In vitro and in silico studies of antibacterial activities of secofriedelane derivatives from Senna alata (L) Roxb

Abstract

In this study, six compounds were obtained from a methanolic extract of air-dried leaves of Senna alata and one of them, a triterpenoid (secofriedelane) named as 7-(2-carboxyethyl)-3, 4b, 6a, 8, 10a, 12a-hexamethyl-8-vinyloctadecahydrochrysene-3-carboxylic acid (5) was isolated for the first time from this plant. Then, its chemical structure was detailed and characterised by FT-IR, ¹H and ¹³C- NMR and ESI-MS. Besides, two chemical-modified derivatives of secofriedelane (5a, 5b) were synthesised by methylation and allylation reactions, respectively, and their in vitro antibacterial activities were also evaluated. The results revealed that all the triterpenes showed, against gram-positive and -negative bacterial strains, good and moderate antibacterial activities with bactericidal effects that were enhanced by the methyl groups and altered with the allyl ones. Moreover, the molecular docking results of 5, 5a and 5b in the DNA gyrase (2XCT) active site showed that triterpene 5 has a good score very close to reference (ciprofloxacin).

Graphical Abstract

Keywords:

• Senna alata
• secofriedelane
• antibacterial study
• drug likeness
• pharmacokinetics
• molecular docking

Acknowledgments

Our thanks to Yaounde-Bielefeld Graduate School Natural Products with Antiparasitic and Antibacterial Activity (YaBiNaPA) for having carried out antibacterial tests.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.