The structure of bonellin and its derivatives. Unique physiologically active chlorins from the marine echurian Bonellia viridis

Abstract

The structure of bonellin, the physiologically active pigment of the marine echurian worm Bonellia viridis, has been established as (10a), a unique type of alkylated chlorin, by a combination of physical methods. The structure was confirmed by an X-ray crystallographic study on anhydrobonellin methyl ester (12b).Bonellin is accompanied in the organism by a series of mono-amino-acid conjugate derivatives of general structure (14a) in which valine, leucine, isoleucine, and alloisoleucine are the major amino-acid constituents.