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

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Antiplasmodial and cytotoxic activity of lanostane type triterpenoids isolated from Leplaea mayombensis

International audienceLeplaeric acid E 5, leplazarin 6a and 21-epileplazarin 6b, three new 3,4-seco-lanostane type triterpenes have been isolated from the stem bark of Leplaea mayombensis (Pellegr.) Staner along with fourteen known compounds from the fruits and roots. Leplaeric acid E, leplazarin and 21-epileplazarin, 15-α-hydroxy-3,4-seco-lanosta-4(28),8,24-triene-3,21-dioic acid, mayomlactones A and B, lanosta-7,24-dien-3-one, leplaeric acid A, B and C were screened in vitro for antiplasmodial activity against chloroquine-sensitive (Pf3D7) and chloroquine-resistant (PfINDO) strains of Plasmodium falciparum and for cytotoxicity against CAL-27, CaCo2, Skov-3, and HepG2 cells line. Three compounds including 15-α-hydroxy-3,4-seco-lanosta-4(28),8,24-triene-3,21-dioic acid (IC50 5.65–7.09 μM), lanosta-7,24-dien-3-one (IC50 7.18–9.07 μM), and leplaeric acid C (IC50 7.59–8.47 μM) were the most active against both strains of P. falciparum. All the compounds exhibited cytotoxicity against the three-cell lines with IC50 ranging from 12.30 to 181.88 μM. These results confirm the usage of the medicinal plant L. mayombensis for the management of malaria and suggest that further lead optimization studies on potent compounds identified from this study could lead to the identification of potential of lead molecules as scaffold for new antimalarial drug discovery

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

Oligoamide, a new lactam from the leaves of <i>Angylocalyx oligophyllus</i>

<p>A new lactam, oligoamide (<b>1</b>), along with three known compounds (<b>2</b>–<b>4</b>), stigmasterol-3-O-β-D-glucopyranoside (<b>2</b>), formononetin (<b>3</b>) and (-)-pinitol (<b>4</b>) were isolated from the CH₂Cl₂/CH₃OH (1:1) extract of the leaves of <i>Angylocalyx oligophyllus</i> by chromatographic separation. Their structures were elucidated on the basis of spectroscopic analysis (UV, IR, MS, 1D, and 2D NMR). Compound <b>1</b> was found to have weak antioxidant and urease inhibitory potential.</p

Antiproliferative and cytotoxic secondary metabolites from fruits of <i>Leplaea mayombensis</i>

<p>Two new <i>seco</i>-lanostane-type triterpenes, named mayomlactones A (<b>1</b>) and B (<b>2</b>) were isolated from the fruits of <i>Leplaea mayombensis</i> together with 10 known compounds (<b>3</b>–<b>12</b>). Structures of the new compounds were elucidated by extensive spectroscopic studies. Except compounds <b>11</b> and <b>12</b>, all the other chemical compounds are newly reported from <i>Leplaea</i> genus. From the results of this investigation, compounds <b>1</b>–<b>10</b> were examined for antiproliferative activity against HeLa cells as well as cytotoxicity against 3T3 cell line. Compounds <b>3</b> and <b>4</b> showed moderate antiproliferative activity with IC₅₀ values of 10.4 ± 0.1 and 18.6 ± 0.2 μM, respectively. On the other hand, compounds <b>1</b>, <b>4</b> and <b>9</b> showed weak cytotoxicity with IC₅₀ values 44.1 ± 0.5, 55.8 ± 0.7 and 55.1 ± 0.5 μM. Overall, none of the tested compounds showed good selectivity (SI ranging from 0.51 to 3.06) but high toxicity against the 3T3 cell line.</p

Bioactive Seco-Lanostane-Type Triterpenoids from the Roots of Leplaea mayombensis

International audienceFractionation of the ethyl acetate-soluble extract of the roots of Leplaea mayombensis afforded two new 3,4-seco-lanostane-type triterpenoids, leplaeric acids A and B (1, 2), the new lanostane-type triterpenoid leplaeric acid C (3), and six known natural products (5–10). Derivatization of the main constituent, 1, afforded the dimethyl ester 4, the monoamide 11, and diamide 12 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 1. 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 1, 2, 4, and 11 have modest cytotoxic activity. Compound 2 was the most active, with an IC50 of 55 ± 7 μM. From these results, the amides (11, 12) derived from triterpenoid 1 were found to be less active than the derived esters (2, 4)

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>)