Analysis of fatty acids, aliphatic esters, and in vitro studies of antioxidant and antimicrobial activities for Recineckea carnea and Tupistra chinensis from the Guizhou Province.

Abstract

Recineckea carnea and Tupistra chinensis collected from the Guizhou province (China) were evaluated in this study. Petroleum ether fractions from the two herbs were subjected to gas chromatography-mass spectrometry analysis; 10 species, which were fatty acids or aliphatic esters, were identified. The antimicrobial activities of a variety of extracts were evaluated against four microorganisms. The methanol extract (ME), chloroform fraction, and ethyl acetate fraction from T. chinensis exhibited antimicrobial activities comparable to standard antibiotics, whereas none of the investigated extracts from R. carnea demonstrated any antimicrobial activities. The antioxidant potential was evaluated in vitro using ferric-reducing antioxidant power (FRAP) and the 2,2-diphenyl-1-picrylhydrazil (DPPH) radical method. The FRAP value of the ME from T. chinensis (4.19±0.088 mmol/g) was found to be significantly higher than the analogous extract from R. carnea (2.39±0.092 mmol/g); the EC₅₀ of the ME from R. carnea (0.32±0.011 mg/mL) was found to be significantly higher than that of T. chinensis (0.30±0.015 mg/mL). Total phenolic content was estimated by the Folin-Ciocalteu's colorimetric method. A positive correlation was found between total phenolic content and antioxidant activities (FRAP value and the reciprocal of EC₅₀). The results suggested that the phenolic compounds contributed significantly to the antioxidant capacity of R. carnea and T. chinensis.