Abstract: Cytotoxin-targeting molecule conjugates comprising cytotoxin and an antibody, growth factor, or polysaccharide together with a pH-sensitive or redox potential-sensitive linker. Novel ansamitocins and recombinant genes and organisms that produce them. The use of the described conjugates in the treatment of cancer and other hyperproliferation diseases.

Abstract: Compounds of formula IA and IB are new 1

Abstract: The present invention provides novel sixteen-membered macrolide compounds that are useful as anti-infective agents or as intermediates thereto. The present invention also provides methods for the preparation of these compounds, and methods and formulations for their use. In one aspect of the present invention, sixteen-membered macrolide possessing a side chain Z are provided where Z is aliphatic, aryl, alkylaryl, halide, ═NOR3, ═NNHR3, or —W—R3 where W is O, S, NC(═O)R4, NC(═O)OR4, NC(═O)NHR4 or NR4 where R3 and R4 are each independently hydrogen, aliphatic, aryl or alkylaryl. In another aspect of the present invention, bicyclic compounds are provided where one of the cyclic-components is a sixteen-membered macrolide and the other is a cyclic moiety whose cyclic structure is formed by between 3 and 10 atoms. In another aspect of the present invention, sixteen-membered macrolide compounds that bind to the domain II region of the 23S RNA are provided.

Abstract: The present invention relates to compounds made by a subset of modules from one or more polyketide synthase (“PKS”) genes that are used as starting material in the chemical synthesis of novel molecules, particularly naturally occurring polyketides or derivatives thereof. The biologically derived intermediates (“bio-intermediates”) generally represent particularly difficult compounds to synthesize using traditional chemical approaches due to one or more stereocenters. In one aspect of the invention, an intermediate in the synthesis of epothilone is provided that feeds into the synthetic protocol of Danishefsky and co-workers. In another aspect of the invention, intermediates in the synthesis of discodermolide are provided that feed into the synthetic protocol of Smith and co-workers.