Two new triterpenoid saponins from the flowers of Albizia lebbeck.

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.

Structural characterization of a complex triterpenoid saponin from Albizia lebbeck and investigation of its permeability property and supramolecular interactions with membrane constituents.

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.

The effect of a single dose versus a daily dose of cholecalciferol on the serum 25-hydroxycholecalciferol and parathyroid hormone levels in the elderly with secondary hyperparathyroidism living in a low-income housing unit.

We designed a randomized, double-blind, controlled clinical trial to compare the effect of two regimens for administering cholecalciferol on the serum 25-hydroxycholecalciferol [25(OH)D] levels and in the reversion of secondary hyperparathyroidism in the elderly living in a low-income housing unit in the city of Porto Alegre, southern Brazil. We studied 28 individuals ranging in age from 65 to 102 years with serum parathyroid hormone (PTH) levels greater than 48 pg/ml and normal or reduced serum calcium levels. Subjects were randomized to receive oral cholecalciferol, as a single dose of 300 000 IU (group 1) or 800 IU (group 2) daily for 9 months. Both groups received 1250 mg calcium carbonate per day. Serum 25(OH)D and PTH levels were measured at baseline and after 1, 2, 3, 6, and 9 months. Serum 25(OH)D levels in group 1 were significantly higher than in group 2 during the study (P < 0.001). After 1 (P < 0.001) and 2 (P < 0.04) months of treatment, mean serum 25(OH)D levels were higher in group 1. The number of subjects who reached serum 25(OH)D levels >/=20 ng/dl was higher in group 1, after the first (P < 0.001) and third (P = 0.008) months. In the short term, a single 300 000 IU oral dose of vitamin D(3) was more effective than 800 IU per day to increase serum 25(OH)D levels in elderly persons, living in a low-income housing unit, who were taking 500 mg elementary calcium supplement per day.