Biotransformation of Valdecoxib by Plant Cell Cultures

Abstract

Valdecoxib is a new anti-inflammatory drug that is highly selective for inhibition of the inducible form of cyclooxygenase (COX-2). In the present study, biotransformation of valdecoxib was investigated in cell cultures of five medicinal plants, viz., Catharanthus roseus, Azadirachta indica, Capsicum annuum, Ervatamia heyneana, and Nicotiana tabacum. Identification of the biotransformed products was carried out by using high-performance liquid chromatography coupled with diode array detection and liquid chromatography--tandem mass spectrometry analysis. All the cultures transformed valdecoxib into more polar compounds, and C. roseus also produced one unknown compound that is less polar than the substrate. The reactions performed by these plant cell cultures include hydroxylation, methylation, and demethylation. Optimization studies were performed to investigate the effect of the day of extraction and substrate concentration on biotransformation.

Biotransformation of Carvedilol Using Plant Cell Culture of Decalepis hamiltonii and Nicotiana tabacum

“…The plants are genetically diverse and possess a rich repertory of enzymes. [2] The reactions involved in the biotransformation of organic compounds by cultured plant cells include oxidation, reduction, hydroxylation, esterification, methylation, isomerization, hydrolysis, and glycosylation. [3] The ability of cultured plant cells to metabolize foreign substrates or to convert these substrates to more useful substances is of considerable interest because of the specificity of the transformation which may be affected by cultured cells.…”