Ochracines A-E, chamigrane-related norsesquiterpene derivatives from the basidiomycete Steccherinum ochraceum HFG119

Ochracines A-E, five previously undescribed norsesquiterpenes featured by unusual scaffolds biogenetically related to chamigrane, were isolated from the cultures of Steccherinum ochraceum. Ochracines A (1) and B (2) represent the first examples of norsesquiterpenes with an unprecedented 1,2-6,7-diseco-1,8-cyclochamigrane scaffold. Ochracines C-D (3–5) possess an unusual 1,2-6,7-diseco-chamigrane skeleton. Their structures were elucidated by...