1. BSc in Organic Chemistry , GAUHATI UNIVERSITY , 1989

2. MSc in Organic Chemistry , Gauhati University , 1992

3. PhD: Gauhati University , Title: Characterization Of Carotenoids in Red Algae and The Culture of Selected Algae, 2015

1. ABSTRACT Saponification of carotenoid esters leads to decomposition at high temperature and high concentration of alkali. Lutein ester is collected from marigold flower. The saponification of purified lutein ester is studied at different parameters using UV-visible spectrophotometer, HPLC. Findings showed efficient saponification in 0.5 M KOH at 500C for 30minutes. Keywords: Lutein ester, Saponification, HPLC. www.scholarsresearchlibrary.Available online at com Scholars Research Library Annals of Biological Research, 2012, 3 (3):1461-1466 (http://scholarsresearchlibrary.com/archive.html)

1. ABSTACT Algae are a rich source of carotenoids. Carotenoids from algae can be used as a food colorant, food additive, cosmetics, antioxidants and nutraceuticals etc. Selection of solvents for extraction of carotenoid from algae is a tedious job and is generally carried out in organic solvent. In this study, different solvents ranging from organic to aqueous and their mixture were used to achieve the maximum extractability of total carotenoids. The extracted total carotenoids were estimated using UV- visible spectrophotometer and identified by Reversed Phase High Performance Liquid Chromatography (RPHPLC). Key words: Algae, carotenoid, antioxidant, UV-visible spectrophotometer, HPLC. Available online at www.pelagiaresearchlibrary.com Pelagia Research Library Asian Journal of Plant Science and Research, 2012, 2 (4):546-549 ISSN

1. Retinoic acid is highly effective against photo aging. But its carboxyl end group results in a number of side effects. To overcome this difficulty an attempt has been made to develop a derivative of retinoic acid without carboxyl group using 3,4-didehydroretinol. 3,4-Didehydroretinol is purified from a natural source of Wallago attu fish liver. Both retinoic acid and didehydroretinol are allowed to react in presence of N,N-carbonyl diimidazole and dimethyl amino pyridine. The yield of the purified product retinyl retinoate is 55% with respect to didehydroretinol. The purified product is characterised with the help of UV-visible spectrophotometer, HPLC, LC-MS and NMR spectra. It is a new hybrid compound containing both retinoic acid and didehydroretinol. Keywords: Retinoic acid, 3,4-didehydroretinol, retinyl retinoate, HPLC, LC-MS. Indian Journal of Chemistry Vol. 53B, January 2014, pp. 111-114

1. Retinoic acid is highly effective against photo aging. But its carboxyl end group results in a number of side effects. To overcome this difficulty an attempt has been made to develop a derivative of retinoic acid without carboxyl group using 3,4-didehydroretinol. 3,4-Didehydroretinol is purified from a natural source of Wallago attu fish liver. Both retinoic acid and didehydroretinol are allowed to react in presence of N,N-carbonyl diimidazole and dimethyl amino pyridine. The yield of the purified product retinyl retinoate is 55% with respect to didehydroretinol. The purified product is characterised with the help of UV-visible spectrophotometer, HPLC, LC-MS and NMR spectra. It is a new hybrid compound containing both retinoic acid and didehydroretinol. Keywords: Retinoic acid, 3,4-didehydroretinol, retinyl retinoate, HPLC, LC-MS. Indian Journal of Chemistry Vol. 53B, January 2014, pp. 111-114

1. Retinoic acid is highly effective against photo aging. But its carboxyl end group results in a number of side effects. To overcome this difficulty an attempt has been made to develop a derivative of retinoic acid without carboxyl group using 3,4-didehydroretinol. 3,4-Didehydroretinol is purified from a natural source of Wallago attu fish liver. Both retinoic acid and didehydroretinol are allowed to react in presence of N,N-carbonyl diimidazole and dimethyl amino pyridine. The yield of the purified product retinyl retinoate is 55% with respect to didehydroretinol. The purified product is characterised with the help of UV-visible spectrophotometer, HPLC, LC-MS and NMR spectra. It is a new hybrid compound containing both retinoic acid and didehydroretinol. Keywords: Retinoic acid, 3,4-didehydroretinol, retinyl retinoate, HPLC, LC-MS. Indian Journal of Chemistry Vol. 53B, January 2014, pp. 111-114