Synthesis, structures, and biological studies of heterobimetallic Au(I)-Ru(II) complexes involving N-heterocyclic carbene-based multidentate ligands

Three heterobimetallic gold(I)-ruthenium(II) complexes containing heteroditopic bipyridine-N-heterocyclic carbene (NHC) ligands were synthesized and fully characterized by spectroscopic methods and in one case by single-crystal X-ray diffraction. In addition, the in vitro cytotoxic, antileishmanial, and antimalarial activities of these new heterobimetallic complexes were assessed. Moreover, the photophysical properties of two compounds have been used to localize them in tumor cells by confocal microscopy

Zebiriosides A-P, oleanane saponins isolated by LC-SPE-NMR hyphenation from the roots of Dendrobangia boliviana

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A new phthalide derivative from Peperomia nivalis

One new phthalide (1) was isolated from aerial parts of Peperomia nivalis, along with known compounds (2 and 3), reported in this species for the first time. The structure of the new compound was characterised on the basis of 1D (H-1 and C-13 NMR), 2D (COSY, HMQC, HMBC and NOESY) NMR and high-resolution mass spectral (HRMS) data. Compound 2 was isolated from a natural source for the first time but previously synthesised. Compounds 1-3 were evaluated for their anti-Helicobacter pylori and anti-Plasmodium falciparum activities. Compound 1 showed moderate activities against H. pylori (MIC 47.5 mu M) and the F32-Tanzania strain of P. falciparum (IC50 8.5 mu M). Compounds 2 and 3 exhibited weak anti-H. pylori activity (MIC 241.3 and 237.6 mu M, respectively) and were inactive against P. falciparum. [GRAPHICS]

Evaluation of antiplasmodial and antileishmanial activities of herbal medicine Pseudelephantopus spiralis (Less.) Cronquist and isolated hirsutinolide-type sesquiterpenoids

Ethnopharmacological relevance: Pseudelephantopus spiralis (Less.) Cronquist is distributed in the Caribbean, Mesoamerica and Latin America. Preparations of the plant are traditionally used in Latin America for the treatment of various diseases including fever, malaria, and spleen or liver inflammations. Materials and methods: Aerial parts of P. spiralis were extracted with either ethanol or distilled water. Seven hirsutinolide-type sesquiterpenoids were isolated: 8-acetyl-13-ethoxypiptocarphol (1), diacetylpiptocarphol (2), piptocarphins A (3), F (4) and D (5), (1S*,4R*,8S*,10R*)-1,4-epoxy-13-ethoxy-1,8,10-trihydroxygermacra-5E,7(11)-dien-6,12-olide (6), and piptocarphol (7). Extracts and isolated compounds (2, 3, 5-7) were screened for their in vitro antiplasmodial activity against the chloroquine-resistant Plasmodium falciparum strain FcM29-Cameroon and antileishmanial activity against three stages of Leishmania infantum. Their cytotoxicities were also evaluated against healthy VERO cell lines and J774A.1 macrophages, the host cells of the Leishmania parasites in humans. Results: Aqueous extracts showed a greater inhibitory effect than alcoholic extracts, with IC50 on P. falciparum of 3.0 mu z/mL versus 211 mu g/mL, and on L infantum of 13.4 mu g/mL versus >50 mu g/mL. Both extracts were found to be cytotoxic to VERO cells (CC50 < 3 mu g/mL). Sesquiterpene lactones 2 and 3 showed the best activity against both parasites but failed in selectivity. Carbon 8 hydroxylated hirsutinolides 5-7 presented the particularity of exhibiting two conformers observed in solution during extensive NMR analyses in CD3OD and UHPLC-MS. The presence of a hydroxyl function at C-8 decreased the activity of 5-7 on the two parasites and also on VERO cells. Conclusion: The antiplasmodial activity displayed by the aqueous extract explains the traditional use of P. spiralis in the treatment of malaria. This activity seems to be attributable to the presence of sesquiterpene lactones 2 and 3, the most active against P. falciparum. Aqueous extract and compounds 2, 3 and 6 were also active against L infantum but lacked in selectivity due to their cytotoxicity towards macrophages. Exploring the safety and antiplasmodial efficacy of this traditional remedy will require further toxicological and in vivo studies in the light of the cytotoxicity towards healthy cell lines displayed by the aqueous extract and compounds 2 and 3

Discovery of new thienopyrimidinone derivatives displaying antimalarial properties toward both erythrocytic and hepatic stages of Plasmodium

A preliminary in vitro screening of compounds belonging to various chemical families from our library revealed the thieno[3,2-d]pyrimidin-4(3H)-one scaffold displayed a promising profile against Plasmodium falciparum. Then, 120 new derivatives were synthesized and evaluated in vitro; compared to drug references, 40 showed good activity toward chloroquine sensitive (IC50 35-344 nM) and resistant (IC50 45-800 nM) P. falciparum strains. They were neither cytotoxic (CC50 15-50 mu M) toward HepG2 and CHO cells, nor mutagenic. Structure activity relationships were defined. The lead-compound also appeared active against the Plasmodium liver stages (Plasmodium yoelii IC50 = 35 nM) and a preliminary in vivo evaluation indicated the in vitro activity was preserved (45% reduction in parasitemia compared to untreated infected mice). A mechanistic study demonstrated these molecules do not involve any of the pathways described for commercial drugs and exert a specific activity on the ring and trophozoite stages. 2015 Elsevier Masson SAS. All rights reserved