title: Development of a new inhibitor of glucosylceramide synthase.
abstract: Analogs of the potent inhibitor of glucosylceramide (GlcCer) synthase, D-threo-1-phenyl-2-palmitoylamino-3-pyrrolidino-1-propanol (P4), based on substitutions in the palmitoyl group were made by means of a stereo-selective synthetic method in order to elucidate the role of the hydrophobic portion in both the inhibitory action toward the enzyme and the biological effects. While P4 strongly inhibited GlcCer synthase with an IC(50) of 0.5 microM in vitro, it also inhibited cell growth by 50% at the concentration of 7 microM. The shorter N-acyl chain analogs including decanoyl, octanoyl, and hexanoyl groups showed similar IC(50) values for GlcCer synthase (around 2 microM) but the hexanoyl analog exhibited only a slight inhibitory effect on cell growth, showing the dissociation between GlcCer depletion and cell growth. Several compounds which exhibit similar hydrophobicity to the hexanoyl analog of P4 were subsequently designed. We found that D-threo-1-phenyl-2-benzyloxycarbonylamino-3-pyrrolidino-1-pr opanol (PBPP) was a most potent inhibitor, showing an IC50 of 0.3 microM. In cultured cells, PBPP was able to deplete glycosphingolipids without affecting cell growth or the ceramide level.
authors.affiliation: Tokyo Research Institute, Seikagaku Corp., Tateno, Higashiyamato, Tokyo 207-0021, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Jimbo
authors.forename: K
authors.initials: K
authors.lastname: Yamagishi
authors.forename: T
authors.initials: T
authors.lastname: Yamaki
authors.forename: K
authors.initials: K
authors.lastname: Nunomura
authors.forename: K
authors.initials: K
authors.lastname: Kabayama
authors.forename: Y
authors.initials: Y
authors.lastname: Igarashi
authors.forename: J I
authors.initials: JI
authors.lastname: Inokuchi
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000187:drug effects; D005964:Glucosyltransferases / Q000037:antagonists & inhibitors*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D009025:Morpholines / Q000737:chemistry; D011352:Procyclidine / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D011412:Propanolamines / Q000737:chemistry; D011759:Pyrrolidines / Q000737:chemistry; D051381:Rats; D013107:Sphingolipids / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: C408146:1-phenyl-2-benzyloxycarbonylamino-3-pyrrolidino-1-propanol; C401299:1-phenyl-2-palmitoylamino-3-pyrrolidino-1-propanol; D009025:Morpholines; D011412:Propanolamines; D011759:Pyrrolidines; D013107:Sphingolipids; C033110:RV 538; D011352:Procyclidine; D005964:Glucosyltransferases; C023246:ceramide glucosyltransferase