Antiparasitic and Antimicrobial Isoflavanquinones from Abrus schimperi

Abstract

The EtOH extract of Abrus schimperi (Fabaceae), collected in Kenya, demonstrated significant activity against Leishmania donovani promastigotes with IC50 value of 3.6 μg/mL. Bioassay-guided fractionation of CHCl3 fraction using Centrifugal Preparative TLC afforded two antiparasitic isoflavanquinones, namely amorphaquinone (1) and pendulone (2). They displayed IC50 values of 0.63 μg/mL and 0.43 μg/mL, respectively, against L. donovani promastigotes. Both the compounds were also evaluated against L. donovani axenic amastigotes and amastigotes in THP1 macrophage cultures. In addition, compounds 1 and 2 showed antiplasmodial activity against Plasmodium falciparum D6 and W2 strains, while 2 displayed antibacterial activity against Staphylococcus aureus and methicillin-resistant S. aureus (each IC50 1.44 μg/mL). The 1H and 13C data of 1, not fully assigned previously, were unambiguously assigned using 1D and 2D NMR HMBC and HMQC experiments. In addition, the absolute stereochemistry of the isolated compounds 1 and 2 was revised as C-(3S) based on Circular Dichroism experiments. This appears to be the first report of amorphaquinone (1) and pendulone (2) from the genus Abrus.

Antiplasmodial Isoflavanes and Pterocarpans from Apoplanesia paniculata

“…The known compounds amorphaquinone (1) [7], pendulone (2) [8], and melilotocarpan C (3) [9] were identified by comparison of their spectroscopic and physical data with literature data. The 3R configuration of compounds 1 and 2 were con- Supporting information available online at http://www.thieme-connect.de/products firmed by comparison of their circular dichroism spectra with those of previously reported data [10,11]. Compound 4 (apoplanesiacarpan A) was obtained as a white powder.…”

“…Quinones 1 and 2 showed moderate inhibition of the growth of the drug-resistant Dd2 strain of P. falciparum, with IC 50 values of 6 ± 2 and 7 ± 1 µM, respectively, and also displayed moderate antiproliferative activity against the A2780 human ovarian cancer cell line, with IC 50 values of 6.6 and 19.6 µM. Quinones 1 and 2 have been reported to exhibit antileishmanial [16], antitumor [17], antiparasitic, and antimicrobial activities [11]. Melilotocarpan C (3) exhibited weak antiplasmodial activity (42 ± 5 µM), while apoplansiacarpan A (4) and apoplansiacarpan B (5) were inactive (IC 50 > 20 µg/mL).…”

New Polyisoprenylated Polycyclic Phloroglucines from Clusia gundlachii

“…The samples were dried using a Savant Speed Vac Plus SC210A. Antileishmanial Assay: The in vitro antileismanial assay was done on a culture of L. donovani promastigotes by AlamarBlue assay (14). In a 96 well microplate the samples with appropriate dilution were added to the leishmania promastigotes culture (2x106 cells/mL).…”

“…Antiplasmodial Assay: The in vitro antiplasmodial activity, as described previously [14], was measured by a colorimetric assay that determines the parasitic lactate dehydrogenase (pLDH) activity [16]. All the samples were tested at least in duplicates.…”

A review on medicinal plant extracts and their active ingredients against methicillin-resistant and methicillin-sensitive Staphylococcus aureus

“…Two new flavonoids, called bakuisoflavone and bakuflavanone, were identified in the Psoralea corylifolia fruit; these compounds exhibited significant anti-MRSA effects (90). In the genus Abrus from this family, amorphaquinone and pendulone compounds have been shown to be effective not only against Leishmania donovani and Plasmodium falciparum, but also on S. aureus and MRSA (35). A large number of studies have been carried out on the identification of the antimicrobial effects of plant compounds on different microbial agents (97), which have also yielded favorable results.…”