Fa-Wu Dong

Cytotoxic bibenzyl dimers from the stems of Dendrobium fimbriatum Hook

The bioassay-guided chemical investigation of the stems of Dendrobium fimbriatum Hook led to the isolation of seven first reported bibenzyl dimers with a linkage of a methylene moiety, fimbriadimerbibenzyls A-G (1-7), together with a new dihydrophenanthrene derivative (S)-2,4,5,9-tetrahydroxy-9,10-dihydrophenanthrene (8) and thirteen known compounds (9-21). The structure of the new compound was established by spectroscopic analysis. Biological evaluation of bibenzyl derivatives against five human cell lines indicated that seven of those compounds exhibited broad-spectrum and cytotoxic activities with IC50 values ranging from 2.2 to 21.2 μM. Those rare bibenzyl dimers exhibited cytotoxic activities in vitro and the cytotoxicity decreased as the number of oxygen-containing groups in the structure decreases.

Five new phenolic compounds from Dendrobium aphyllum.

One new phenanthrene, aphyllone A (1) and four new bibenzyl derivatives, aphyllone B (2) and aphyllals C-D (3-5), together with nine known compounds (6-14), were isolated from the stems of Dendrobium aphyllum (Roxb.) C. E. Fischer. The structures of these new compounds were elucidated by means of extensive spectroscopic analyses, and the absolute configuration of compound 1 was determined by single crystal X-ray diffraction and quantum calculations. Compounds 6, 8 and 14 inhibited NO production at the concentration of 25 μM in LPS-stimulated RAW264.7 cells with the inhibition (%) of 32.48, 35.68, and 38.50. Compound 2 possessed significant DPPH radical scavenging activity with scavenging percentage of 87.97% at the concentration of 100 μg/mL.

Iridoids and sesquiterpenoids from the roots of Valeriana jatamansi Jones

Three new iridoids, jatamanvaltrates R-S (1-2) and jatamanin Q (3), as well as three new sesquiterpenoids, valeriananoids D-E (4, 5) and clovane-2β-isovaleroxy-9α-ol (6), together with nine known compounds were isolated from the roots of Valeriana jatamansi Jones. Compound 2 was the first reported iridoid with fatty acid esters in the Valerianaceae family. The structures of new compounds were established on the basis of extensive spectroscopic analysis. Moreover, all the isolates were evaluated for inhibitory activity on acetylcholinesterase (AChE).

Cycloartane triterpenoid saponins from water soluble of Passiflora edulis Sims and their antidepressant-like effects.

ETHNOPHARMACOLOGICAL RELEVANCE Various species of genus Passiflora have been used as traditional folk medicines owing to their sedative and anti-hypertensive properties. Passiflora edulis Sims most widely grown in the warm temperate for their fragrant fruits and their twigs and leaves are used as a folk medicine for treating both anxiety and nervousness in American countries. The present study was to evaluate the antidepressant-like effect and the active components of this plant. MATERIALS AND METHODS The alcohol extracts of the stems (PES, 10 and 2 g/kg of the plant materials) and leaves (PEL, 10 and 2 g/kg of the plant materials) of Passiflora edulis Sims were orally administered to mice for 7 day. The animals were tested in the forced swim test (FST) and tail suspension test (TST). After behavioral assay of ethanol extract, phytochemical research of the stems and leaves (5.7 kg) of Passiflora edulis Sims were developed and further bioactive verification of monomeric compounds were conducted. RESULTS There are mainly cycloartane triterpenoids and their saponins isolated from this plant, including two new cycloartane triterpenoid saponins named cyclopassifloside ХII (1) and ХIII (2), together with six known cycloartane triterpenoids, cyclopassifloic acids B and E, cyclopassiflosides II, VI, IX and XI. The ethanol extract of Passiflora edulis Sims together with isolated compounds cyclopassiflosides IX and XI may possess antidepressant-like effect. CONCLUSIONS Cycloartane triterpenoid was one of the main compositions of Passiflora edulis Sims and possess antidepressant-like activity.

Iridoids and sesquiterpenoids of Valeriana stenoptera and their effects on NGF-induced neurite outgrowth in PC12 cells

Twenty-one compounds (nine iridoids and twelve sesquiterpenoids), including ten previously unknown (five iridoids and five sesquiterpenoids) were isolated from whole dried material of Valeriana stenoptera. Structures were established on the basis of extensive spectroscopic analysis and the relative stereochemistry of 13-hydroxypatchoulol A was further confirmed by X-ray crystallographic data. All isolates were evaluated for their effects on nerve growth factor (NGF)-mediated neurite outgrowth in pheochromocytoma (PC12) cells and seven compounds showed potent promoting effects.

