-This study developed a methodology for callus induction in leaf segments of B. verbascifolia and evaluated the bioactive phenolic compounds production. Leaf explants were cultured in MS medium with 30 g L -1 sucrose, solidified with 7 g L -1 agar supplemented with 2,4-D (0; 4.52; 9.05; 18.10 M) and BAP (0; 4.44; 8.88; 17.75 M ) in the presence and absence of light. Forty-five days after inoculation we assessed the percentage of callus induction, color, consistency, fresh and dry matter, total phenols, flavonoids, tannins contents, and chromatographic profile by HPLC-DAD method. Callus induction occurred only in medium with growth regulators. Maximal induction (100%) was found in medium containing 2,4-D combined with BAP in the presence and absence of light. We obtained friable and compact callus in yellow, green, and red. Culture media containing 4.52 M 2,4-D + 4.44 M BAP induced 100% of friable callus with higher fresh and dry weight in the absence of light. The callus produced higher amounts of total phenols and flavonoids than the initial explant.

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Metastasis remains the most common cause of death in cancer patients. Inhibition of metalloproteinases (MMPs) is an interesting approach to cancer therapy because of their role in the degradation of extracellular matrix (ECM), cell-cell, and cell-ECM interactions, modulating key events in cell migration and invasion. Herein, we show the cytotoxic and antimetastatic effects of the third fraction (FR3) from Bauhinia variegata candida (Bvc) stem on human cervical tumor cells (HeLa) and human peripheral blood mononuclear cells (PBMCs). FR3 inhibited MMP-2 and MMP-9 activity, indicated by zymogram. This fraction was cytotoxic to HeLa cells and noncytotoxic to PBMCs and decreased HeLa cell migration and invasion. FR3 is believed to stimulate extrinsic apoptosis together with necroptosis, assessed by western blotting. FR3 inhibited MMP-2 activity in the HeLa supernatant, differently from the control. The atomic mass spectrometry (ESI-MS) characterization suggested the presence of glucopyranosides, D-pinitol, fatty acids, and phenolic acid. These findings provide insight suggesting that FR3 contains components with potential tumor-selective cytotoxic action in addition to the action on the migration of tumor cells, which may be due to inhibition of MMPs.

The main challenge in the control of malaria has been the emergence of drug-resistant parasites. The presence of drug-resistant Plasmodium sp. has raised the need for new antimalarial drugs. Molecular modelling techniques have been used as tools to develop new drugs. In this study, we employed virtual screening of a pyrazol derivative (Tx001) against four malaria targets: plasmepsin-IV, plasmepsin-II, falcipain-II, and PfATP6. The receiver operating characteristic curves and area under the curve (AUC) were established for each molecular target. The AUC values obtained for plasmepsin-IV, plasmepsin-II, and falcipain-II were 0.64, 0.92, and 0.94, respectively. All docking simulations were carried out using AutoDock Vina software. The ligand Tx001 exhibited a better interaction with PfATP6 than with the reference compound (-12.2 versus -6.8 Kcal/mol). The Tx001-PfATP6 complex was submitted to molecular dynamics simulations in vacuum implemented on an NAMD program. The ligand Tx001 docked at the same binding site as thapsigargin, which is a natural inhibitor of PfATP6. Compound TX001 was evaluated in vitro with a P. falciparum strain (W2) and a human cell line (WI-26VA4). Tx001 was discovered to be active against P. falciparum (IC50 = 8.2 µM) and inactive against WI-26VA4 (IC50 > 200 µM). Further ligand optimisation cycles generated new prospects for docking and biological assays.

The study of the metabolic variations in plant roots up to 96 h after their inoculation with second-stage juveniles (J2) of Meloidogyne incognita revealed that soybean cultivars resistant to this nematode produced more soluble phenols and alkaloids. In tomato plants the resistance to M. incognita correlates with the production of soluble phenols, the concentrations of which were always higher in the resistant cultivar. For common bean plants the production of soluble carbohydrates, especially sucrose, increased after their inoculation. However, the extracts of roots from plants resistant to M. incognita did not increase the in vitro mortality of J2.

A series of organotin(IV) derivatives of bis(pyrimidin-2-ylthio)methane ( ptm ), 1,2-bis(pyrimidin-2-ylthio)ethane ( pte ) and 1,6-bis(pyrimidin-2-ylthio)hexane ( pth ) have been prepared in dichloromethane at room temperature. The 2:1 (M/L) molar ratio compounds have a general formula of [Sn 2 Cl x Ph 8-x L] ( x = 2, 4, 6, 8; L = ptm , pte and pth ). A 1:1 complex was also obtained by reacting SnClPh 3 with pth . The organotin derivatives were characterised by multinuclear NMR ( 1 H, 13 C and 119 Sn) and infrared spectroscopy, gel permeation chromatography (GPC), microanalysis and melting point. In the triphenyltin derivatives, 1 , 5 , 9 and 10 the tin atoms show a distorted trigonal-bipyramidal confi guration where the ligand is monodentate towards the metal atom. In the compounds 2 -4 , 6 -8 and 11 -13 , the tin atoms each exhibit a distorted octahedral confi guration. Chelation is formed between the tin nucleus and the coordinating sulphur and nitrogen atoms. The correlation between the 1 J ( 13 C-119 Sn) and C-Sn-C bond angle indicates formation of 5-coordinate compounds.

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