Isolation of Lobane and Prenyleudesmane Diterpenoids from the Soft Coral Lobophytum varium.

ABSTRACT: Further chemical investigation of the EtOAc extract of the soft coral Lobophytum varium resulted in the discovery of eleven new diterpenoids lobovarols F-P (1-11) of lobane- and prenyleudesmane-types, along with two known metabolites (12 and 13). The structures of the new metabolites were established by spectroscopic analyses, including 2D NMR experiments. The absolute configuration of 1 was determined using Mosher's method. The complete assignment of ¹H and ¹³C NMR spectroscopic data of 12 and 13 and the identification of pyran-derived moieties in the prenyleudesmanes were reported for the first time. Anti-inflammatory activities of the isolated compounds in suppressing elastase release and superoxide anion generation in human neutrophils were disclosed for 1, 2, 4, 12, and 13. A stereospecific biosynthesis for lobanes and prenyleudesmanes from the related prenylgermacranes could explain the coexistence of lobanes and prenylgermacranes in L. varium.

SUBMITTER: Chang CH 

PROVIDER: S-EPMC7230303 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature