Trypanocidal and leishmanicidal activity of six limonoids

Six limonoids [kotschyienone A and B (1, 2), 7-deacetylgedunin (3), 7-deacetyl-7-oxogedunin (4), andirobin (5) and methyl angolensate (6)] were investigated for their trypanocidal and leishmanicidal activities using bloodstream forms of Trypanosoma brucei and promastigotes of Leishmania major. Whereas all compounds showed anti-trypanosomal activity, only compounds 1–4 displayed anti-leishmanial activity. The 50% growth inhibition (GI 50) values for the trypanocidal and leishmanicidal activity of the compounds ranged between 2.5 and 14.9 μM. Kotschyienone A (1) was found to be the most active compound with a minimal inhibition concentration (MIC) value of 10 μM and GI 50 values between 2.5 and 2.9 μM. Only compounds 1 and 3 showed moderate cytotoxicity against HL-60 cells with MIC and GI 50 values of 100 μM and 31.5–46.2 μM, respectively. Compound 1 was also found to show activity against intracellular amastigotes of L. major with a GI 50 value of 1.5 μM. The results suggest that limonoids have potential as drug candidates for the development of new treatments against trypanosomiasis and leishmaniasis

Antiplasmodial and Cytotoxic Activities of Extracts from Jacaranda mimosifolia and Pseudospondias microcarpa

International audienc

A NEW SOURCE OF KOJIC ACID ISOLATED FROM KIGELIA AFRICANA: A POSSIBLE PRECURSOR FOR QUINONE BIOSYNTHESIS

ABSTRACT Kojic acid (5-hydroxy-2-hydroxymethyl-γ-pyrone) a fungal metabolite produced by Aspergillus spp., Penicillium spp. and belonging mainly to the flavus-oryzaetamarii groups was isolated for the first time from Kigelia africana as the major constituent by mass fragmentation guided isolation. From a biosynthetic consideration, Kojic acid is a possible intermediate in the synthesis of the quinone scaffolds

Bioactive Seco-Lanostane-Type Triterpenoids from the Roots of <i>Leplaea mayombensis</i>

Fractionation of the ethyl acetate-soluble extract of the roots of <i>Leplaea mayombensis</i> afforded two new 3,4-seco-lanostane-type triterpenoids, leplaeric acids A and B (<b>1</b>, <b>2</b>), the new lanostane-type triterpenoid leplaeric acid C (<b>3</b>), and six known natural products (<b>5</b>–<b>10</b>). Derivatization of the main constituent, <b>1</b>, afforded the dimethyl ester <b>4</b>, the monoamide <b>11</b>, and diamide <b>12</b> for SAR studies. The structures of these compounds were established through spectroscopic methods, and a single-crystal X-ray diffraction analysis was used to confirm the relative configuration of compound <b>1</b>. These lanostane derivatives are unique since they are the first C-21-oxygenated lanostanes isolated from plant sources. Preliminary biological assays against the MDA MB 231 breast cancer cell line showed that compounds <b>1</b>, <b>2</b>, <b>4</b>, and <b>11</b> have modest cytotoxic activity. Compound <b>2</b> was the most active, with an IC₅₀ of 55 ± 7 μM. From these results, the amides (<b>11</b>, <b>12</b>) derived from triterpenoid <b>1</b> were found to be less active than the derived esters (<b>2</b>, <b>4</b>)