Abstract: Lichen-derived organic acids such as vulpinic acid and usnic acid have been found to be effective inhibitors of eukaryotic protein kinase activity. Thus, eukaryotic protein kinase activity present in a sample or organism can be inhibited by adding to the sample or organism an effective inhibitory amount of a lichen-derived organic acid.

Abstract: The present invention relates to a novel drug discovery system for generating molecular diversity. The system provides methods for subjecting the genetic materials from a plurality of species of organisms to homologous or homeologous recombination to create novel genes and metabolic pathways. The recombined genetic materials are cloned to form recombined combinatorial gene expression libraries. Methods for screening such gene expression libraries containing recombined genes and metabolic pathways for novel activities and compounds are also provided.

Abstract: A compound selected from the group consisting of a 5,6-dihydro-&agr;-pyrone of formula (I): wherein bond a is oriented either or ; X is O or NH; R1 is selected from the group consisting of: a group R3(O)C— wherein R3 is selected from the group consisting of: (i) a group of formula R4—CH═CH— wherein R4 is C1-C20 alkyl, C2-C20 alkenyl, an aryl group, or a 5- or 6-membered unsaturated heterocyclic ring containing one or two O, N or S atoms, (ii) C2-C20 alkyl; and (iii) an aryl group or a substituent which is a fused ring system of formula (1) or (2):  wherein each of R′ and R″, which are the same or different and may occupy any position on ring a or ring b of said fused ring system, is H or C1-C6 alkyl; a group ArCH2— wherein Ar is an aryl group; and a group R5O—CH2— wherein R5 is C1-C6 alkyl optionally interrupted by one or two O atoms; and R2 is CH3 or, when R1 is a group of formula (A) as defined below, R2 i

Abstract: Lichen-derived organic acids such as vulpinic acid and usnic acid have been found to be effective inhibitors of eukaryotic protein kinase activity. Thus, eukaryotic protein kinase activity present in a sample or organism can be inhibited by adding to the sample or organism an effective inhibitory amount of a lichen-derived organic acid.