methylenomycin b methylenomycin b methylenomycin b is a cyclopentanone derived antibiotic produced by streptomyces coelicolor a3(2) that is effective against both gram-negative and gram-positive bacteria. methylenomycins are naturally produced in two variants: a and b. methylenomycin b names iupac name 2,3-dimethyl-5-methylene-2-cyclopenten-1-one identifiers cas number 52775-77-6 y 3d model (jsmol) interactive image chemspider 2303992 y pubchem cid 3040648 unii wlo3e84kas y comptox dashboard (epa) dtxsid50200755 inchi inchi=1s/c8h10o/c1-5-4-6(2)8(9)7(5)3/h2,4h2,1,3h3 ykey: ydxieahuyzkjoh-uhfffaoysa-n yinchi=1/c8h10o/c1-5-4-6(2)8(9)7(5)3/h2,4h2,1,3h3key: ydxieahuyzkjoh-uhfffaoyan smiles o=c/1\c(=c)cc(=c\1c)\c properties chemical formula c8h10o molar mass 122.167 g·mol−1 except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). y verify (what is yn ?) infobox references