Chemical composition, total phenolic and flavonoid contents, and in vitro antimicrobial and antioxidant activities of crude extracts from red chilli seeds (Capsicum frutescens L.)

Abstract

The objectives of present study were to assess the antimicrobial and antioxidant potential of Capsicum frutescens L. seeds and to characterize the chemical constituents of the crude extracts. The n-hexane and chloroform extracts were analyzed using gas chromatography–mass spectroscopy (GC–MS), which showed the presence of many biologically important volatile constituents, including heterocyclic compounds, β-diketones, hydrocarbons, long chain aliphatic carboxylic acids, and their derivatives, such as esters, hydroxy ester, and aromatic compounds. The amounts of the total phenolic content and the total flavonoid content in same the extracts were in the ranges of 7.95–26.15 gallic acid equivalents (GAE mg/g) and 4.64–12.84 rutin equivalents (RU mg/g) of dry weight of extract, respectively. In the determination of the in vitro antimicrobial activity, seed extracts prevented the growth of most of the tested pathogens by forming significant inhibition zones. The inhibitory activity was especially remarkable (inhibition zone≥13mm) against Pesudomaonas aeruginosa, Klebsilla pneumonae, Staphylococcus aureus and Candida albicans. During the evaluation of the in vitro antioxidant activity via DPPH assay, n-hexane and chloroform extracts showed 26.9% and 30.9% free radical scavenging abilities, respectively, at the concentration of 1mg/mL. Considering these results, C. frutescens seeds can be used as a source of novel antimicrobial and antioxidant compounds.