Submitted to: Organic Letters
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/22/2002
Publication Date: 9/25/2002
Citation: LI, C., GLOER, J.B., WICKLOW, D.T., DOWD, P.F. THIERSININES A AND B: NOVEL ANTIINSECTAN INDOLE DITERPENOIDS FROM A NEW FUNGICOLOUS PENICILLIUM SPECIES (NRRL 28147). ORGANIC LETTERS. 4(18): 3095-3098. 2002 Interpretive Summary: There is an urgent need for new sources of antiinsectan agents that can be used in combating insect pests of crops and species of wild mushrooms which are typically free of insects offer a potential source of novel insecticides useful to agriculture. The fungus Penicillium thiersii produced several antiinsectan agents with potent activity against larvae of the fall armyworm (Spodoptera frugiperda), an important insect pest of corn and other crops. Chemical studies revealed that two of these antiinsectan metabolites are new to science while others represent known compounds. Insect resistance to pesticides has become increasingly problematic in recent years and new classes of environmentally friendly agricultural pesticides are also needed.
Technical Abstract: Two novel antiinsectan indole diterpenoids, thiersinines A (1) and B (2), along with seven known paxilline-type compounds, were isolated from organic extracts of a new Penicillium species (P. thiersii NRRL 28147). The structures of 1 and 2 were determined by analysis of 2D NMR data. Thiersinines A and B possess a unique spirocyclic subunit that is unprecedented in previously known compounds of this class. Both compounds exhibit potent activity against the fall armyworm (Spodoptera frugiperda).