On the fate of catharanthine and vindoline during the peroxidase-mediated enzymatic synthesis of alpha-3',4'-anhydrovinblastine

• Type: Article in International Scientific Journal
• Date: 1997

Authors

Sottomayor, M (Author) FCUP; DiCosmo, F (Author) Other; Barcelo, AR (Author) Other

Journal

Title: Enzyme and Microbial Technology

Vol. 21

Pages: 543-549

ISSN: 0141-0229

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 11 Citations

Scopus - 19 Citations

Scientific classification

FOS: Natural sciences > Biological sciences

Other information

Authenticus ID: P-001-AAD

DOI: 10.1016/s0141-0229(97)00067-7

Abstract (EN): The fate of catharanthine and vindoline during the peroxidase-mediated enzymatic synthesis of alpha-3',4'-anhydrovinblastine (AVLB) has been studied. The results showed that catharanthine and vindoline are suitable electron donors for the oxidizing intermediates of horseradish peroxidase (compound I and compound II). The reduction of peroxidase compound II is one of the limiting steps in the coupling reaction. In fact, k(3) (compound II reduction constant) values were 2.53 X 10(3) M-1 S-1 and 3.57 X 10(3) M-1 S-1 for catharanthine and vindoline, respectively. These values are extremely low if we compare them with those found for other substrates of peroxidase-catalyzed oxidations. From these results and the analysis of the reaction products in conditions in which coupling occurred, we propose a mechanism where vindoline-free radicals resulting from reaction of vindoline with the oxidized states of peroxidase are deactivated by reaction with catharanthine. Catharanthine radicals actually set off the coupling reaction. (C) 1997 Elsevier Science Inc.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7