Publications by authors named "Long-Mei Zeng"

One new precursor of tetraterpenoids, Sarglaucol (1), along with eight known compounds have been isolated from the soft coral Sarcophyton glaucum collected from the Sanya Bay, Hainan Island, China. Their structures were elucidated through spectroscopic techniques including 1D- and 2D-NMR, and their relative configurations were also assigned by NMR and NOESY analysis. Compounds 1 showed weak antitumour activities.

View Article and Find Full Text PDF

A new norsesquiterpene nephthediol (1) and a new sesquiterpene nephthetetraol (2) were isolated with guaianediol (3) from a soft coral of the genus Nephthea. Their structures were deduced on the basis of spectroscopic methods.

View Article and Find Full Text PDF

Two new sesquiterpenoids, polydactins A (1) and B (2) and a known sesquiterpene, 10alpha-hydroxycadin-4-en-15-al (3), were isolated from the soft coral Sinularia polydactyla (Ehreberg). Their structures were determined mainly by spectroscopic methods. Polydactin A (1) showed moderate cytotoxic activities against human oral epidermoid carcinoma cell lines (KB) and human breast carcinoma (MCF) tumour cell lines (in vitro).

View Article and Find Full Text PDF

Two new sesquiterpenes, 1S*, 4R*, 5S*, 6R*, 7S*, 10S*-1(5), 6(7)-diepoxy-4-guaiol (1) and 1S*, 4S*, 5S*, 10R*-4,10-guaianediol (2) have been isolated from the ethyl acetate soluble portion of the soft coral Sinularia sp., and their stereostructure were determined by spectroscopic methods and by X-ray single crystal analysis. Both compounds showed antioxidant and cytotoxic activities.

View Article and Find Full Text PDF

The soft coral Sinularia microclavata collected from the bay of Sanya, Hainan Island, China, yielded a new diterpenoid, microclavatin (1), and a known cembranolide, capillolide (2). The structure of compound 1 was determined on the basis of spectroscopic methods and X-ray single-crystal diffraction analysis. Microclavatin (1) showed cytotoxic activities against tumor cell lines KB and MCF with IC50 values of 5.

View Article and Find Full Text PDF

[structure: see text] A new hemiketal steroid, named cladiellin A (1), was first isolated from the soft coral Cladiella sp. Its structure was determined by spectroscopic methods and X-ray analysis. Compound 1 easily converted to 1a when NMR spectra were measured in CDCl(3) solution and quickly changed to 1b when pyridine was used.

View Article and Find Full Text PDF

The new tetracyclic diterpenoid confertdiate (1) and two new ceramides, (2) and (3), have been isolated from the soft coral Sinularia conferta, collected from Sanya Bay, Hainan Island, China. Their structures have been elucidated by spectroscopic analysis, and comparison of the 13C NMR data with those of the known diterpenoid isomandapamate confirmed the structure of 1.

View Article and Find Full Text PDF
Article Synopsis
  • Two new cytotoxic compounds, methyl tortuoate A and B, were discovered from the soft coral Sarcophyton tortuosum, along with a known compound, methyl sartortuoate.
  • The structures of these new compounds were determined using 2D NMR spectroscopy and confirmed through X-ray diffraction.
  • Their potential effectiveness against cancer was tested in vitro on human and mouse cancer cell lines.
View Article and Find Full Text PDF

Using stigmasterol as the starting material, 24-methylenecholest-4-en-3beta,6 alpha-diol (2) was synthesized in eight steps in 13% overall yield. The introduction of the sterol side-chain was carried out using (3-methyl-2-oxobutyl)-triphenylarsonium bromide (11) and K(2)CO(3) in a solid-liquid phase-transfer Wittig reaction. Construction of the steroidal nucleus was finished by oxidation of 24-methylenecholest-5-en-3beta-ol (9) with pyridinium chlorochromate (PCC) in dichloromethane at ambient temperature and by reduction of 24-methylenecholest-4-en-3,6-dione (10) with NaBH(4) in the presence of CeCl(3).

View Article and Find Full Text PDF