Chemical investigation on the stems of potka (grewia microcos linn) and shetodrone (leucas zeylanica linn)

Abstract

Leucas zeylanica (Labiatae) and Grewia microcos (Tiliaceae) grow allover Bangladesh. Leucas zeylanica (Labiatae) is locally .known as "Shetodrone" and Grewia microcos (Tiliaceae) is popularly known as "Potka". Both these plants are medicinally important. Leucas zeylanica is used in the countryside for the treatment of cold, headache, snake-bite, ulcer and skin diseases (Kirtikar and Basu, 1980). On the other hand, Grewia microcos is taken by the patients for the remedy of eczema, small pox, typhoid fever, dysentery and ulcer (Kirtikar and Basu, 1980). A literature survey revealed that a lot of work have been carried out on ~any species of both the genera Leucas and Grewia. But there appears no report of any work on both these plants. This fact has prompted us to investigate these plants thoroughly. Leucas Zeylanica was collected from Dinajpur and Grewia microcos was procured from the bushy area of Jahangir Nagar University campus, Savar, Dhaka. The stems of the individual plants were separated manually, dried in shade, powdered, extracted with pet ether, EtOAc, MeOR and 80% EtOR successively. The extracts of Leucas Zeylanica yielded LZFA, LZ1, LZ2, LZ3, LZ4, LZ5 and LZW. = VII = LZFA was identified as a mixture of fatty acid esters. LZl was characterized as stimastan-7,22-di-ene-3-~-01 ( 22 ). LZ2 was J identified as a new compound, 28-epoxy-stimaststan-7 ,22-di-ene-3-~- O-glucopyranoside ( 23 ). Also '~ts acetyl derivative was prepared and identified. LZ3 was identified as a stereoisomer of the compound LZ2 ( 23 ). LZ4 has been established as a 2-hydroxy-dicyclo-2,5-di-ene- 7,8-dimethyl-3-0-~-D-glucopyranoside ( 24 ). This compound is also a new one. LZ5 ~Ias not conclusively identified but assumed to be a halogenated compound ..LZW was examined by paper chromatography, and its aId ito 1 acetate derivative was analyzed by GLC. The results confirmed the presence of glucose, galactose, arabinose and xylose. The individual extracts of Grewia microcos were concentrated and subjected to chromatography ( CC, VLC and PTLC ) while the compounds GMP1, GMFA, GME2 and GMM3. were isolated in pure form. Their IR spectra were recorded and analyzed to their identification . The compound GMPl has been assumed as a triterpenoid carboxylic acid type compound on the basis of its IR spectrum and its NMR spectrum ( 60 MHz ). The techniques IR, lH-NMR, 13c NMR, 2D NMR and ElMS have been extensively used for the characterization of the compounds. Significance of the compounds has been discussed to focus their medicinal importance and their chemotaxonomic value.