Molecular orbital and topological electron density study of n → π* interactions: amides and thioamides cases.

The n → π* interactions were studied in amides and thioamides systems models, through the analysis of the electron density topology along with the Natural Bonding Orbital (NBO) approach. The effect of the dispersion terms was assessed using different DFT functionals. The NBO, independent gradient model (IGM), and the analysis of the reduced density gradient outcomes show that dispersion forces play a significant role in the strength of n → π* interactions.

Effect of extracts from several sponges of Yucatan Coast on and preliminary chemical investigation of the bioactive extract of () .

In this study, twenty-four organic extracts from six marine sponge species, collected at shallows of Yucatan, Mexico, were evaluated against trophozoites and Vero cells. The dichloromethane and hexane extracts of exhibited the highest antigiardiasic activity (IC = 1.00 and 2.

Microwave-enhanced synthesis of 26-amino-22-oxocholestanes and their cytotoxic activity.

The synthesis of a series of 26-amino-22-oxocholestanes derived from diosgenin was accomplished via the substitution of an iodine atom at C-26 by primary and secondary amines. The reactions were conducted in refluxing acetonitrile and through microwave-assisted heating. The latter shows significant improvements in terms of reaction times going from hours to a few minutes or even seconds for completion.

Cytotoxic and antiproliferative activity of thiazole derivatives of Ochraceolide A.

A series of 15 novel 1,3-thiazole amide derivatives of the pentacyclic triterpene Ochraceolide A () was synthesized, characterized, and evaluated against three human cancer cell lines (MCF-7, MDA-MB-231 and SiHa) and a normal cell line (Vero). Synthetic derivatives were obtained by acylation of the 2-aminothiazole triterpene , previously reported. Remarkably, the 5-nitrofuramide derivative () showed better cytotoxic and antiproliferative activity than compound and the other derivatives against the three cancer cell lines with CC and IC values of 1.

Cytotoxic activity against breast cancer cells of two species of marine sponges from shallows of Yucatan peninsula.

This study aimed to evaluate the activity of extracts of two marine sponge species, occurring in the shallows of the Yucatan peninsula coast, on two cancer and one normal mammalian cell lines. Hexane, dichloromethane, ethyl acetate and methanol extracts of and were screened for their cytotoxic activity against hormone-dependent breast cancer (MCF-7) and human cervix cancer (SiHa) cell lines. The ethyl acetate extract of exhibited significant cytotoxicity against MCF-7 cells to a CC of 0.

Trichomonicidal activity of a new anthraquinone isolated from the roots of Morinda panamensis Seem.

Trichomoniasis, caused by the protozoan parasite Trichomonas vaginalis, is the most common nonviral sexually transmitted infection worldwide. Although drug treatment is available, unpleasant side effects and increased resistance to the nitroimidazole family have been documented. Hence, there is a need for the identification of new and safe therapeutic agents against T.

Crystal structure of ochraceolide A isolated from (Turcz.) Lundell.

The title compound, CHO [systematic name: 6a,6 b,8a,9a,12a,14b)-4,4,6a,6;b,8a,14b-hexa-methyl-12-methyl-eneicosa-hydro-3-phenanthro[1',2':6,7]indeno-[2,1-]furan-3,11(2)-dione], is a triterpene lactone, which was isolated from di-chloro-methane extract of (Turcz.) Lundell (celastraceae) stem bark. The compound has a lupane skeleton and consists of four fused six-membered rings and two five-membered rings.

ANTIPROTOZOAL ACTIVITY OF EXTRACTS OF (CELASTRACEAE).

Background: Chagas disease, amebiasis, giardiasis and trichomoniasis represent a serious health problem in Latin America. The drugs employed to treat these illnesses produce important side effects and resistant strains have appeared. The present study was aimed to evaluate the antiprotozoal activity of leaves, stem bark and root bark of , a celastraceus, that is used in Mexico as an anti-infective in febrile-type diseases.

Development of newly sanguinarine biosynthetic capacity in in vitro rootless shoots of Argemone mexicana L. Mexican prickly poppy.

Objective: To analyze berberine and sanguinarine biosynthetic capacities of both in vitro shoot and root cultures of Argemone mexicana and tissues from entire plants at different developmental stages.

