Catharanthus roseus is one of the most studied medicinal plants due to the interest in their dimeric terpenoid indole alkaloids (TIAs) vinblastine and vincristine, which are used in cancer chemotherapy. These TIAs are produced in very low levels in the leaves of the plant from the monomeric precursors vindoline and catharanthine and, although TIA biosynthesis is reasonably well understood, much...

Isochorismate is an important metabolite formed at the end of the shikimate pathway, which is involved in the synthesis of both primary and secondary metabolites. It is synthesized from chorismate in a reaction catalyzed by the enzyme isochorismate synthase (ICS; EC 5.4.99.6). We have purified ICS to homogeneity from elicited Catharanthus roseus cell cultures. Two isoforms with an apparent mole...

Hydroxylation at the C-16 position of the indole alkaloid tabersonine has been suggested as the first step toward vindoline biosynthesis in Catharanthus roseus. Tabersonine 16-hydroxylase (16-OH) activity was detected in total protein extracts from young leaves of C. roseus using a novel coupled assay system. Enzyme activity was dependent on NADPH and molecular oxygen and was inhibited by CO, c...

The overproduction of specialized metabolites requires plants to manage the inherent burdens, including the risk of self-intoxication. We present a control mechanism that stops the expression of phytoalexin biosynthetic enzymes by blocking the antecedent signal transduction cascade. Cultured cells of Eschscholzia californica (Papaveraceae) and Catharanthus roseus (Apocynaceae) overproduce benzo...

Marián Boguñá, Romualdo Pastor-Satorras, and Alessandro Vespignani Departament de F́ısica Fonamental, Universitat de Barcelona, Av. Diagonal 647, 08028 Barcelona, Spain Departament de F́ısica i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Campus Nord, 08034 Barcelona, Spain The Abdus Salam International Centre for Theoretical Physics, P.O. Box 586, Trieste, I-34014, Italy (Dated: Mar...

A particulate enzyme system from Micrococcus roseus R2J has been obtained which catalyzes the biosynthesis of a peptidoglycan. The preparation catalyzes the incorporation of L-threonine onto the e-amino group of lysine in the presence of transfer RNA @RNA), supernatant solution, and ATP. Crude l%-L-threonyl-tRNA will substitute for these additional requirements. The threonyl-tRNAs of this organ...

Knowledge on the biosynthetic pathways of the monoterpene alkaloids is enormous, but little is known about their mechanism of transporting system from the plant cell. There is not concrete evidence confirming the role of ABC transporters in the secretion of monoterpene indole alkaloids (MIAs) in Catharanthus roseus. Therefore, in order to determine the role of different transporting systems inv...

Free radicals play an important role in pathological processes such as aging and developing cancer; hence, natural products inhibit free radical production, and can play an important role in preventing diseases. We aimed to evaluate the scavenging activity of free radicals, reducing power, inhibition of lipid peroxidation and malondialdehyde (MDA) formation, and the antioxidant composition of r...

In India, native remedies have been used in diabetes treatment. Plants have always been an ideal source of drugs and many of the plants either directly or indirectly are used to formulate the present available drugs. The present investigation was to find out the antihyperglycemic and antihyperlipidaemic effects of ethanolic leaves extracts of Catharanthus roseus in normal and streptozotocin (ST...