title: Chemical synthesis and biological properties of pyridine epothilones.
abstract: BACKGROUND
  Numerous analogs of the antitumor agents epothilones A and B have been synthesized in search of better pharmacological profiles. Insights into the structure-activity relationships within the epothilone family are still needed and more potent and selective analogs of these compounds are in demand, both as biological tools and as chemotherapeutic agents, especially against drug-resistant tumors.
  
  
  RESULTS
  A series of pyridine epothilone B analogs were designed, synthesized and screened. The synthesized compounds exhibited varying degrees of tubulin polymerization and cytotoxicity properties against a number of human cancer cell lines depending on the location of the nitrogen atom and the methyl substituent within the pyridine nucleus.
  
  
  CONCLUSIONS
  The biological screening results in this study established the importance of the nitrogen atom at the ortho position as well as the beneficial effect of a methyl substituent at the 4- or 5-position of the pyridine ring. Two pyridine epothilone B analogs (i.e. compounds 3 and 4) possessing higher potencies against drug-resistant tumor cells than epothilone B, the most powerful of the naturally occurring epothilones, were identified.
authors.affiliation: Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. kcn@scripps.edu
authors.forename: K C
authors.initials: KC
authors.lastname: Nicolaou
authors.forename: R
authors.initials: R
authors.lastname: Scarpelli
authors.forename: B
authors.initials: B
authors.lastname: Bollbuck
authors.forename: B
authors.initials: B
authors.lastname: Werschkun
authors.forename: M M
authors.initials: MM
authors.lastname: Pereira
authors.forename: M
authors.initials: M
authors.lastname: Wartmann
authors.forename: K H
authors.initials: KH
authors.lastname: Altmann
authors.forename: D
authors.initials: D
authors.lastname: Zaharevitz
authors.forename: R
authors.initials: R
authors.lastname: Gussio
authors.forename: P
authors.initials: P
authors.lastname: Giannakakou
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D002455:Cell Division / Q000187:drug effects; D015195:Drug Design; D004353:Drug Evaluation, Preclinical; D019008:Drug Resistance, Neoplasm; D034261:Epothilones; D004852:Epoxy Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D020128:Inhibitory Concentration 50; D018942:Macrolides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D008958:Models, Molecular; D015394:Molecular Structure; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D013329:Structure-Activity Relationship; D013844:Thiazoles / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology* / Q000627:therapeutic use; D014404:Tubulin / Q000737:chemistry / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D034261:Epothilones; D004852:Epoxy Compounds; D018942:Macrolides; D011725:Pyridines; D013844:Thiazoles; D014404:Tubulin; C093787:epothilone A; C093788:epothilone B