Four new glycosides from the stems of Dendrobium fimbriatum Hook

Abstract Four new glucosides, named as gigantol-5-O-β-d-glucopyranoside (1), 9,10-dihydro-aphyllone A-5-O-β-d-glucopyranoside (2), ficusal-4-O-β-d-glucopyranoside (3), botrydiol-15-O-β-d-glucopyranoside (4), together with eight known compounds (5–12) were isolated from the n-BuOH extract of the stems of Dendrobium fimbriatum Hook. Their structures were elucidated by the analyses of spectroscopic data.

Inhibitory activities on nitric oxide production of stilbenoids from Pholidota yunnanensis.

Three new stilbenoids, 1-(4′-hydroxybenzyl)-imbricatin (1), (E)-4′-hydroxy-2′,3,3′,5-tetramethoxystilbene (2), and (E)-3,4′-dihydroxy-2,6-bis(4-hydroxybenzyl)-2′,3′,5-trimethoxystilbene (3), together with 15 known stilbene derivatives, were isolated from Pholidota yunnanensis. Their structures were elucidated by spectroscopic methods and by comparison of their NMR data with those of related compounds. Furthermore, the inhibitory activities on nitric oxide (NO) production of the isolated compounds were examined in murine macrophages (RAW 264.7) activated by lipopolysaccharide. The cytotoxicity of 18 compounds was determined by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay. Among the tested compounds, eight stilbenoids, including three dihydrophenanthrenes, three stilbenes, and one bibenzyl derivative showed inhibitory effects on NO production without cytotoxicity with IC50 values ranging from 4.07 to 7.77 μM, as compared to MG-132, which was used as a positive control (IC50 of 0.10 μM). One dihydrophenanthrene, phoyunnanin C (5), showed cytotoxic effects at the test concentrations.

Dendrowardol C, a novel sesquiterpenoid from Dendrobium wardianum Warner

Dendrowardol C (1)—a novel sesquiterpenoid, with an unprecedented 4/5/6/6 tetracyclic carbon backbone, together with two known cyclopacamphane-type sesquiterpenoids; dendronobilin I (2) and dendrobane A (3) were isolated from the stems of Dendrobium wardianum Warner. The structure of 1 was established on the basis of spectroscopic data and the absolute configuration was determined by single-crystal X-ray diffraction crystallography. The hypothetical biosynthetic pathway of 1 was postulated. Compound 1 showed no cytotoxic activity against human tumor cell lines HL-60, SMMC-7721, A-549, MCF-7, and SW480.

Chemical components of Dendrobium crepidatum and their neurite outgrowth enhancing activities

Abstract15 compounds, including two new ones crepidatuols A (1) and B (2) were isolated from the stems of Dendrobium crepidatum. The planar structures of these compounds were elucidated by spectroscopic methods (NMR, MS, UV, and IR) and comparison with those from literatures. 10 compounds were send for enhancing activities on nerve growth factor (NGF) medicated neurite outgrowth in PC12 cells and the results indicated that crepidatuol A (1), confusarin and 3-(2-acetoxy-5-methoxy)-phenylpropanol showed enhancing activities at the concentration of 10.0 µM.

Seco-Dendrobine-Type Alkaloids and Bioactive Phenolics from Dendrobium findlayanum

Investigation of the 95% EtOH extract of stems of Dendrobium findlayanum afforded four new seco-dendrobines, findlayines A-D (1-4); two known dendrobines, dendrobine (5) and 2-hydroxydendrobine (6); and four new phenolic compounds, dendrofindlaphenols A-C (7, 9, and 10) and 6″-de-O-methyldendrofindlaphenol A (8). Compounds 1 and 2 are the first seco-dendrobines possessing a seven-membered lactam moiety, with 3 and 4 derived from the oxidative cleavage of the C-2-C-3 bond of dendrobine. The structures were established using spectroscopic methods and by comparison with literature data. The absolute configurations of 1-4 were confirmed via single-crystal X-ray diffraction data. Cytotoxic activity assays against HL-60, SMMC-7721, A-549, MCF-7, and SW480 human cancer cell lines revealed IC50 values ranging from 2.3 to 5.3 μM for compound 7, from 19.4 to 34.4 μM for 8, and from 49.4 to 96.8 μg/mL for the EtOAc extract. An assay of the inhibition of NO production with RAW 264.7 cells indicated that 8 had an IC50 value of 21.4 μM, and the EtOAc extract, 10.5 μg/mL. The EtOAc extract possessed DPPH radical scavenging activity of 69.93% at 100 μg/mL.