RESUMEN

The chemical investigation of the fresh flowers of Albizia lebbeck (L.) Benth. (Fabaceae, Mimosoideae) led to the isolation of two new echinocystic acid saponins. They were isolated by using chromatographic methods and their structures were elucidated by detailed 1H and 13C NMR spectral data including 2 D-NMR (COSY, HSQC, HMBC and APT) spectroscopic techniques, high-resolution electrospray ionization mass spectrometry (HRESIMS) and acid hydrolysis. Their structures were established as 16-hydroxy-3-[[O-ß-D-xylopyranosyl-(1→2)-O-α-L-arabinopyranosyl-(1→6)-2-(acetylamino)-2-deoxy-ß-D-glucopyranosyl]oxy]-(3ß,16α)-olean-12-en-28-oic acid O-6-deoxy-α-L-mannopyranosyl-(1→4)-O-6-deoxy-α-L-mannopyranosyl-(1→2)-ß-D-glucopyranosyl ester (1) and 16-hydroxy-3-[[O-ß-D-xylopyranosyl-(1→2)-O-α-L-arabinopyranosyl-(1→6)-2-(acetylamino)-2-deoxy-ß-D-glucopyranosyl]oxy]-(3ß,16α)-olean-12-en-28-oic acid 6-O-[(2S,3R,4R)-tetrahydro-3-hydroxy-4-(hydroxymethyl)-2-furanyl]-ß-D-glucopyranosyl ester (2). Additionally, the permeability property and the capacity of interaction with biological membranes of compounds 1 and 2 were investigated.

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RESUMEN

As part of the ongoing efforts in discovering potentially bioactive natural products from medicinal plants, the present study was conducted to isolate a new complex triterpenoid saponin from the barks of Albizia lebbeck. It was isolated by using chromatographic methods and its structural elucidation was performed using detailed analyses of 1H and 13C NMR spectra including 2D-NMR (COSY, TOCSY, HSQC and HMBC) spectroscopic techniques, high-resolution electrospray ionization mass spectrometry (HRESIMS) analysis and chemical conversions. Its structure was established as 21-[[(2E,6S)-6-[6-deoxy-4-O-[(2E,6S)-6-hydroxy-2-(hydroxymethyl)-6-methyl-1-oxo-2,7-octadienyl]-[(ß-d-glucopyranosyl)oxy]-2-(hydroxymethyl)-6-methyl-1-oxo-2,7-octadienyl]-[(ß-d-glucopyranosyl)oxy]-2,6-dimethyl-1-oxo-2,7-octadienyl]oxy]-16-hydroxy-3-[[O-ß-d-xylopyranosyl-(1 → 2)-O-α-l-arabinopyranosyl-(1 → 6)-2-(acetylamino)-2-deoxy-ß-d-glucopyranosyl]oxy]-(3ß,16α,21ß)-olean-12-en-28-oic acid O-α-l-arabinofuranosyl-(1 → 4)-O-[ß-d-glucopyranosyl-(1 → 3)]-O-6-deoxy-α-l-mannopyranosyl-(1 → 2)-ß-d-glucopyranosyl ester (1). Additionally, this study aimed to investigate the permeability property of 1, its activity on membrane integrity and supramolecular interactions with cellular constituents using in vitro experimental models.

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A new polysaccharide with an estimated weight-average molar mass of 2.6×10(3) was isolated from Allium ampeloprasum var. porrum by hot water extraction, and purified by Sephacryl S-300 HR high-resolution chromatography. It was composed of D-fructose and D-glucose in 10:6 molar ratio, respectively. The structure of the glucofructan was investigated by chemical and spectroscopic methods, including methylation analysis, nuclear magnetic resonance, and electrospray mass spectrometry (ES-MS). The results permitted the structure of the glucofructan to be written as α-D-Glcp-(1→1)-ß-D-Fruf-(2→1)-{[α-D-Glcp-(1→6)-ß-D-Fruf-(2→6)]-ß-D-Fruf-(2→1)}4-ß-D-Fruf-(2↔1)-α-D-Glcp. Results of the present study indicated that this new glucofructan exhibited significant gastroprotective property, using in vivo experimental models.

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A polysaccharide with an estimated weight-average molar mass of 5.35×10(5) was obtained from an aqueous extract of pseudobulbs of Cyrtopodium andersonii R. Br. It was composed of d-glucose and d-mannose in 1:3 molar ratio. Chemical and spectroscopic analyses revealed a linear structure of the polymer with a backbone composed of (1→4)-linked ß-d-glucopyranosyl and mannopyranosyl units slightly branched at C-2, C-3, and C-6 by side chains, as terminal non reducing residues of d-mannopyranose and d-glucopyranose. It was found to contain 14.6% of acetyl groups substituted at C-2 of (1→4)-linked ß-d-mannopyranosyl units. The acetylated glucomannan demonstrated antiinflammatory and antiulcerogenic activities.

