Publications by authors named "Sheng-Fa Tsai"

Article Synopsis
  • * Researchers isolated seven compounds from mint, using techniques like NMR and mass spectrometry, and evaluated their effectiveness in drug combinations.
  • * Two synthesized derivatives of methyl rosmarinate showed significantly better antiviral activity against the Omicron BA.1 variant, with improved efficacy compared to the original compound.
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is a traditional Chinese medicine with various biological activities. With its limited natural supply, cultured has become the major alternative source, and the culture conditions may affect the chemical compositions. To improve the production of chemical ingredients, was cultured with three different media, including rice only, rice plus 3% tea leaves, and rice plus 3% droppings of .

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Ten compounds were isolated from the root bark of Bombax malabarica, including two new compounds, bombamalin (1) and 3,4,5-trimethoxyphenol-1-[β-xylopyranosyl-(1 → 2)]-β-glucopyranoside (3), and shorealactone (4), a rare dehydroascorbic acid fused l-ε-viniferin. Compound 1 is an unusual bissesquiterpene, containing a 1,4-dioxene ring formed by fusing isohemigossypol with ent-cadinen-2-one. Their structures were elucidated by extensive spectroscopic analysis.

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The seed of Hyptis suaveolens, commonly known as wild flour ball (san fen yuan) in Taiwan, serves as a main refreshing drink substance in several regions. This study investigated firstly its secondary metabolites, leading to the isolation of five major caffeoylquinic acid derivatives (1-5) from the ethanol extract. In addition, ten minors, including three caffeoylquinic acid derivatives (12-14), were characterized via assistance of HPLC-SPE-NMR.

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Bioassay guided fractionation and separation of the EtOH extract of the kernels of Palaquium formosanum against PC-3 cells via Sephadex LH-20 and reverse phase C-18 columns led to the isolation of 13 protobassic saponins. One of these saponins is new and was characterized as 3‴-O-rhamnopyranosyl-arganin C, a bisdesmoside of 16α-hydroxyprotobassic acid at the C-3 and C-28 positions. The structures of these compounds were determined on the basis of 1D NMR (H, C), 2D NMR (H-H COSY, HSQC, HMBC, and NOESY), and selectively excited 1D TOCSY spectroscopic analyses and MS data, and comparison with literature data.

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Bioassay guided fractionation against a-glucosidase and separation of the ethanolic extract of Pasania formosana leaf by chromatographic methods led to the isolation of a novel secocycloartane triterpene. This compound, named pasasecocycloartenoic acid, was elucidated as 21,24(R)-epoxy-25-hydroty-3;4- secocycloart-4(28)-en-3-oic acid through analysis of 1D and 2D NMR spectra and on the basis of HRESIMS data. The compound showed weak activity against α-glucosidase, but its poor solubility hampered the bioassay.

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Bioassay guided fractionation and separation of the EtOH extract of Annona glabra leaf against acetylcholinesterse led to the characterization of 15 alkaloids. Among them, (-)-actinodaphnine (2) and (-)-(6aS,7R)-7-hydroxyactinodaphnine (9) are new aporphines, although (+)-2 and (±)-2 have been found in several plants. Their structures were established by spectroscopic analysis.

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Chemical investigation of the n-BuOH-soluble fraction of the EtOH extract of the aerial part of Curcuma longa led to the isolation of 11 flavonol glycosides and one dihydroflavonol glucoside (1) via chromatography over Sephadex LH-20 and Lobar RP-18 columns. Although they are known, the 1H and 13C NMR data recorded in CD3OD rather than the common DMSO-d6 are doubly checked via extensive 2D NMR spectroscopic analyses, leading to some revisions of the reported data, especially for the glycon part.

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The active fraction from the EtOH extract of Hyptis rhomboides against xanthine oxidase was identified by use of an HPLC microfractionation-centrifugal vacuum evaporation-bioassay hyphenated technique. Scale-up separation of the active subfractions using semi-preparative RP-HPLC provided 13 phenylpropanoid compounds, including O-styrenylneolignans, hyprhombins A-C, epihyprhombin B, and hyprhombin B methyl ester, and O-caffeoylnorneolignans, hyprhombins D and E. All of these compounds shared a common 1,4-benzodioxane skeleton, as established by spectroscopic analyses.

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Triterpenoids, 1-3, 8 and 9, along with 24 known compounds were isolated from leaves and twigs of Fagus hayatae. Of these, compound 1, 1,10-seco-3β,10α,23-trihydroxyolean-12-ene-1,28-dioic acid 1,23-lactone, possesses a hitherto unknown 1,10-seco-oleanane skeleton. In addition, 2,3-seco-20(29)-lupene-2,3-dioic acid (16), previously described as a synthetic product, is now established as a plant natural product; the neolignan-9'-O-rhamnoside 19 is also characterized herein.

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The active fraction of the EtOH extract of the stem of Annona glabra against acetylcholinesterase (AChE) was analyzed by combining HPLC microfractionation with a bioassay. The analytical-scale sample was fractionated by HPLC-DAD into 96-well microplates, which, after evaporation, were assayed against AChE. The active subfractions were scaled up by separation over semipreparative HPLC to give 20 compounds.

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