Sunilkumar Talapatra

Bio: Sunilkumar Talapatra is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 16 citations.

The alkaloids of Rauwolfia serpentina benth

Abstract: Rauwolfia is an important genus of the plant family Apocynaceae. There are nearly one hundred and twenty‐five species of Rauwolfia which are distributed all over the tropical regions of the world (1‐8). The most important member of the genus is R. serpentina Benth; the crude drug was known to the ancient Indians as a useful febrifuge (8), a remedy for snake bite, and as a cure for dysentery. In more recent times it has been used for insomnia, hypochondria and insanity. The presence of alkaloidal principles in R. serpentina was first pointed out in 1890 by Greshoff (9). In 1933, Chopra, Gupta, and Mukherjee (10) reported the hypotensive activity of the material extracted from the plant and in 1931 Siddiqui and Siddiqui (11) isolated a series of crystalline alkaloids from R. serpentina. Active chemical and pharmacological interest in R. serpentina has resulted in the discovery of several new alkaloids (Table I). The isolation by Muller, Schlittler, and Bein (12) of reserpine, an alkaloid with pronounced hypotensive and sedative activity, has lent further impetus to the pharmacological and chemical study of the alkaloids of R. serpentha. A brief summary of the chemical aspects of R. serpentina will be presented in this review.

A spectrophotometric method for the estimation of reserpine.

Abstract: A spectrophotometric method for the estimation of reserpine in crude drugs and pharmaceutical preparations has been described. The method is capable of detecting microquantities of reserpine (0.25 μg./ml.). It is capable of estimating reserpine in crude drugs, alkaloidal mixtures, reserpine and serpentina tablets. The reserpine content in samples of Dehradun and Bengal varieties of R. serpentina has been found to be 0.117 and 0.103 per cent respectively.

Identification of novel human dipeptidyl peptidase-IV inhibitors of natural origin (Part II): in silico prediction in antidiabetic extracts.

Abstract: Background Natural extracts play an important role in traditional medicines for the treatment of diabetes mellitus and are also an essential resource for new drug discovery. Dipeptidyl peptidase IV (DPP-IV) inhibitors are potential candidates for the treatment of type 2 diabetes mellitus, and the effectiveness of certain antidiabetic extracts of natural origin could be, at least partially, explained by the inhibition of DPP-IV.

The ajmaline group of indole alkaloids.

Abstract: Publisher Summary This chapter discusses an area of indole alkaloids, which has been neglected in the series for over 30 years—namely, the ajmaline group of alkaloids, where numerous advances in chemistry and biosynthesis have been made recently. The number of known ajmaline structures has grown markedly in recent years to a present count of 77. Some of these might be artefacts and a few structures have not been convincingly determined. In addition, seven bisindole alkaloids containing at least one monomeric ajmalan unit have been isolated, increasing the total number to 84. Ajmaline alkaloids contain the polycyclic ajmalan ring system. The “biogenetic numbering” of Le Men and Taylor is used throughout the chapter. The priority sequence for the C-17 substituents in the Cahn–Ingold–Prelog system is different in the absence and presence of the COOCH, substituent at C-16. All of the ajmaline alkaloids found thus far occur in the plant family Apocynaceae. They have been recognized in the following genera Alstonia , Aspidospenna , Cabucala , Melodinus , Rauvolfia , Tonduzia (Alstonia), and Vinca .