Steroid and Antibacterial Steroidal Glycosides from Marine Green Alga Codium Iyengarii Borgesen

The ethyl acetate soluble part of methanolic extract of marine green alga Codium iyengarii collected from Karachi coast of Arabian Sea afforded a new steroid ( 1 , iyengadione) and two new steroidal glycosides [iyengaroside-A ( 2 ) and B ( 3 )] along with clerosterol galactoside ( 4 ). Their structures were elucidated with the aid of 1D-NMR spectroscopy and reconfirmed through HMBC experiments. The bactericidal activity of 1 - 4 was also explored and found positive response from iyengaroside-A ( 2 ) and clerosterol galactoside ( 4 ).