In Vitro and In Silico Antistaphylococcal Activity of Indole Alkaloids Isolated from Tabernaemontana cymosa Jacq (Apocynaceae)

Abstract

The species of the genus Tabernaemontana have a long tradition of use in different pathologies of infectious origins; the antibacterial, antifungal, and antiviral effects related to the control of the pathologies where the species of this genus are used, have been attributed to the indole monoterpene alkaloids, mainly those of the iboga type. There are more than 1000 alkaloids isolated from different species of Tabernaemontana and other genera of the Apocynaceae family, several of which lack studies related to antibacterial activity. In the present study, four monoterpene indole alkaloids were isolated from the seeds of the species Tabernaemontana cymosa Jacq, namely voacangine (1), voacangine-7-hydroxyindolenine (2), 3-oxovoacangine (3), and rupicoline (4), which were tested in an in vitro antibacterial activity study against the bacteria S. aureus, sensitive and resistant to methicillin, and classified by the World Health Organization as critical for the investigation of new antibiotics. Of the four alkaloids tested, only voacangine was active against S. aureus, with an MIC of 50 µg/mL. In addition, an in silico study was carried out between the four isolated alkaloids and some proteins of this bacterium, finding that voacangine also showed binding to proteins involved in cell wall synthesis, mainly PBP2 and PBP2a.

Antimicrobial Secondary Metabolites from the Mangrove Plants of Asia and the Pacific

“…developed halos with a broad-spectrum of bacteria [ 221 ] and the ethanol extract of fruits suppressed Aspergillus flavus , Fusarium oxysporum , and Penicillium citrum [ 222 ]. Note that Apocynaceous indole alkaloids are often antistaphylococcal [ 223 ]. The ethanol extract of the leaves (500 µg/well) of Hoya parasitica (Roxb.)…”

“…Using these criteria, the strongest antimicrobial extracts from mangrove and mangrove-associated plants that could be of value for shrimp farming are from C. inophyllum ( S. aureus , T. rubrum ) [ 63 ], T. catappa ( E. faecalis ) [ 129 ]., C. manghas ( E. coli , P. aeruginosa , VSV) [ 17 , 220 ], and C. odollam (HSV) [ 223 ].…”