JBIR-12, a novel antioxidative agent from Penicillium
sp. NBRC 103941
In the course of our screening program for active compounds from fungal metabolites, we isolated JBIR-12 (1) as a free radical
scavenger from the culture broth of Penicillium sp. NBRC 103941. Structure elucidation of 1 was carried out using methylated
and/or acetylated derivatives of 1. As a consequence, the structure of 1 was determined to be a novel highly oxygenated
tetrahydronaphthalene species attached to an acyl chain moiety on the basis of NMR and other spectroscopic data. It was
interesting that 1 was spontaneously methylated when left in methanol. Furthermore, isomerization or rearrangements could
occur during the derivatization of 1. Compound 1 exhibited potent radical scavenging activity against 1,1-diphenyl-2-
picrylhydrazyl radical with an IC50 value of 75 mM.