Studies On The Bioactive Constituents From Pentaceraster Sp.

Pentaceraster sp. distributed abundantly in South China Sea especially in Sanya Gulf, Hainan province. Up to date, only few chemical works have been performed on these starfishes. Guided by P. oryzae bioassay model, the anticancer and antifungal constituents of Pentaceraster sp. has been investigated by various chromatography methods including LPLC, MPLC, HPLC on resin, silica gel, ODS RP C-18 and Zobax SB C-18 respectively.Thirteen compounds were isolated; Seven compounds were elucidated by chemical and spectral analysis(IR; EI-MS, HREI-MS, ESI-MS;¹HNMR, ¹³CNMR, HMQC, TOCSY,¹H-¹H COSY, DQF-COSY, HMBC, NOESY).Seven steroidal glycosides were isolated from the starfish Pentaceraster sp.(from Shanya Gulf, Hainan province) and elucidated as: 3-O-[(2'-methoxyl)-xylopyranosides]- 6β,8,16β,29-tetrahydroxy-5a-cholestanol-15α-O-sodium sulfonate(Ps-1), 6α-O-{β-D-quinovopyranosyl-(1→3)-β-D-galactopyranosyl-(1→4)-[β-D-quinovopyranosyl-(1→2)]-β-D-fucopyranosyl-(1→3)-β-D-quinovopyranosyl}-16,22-epoxy-20-hydroxy-24-methyl-5α-cholest-9(11)-en-3β-O-sodium sulfonate(Ps-2), 24-O-[(2'-methoxyl)-β-D-xylopyranosyl-(1→2) -α-L-arabinofuranosyl]-3β,5,6α,8,15-pentahydroxy-5-cholestanol(Ps-3), 6α- O-{β-D-fucopyranosyl-(1→2)-β-D-quinovopyranosyl-(1→4)-[β-D-(3'-methoxyl)-quinovopyranosyl-(1→2)]-β-D-xylopyranosyl-(1→3)-β-D-quinovopyranosyl}-20-methyl-25-methoxyl-5α- cholest -9(11),23-diene-22-one-3β- O-sodium sulfonate(Ps-4), 6α- O-{β-D-fucopyranosyl-(1→2)-β-D- quinovopyranosyl-(1→4)-[β-D-(3'-methoxyl)-quinovopyranosyl-(1→2)]-β-D-xylopyranosyl-(1→3)-β-D-quinovopyrano-syl}-20,25-dimethyl-5α- cholest -9(11),23-diene-22-one-3β- O-sodium sulfonate(Ps-5), 6a-O-{β-D-fucopyranosyl-(1→2)-α-L- arabinopyranosyl-(1→4)-[β-D-quinovopyranosyl-(1→2)]-β-D-xylopyranosyl-(1→3)-β-D-quinovopyranosyl}-5α-pregn-9(11)-en-20-one-3β-O-sodium sulfonate(Ps-6), 6α- O-{β-D-fucopyranosyl-(1→2)-β-D-galactopyranosyl-(1→4)-[β-D-quinovopyranosyl-(1→2)]-β-D-xylopyranosyl-(1→3)- β-D-quinovopyranosyl}-5α-pregn-9(11)-en-20-one-3β- O-sodium sulfonate(Ps-7).The compounds showed moderate cytotoxity in vitro against many human tumor cell lines such as P388 and BEL7402. Ps-2 showed strongantifungalactivity against Candida albicans with MIC 3.4ug/ml, C. parapsilosis with MIC 1.7ug/ml, C. neoformans with MIC 3.4ug/ml, C. pseudotropicalis with MIC 3Aug/ml,Sporothrixschenckii with MIC 2.2ug/ml, Aspergillus fumigantus with MIC 4.1ug/ml, Trichophyton rubrum with MIC 6.9ug/ml.Ps-1,4～5 showed strong antifungal activity against Candida albicans,C. parapsilosis,C. neoformans, C. pseudotropicalis, Sporothrixschenckii, Aspergillus fumigantus, Trichophyton rubrum with MIC from 1.1ug/ml to 125ug/ml.Our studies focused on bioactive constituents of Pentaceraster sp. established a foundation for further development of the kind starfish with abundant resources in South China Sea. We are in the process of applying for patents for the structures of Ps-1～7 and their remarkable cell growth inhibitory activity against human tumor cell lines.