Intramolecular 5-endo-trig aminomercuration of β-hydroxy-γ-alkenylamines: efficient route to a pyrrolidine ring and its application for the synthesis of (+)-castanospermine and analogues

The intramolecular aminomercuration reaction of sugar-derived β-hydroxy-γ-alkenylamines 8a-c undergoes 5-endo-trig cyclization in high yield. The sugar-substituted pyrrolidines thus obtained were elaborated to the synthesis of polyhydroxylated indolizidine alkaloids, namely, castanospermine 1a, 1-epi-castanospermine 1b, and 8a-epi-castanospermine 1c, having promising glycosidase inhibitory activities

A cross-sectional study of the sociodemographic profile of juveniles under institutional care in the city of Mumbai

Objectives: To study the sociodemographic profiles of children under institutional care, identify the characteristic features of the families prone to have destitute children, and suggest measures for prevention of destitution of children in the community. Material and Methods: A questionnaire-based cross-sectional study was conducted in a population of 507 boys and girls from 6 to 18 years admitted to four different institutes for care and support. A sample of 170 children was selected using systematic random sampling technique. A survey was done to study the health status of the children. Data was analyzed using SPSS software. Frequency and proportion were calculated and chi square test was used. P value of >0.05 was considered significant. Results: 65.9% of children were in the 6 to 12 age group. 63.5% were Hindu by religion. The majority i.e., 80.9% of the boys and 80% of the girls were urban in origin, 82.4% of the juveniles were from nuclear families, 40.0% of boys and 62.3% of the girl juveniles were from lower socioeconomic status. 75% of boys and 25% of the girls had been child laborers just before institutionalization. Only 12.7% of juveniles were from large families, the rest, the majority (87.3%) were from medium to small sized families. Conclusions: Nuclear families of medium to small size which belong to the lower socioeconomic status and of urban origin were found to be unable to provide care and support to their children putting them at the risk of becoming destitute

Phytochemical analysis and free radical scavenging activity of medicinal plants Gnidia glauca and Dioscorea bulbifera.

Gnidia glauca and Dioscorea bulbifera are traditional medicinal plants that can be considered as sources of natural antioxidants. Herein we report the phytochemical analysis and free radical scavenging activity of their sequential extracts. Phenolic and flavonoid content were determined. Scavenging activity was checked against pulse radiolysis generated ABTS(•+) and OH radical, in addition to DPPH, superoxide and hydroxyl radicals by biochemical methods followed by principal component analysis. G. glauca leaf extracts were rich in phenolic and flavonoid content. Ethyl acetate extract of D. bulbifera bulbs and methanol extract of G. glauca stem exhibited excellent scavenging of pulse radiolysis generated ABTS(•+) radical with a second order rate constant of 2.33 × 10(6) and 1.72 × 10(6), respectively. Similarly, methanol extract of G. glauca flower and ethyl acetate extract of D. bulbifera bulb with second order rate constants of 4.48 × 10(6) and 4.46 × 10(6) were found to be potent scavengers of pulse radiolysis generated OH radical. G. glauca leaf and stem showed excellent reducing activity and free radical scavenging activity. HPTLC fingerprinting, carried out in mobile phase, chloroform: toluene: ethanol (4: 4: 1, v/v) showed presence of florescent compound at 366 nm as well as UV active compound at 254 nm. GC-TOF-MS analysis revealed the predominance of diphenyl sulfone as major compound in G. glauca. Significant levels of n-hexadecanoic acid and octadecanoic acid were also present. Diosgenin (C₂₇H₄₂O₃) and diosgenin (3á,25R) acetate were present as major phytoconstituents in the extracts of D. bulbifera. G. glauca and D. bulbifera contain significant amounts of phytochemicals with antioxidative properties that can be exploited as a potential source for herbal remedy for oxidative stress induced diseases. These results rationalize further investigation in the potential discovery of new natural bioactive principles from these two important medicinal plants

Diosgenin from <i>Dioscorea bulbifera</i>: Novel Hit for Treatment of Type II Diabetes Mellitus with Inhibitory Activity against α-Amylase and α-Glucosidase

<div><p>Diabetes mellitus is a multifactorial metabolic disease characterized by post-prandial hyperglycemia (PPHG). α-amylase and α-glucosidase inhibitors aim to explore novel therapeutic agents. Herein we report the promises of <i>Dioscorea bulbifera</i> and its bioactive principle, diosgenin as novel α-amylase and α-glucosidase inhibitor. Among petroleum ether, ethyl acetate, methanol and 70% ethanol (v/v) extracts of bulbs of <i>D. bulbifera</i>, ethyl acetate extract showed highest inhibition upto 72.06 ± 0.51% and 82.64 ± 2.32% against α-amylase and α-glucosidase respectively. GC-TOF-MS analysis of ethyl acetate extract indicated presence of high diosgenin content. Diosgenin was isolated and identified by FTIR, ¹H NMR and ¹³C NMR and confirmed by HPLC which showed an α-amylase and α-glucosidase inhibition upto 70.94 ± 1.24% and 81.71 ± 3.39%, respectively. Kinetic studies confirmed the uncompetitive mode of binding of diosgenin to α-amylase indicated by lowering of both Km and Vm. Interaction studies revealed the quenching of intrinsic fluorescence of α-amylase in presence of diosgenin. Similarly, circular dichroism spectrometry showed diminished negative humped peaks at 208 nm and 222 nm. Molecular docking indicated hydrogen bonding between carboxyl group of Asp300, while hydrophobic interactions between Tyr62, Trp58, Trp59, Val163, His305 and Gln63 residues of α-amylase. Diosgenin interacted with two catalytic residues (Asp352 and Glu411) from α-glucosidase. This is the first report of its kind that provides an intense scientific rationale for use of diosgenin as novel drug candidate for type II diabetes mellitus.</p></div

Percent crude murine pancreatic amylase inhibition by plant extracts and isolated compound D.

<p>Acarbose is taken as standard inhibitor. The data is indicated as the mean SEM; [<i>n</i>  =  3].</p

Quenching of intrinsic fluorescence of porcine pancreatic α-amylase bound to isolated compound D.

<p>Quenching of intrinsic fluorescence of porcine pancreatic α-amylase bound to isolated compound D.</p

Binding of diosgenin to α-glucosidase active pocket.

<p>(a) Depicts docked conformation of diosgenin with yeast alpha glucosidase (3AXI.pdb), (b) hydrogen bonding and hydrophobic interactions from alpha glucosidase-diosgenin inhibitor complex.</p

Kinetic analysis of porcine pancreatic α-amylase inhibition by isolated compound D by Lineweaver–Burk plot with starch as substrate.

<p>Kinetic analysis of porcine pancreatic α-amylase inhibition by isolated compound D by Lineweaver–Burk plot with starch as substrate.</p

Percent <i>α</i>-amylase inhibition by plant extracts and isolated compound D.

<p>Acarbose is taken as standard inhibitor. The data is indicated as the mean SEM; [<i>n</i>  =  3].</p