compound 3-dehydro-4-methylzymosterol CHEBI:50593 UPa:UPC15816 C28H44O InChI=1S/C28H44O/c1-18(2)8-7-9-19(3)22-12-13-24-21-10-11-23-20(4)26(29)15-17-28(23,6)25(21)14-16-27(22,24)5/h8,19-20,22-24H,7,9-17H2,1-6H3/t19-,20?,22?,23+,24?,27-,28+/m1/s1 KEGG:C15816 3-keto-4-methylzymosterol compound