Publications by authors named "Li-She Gan"

The practice of Chinese herbal medicines for the treatment of COVID-19 in China played an essential role for the control of mortality rate and reduction of recovery time. The iridoids is one of the main constituents of many heat-clearing and detoxifying Chinese medicines that were largely planted and frequently used in clinical practice. Twenty-three representative high content iridoids from several staple Chinese medicines were obtained and tested by a SARS-CoV-2 pseudo-virus entry-inhibition assay on HEK-293 T/ACE2 cells, a live HCoV-OC43 virus infection assay on HRT-18 cells, and a SARS-CoV-2 3CL protease inhibitory FRET assay followed by molecular docking simulation.

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Thirteen compounds were isolated and identified from 70% ethanol extract of the roots of Gentiana macrophylla by multi-chromatographic methods, including microporous resin, silica gel, and C_(18) reversed-phase column chromatography, as well as HPLC as follows: macrophylloside G(1), macrophylloside D(2), 5-formyl-2,3-dihydroisocoumarin(3),(+)-medicarpin(4),(+)-syringaresinol(5), liquiritigenin(6),(3R)-sativanone(7),(3R)-3'-O-methylviolanone(8), 4,2',4'-trihydroxychalcone(9), latifolin(10), gentioxepine(11), 6α-hydroxycyclonerolidol(12), and ethyl linoleate(13). Compound 1 was a new benzopyran glycoside. Compounds 4, 6-10, 12, and 13 were isolated for the first time from Gentiana plants.

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Article Synopsis
  • A study focused on a traditional herb used in Guangdong, China, for treating rheumatism identified eight diterpenoids, including a new compound with a unique structure.
  • The most abundant compound, orthosiphol K, was modified to create seven new derivatives, which were tested for their effectiveness against rheumatoid arthritis in a lab model.
  • Results indicated that one derivative had the strongest anti-inflammatory effects, impacting key proteins involved in inflammation and suggesting potential therapeutic uses for these compounds.
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Ten lignans, including six previously undescribed phenolic ester glycosyl lignans (1-6), were isolated from a well-known traditional Chinese medicine, Qin-Jiao, which is the dry root of Gentiana macrophylla Pall. (Gentianaceae). Their structures were determined by spectroscopic and chemical methods, especially 2D NMR techniques.

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Four previously undescribed terpenoid glucosides, including one sesquiterpenoid di-glucoside (), two new iridoid glucosides (, ), and a new triterpenoid tri-glucoside (), were isolated from a 70% ethanol extract of the root of (Gentianaceae), along with eight known terpenoids. Their structures were determined by spectroscopic techniques, including 1D, 2D NMR, and HRMS (ESI), as well as chemical methods. The absolute configuration of compound was determined by quantum chemical calculation of its theoretical electronic circular dichroism (ECD) spectrum.

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Two rarely occurring diphenylheptanoid-phenylheptanoid hybrid dimers ( and ) and one new oxygenated fatty acid (), as well as two known fatty acid analogues ( and ), were isolated from the 70% EtOH extract of the pollen of . Their planar structures were established by interpretation of MS and NMR spectroscopic data, and the absolute configurations of and were determined by Mosher's method and quantum chemical TD-DFT calculations of ECD spectra. An anti-diabetic evaluation of these isolates revealed that compounds and exhibited promising inhibitory activity against α-glucosidase with IC values of 11.

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Six previously undescribed N-acetyldopamine (NADA) trimmer racemates, percicamides A-F (1-6), were isolated from a 70% ethanol extract of Cicadae Periostracum. Subsequent chiral-phase separation afforded six pairs of enantiomers, (+)- and (-)-percicamides A-F (1a/1b-6a/6b). Their structures including absolute configurations were elucidated by combined extensive spectroscopic data and quantum chemical calculations.

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Six pairs of undescribed phenylglycerol benzoate enantiomers, (±)-mollifolines A-F, which can also be categorized into three two-pairs of epimers, were isolated from Cinnamomum mollifolium H. W. Li (Lauraceae).

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(±)-Heterocageflavone (1), a pair of enantiomeric isoprenylated flavonoids, were isolated from Artocarpus heterophyllus. Compound 1 incorporates an unusual tricyclo[5.3.

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Five new α-pyrones, cryptowratones A-E (1-5), and five known congeners (6-10), together with four other known compounds 11-14 were isolated from the twigs of Cryptocarya wrayi. The structures of the new compounds were elucidated on the basis of extensive spectroscopic data analysis and ECD calculations. All α-pyrones except 6 were evaluated for their stimulatory effects on glucose uptake in vitro with CHO-K1/GLUT4 cells.

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Two new isoquinoline alkaloids, cryptowrayines A (1) and B (2), along with one known pavine alkaloid (-)-12-hydroxyeschscholtzidine (3), were isolated from the twigs of Cryptocarya wrayi. The structures of new compounds were elucidated by extensive spectroscopic data analysis and electronic circular dichroism (ECD) calculations. Both compounds 1 and 2 exhibited moderate quinone reductase inducing activity in Hepa 1c1c7 cells.