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RESUMEN

Many classes of phytochemical products are finding therapeutic use, for example, complex triterpenoid saponins containing in their structures monoterpene moieties. Some of these compounds possess cytotoxic, anti-HIV and adjuvant activities. This review aims to give an overview of these complex triterpenoid saponins with biological activity from the Leguminosae.

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Two new steroidal saponins were isolated from the rhizomes of Costus spiralis Rosc. Their structures were established as (3beta,25R)-26-(beta-D-glucopyranosyloxy)-22-hydroxyfurost-5-en-3-yl O-D-apio-beta-D-furanosyl-(1-->2)-O-[alpha-L-rhamnopyranosyl-(1-->4)]-beta-D-glucopyranoside (1) and (3beta,25R)-26-(beta-D-glucopyranosyloxy)-22-hydroxyfurost-5-en-3-yl O-D-apio-beta-D-furanosyl-(1-->4)-O-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-D-glucopyranoside (2). Their structural identifications were performed using detailed analyses of 1H and 13C NMR spectra including 2D NMR spectroscopic techniques (DEPT, COSY, HETCOR and COLOC) and chemical conversions. The steroidal saponins were evaluated for anti-inflammatory activity.

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A polysaccharide, an alpha-D-glucan with an apparent molecular weight of 6.85 x 10(4), called PSa glucan, was isolated from fresh seeds of Sorghum arundinaceum by fractionation on Sephacryl S-300 HR and Sephadex G-25. Chemical and spectroscopic studies indicated that it has a highly branched glucan type structure composed of alpha-(1-->4) linked D-glucopyranose residues with (1-->3), (1-->6) branching points, and a significant amount of alpha-(1-->6) branching to alpha-(1-->3) linked D-glucopyranose residues. The anti-inflammatory activity of the polysaccharide was performed using the capillary permeability assay.

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A new steroidal saponin was isolated from the leaves of Agave attenuata Salm-Dyck. Its structure was established as (3beta,5beta,22alpha,25S)-26-(beta-D-glucopyranosyloxy)-22-methoxyfurostan-3-yl O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->2)-O-[beta-D-glucopyranosyl-(1-->3)]-beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranoside. The structural identification was performed using detailed analyses of 1H and 13C NMR spectra including 2D NMR spectroscopic techniques (COSY, HETCOR and COLOC) and chemical conversions. The haemolytic potential of the steroidal saponin was evaluated and the anti-inflammatory activity was performed using the capillary permeability assay.

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An arabinogalactan with mean Mr of 6.85 x 10(4), was isolated from the pulps of Melocactus depressus Hook by fractionation on Sephacryl S-300 HR. Chemical and spectroscopic studies indicated that it has a branched arabinogalactan type structure composed of beta-(1-->4) linked D-galactopyranose residues with beta-(1-->3) and beta-(1-->6) branching points. Its structural features include also alpha-(1-->2), alpha-(1-->3) and alpha-(1-->5) linked L-arabinofuranose residues. The polysaccharide demonstrated a phagocytosis stimulating property.

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Descreve-se o aproveitamento do resíduo do desfibramento das folhas de Agave sislana, como um larvicida para o combate a mosquitos transmissores de doenças tropicais. Durante 24 horas, larvas de Aedes aegypti e Culex quinquefasciatus foram expostas a concentraçöes diferentes do extrato da planta para determinar as concentraçöes letais. Para aegypti foi constatada a CL50 em 322ppm e para C. quinquefasciatus em 183ppm. Foi investigada a açäo de saponinas existentes na planta, ficando evidenciado que o resíduo de sisalana é ativo através da interaçäo de vários dos seus componentes. Este extrato poderá ser utilizado em campo, na concentraçäo de 100ppm para C. quinquefasciatus com um aumento do tempo de exposiçäo para três dias, obtendo-se uma mortalidade de 100 por cento das larvas. Este produto, porém, nao é recomendado para o controle de A. aegypti, devido à necessidade de uma alta concentraçäo para a obtençäo de 100 por cento de mortalidade das larvas ao fato destas se desenvolverem preferencialmente em água potável

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A new rotenoid, named 9-demethylclitoriacetal, together with the known compounds, 11-deoxyclitoriacetal, 6-deoxyclitoriacetal, clitoriacetal and stemonal, was isolated from roots of Clitoria fairchildiana. Its structure was elucidated as 6a,12a-dihydro-6,9,11,12a-tetrahydroxy-2,3-dimethoxy-[1]benzopyrano[3,4-b] [1]benzopyran-12(6H)-one (1), on the basis of spectroscopic and chemical evidence.