Research for innovative drugs is crucial to contribute to parasitic infections control and eradication. Inspired by natural antiprotozoal triterpenes, a library of 12 hemisynthetic 3-O-arylalkyl esters was derived from ursolic and oleanolic acids through one-step synthesis. Compounds were tested on Trypanosoma, Leishmania and the WI38 cell line alongside with a set of triterpenic acids.
View Article and Find Full Text PDFThe current chemotherapy of Chagas disease needs to be urgently improved. With this aim, a series of 16 hybrids of alkaloids and bile acids were prepared by functionalization at position C-2 of the quinoline nucleus by a radical attack of a norcholane substituent via a Barton-Zard decarboxylation reaction. The antitrypanosomal activity of the hybrids was tested on different stages and strains of In particular, eight out of 16 hybrids presented an IC ≤1 μg/mL against trypomastigotes of the CL Brener strain and/or a selectivity index higher than 10.
View Article and Find Full Text PDFThe aim of this pilot study was to evaluate the effects of a sunflower () seed extract, standardized for 40% chlorogenic acids on weight and body composition of obese adults. Fifty subjects were randomly assigned to sunflower extract or isocaloric placebo groups, receiving respectively 500 mg/day of treatment for 12 weeks. At the end of the intervention, a significant decrease in body weight, Body Mass Index (BMI), and waist circumference was observed, especially for obese female subjects above 30 years.
View Article and Find Full Text PDFIn this work, a series of hybrid compounds were tested as antiparasitic substances. These hybrids were prepared from bile acids and a series of antiparasitic Cinchona alkaloids by the formation of a covalent C-C bond via a decarboxylative Barton-Zard reaction between the two entities. The bile acids showed only weak antiparasitic properties, but all the hybrids exhibited high in vitro activities (IC50: 0.
View Article and Find Full Text PDFA phytochemical investigation of the methanolic extract of the bark of Endiandra kingiana led to the isolation of seven new tetracyclic endiandric acid analogues, kingianic acids A-G (1-7), together with endiandric acid M (8), tsangibeilin B (9) and endiandric acid (10). Their structures were determined by 1D- and 2D-NMR analysis in combination with HRMS experiments. The structure of compounds 9 and 10 were confirmed by single-crystal X-ray diffraction analysis.
View Article and Find Full Text PDFA series of 16 hybrids of Cinchona alkaloids and bile acids (4a-h, 5a-h) was prepared by means of a Barton-Zard decarboxylation reaction. Quinine, quinidine, cinchonine and cinchonidine were functionalized at position C-2 of the quinoline nucleus by radical attack of a norcholane substituent. The newly synthesized hybrids were evaluated in vitro for their antitrypanosomal, antileishmanial and antiplasmodial activities, along with their cytotoxicity against WI38, a normal human fibroblast cell line.
View Article and Find Full Text PDFAn in vitro biological screening of Malaysian plants allowed the selection of several species with a significant binding affinity for the antiapoptotic protein Bcl-xL. The chemical investigation of Endiandra kingiana led to the isolation of a series of polyketides named kingianins A-N, having a pentacyclic carbon skeleton described for the first time in nature. Fourteen compounds were isolated as racemic mixtures, and characterized by mass spectrometryand extensive one- and two-dimensional NMR spectroscopy.
View Article and Find Full Text PDFA short, convergent, and selective synthesis of meiogynin A, an inhibitor of the antiapoptotic protein Bcl-xL, has been performed. This synthesis, based on a biomimetic approach, allowed the determination of its absolute configuration. Three isomers of meiogynin A have also been elaborated.
View Article and Find Full Text PDFA new natural pentacyclic compound, named kingianin A, was isolated as a racemic mixture from the barks of Endiandra kingiana (Lauraceae). Its structure was elucidated by comprehensive analysis of NMR spectroscopic data, X-ray crystallography, and ECD calculations. The pentacyclic skeleton may be formed by a Diels-Alder reaction between two monomers having a bicyclo[4.
View Article and Find Full Text PDFIn our search for inhibitors of the antiapoptotic protein Bcl-xL, investigation of Xylopia caudata afforded a new diterpenoid, ent-trachyloban-4beta-ol (2), and five known ent-trachylobane or ent-atisane compounds. Only ent-trachyloban-18-oic acid (1) exhibited weak binding activity to Bcl-xL. These compounds exhibited cytotoxicity against KB and HCT-116 cell lines with IC(50) values between 10 and 30 microM.
View Article and Find Full Text PDF