21787-66-6 Antibiotic VD 846 B BRN 0519939 Formamide, N-(5-oxo-4,5-dihydro-1,2-dithiolo(4,3-b)pyrrol-6-yl)- N-(5-Oxo-4,5-dihydro-1,2-dithiolo(4,3-b)pyrrol-6-yl)formamide VD 846 VD 846 B