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The search for antileishmanial plants used in traditional medicine led to the choice of CH2Cl2–MeOH (1:1) crude extract of the fruits and stem bark of Pentadesma butyracea Sabine (Clusiaceae) which displayed good activity in vitro against Leishmania donovani 1S (MHOM/SD/62/1S) promastigotes during preliminary screening with IC50 values 5.96 and 26.43 μg mL−1, respectively. The fractionation of both extracts using flash chromatography yielded active fractions with IC50 values ranging from 2.71 to 18.88 μg mL−1. Fourteen compounds (1–14) were isolated from the obtained fractions using successive column chromatographies and their structures were elucidated based on the analysis of their NMR and MS data. Daphnifolin (1), epicathechin (3), α-mangostin (9) and 9-hydroxycalabaxanthone (14) exhibited potent antileismanial activity against L. donovani 1S (MHOM/SD/62/1S) promastigotes with IC50 values of 2.01, 9.09, 3.37, and 6.87 μg mL−1, respectively and good selectivity towards Raw 264.7 macrophage cells (SI > 2.4). Extracts, fractions and some isolates were also assessed in vitro for their antibacterial activity against six bacterial strains [Salmonella typhi (CPC), Enterobacter cloacae (CPC), Pseudomonas aeruginosa HM801, Staphylococcus aureus ATCC 43300, Streptococcus pneumoniae ATCC 491619, Escherichia coli ATCC 25322] using serial microdilution method. Among the tested samples, the stem bark extract of P. butyracea as well as compounds 2 and 8 showed good to moderate activity against the aforementioned bacterial strains with MIC ≤ 250 μg mL−1.

The CH2Cl2–MeOH (1:1) extract of Adenia lobata (stem bark) and the MeOH extracts of Endodesmia calophylloides (stem bark and leaves) displayed in vitro antileishmanial activities during preliminary screening against Leishmania donovani promastigotes with IC50 values ranging from 17.75–24.33 µg/mL. The fractions obtained from these extracts were also assessed for their antileishmanial (IC50 values between 9.19 and 100 µg/mL) and cytotoxicity activities. The purification of the active fractions led to the isolation of 24 compounds: seven from A. lobata (1-7) including one new ceramide (1) and seventeen from E. calophylloides (8-24). Their structures were elucidated based on the analysis of their NMR and MS data. The isolates were assessed for their antileishmanial activity and for their cytotoxicity. Germanicol caffeoyl ester (3), the (1:1) mixture of isoxanthochymol (18)/cycloxanthochymol (19), and the (1:1) mixture of tachioside (10)/isotachioside (11) displayed potent antileishmanial activity with IC50 values of 6.03, 4.77, and 8.66 µg/mL, respectively, with SI˃1.

The chemical investigation of the CH2Cl2/MeOH (1:1) extract from the aerial part of Mussaenda erythrophylla Schumach. & Thonn. (Rubiaceae) resulted in the isolation of sixteen known compounds (1-16) distributed in coumarins, flavonoid glucosides, quinic acid derivatives, triterpenoids, monoglycerid, steroids, tetraterpenoid and polyol. The structures of the compounds were determined by spectrometric and spectroscopic analysis including MS and NMR data followed by their comparison with reported ones in the literature. The chemophenetic significance of the isolated compounds was discussed. The crude extract and some of the isolated compounds were assessed in vitro for their antileishmanial, cytotoxic and antiplasmodial activities. The crude extract of M. erythrophylla showed moderate antileishmanial activity (IC50 = 61.6 mu g/mL) while the hexane soluble fraction showed good antileishmanial activity (IC50 = 31.06 mu g/mL) compared to the reference drug amphotericin B (IC50 = 0.11 mu M). Compounds 11 and 9 also exhibited potent antileishmanial activity (IC50 = 53.7-52.0 mu M). The crude extract as well as the ethyl acetate soluble fraction also exhibited good antiplasmodial activity (IC50 = 7.43 +/- 0.00 mu g/mL and 14.49 +/- 2.96 mu g/mL respectively), while compounds 11, 15 and 16 showed weak activity with IC50 > 20 mu M compared to the reference drug artemisinin (IC50 = 0.014 +/- 0.001 mu M).

The chemical investigation of the CH2Cl2/MeOH (1:1) extract of the trunk bark and leaves of Baphia leptobotrys Harms (Fabaceae) led to the isolation of nineteen compounds (1–19). Their structures were elucidated based on the analysis of their NMR and MS data. Except for compounds 3–5, 14 and 15, all the isolated compounds are reported from the genus Baphia for the first time. Furthermore, compounds 8, 10, 16, 17 are isolated from the Fabaceae family for the first time. The crude extract and isolated compounds were screened in vitro for their antileishmanial activity against Leishmania donovani 1S (MHOM/SD/62/1S) promastigotes and cytotoxicity towards Raw 264.7 macrophage cells. The crude extract of B. leptobotrys exhibited moderate activity (IC50 = 63.40 μg/mL). Amongst the tested compounds, ergosterol peroxide (9) and germanicol caffeoyl ester (8) exhibited good activity with IC50 values of 9.43 and 10.24 μM, respectively and showed acceptable selectivity towards macrophage cells (SI > 3.85). The chemophenetic significance of these compounds is also discussed.

The chemical investigation of the CH2Cl2/MeOH (1:1) extract of the leaves of Rothmannia hispida (K. Schum.) Fagerl. (Rubiaceae) led to the isolation of a new ceramide rothmanniamide (1) and a naturally isolated alkyl cinnamate derivative n-heptadecyl-4-hydroxy-trans-cinnamate (2), along with fifteen known compounds including lupeol palmitate (3), lupeol (4), a mixture of uvaol (5) and erythrodiol (6), ursolic acid (7), 30-nor2 alpha,3 beta-dihydroxyurs-12-ene (8), hederagenin (9), stigmast-22-en-3-ol (10), a mixture of beta-sitosterol (11) and stigmasterol (12), stigmast-4,22-dien-3-ol (13), stigmasterol 3-O-beta-D-glucoside (14), triacontan-1-ol (15), kaempferol 3-O-beta-D-glucopyranoside (16) and D-mannitol (17). Their structures were elucidated with the help of MS and NMR data. Compounds 8, 10 and 15 were isolated for the first time from the Rubiaceae family. The crude extract and the isolates were assessed in vitro for their antileishmanial activity against Leishmania donovani 1 S (MHOM/SD/62/1 S) promastigotes and cytotoxicity on RAW 264.7 macrophage cells. Compounds 7 and 8 exhibited a highly potent antileishmanial activity with IC50 values of 0.88 and 1.75 mu g/mL, respectively, with good selectivity indexes (SI > 57). The chemophenetic significance of these compounds is also discussed.