A unique spiro-β-triazinedione-γ-hydantoin type alkaloid with antiviral activity against tobacco mosaic virus from Streptomyces gamaensis
Chemical investigation of a soil actinomycete strain Streptomyces gamaensis NEAU-Gz11 led to the isolation of three alkaloids 1–3 with antiviral activity. Their structures were determined by extensive spectroscopic and X-ray crystallographic analyses. Compound 1 possesses a new and unique spiro-β-triazinedione-γ-hydantoin skeleton. The racemic feature and the chemical conversion experiments led us to propose a biosynthetic pathway for 1. Compound 1 (100 mg L−1) showed a strong anti-TMV (tobacco mosaic virus, TMV) activity on the host plants of tomatoes and peppers with inhibition rates of 72.34% and 62.09%, respectively.