Evaluation of the antiproliferative activity of the leaves from Arctium lappa by a bioassay-guided fractionation.

Arctium lappa L. (Asteraceae) is used in folk medicine around the World, and shows several kinds of biological activity, particularly in vitro antitumor activity in different cell lines. This study evaluated the antiproliferative activity of the crude extract, semipurified fractions, and isolated compounds from the leaves of A. lappa, through bioassay-guided testing in Caco-2 cells. The crude extract was obtained with a 50% hydroethanolic extract and then partitioned with hexane, ethyl acetate, and n-butanol. The ethyl-acetate fraction (EAF) showed antiproliferative activity. This fraction was subjected to sequential column chromatography over silica gel to afford onopordopicrin (1), mixtures of 1 with dehydromelitensin-8-(4'-hydroxymethacrylate) (2), a mixture of 2 with dehydromelitensin (3), mixture of 1 with melitensin (4), dehydrovomifoliol (5), and loliolide (6). The compounds were identified by spectroscopic methods (NMR, MS) and comparison with literature data. This is the first description of compounds 2-5 from this species. The compounds tested in Caco-2 cells showed the following CC(50) (µg/mL) values: 1: 19.7 ± 3.4, 1 with 2: 24.6 ± 1.5, 2 with 3: 27 ± 11.7, 1 with 4: 42 ± 13.1, 6 30 ± 6.2; compound 5 showed no activity.

Resveratrol-derived stilbenoids and biological activity evaluation of seed extracts of Cenchrus echinatus L.

A phytochemical study of the ethyl acetate fractions from the partition of seeds and roots methanol extracts of Cenchrus echinatus L. led to the isolation of three resveratrol-derived stilbenoids: pallidol (1), carasiphenol C (2) and nepalensinol B (3). The results of a topic anti-inflammatory evaluation, DPPH assay and antiproliferative activity against adenocarcinoma cells (Caco 2) are described.

Synthesis and antiviral activity of beta-carboline derivatives bearing a substituted carbohydrazide at C-3 against poliovirus and herpes simplex virus (HSV-1).

Several novel 1,3-disubstituted beta-carboline derivatives bearing a substituted carbohydrazide group at C-3 were synthesized and evaluated for their antiviral activity against vaccinal poliovirus (VP) and herpes simplex virus type 1 (HSV-1). The cytotoxicity and selectivity index of the active compounds were also evaluated. Among the synthesized derivatives, compounds 10 and 11 displayed potent activity against both vaccinal poliovirus and HSV-1 virus. Compound 10 presented the highest selectivity index (SI=2446.8) against HSV-1 virus and low cytotoxicity (CC(50)=1150.0+/-67.3 microM). The virus yield inhibition assay showed that compound 10 was able to inhibit HSV-1 plaque formation before and during the virus adsorption. The characteristic small plaque pattern observed in compound-treated cells suggested that compound 10 inhibited viral dissemination to neighboring cells. A computational study for prediction of ADME properties of the novel synthesized beta-carbolines derivatives was performed by determination of lipophilicity, topological polar surface area (TPSA), absorption (% ABS) and simple molecular descriptors, using Lipinski's rule.