Results: Berberine and sanguinarine were equally distributed in roots and aerial tissues of developing plantlet whereas, in juvenile plants, sanguinarine was only detected in roots. This alkaloid distribution was consistent with that of biosynthetic transcripts in juvenile plants.

Resin glycosides from Ipomoea tyrianthina and their sedative and vasorelaxant effects.

The methanol-soluble extract from the root of Ipomoea tyrianthina was studied in order to isolate compounds with activity on the central nervous system and vasorelaxant effects. Chromatographic methods were used to isolate and purify seven new glycolipids (2-8). The structures of compounds 1-8 were elucidated by a combination of NMR spectroscopy and mass spectrometry.

Cytotoxic diterpenes from roots of Crossopetalum gaumeri, a Celastraceae species from Yucatan Peninsula.

Four new diterpenes, crossogumerins A-D (1-4) along with six known ones (5-10) were isolated from the root bark of Crossopetalum gaumeri, an endemic medicinal plant from the Yucatan Peninsula. Their structures were elucidated on the basis of 1D and 2D NMR techniques, including HMQC, HMBC, and ROESY experiments. Compounds 1-5, 8-10 were evaluated for cytotoxicity against HeLa (carcinoma of the cervix) and Hep-2 (lung carcinoma) human tumor cells lines and against normal Vero cells (African green monkey kidney) in lag and log phase of growth.

4-Methyl-N-(4-methyl-phenyl-sulfon-yl)-N-[4-(4-methyl-phen-yl)-1,3-thia-zol-2-yl]benzene-sulfonamide.

There are two independent mol-ecules in the asymmetric unit of the title compound, C24H22N2O4S3. In each, the sulfonamide N atoms reveal nearly a trigonal-planar geometry with two S atoms of the O=S=O groups and one C atom of the thia-zole ring; the angles around the N atoms are between 117.00 (13) and 123.

Dihydrospinochalcone-a and epi-flemistrictin-B, natural isocordoin derivatives from the root extract of Lonchocarpus xuul.

Purification of the root extract of Lonchocarpus xuul resulted in the isolation and identification of dihydrospinochalcone A (1) and epi-flemistrictin B (2) as additional natural isocordoin derivatives. Identification was based on the analysis of their spectroscopic data and by comparing these with those of previously reported metabolites.

Design, synthesis, and in vitro antiprotozoal, antimycobacterial activities of N-{2-[(7-chloroquinolin-4-yl)amino]ethyl}ureas.

We have synthesized a new series of quinoline tripartite hybrids from chloroquine, ethambutol, and isoxyl drugs, using a short synthetic route. Compounds 1-8 were tested in vitro against five protozoa (Giardia intestinalis, Trichomonas vaginalis,Entamoeba histolytica, Leishmania mexicana and Trypanosoma cruzi) and Mycobacterium tuberculosis. N-(4-Butoxyphenyl)-N'-{2-[(7-chloroquinolin-4-yl)amino]ethyl}urea (6) was the most active compound against all parasites tested.

Glycolipid ester-type heterodimers from Ipomoea tyrianthina and their pharmacological activity.

Tyrianthins A (1) and B (2), two new partially acylated glycolipid ester-type heterodimers were isolated from Ipomoea tyrianthina. Scammonic acid A was determined as the glycosidic acid in both monomeric units. Tyrianthin A (1) (IC(50) 0.

Tyrianthinic acids from Ipomoea tyrianthina and their antimycobacterial activity, cytotoxicity, and effects on the central nervous system.

Four new partially acylated tetrasaccharides of 11-hydroxyhexadecanoic acid (1-4) were isolated from a methanolic extract of Ipomoea tyrianthina. The structures of these compounds were elucidated by spectroscopic and chemical methods. The resin glycoside composition of I.

Resin glycosides from the roots of Ipomoea tyrianthina and their biological activity.

Seven new tetrasaccharide glycosides, tyrianthins 1-7 (1-7), along with six known glycolipids were isolated from the roots of Ipomoea tyrianthina, and their structures were elucidated by spectroscopic and chemical methods. The content of resin glycosides in samples collected in three different regions was analyzed and compared, and the results showed that the flowering or dry season did not have any effect on the chemical composition for the same locality, but the growing location itself did affect the chemical composition of resin glycosides. Intraperitoneal administration to mice of tyrianthin 6 (6) resulted in antidepressant activity.