University of Madras

About: University of Madras is a education organization based out in Chennai, Tamil Nadu, India. It is known for research contribution in the topics: Ring (chemistry) & Lipid peroxidation. The organization has 8496 authors who have published 11369 publications receiving 211152 citations. The organization is also known as: Madras University & University of Chennai.

Beneficial effects of Momordica charantia seeds in the treatment of STZ-induced diabetes in experimental rats.

Abstract: The aim of the present study was to evaluate the effect of the aqueous extract of seeds of two varieties, namely a country and hybrid variety of Momordica charantia (MCSEt1 and MCSEt2) on oxidative stress in plasma and pancreas of streptozotocin (STZ) induced diabetic rats. Oral administration of each of the seed extracts at a dosage of 150 mg/kg body weight for 30 d resulted in a significant reduction in plasma glucose, thiobarbituric acid-reactive substances, lipid-hydroperoxides, alpha-tocopherol and significant improvement in ascorbic acid, reduced glutathione and insulin. The treatment also resulted in a significant reduction in thiobarbituric acid reactive substances, lipid-hydroperoxides, superoxide dismutase, catalase, glutathione peroxidase and significant improvement in reduced glutathione in pancreas of drug treated diabetic rats when compared to the untreated diabetic rats. On the basis of results obtained, it may be concluded that the treatment of Momordica charantia seed varieties may effectively normalize the impaired oxidative stress in streptozotocin induced-diabetes than the glibenclamide treated groups.

Studies on the conformation of amino acids. VI. Conformation of the proline ring as observed in crystal structures of amino acids and peptides.

Abstract: The paper deals with an analysis of the available crystal structure data related to proline compounds so as to obtain information about bond lengths, bond angles, and the conformation of the pyrrolidine ring. The interesting results are: 1. The atoms Cβ, Cα, N, and Cs are nearly coplanar, with the torsion angle 0 about the Cα - N bond varying from about -15° to -15°. The Cγ atom is displaced from this plane, either up or down, so that the ring exists in one of the two puckered conformations, designated A and B. Conformation A is characterized by negative and may be termed Cγ-exo when referred to the displacement of the carbonyl carbon C. Conformation B has positive x l and is Cγ-endo; Cγ-exo is slightly preferred over C-endo, although both conformations occur simultaneously in some crystal structures with partial probabilities. In the other structures, the non-occurring position for C y is found to be disallowed by intermolecular contacts. The proline conformations observed correspond to the 'envelope' type of conformation of the cyclopentane ring. In peptides, the three bonds at N are nearly coplanar, and the torsion about N- Cα bond is nearly - 60°. 2. The observed ranges of (x 1 , x 2 , x 3 , x 4 ) are (0 to –30°, 15 to 50°, –15 to - -30°, 5 to 25°) for conformation A and (20 to 35 0 , -30 to - 40 0 , 20 to 35°, 5 to -20°) for conformation B; for θ and φ the ranges are -15° to -15°, -45 to -75°. The bond lengths and bond angles are not influenced by the conformation of the ring, unlike ribose.