Kasmiati Thamrin
Nagoya University,Japan
Title: Anti-phytopathogenic and Anti-cytotoxic Brominated Sesquiterpenes from the Indonesian Red Seaweed Laurencia intricata
Biography
Biography: Kasmiati Thamrin
Abstract
Marine natural products have been providing structurally novel bioactive substances, some of which were developed as medicines or were promising leads for new drugs. During the search for bioactive substances from marine organisms, we detected anti-phytophatogenic (an oomycete of Phytophthora) activity for extracts of the Indonesian red seaweed Laurencia intricata. The active hexane and 90% methanol extracts were combined and separated on silica gel and then purified by reversed-phase HPLC to obtain four related compounds. Based on 2D NMR and MS analysis, they were identified as aplysistatin, palisadin A, palisol, and 5ï¢-hydroxypalisadin B, which are all known brominated sesquiterpenes. The minimum doses to inhibit Phytophthora capsici are 100, 300, 300, and 300 ïg/disk, respectively. Cytotoxic activity of these compounds was also evaluated against human epidermoid carcinoma A431 cells, showing the IC50 values of 0.15, 1.42, 0.59, and 0.45 ïg/ml, respectively.