• S R Gupta

      Articles written in Proceedings – Section A

    • A study of apiin from the parsley seeds and plant

      S R Gupta T R Seshadri

      More Details Abstract Fulltext PDF

      An effective method for purifying apiin from parsley seeds is to convert it into the lead salt and recover it by decomposition with hydrogen sulphide. It then crystallises readily from alcohol and yields a crystalline acetate. The work on the complete methylation and hydrolysis has been revised using the pure sample and also purifying the methylated glycoside obtained as intermediate. The resulting 5:4′-o-dimethyl apigenin is found to melt correctly at 297–8° as mentioned by Bakeret al. Even the impure sample obtained earlier from crude apiin can be purified through its acetate, and then its melting point is found to be higher as mentioned above.

      Extraction of the parsley plant grown in Delhi yielded only apiin as the anthoxanthin component and the presence of luteolin glycoside reported by von Gerichten could not be detected.

    • Nuclear oxidation in flavones and related compounds - Part XLIII. The preparation andp-oxidation of flavones analogous to datiscetin and morin

      S R Gupta T R Seshadri

      More Details Abstract Fulltext PDF

      The synthesis of 5∶7∶2′-trihydroxy and 5∶7∶2′∶4′-tetrahydroxy flavones has been repeated using Allan-Robinson condensation and both hydriodic acid and anhydrous aluminum chloride as demethylating agents. With these reagents and under ordinary conditions isomeric change involving the 2′-hydroxyl group does not occur. The tetrahydroxy flavone has also now been prepared by the procedure of Algaret al. The sample is found to be identical with the one obtained by the method of Robinson and Venkataraman and is different from lotoflavin. The nuclear oxidation of the partial methyl ethers of the two flavones has been carried out using alkaline persulphate.

  •  

© 2021-2022 Indian Academy of Sciences, Bengaluru.