Seven steroids were isolated from the methanol extract of the soft corals Sinularia conferta. These steroids were elucidated as 7 -methoxyergosta-5,24(28)-diene-3 -ol (1), ergosta-5-ene-3β,7α-diol (2), 3β,7α-dihydroxyergosta5,24(28)-diene (3), 3β-hydroxyergosta-5,24(28)-diene-7-one (4), ergosta-24(28)-ene-3β,5α,6β-triol-6-acetate (5), ergosta-24(28)-ene-3β,5α,6β-triol (6), and ergosta-3β,5α,6β-triol (7) by 1D and 2D-NMR experiments and comparison with reported data. | Vietnam Journal of Chemistry, International Edition, 55(5): 552-556, 2017 DOI: Structure elucidation of seven steroids from Sinularia conferta Ninh Thi Ngoc1,2, Pham Thi Mai Huong1, Nguyen Thi Phuong Chi1, Do Cong Thung3, Nguyen Xuan Cuong1, Nguyen Van Thanh1, Nguyen Hoai Nam1*, Chau Van Minh1 1 Advanced Center for Bioorganic Chemistry, Institute of Marine Biochemistry, Vietnam Academy of Science and Technology (VAST) 2 Graduate University of Science and Technology, VAST 3 Institute of Marine Environment and Resources, VAST Received 22 May 2017; Accepted for publication 22 October 2017 Abstract Seven steroids were isolated from the methanol extract of the soft corals Sinularia conferta. These steroids were elucidated as 7 -methoxyergosta-5,24(28)-diene-3 -ol (1), ergosta-5-ene-3β,7α-diol (2), 3β,7α-dihydroxyergosta5,24(28)-diene (3), 3β-hydroxyergosta-5,24(28)-diene-7-one (4), ergosta-24(28)-ene-3β,5α,6β-triol-6-acetate (5), ergosta-24(28)-ene-3β,5α,6β-triol (6), and ergosta-3β,5α,6β-triol (7) by 1D and 2D-NMR experiments and comparison with reported data. Keywords. Sinularia conferta, Alcyoniidae, soft coral, steroid. 1. INTRODUCTION The phylum Cnidaria are traditionally divided into three classes: Anthozoa, Hydrozoa, and Scyphozoa. The best-known representatives of the class Anthozoa are the gorgonians and soft corals. Soft corals attracted considerable attention because of the wide range of their bioactive secondary metabolites. Among these marine invertebrates, genus Sinularia is one of the most widely distributed soft corals and constitutes a dominant portion of the biomass in the tropical reef environment [1, 2]. Prior investigations demonstrated that Sinularia species are a rich source of steroids and terpenoids [2-5]. As a part of our recent investigations on chemical constituents and biological activities of Vietnamese Sinularia soft corals, we have recently reported twelve steroids from the Sinularia conferta species .
