Secondary metabolite contents and antimicrobial activity of leaf extracts reveal genetic variability of Vernonia amygdalina and Vernonia calvoana morphotypes

This study was therefore aimed at evaluating the genetic variability ofVernonia amygdalina (VAA and VALF) andV.calvoana (VCAB, VCAV, VCSB and VCSV) morphotypes in 2016 based on secondary metabolite contents and antimicrobial properties. This involved phytochemical analysis by HPLC/MS for the detection of alkaloids, flavonoids, phenols, and tannins in leaves from each of the six genotypes. Results showed that all tested genotypes are rich in phenols (18 analyzed), flavonoids and tannins with, VAA richer in phenols (206.1 ± 3.12 μg/g of dry extract), followed by VCAV (197.9 ± 18.03 μg/g). The lowest level of flavonoid was found in VCSV (81.6 ± 7.21 μg/g) while the highest was from VCAB (132.8 ± 31.5 μg/g). VCSV (56.3 ± 4.08 μg/g) had the lowest level of tannins, while VCAB (97.8 ± 23.8 μg/g) had the highe st levels. Assessment of antimicrobial activity of leaf extracts from the six genotypes was done by culture on Mueller Hinton (MH) agar and MH broth agar for bacteria and in Sabouraud dextrose agar and Sabouraud dextrose broth media for fungi, respectively. All morphotypes exhibited inhibitory activ ity on bacteria except VAA, with isoquercetin characteristic of VCSV. Chemotaxonomic analyses ofVernonia morphotypes highlighted the genetic diversity within species and variability of antimicrobial properties of ethanolic leaf extracts among morphotypes. These results provide baseline data in the valuation of genetic resources and the establishment of improvement progr...
Source: Biotechnology and Applied Biochemistry - Category: Biochemistry Authors: Tags: Original Article Source Type: research