Four steroids namely 3β-hydroxyergosta-5,24(28)-diene-7-one (1), dissesterol (2), 16αhydroxysarcosterol (3), and sarcophytosterol (4) were isolated from the soft coral Sinularia nanolobata using various chromatographic methods. Their structures were elucidated by detailed analysis of the 1D and 2D NMR data and comparison with the reported values. | Vietnam Journal of Science and Technology 55 (3) (2017) 258-262 DOI: STRUCTURE ELUCIDATION OF FOUR STEROIDS FROM THE SOFT CORAL SINULARIA NANOLOBATA Ninh Thi Ngoc1, 2, Nguyen Van Thanh1, Nguyen Xuan Cuong1, Nguyen Hoai Nam1, *, Do Cong Thung3, Chau Van Minh1 1 Institute of Marine Biochemistry, Vietnam Academy of Science and Technology (VAST), 18 Hoang Quoc Viet, Cau Giay, Hanoi 2 Graduate University of Science and Technology, VAST, 18 Hoang Quoc Viet, Cau Giay, Ha Noi 3 Institute of Marine Environment and Resources, VAST, 246 Da Nang, Ngo Quyen, Hai Phong * Email: namnguyenhoai@ Received: 20 October 2016, Accepted for publication: 10 January 2017 ABSTRACT Four steroids namely 3β-hydroxyergosta-5,24(28)-diene-7-one (1), dissesterol (2), 16αhydroxysarcosterol (3), and sarcophytosterol (4) were isolated from the soft coral Sinularia nanolobata using various chromatographic methods. Their structures were elucidated by detailed analysis of the 1D and 2D NMR data and comparison with the reported values. Keywords: Sinularia nanolobata, soft coral, steroids. 1. INTRODUCTION Soft corals are marine invertebrates of the order Alcyonacea, subclass Octocorallia, class Anthozoa, and phylum Cnidaria. Among these marine invertebrates, the genera Cespitularia, Clavularia, Gersemia, Lobophytum, Nephthea, Sarcophyton, and Sinularia are the most prolific [1]. The Sinularia soft corals are a rich source of hydroxylated steroids having cytotoxic effects [2 – 8]. Within the frame of our recent investigations on chemical constituents and biological activities of Vietnamese Sinularia soft corals [9, 10], we have recently reported six steroids from the soft coral Sinularia nanolobata and evaluation of their cytotoxic activity [11]. The current paper deals with detailed structure elucidation of four steroids from this species. 2. EXPERIMENTAL . General methods The NMR spectra were recorded on a Bruker AVANCE III HD 500 spectrometer with TMS
