title: Induction of ajmalicine formation and related enzyme activities in Catharanthus roseus cells: effect of inoculum density.
abstract: In Catharanthus roseus cell cultures the time courses of four enzyme activities, tryptophan decarboxylase (TDC), strictosidine synthase (SSS), geraniol-10-hydroxylase (G10H) and anthranilate synthase (AS), and alkaloid accumulation were compared under two different culture conditions (low-inoculum density and high-inoculum density on induction medium) and a control on growth medium. In growth medium a transient increase in TDC activity was first observed after which G10H reached its maximum activity; only tryptamine accumulated, no ajmalicine could be detected. Apparently, a concerted induction of enzyme activities is required for ajmalicine formation. Cells inoculated in induction medium showed such a concerted induction of AS, TDC and G10H activities. After 30 days the low-density culture had accumulated six times more ajmalicine (in mumoles/g) than the high-density culture. Thus, increase in biomass concentration (high-density cultures) did not enhance the total alkaloid production. The major differences observed in enzyme levels between high- and low-density cultures were in the AS and TDC activities, which were two to three times higher in the low-density culture, indicating that there is a positive correlation between ajmalicine formation and AS and TDC activities.
authors.affiliation: Division of Pharmacognosy, Leiden University, The Netherlands.
authors.forename: P R
authors.initials: PR
authors.lastname: Moreno
authors.forename: J E
authors.initials: JE
authors.lastname: Schlatmann
authors.forename: R
authors.initials: R
authors.lastname: van der Heijden
authors.forename: W M
authors.initials: WM
authors.lastname: van Gulik
authors.forename: H J
authors.initials: HJ
authors.lastname: ten Hoopen
authors.forename: R
authors.initials: R
authors.lastname: Verpoorte
authors.forename: J J
authors.initials: JJ
authors.lastname: Heijnen
mesh_terms: D000080462:Acyclic Monoterpenes; D000878:Anthranilate Synthase / Q000378:metabolism; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000378:metabolism*; D000970:Antineoplastic Agents / Q000378:metabolism*; D001142:Aromatic-L-Amino-Acid Decarboxylases / Q000378:metabolism; D019759:Carbon-Nitrogen Lyases; D002478:Cells, Cultured; D004790:Enzyme Induction; D005947:Glucose / Q000378:metabolism; D006900:Hydroxylation; D006899:Mixed Function Oxygenases / Q000378:metabolism; D010946:Plants, Medicinal / Q000378:metabolism; D046948:Secologanin Tryptamine Alkaloids; D013729:Terpenes / Q000378:metabolism; D014166:Transferases / Q000378:metabolism; D014363:Tryptamines / Q000378:metabolism; D015016:Yohimbine / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D000080462:Acyclic Monoterpenes; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000970:Antineoplastic Agents; D046948:Secologanin Tryptamine Alkaloids; D013729:Terpenes; D014363:Tryptamines; D015016:Yohimbine; C030820:tryptamine; C005709:raubasine; D006899:Mixed Function Oxygenases; D014166:Transferases; D001142:Aromatic-L-Amino-Acid Decarboxylases; D000878:Anthranilate Synthase; D019759:Carbon-Nitrogen Lyases; C022684:strictosidine synthetase; D005947:Glucose; C007836:geraniol