of aggregation of Trichuris spp., Ascaris spp., and Moniezia spp. also suggests that some individual hosts had less ability to resist pathogens and greater transmission potential than others. These conclusions suggest that a focus on disease control strategies could improve the health of forest musk deer in captivity.
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http://dx.doi.org/10.1016/j.actatropica.2017.09.021DOI Listing
January 2018

Anti-inflammatory Meroterpenoids from Baeckea frutescens.

J Nat Prod 2017 08 28;80(8):2204-2214. Epub 2017 Jul 28.

State Key Laboratory of Natural Medicines, Department of Natural Medicinal Chemistry, and ‡Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University , Nanjing 210009, People's Republic of China.

Frutescones H-R (1-11), new sesqui- or monoterpene-based meroterpenoids, were isolated from the aerial parts of Baeckea frutescens. Their structures and absolute configurations were established by means of spectroscopic analyses (HRESIMS, 1D and 2D NMR, and ECD), as well as single-crystal X-ray crystallography of 1, (-)-7, and 9. The anti-inflammatory activities of all isolates were evaluated by measuring their inhibitory effects on NO production in LPS-stimulated RAW 264.7 macrophages, and the structure-activity relationships of 1-11 are also discussed. Compound 8 exhibited anti-inflammatory activity with an IC value of 0.36 μM, which might be related to the regulation of the NF-κB signaling pathway via the suppression of p65 nuclear translocation and the consequent decrease of IL-6 and TNF-α.
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http://dx.doi.org/10.1021/acs.jnatprod.7b00042DOI Listing
August 2017
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