Search for Antimicrobial Activity Among Fifty-Two Natural and Synthetic Compounds Identifies Anthraquinone and Polyacetylene Classes That Inhibit .

Drug-resistant tuberculosis threatens to undermine global control programs by limiting treatment options. New antimicrobial drugs are required, derived from new chemical classes. Natural products offer extensive chemical diversity and inspiration for synthetic chemistry.

Anti-leukemic activity of semisynthetic derivatives of lupeol.

In our previous work, lupeol was isolated from aerial parts of and modified by semisynthetic approach. The purpose of this study was to investigate the cytotoxicity of lupeol and its derivatives previously prepared on the human K562 acute myeloid leukemia cell and human Jurkat acute lymphoid leukemia cell . Compounds 3β-hydroxylup-20(29)-en-30-al (), lup-20(30)-en-3β,29-diol (), 3β-acetoxylup-20(29)-en-30-al () and 3β-acetoxy-30-hydroxylup-20(29)-ene () presented cytotoxicity with IC ranging from 11.

Synthesis of lupeol derivatives and their antileishmanial and antitrypanosomal activities.

The natural product lupeol 1 was isolated from aerial parts of Vernonia scorpioides with satisfactory yield, which made it viable to be used as starting material in semisynthetic approach. Ten lupeol derivatives 2-11 were prepared by classical procedures. Including, five new esters derivatives 7-11, which were obtained by structural modifications in the isopropylidene fragment.

Multivariate SAR and QSAR of cucurbitacin derivatives as cytotoxic compounds in a human lung adenocarcinoma cell line.

This article describes structure-activity relationship (SAR/QSAR) studies on the cytotoxic activity in a human lung adenocarcinoma cell line (A549) of 43 cucurbitacin derivatives. Modeling was performed using the methods partial least squares with discriminant analysis (PLS-DA) and PLS. For both studies, the variables were selected using the ordered predictor selection (OPS) algorithm.

Chemical modification produces species-specific changes in cucurbitacin antifeedant effect.

Cucurbitacins are secondary metabolites that mediate insect plant interactions not only as allomones against generalists but also as kairomones for specialist herbivores. This study was undertaken to identify the potential of cucurbitacin derivatives as insect antifeedant agents. The antifeedant capacity against a Cucurbitaceae specialist [ Epilachna paenulata (Coleoptera: Coccinellidae)] and a polyphagous insect [ Pseudaletia adultera (Lepidoptera: Noctuidae)] was evaluated in preference tests in which the insects were given a choice between food plants either treated with the cucurbitacin derivatives or treated with the solvent.

Synthesis and cytotoxic activity evaluation of dihydrocucurbitacin B and cucurbitacin B derivatives.

Two cucurbitacins, dihydrocucurbitacin B (1) and cucurbitacin B (2), which can be obtained in large amounts from the roots of Wilbrandia ebracteata and from the fruits of Luffa operculata, respectively, were used as starting materials for the preparation of a library of 29 semi-synthetic derivatives. The structural changes that were performed include the removal, modification or permutation of functional groups in rings A and B as well as in the side chain. All new semisynthetic compounds, as well as 1 and 2, were tested in vitro for their cytotoxic effects on non-small-cell lung cancer cells (A549 cells).