Anti-inflammatory, antimicrobial and antioxidant activities of Diospyros bipindensis (Gürke) extracts and its main constituents

Extensive phytochemical investigation of the polar constituents of Diospyros bipindensis Gürke traditionally used by Baka pygmies

“…In addition to the antibacterial and anti-inflammatory activity described in our previous study (Cesari et al, 2013), the different extracts were subjected to a sensitive antifungal TLC bioautography assay to determine whether the plant possesses antifungal properties against Candida albicans, which is one of the most common causes of invasive mycoses infections worldwide (Mayer et al, 2013;Patterson, 2005;Rahalison et al, 1994). The hexane and dichloromethane extracts presented a minimal inhibitory quantity (MIQ) below 25 lg, whereas the methanolic extract presented a MIQ at 25 lg, and the traditional aqueous infusion was found to be inactive (Fig.…”

“…1S in the Supplementary information). According to our previous study, the comparison of the HPLC-PDA and HPLC-MS profiles of the hexane, methanolic and water extracts with the dichloromethane extract previously investigated (Cesari et al, 2013) allowed the identification of five known compounds: 4-hydroxyl-5-methylcoumarin (12) (Zakaria, 1989), canaliculatin (13) , plumbagin (14) (Dzoyem et al, 2007), ismailin (15) and betulinic acid (16) (Yogeeswari and Sriram, 2005) (Fig. 1S).…”

“…The fragment observed at m/z 175.0 for 4, 5 and 6 most likely corresponded to a coumarin aglycone substituted by one hydroxyl and one methyl group. This hypothesis was reinforced by the identification of 4-hydroxyl-5-methylcoumarin (12) from the dichloromethane extract of this plant in our previous study (Cesari et al, 2013). Based on these results alone, a complete dereplication of these isomers, however, was not possible.…”

“…1S) that were also found to be active. 14 was unambiguously identified by comparing its retention time and UV and MS spectra to a standard of plumbagin previously isolated from the dichloromethane extract of D. bipindensis (Cesari et al, 2013). Plumbagin (14) is a known antifungal compound that was previously isolated from the stem bark of other Diospyros species such as Diospyros crassiflora Hiern (Ebenaceae) (Dzoyem et al, 2007).…”

“…A previous phytochemical investigation revealed the presence of a conjugated naphthoquinone dimer called diosindigo together with traces of isodiospyrin (Waterman and Mbi, 1979). Recently, we demonstrated that the dichloromethane extract of D. bipindensis contains 4-hydroxy-5-methyl-coumarin (12), canaliculatin (13), betulinic acid (16), plumbagin (14) and ismailin (15), of which the two latter compounds are responsible for the antibacterial and in vitro antiinflammatory activities of this extract (Cesari et al, 2013). The present study presents the isolation and structure elucidation of all major polar compounds from the stem bark methanolic extract that were dereplicated in the traditional water maceration.…”