title: Biosynthesis of sterols and triterpenes in cell suspension cultures of Uncaria tomentosa.
abstract: Pectin administered to Uncaria tomentosa cell suspension cultures, was found to increase the production of triterpene acids (ursolic and oleanolic acid), however, neither growth nor sterol accumulation were affected. Cell cultures showed that pectin treatment caused a rapid threefold increase in the activities of enzymes involved in the biosynthesis of C(5) and C(30 )isoprenoid, such as isopentenyl diphosphate isomerase and squalene synthase. The activity of a farnesyl diphosphatase, which could divert the flux of farnesyl diphosphate to farnesol, was two times lower in elicited than in control cells. Elicited cells also transformed more rapidly a higher percentage of [5-(3)H]mevalonic acid into triterpene acids. Interestingly, addition of terbinafine, an inhibitor of squalene epoxidase, to elicited cell cultures inhibited sterol accumulation while triterpene production was not inhibited. These results suggest that in U. tomentosa cells, both the previously mentioned enzymes and those involved in squalene 2,3-oxide formation play an important regulatory role in the biosynthesis of sterols and triterpenes.
authors.affiliation: Departamento de Biotecnología y Bioingeniería, Centro de Investigación y Estudios Avanzados IPN, Av. Politécnico 2508, CP.07360, México, D.F. México.
authors.forename: Isvett J
authors.initials: IJ
authors.lastname: Flores-Sánchez
authors.forename: Jaime
authors.initials: J
authors.lastname: Ortega-López
authors.forename: María
authors.initials: M
authors.lastname: del Carmen Montes-Horcasitas
authors.forename: Ana C
authors.initials: AC
authors.lastname: Ramos-Valdivia
mesh_terms: D019748:Carbon-Carbon Double Bond Isomerases / Q000187:drug effects / Q000378:metabolism; D020948:Cat's Claw / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology; D013186:Farnesyl-Diphosphate Farnesyltransferase / Q000187:drug effects / Q000378:metabolism; D045782:Hemiterpenes; D008798:Mevalonic Acid / Q000378:metabolism; D009281:Naphthalenes / Q000494:pharmacology; D009828:Oleanolic Acid / Q000378:metabolism; D010105:Oxygenases / Q000187:drug effects; D010368:Pectins / Q000494:pharmacology; D010744:Phosphoric Monoester Hydrolases / Q000187:drug effects / Q000378:metabolism; D010840:Phytosterols / Q000096:biosynthesis*; D012855:Sitosterols / Q000037:antagonists & inhibitors; D013185:Squalene / Q000037:antagonists & inhibitors; D050603:Squalene Monooxygenase; D000077291:Terbinafine; D014315:Triterpenes / Q000378:metabolism*; D014316:Tritium / Q000378:metabolism; D000097245:Ursolic Acid
chemical_list: D019748:Carbon-Carbon Double Bond Isomerases; D004791:Enzyme Inhibitors; D013186:Farnesyl-Diphosphate Farnesyltransferase; D045782:Hemiterpenes; D008798:Mevalonic Acid; D009281:Naphthalenes; D009828:Oleanolic Acid; D010105:Oxygenases; D010368:Pectins; D010744:Phosphoric Monoester Hydrolases; D010840:Phytosterols; D012855:Sitosterols; D013185:Squalene; D050603:Squalene Monooxygenase; D000077291:Terbinafine; D014315:Triterpenes; D014316:Tritium; D000097245:Ursolic Acid; C025473:gamma-sitosterol; C438007:prenyl-pyrophosphatase; C021453:isopentenyldiphosphate delta-isomerase