Micropyrones A and B, two new α -pyrones from the actinomycete Microbacterium sp. GJ312 isolated from Glycyrrhiza uralensis Fisch.

Two new -pyrones, micropyrones A () and B (), along with four known -pyrones, nocapyrone D (), nocapyrone A (), marinactinone A (), and nocapyrone H (), were isolated from the culture extract of actinomycete sp. GJ312, which was isolated from . The structures of these compounds were identified by analysis of spectral data. They are the first - and -pyrones reported from the genus . The antibacterial activity of all compounds against and methicillin resistant was evaluated. However, none of them showed significant activity. This study represents the first phytochemical example of a -derived actinomycete.