Biotransformation of isonitrosoacetophenone (2-keto-2-phenyl-acetaldoxime) in tobacco cell suspensions
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Nicotiana tabacum cell suspensions, 2 g wet wt/ml, rapidly took up 1 mM isonitrosoacetophenone (INAP), a plant-derived stress metabolite with anti-oxidative and anti-fungal properties, producing 4′-hexopyranosyloxy-3′-methoxyisonitrosoacetophenone in 54 % yield over 18 h. Unconverted INAP was at 33 μM. UPLC–MS/MS analyses with MassFragment software were used for metabolite identification. INAP had been hydroxylated at its meta- and para-positions as well as undergoing subsequent methoxylation and glycosylation. INAP is thus recognized by the enzymatic machinery of the phenylpropanoid pathway and is converted to a molecule with a substitution pattern similar to ferulic acid.
KeywordsBiotransformation Isonitrosoacetophenone 2-keto-2-phenyl-acetaldoxime Metabolism Nicotiana tabacum Solanaceae Xenobiotics
This work was supported in part by the South African National Research Foundation (NRF) and the University of Johannesburg. The NRF RISP/NEP program is thanked for partial funding of the Synapt HD-MS system. M. George and F. Tugizimana are thanked for helpful discussions and support.
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