Triterpenoids from the Mangrove Plant Hibiscus tiliaceus

Abstract Three new triterpenoids with the rarely occurring nigrum skeleton, namely (20E)‐22‐hydroxynigrum‐20‐en‐3‐one (1), 21β‐hydroxynigrum‐22(29)‐en‐3‐one (2), and 21α‐hydroxynigrum‐22(29)‐en‐3‐one (3), were isolated from the mangrove plant Hibiscus tiliaceus. Additionally, five known triterpenoids including friedelin (4), 12‐oleanen‐3β‐ol (5), 3β‐hydroxy‐12‐oleanen‐28‐oic acid (6), 20(29)‐lupen‐3β,28‐diol (7), and cucurbita‐5,23‐dien‐3β,25‐diol (8) were also isolated and identified. The latter structures were elucidated by a detailed NMR and MS analyses, as well as by comparison with reported literature data.