Sesquiterpenes from a deep-sea-derived fungus Graphostroma sp MCCC 3A00421

Two structurally corrected sesquiterpenes (1 and 2) and nine new ones (3-11) were isolated from Graphostroma sp. MCCC 3A00421, a deep-sea-derived fungus obtained from hydrothermal sulfide deposits of the Atlantic Ocean. Their structures were elucidated mainly by extensive analyses of NMR and MS spectroscopic data, and their absolute configurations were determined by Cu-K alpha single-crystal X-ray diffraction, the modified Mosher's method, as well as ECD spectra. Xylariterpenoid E (3) is the first example of trinor-bergamotane and graphostromabisabol B (11) is the first trinor-bisabolane found in nature. Interestingly, khusinol B (6) exhibited significant anti-inflammatory effect with IC50 value of 17 AM, which was stronger than that of the positive control, aminoguanidine, whose IC50 value was 23 AM. In addition, it also showed weak anti-allergic effect (IC50 = 150 mu M). (C) 2017 Elsevier Ltd. All rights reserved.