Isolation, structure Elucidation and Biological Activity of Chemical constituents of Some Compositae Plants

Abstract

In the three years of project, from 1.4.1990 to 31.3.1993, the following plants belonging to the family Compositae were investigated for their chemical constituents and biological activities. 1) Pluchea arguta 2) Inula grantioides 3) Blumea obliqua 4) Eclipta prostrata 5) Pluchea lanceolata All these plants possess medicinal properties. A number of plants belonging to this family are already popular for the treatment of various ailments like rheumatisms, dyspepsia, bronchitis, excessive sweating in fever, astringent, etc. and also in homeopathic medicines. The plant species mentioned above have been chosen as no information was available concerning their phytochemical investigation so far. Our aim was to investigate the chemical constituents and their biological activities. Pluchea Arguta Fifteen new sesquiterpenes have been isolated from this plant. These are pluchidione (1), pluchidinol (2), 11,12,13-trinor-3, 4-di-epicuauhtemone (3), 3’-chloro-2’-hydroxy-arguticinin (4), dideacetoxy argutin (5), deacetoxy-3’-chloro-2’hydroxy-arguticinin (6), 5α-hydroxy pluchinol (7), odontin (8), odontinin (9), odonticin, (10), odonticinin (11), pluchecin (12), 4,5-di-epicryplomeridiol (13), pluchargutin (14) and 3,4-di-epi-3’-chloro-2’-hydroxy arguticinin (15) They were separated by using different chromatographic techniques. The structure of these compounds were determined by means of spectroscopic techniques including 2D-NMR. Alongwith these new compounds, β-sitosterol, taraxasterol, taraxasterol acetate and vanillic acid are the known compounds isolated from this plant for the first time. 3’-chloro-2’-hydroxy-arguticinin (4) showed significant antimicrobial activity against klebsiella ozaenoe, Proteus vulgaris, and streptococcus lactic. ), 4,5-di-epicryplomeridiol (13) also showed antibacterial activity against P. vulgaris, S. pyogenes, S. pallosumm B. anthracis and K. ozonae, whereas the remaining compounds were inactive. The concentration used for antibacterial and antifungal activity was 1mg/ml Inula grantiodes This plant is recommended for the treatment of asthama. It has insecticidal and antibiotic properties also. Phytochemical investigation yielded three new flavones, grantioidine (16), grantionin (17), and grantioidinin (18). Their structure were determined by means of modern spectroscopic techniques. The compound (16,17,18) showed no antibacterial or antifungal activity. In addition to these nine known compounds, β-sitosterol, taraxasterol, taraxasterol acetate, lupeol, triacontanol, tocopherol-quinone, pluchidione, pectolinarigenine and salvigenin were isolated for the first time from this plant, and their identification was also confirmed by comparing them with authentic samples. Another compound with molecular formula C42H62O6 has also been isolated. Its structure elucidation is in progress. Al these compounds were separated using different chromatographic techniques Blumea obliqua From the hexane extract of the epigeal parts of B. obliqua, a new compound 5’-methyl-2-(4-isovalerylloxybut-3-inyl) dithiophene (19) was microsporum canis, Epidermophyton floccosum, Curvularia lunata and moderate against Aspergillus flavus and Stachbotrys arta in a concentration of 40µg/ml. The medium used for Sabourud dextrose agar. In addition to this some known compounds i.e. apigenin, taraxasterol, taraxasterol acetate, β-amyrin, β-sitosterol and β-amyrin acetate have also been isolated for the first time from this plant. Along with these two other compounds of molecular formula C10H16O7 and C18H20O3S2 have also been isolated and their structure elucidation is in progress. Some flavones have also been detected. Eclipta Prostrata E. prostrata is used in Ayurveda and Siddha System of medicine. Its chemical investigation using different chromatographic techniques yielded angelicaester, which shows antifungal activity against Epidermophyton floccosum, Dularium rotatim, Asperzillus niger at the concentration of 500µg/ml. Angelicaester showed significant antibacterial activity against Pseudomonas pseudomalliae, Aerumonas sobriae, Shigella boydii and Bacillus subtilus. A number of compounds were also isolated from this plant but there were already reported from the same plant. Those were as follows: Mono-, di- and trithyenylacetylene ester derivatives, wedelolactone, dimethyl wedelolactone and dimethyl wedelolactone glucoside, sitosterols, stigmasterols and some thiophenes their derivatives. Pluchea lanceolata Three known compounds namely taraxasterol acetate, β-sitosterol and α-amyrin were isolated and their identification was confirmed by comparing them with authentic samples.