Supradip SahaDINESH KUMAR YADAV2017-06-272017-06-272016http://krishikosh.egranth.ac.in/handle/1/5810023543t-9395Rhizome of turmeric (Curcuma longa) is one of the richest sources of bioactive compounds. Curcuminoids, the active constituent are one of the most researched topic worldwide for its broad spectrum of biological activities. Efforts have been made to incorporate the molecules into commercial food products as a pharmaceutical and nutraceutical agent but the low bioavailability limits its application. The present study aimed at utilization of bioactive terpenoid constituents present in turmeric fixed oil for the improvement of bioavailability of curcuminoids. Turmeric fixed oil (yield 5.7% w/v) from rhizome powder was extracted with hexane and purified by column chromatography for separation of terpenoids. Purified oil mixture was analyzed by GC-MS and found three major peaks in the chromatogram. α, β- turmerone was separated together and their structure was confirmed by GC- EI-MS. ar- turmerone was separated as pure peak and characterized by mass, IR and 1H-NMR. For the separation of curcuminoids, defatted turmeric powder was extracted with ethyl acetate and the extract was purified using column chromatography, followed by prep-TLC to get individual compounds (Rf 0.78, 0.53, 0.25). Purified curcuminoids were analyzed by HPLC using RP-18 column with PDA detector (max 425 nm) under isocratic conditions using mobile phase of acetonitrile 0.1% formic acid (60:40, v/v). Three purified curcuminoids were characterized by FT-IR,1H-NMR and HRMS data. Based on spectroscopic data, the purified compounds were confirmed as 1,7-bis(4-hydroxy-3-methoxyphenyl)- 1,6-heptadiene-3,5-dione or curcumin-I (C); 1-(4-hydroxyphenyl)-7-(4-hydroxy-3- methoxyphenyl)-1,6-heptadiene-3,5-dione or curcumin-II (DC); and 1,7-bis(4- hydroxyphenyl)-1,6-heptadiene-3,5-dione or curcumin-III (BDC). The HPLC method was validated; LOD and LOQ values were calculated as 0.27, 0.33 & 0.42 µg mL-1 and 0.80, 1.00 & 1.25 µg mL-1 for C, Dc and BDC, respectively. Accelerated solvent extraction experiment was conducted using ethanol, ethyl acetate and acetone as extraction solvent, keeping homogenization technique as a control. Ethanol provided maximum physical yield (9.2 %) by ASE experiment followed by acetone (6.1 %) and ethyl acetate (5.8 %), although there is significant differences between ethyl acetate and acetone. Similarly, ethanol yielded maximum extract upon extraction by homogenization. But, opposite trend was recorded in case of acetone and ethyl acetate. No significant differences were observed in ASE as well as homogenization in terms of purity of individual curcuminoids. Antioxidant assay evaluated using DPPH and ABTS assay found that IC50 value of curcuminoids mixture were 78.8 and 145.7 µg mL-1 respectively. The antioxidant activity of three curcuminoids, followed the order C > DC > BDC in both assays. The bioavailability study was carried out individually with each curcuminoids and along with turmerones to observe their effect on bioavailability of curcumin. In-vitro study revealed that in the presence of turmerone and turmerone mixture the bioavailability of curcumin has increased 2 fold and more. The information might be useful for the development of improved bioavailable curcumin formulation.en-USImpact of turmeric terpenoids on bioavailability of curcuminThesis