Studies on α-glucosidase inhibition and anti-glycation potential of Iris loczyi and Iris unguicularis.

AIMS: One of the aims of this research work is the isolation and identification of various constituents of two medicinally important plants (Iris loczyi and Iris unguicularis). Secondly, the prime aim is the biological evaluation of these natural products to discover new potential inhibitors of α-glucosidase enzyme and protein glycation. MAIN METHODS: Plants of the genus Iris contain a variety of secondary metabolites. Chromatographic techniques were applied for the isolation of different compounds from Iris loczyi and Iris unguicularis. All the isolated compounds were screened for their α-glucosidase enzyme inhibition and antiglycation potential. KEY FINDINGS: It is shown in the results that two compounds (Kaempferol and 8-Methoxyeriodictyol) isolated from plant Iris unguicularis and compounds (Arborinone and 5,7-dihydroxy-2',6-dimethoxyisoflavone) isolated from plant Iris loczyi possess promising activity against α-glucosidase enzyme as compare to acarbose which is used as a standard α-glucosidase inhibitor in this study. A flavanone (2',5-dihydroxy-6,7-methylenedioxy) isolated from Iris loczyi was explored as most active anti-glycating agent. SIGNIFICANCE: α-Glucosidase enzyme is a therapeutic target to treat carbohydrate mediated diseases. In this study various inhibitors of α-glucosidase are identified which might be important for the management of diabetes. Similarly, antiglycation agents may have application for the management of late diabetic complications.

Flavonol Glycosides from Euphorbia microsciadia Bioss. with their Immunomodulatory Activities.

FOUR KNOWN FLAVONOIDS: quercetin 3-O-ß-D-rutinoside (Q3Rut), myricetin 3-O-ß-D-galactopyranoside (M3Gal), quercetin 3-O-ß-D-galactopyranoside (Q3Gal) and quercetin 3-O-ß-D-glucopyranoside (Q3Glc), for the first time were isolated from aerial parts of Euphorbia microsciadia. The chemical structure of them was elucidated on the basis of 1 and 2 D-NMR spectra and different spectroscopic techniques. The immunomodulatory activities of isolated compounds were compared using standard T-cell proliferation assay. These data showed that lymphocyte suppression activity of flavonoids (1-4) were comparatively lower than prednisolon as a standard drug. Immunosuppressive activity of flavonoids with hydroxyl groups at both 3'-and 4'-positions in their B-ring (Q3Gal) were more than those with 3'-,4'-and 5'-hydroxyl substitution (M3Gal). In these compounds, Q3Gal showed the most inhibitory activity, whereas M3Gal showed the least lymphocyte antiprolifeartive activity.

A benzil and isoflavone from Iris tenuifolia.

Two compounds, tenuifodione (1) and tenuifone (2), and 12 known compounds, izalpinin (3), alpinone (4), arborinone (5), irilin B (6), irisone A (7), irisone B (8), betavulgarin (9), beta-sitosterol (10), 5,7-dihydroxy-2',6-dimethoxyisoflavone (11), 2',5-dihdroxy-6,7-methylenedioxy flavanone (12), irisoid A (13) and ethyl-beta-d-glucopyranoside (14) were isolated from the whole plant of Iris tenuifolia Pall. All compounds, except 12, were isolated for the first time from this plant. Compounds 2, 3 and 11 have shown a considerable DPPH radical scavenging activity. Structures of these compounds were identified on the basis of spectroscopic techniques, including 2D NMR. Compounds 3, 5 and 7 were also subjected to single-crystal X-ray diffraction analysis and their structures were unambiguously deduced.