Theonegramide, an antifungal glycopeptide from the Philippine lithistid sponge Theonella swinhoei

Spectroscopic analysis of theonegramide, an antifungal glycopeptide from the Philippine lithistid sponge Theonella swinhoei, shows that it contains an arabinose connected to a bicyclic dodecapeptide having unusual amino acids, and histidinoalanine. A comparative study between the structures of theongramide and theonellamide reveals similarities but four of the 12 amino acid residues are different. GC-MS analysis determines the absolute configuration of theonegramide using a chiral column packing.