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The 95% ethanol extract of Baphicacanthis Cusiae Rhizoma et Radix was purified by multi-chromatographic methods including microporous resin, silica gel, Sephadex LH-20, and C_(18) reversed-phase column chromatography. Fourteen compounds were isolated and structurally identified, including five phenylethanoid glycosides, five phenylpropanoids, one lupinane triterpene, two alkaloids, and one flavonoid, listed as follows: 2-(4-hydroxy-3-methoxyphenyl)-3-(2-hydroxy-5-methoxyphenyl)-3-oxo-1-propanol B(1), threo-2,3-bis-(4-hydroxy-3-methoxybenzene)-3-methoxypropanol(2), 2-(3-hydroxy-4-methoxyphenyl)-ethanol-1-O-[3,4-O-di-acetyl-(1→3)-O-α-L-rhamnopyranosyl]-β-D-glucopyranoside(3), verbascoside(4), 2″,3″-di-O-acetyl martynoside(5),(+)-pinore-sinol(6), diospyrosin(7), daidzein(8), wiedemannioside B(9), buddlenol A(10), 2″-O-acetyl martyonside(11), lupeol(12), indirubin(13), and tryptanthrin(14). Compound 3 was a new phenylethanoid glycoside, and the other 10 compounds were isolated for the first time from Baphicacanthis Cusiae Rhizoma et Radix except compounds 12, 13, and 14.

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Article Synopsis
  • A terpene synthase (LcTPS2) was isolated from the plant Leucosceptrum canum, capable of producing unique macrocyclic terpenoids.
  • Engineered versions of bacteria and plants were able to produce six new types of sesterterpenoids, marking a significant advancement in terpenoid research with the largest ring system identified so far.
  • Certain engineered variants of LcTPS2 showed increased production of these compounds and demonstrated the ability to inhibit T-cell production, offering potential applications in biocatalysis and plant biosynthesis.
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Liver fibrosis has accounted for liver diseases and overall mortality, but no relevant drug has been developed. Filamentous fungi are important resources of natural products for pharmaceutical development. is a mushroom endophytic fungus, which primarily produces aurovertins.

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is used in China not only as a functional food but also as an herb to tonify the spleen, enhance immunity, and treat palpitation. Our previous investigation showed that a fraction enriched in glycosides obtained from the roots of possessed pronounced protective effects on H9c2 cells against CoCl-induced hypoxic injury. However, the active compounds responsible for the observed effects were still unknown.

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Compounds -, the rare examples of 9,11- euphane or lanostane triterpenoids featuring an enol-hemiacetal functionality, were isolated from . Their structures were elucidated by a combination of spectroscopic, computational, chemical, and single-crystal X-ray diffraction means, which enables the structure of previously published euphorol J to be revised as . - showed significant cytotoxicities on the breast cancer cell line MDA-MB-468 with IC values in the range of 2.

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Two eudesmane-guaiane/lindenane heterocoupled sesquiterpenoid dimers, horienoids A () and B () with new carbon skeletons, from were characterized by a combined method. Compound featured a unique 2,10-dioxabicyclo[6.2.

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6-Formylisoophiopogonone B () and 8-formylophiopogonone B (), two natural products isolated from , represent a subgroup of rare 6/8-formyl/methyl-homoisoflavonoid skeletons. Herein we report an efficient method for the synthesis of these formyl/methyl-homoisoflavonoids. The synthesized compounds were evaluated for their neuroprotective effects on the MPP-induced SH-SY5Y cell injury model and showed marked activity.

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Fungal natural products are rich sources of clinical drugs. Particularly, the fungicolous fungi have a large number of biosynthetic gene clusters (BGCs) to produce numerous bioactive natural products, but most BGCs are silent in the laboratory. We have shown that a fungicolous fungus NRRL 3705 predominantly produces the highly reduced polyketide-type mycotoxins aurovertins.

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Stimuli-responsive unimolecular chirality switching is a highly intriguing topic because the molecular structure as well as its function can be adjusted simultaneously by a switching process. Herein, a novel acid/base-tunable unimolecular chirality switching system based on a pillar[5]azacrown [1]catenane is reported. The bicyclic pillar[5]azacrown [1]catenane is synthesized through fusing an azacrown ring onto one repeating unit of a pillar[5]arene.

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Utilizing the distinct HMBC cross-peak patterns of ower-ield ange (LFR; 11.80-14.20 ppm) hydroxyl singlets, presented NMR methodology characterizes flavonoid metabolomes both qualitatively and quantitatively.

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Two highly rearranged daphniphyllum alkaloids, daphnillonins A () and B (), were isolated from and structurally characterized by a combination of diverse methods, including the calculation of electronic circular dichroism. Compound possesses an unprecedented carbon architecture with a very unique 8-methyl-6-azabicyclo[3.2.

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Novel antilipid peroxidative carbazole alkaloids, antiostatin A (), antiostatin A (), and (±)-morindolestatin (), were isolated from a new soil-derived sp. Compound possesses an unusual cyclohexene side chain. Compound was a pair of enantiomers featuring an unprecedented [1,4]oxazino[2,3-]carbazole ring system.

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The 70% ethanol extract of the whole plant of Souliea vaginata was purified by multi-chromatographic methods including macroporous resin,silica gel,Sephadex LH-20,and C18-reversed-phase column chromatography. A new spirocyclic cycloartane triterpenoid was isolated and identified as( 16 R*,20 R*,23 S*,24 R*,25 S*)-16,23: 23,26-diepoxy-15α,24,25-trihydroxy-9,19-cycloart-3β-O-β-D-xylopyranoside( 1),and named as soulieoside S. Its planar structure and relative configuration were determined by spectroscopic techniques including 2 D NMR and HRESI-MS.

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Aimed at exploring the dentin biomodification potential of proanthocyanidins (PACs) for the development of dental biomaterials, this study reports the phytochemical and dental evaluation of nine B-type PACs from grape seed extract (GSE). Out of seven isolated dimers (-), four new compounds (, , , and ) involved relatively rare -catechin or -epicatechin monomeric flavan-3-ol units. Low-temperature NMR analyses conducted along with phloroglucinolysis and electronic circular dichroism enabled unequivocal structural characterization and stereochemical assignment.

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