Hongzheng Fu

ent-Strobane and ent-Pimarane Diterpenoids from Siegesbeckia pubescens.

Two strobane diterpenoids, strobols A (1) and B (2), 15 new pimarane diterpenoids (3-6 and 8-18), and the known compounds kirenol (19), darutigenol (20), and ent-2β,15,16,19-tetrahydroxypimar-8(14)-ene (7) were isolated from the aerial parts of Siegesbeckia pubescens Makino. The structures of the new compounds were established based on the interpretation of HRESIMS and NMR analysis. The configurations of 1, 6, and 17 were confirmed by X-ray crystallographic data. Compounds 3, 5, and 11 inhibited the migration of MB-MDA-231 breast cancer cells induced by the chemokine epithelial growth factor, with IC50 values of 4.26, 3.45, and 9.70 μM, respectively.

New Cyclopentenone Derivatives from an Endophytic Streptomyces sp. Isolated from the Mangrove Plant Aegiceras comiculatum

From the mangrove plant Aegiceras comiculatum collected in South China an endophytic Streptomyces sp. was isolated. Following cultivation in a seawater-based medium, four new cyclopentenone derivatives, namely (5R) 3-amino-5-hydroxy-5-vinyl-2-cyclopenten-1-one (1), (5R) 5-hydroxy-3-[(methoxycarbonyl)amino]-5-vinyl-2-cyclopenten-1-one (2), (5R) 5-hydroxy-3-[[2-(4-hydroxyphenyl)ethyl]amino]-5-vinyl-2-cyclopenten-1-one (3), and 3-isobutylpropanamide-2-cyclopenten-1-one (4), were obtained from the fermentation broth. Their structures were elucidated by extensive spectroscopic (UV, IR, ESIMS, and 2D NMR) data analyses.

Isomalabaricane-type compounds from the marine sponge Rhabdastrella aff. distincta.

Fractionation of the marine sponge Rhabdastrella aff. distincta led to the isolation and characterization of four new isomalabaricane analogues, isogeoditin A (1), 13-(E)-isogeoditin A (2), isogeoditin B (3), and 22,23-dihydrostellettin B (4), along with seven known isomalabaricane derivatives (5-11). Methylation of 10 and 11 afforded methyl esters 12 and 13. The structures of compounds 1-4 were determined on the basis of spectroscopic data analysis. All compounds were tested against a small panel of human tumor cell lines.

Polyhydroxylated steroids from the soft coral Sinularia dissecta

A repeated silica gel column chromatography followed by HPLC purification on the methanol extract of marine soft coral Sinularia dissecta, resulted in the isolation of fifteen polyhydroxylated steroids (1-15), involving six new C-18 functionalized steroids, 3beta-acetoxy-1alpha,11alpha-dihydroxygorgost-5-en-18-oic acid (1), gorgost-5-en-1alpha,3beta,11alpha,18-tetrol (2), 18-acetoxy-1alpha,3beta,11alpha-trihydroxygorgost-5-ene (3), 24(S)-3beta-acetoxy-1alpha, 11alpha-dihydroxyergost-5-en-18-oic acid (4), 24(S)-ergost-5-en-1alpha,3beta,11alpha,18-tetrol (5), and dissectolide (6). The structures of the new compounds were determined on the basis of extensive spectroscopic data (IR, MS, (1)H and (13)C NMR, HMQC, HMBC, and NOESY) analysis. Compound 6 was found as an unusual sterol bearing a lactone functionality.

Cerebroside Analogues from Marine-Derived Fungus Aspergillus flavipes

From the mycelium of the marine-derived fungus Aspergillus flavipes, isolated from the sea anemone Anthopleura xanthogrammica, two new cerebroside analogues, namely flavicerebrosides A (1): [(2S,2′R,3R,4E,8E)-N-2′-hydroxyoctadecanoyl-1-O-β-d-galactopyranosyl-9-methyl-4,8-sphingadienine], and B (2): [(2S,2′R,3R,3′E,4E,8E)-N-2′-hydroxy-3′-octadecenoyl-1-O-β-d-galactopyranosyl-9-methyl-4,8-sphingadienine], together with two known glycosphingolipids cerebrosides D (3) and C (4), were isolated. Their structures were identified by means of extensive spectroscopic analysis (IR, UV, 2D NMR, MS, CD) and chemical degradation. All four compounds showed cytotoxic activity against the KB cell line.

Two new constituents from mangrove Bruguiera gymnorrhiza

A lignan and two aromatic compounds were isolated from the branches of the mangrove plant, Bruguiera gymnorrhiza. They were brugunin A (1), bruguierol D (2) and 2,3-dimethoxy-5-propylphenol (3). Among them, 1 and 2 were new compounds; 3 was isolated from a natural source for the first time. The structures of these compounds were determined by NMR spectroscopic studies as well as chemical evidence.

Two new pregnane glycosides from soft coral Cladiella krempfi

Two new pregnane-type steroidal glycosides, pregna-5,20-dien-3-O-α-fucopyranoside (1) and pregna-20-en-3-O-α-fucopyranoiside (2), along with two known pregnane derivatives, were isolated from the soft coral Cladiella krempfi. Their structures were determined by spectroscopic data analysis.

New 4α-methyl steroids from a Chinese soft coral Nephthea sp.

Abstract Three new 4α-methyl steroids, 4α-methyl-ergost-7,24(28)-diene-3β-ol-23-one ( 1 ), 4α-methyl-ergost-8(14),24(28)-diene-3β-ol-23-one ( 2 ), 4α-methyl-ergost-24(28)-en-3β,11β-diol-23-one ( 3 ), and two new polyoxygenated steroids, ergost-5,25-diene-3β,24 S ,28-triol ( 4 ), ergost-5,24(28)-diene-3β,23 S -diol ( 5 ), along with one known steroid 24-methylencholesterol ( 6 ) were isolated from the soft coral Nephthea sp. Their structures including the relative configurations were elucidated by extensive 1D and 2D NMR spectra analysis. The absolute configurations of ( 4 ) and ( 5 ) were determined by the Moshers method.

6-Hydroxy-4-en-3-one sterols from the marine sponge Iotrochoto birotulata

Five sterols with a nucleus skeleton of 6-hydroxy-4-en-3-one, namely cholesta-6β-hydroxy-4-en-3-one (1), ergosta-6β-hydroxy-4,24(28)-dien-3-one (2), ergosta-6α-hydroxy-4,24(28)-dien-3-one (3), ergosta-6α-hydroxy-4,22-E-dien-3-one (4), and ergosta-28-methyl-6β-hydroxy-4,24(28)-dien-3-one (5) have been isolated from the marine sponge Iotrochoto birotulata, collected from the southern China sea. Sterols 2–4 are new compounds, and 1 has been isolated from marine organisms for the first time. The structures have been elucidated on the basis of extensive spectroscopic and chemical properties.

Dimeric Abietane Diterpenoids and Sesquiterpenoid Lactones from Teucrium viscidum.

A new abietane diterpenoid, teuvisone (2), a pair of new dimeric abietane diterpenoid stereoisomers, biteuvisones A (3) and B (4), and three new sesquiterpenoid lactones, teuvislactones A-C (6, 7, and 10), were isolated from the whole plants of Teucrium viscidum, along with four known terpenoids (1, 5, 8, and 9). The structures of the new compounds were elucidated by spectroscopic analysis, and the absolute configurations of 5-10 were determined by electronic circular dichroism analysis. The isolated compounds were evaluated for their cytotoxic effects against five human cancer cell lines and for their α-glucosidase inhibitory effects.