Ageratum conyzoides leaves have afforded six compounds which were identified as tritriacontane, henitriacontane, 23-pentatetraacontanone, 3,4,-seco-lup- 20 (29)-en-3-OMe, 3°butyl triacosanoate and methyl tetracosanoate. All are being reported first time from this plant. The different fractions viz. hexane, benzene, ethyl acetate and methanol Ageratum conyzoides leaves were tested for their plant growth inhibitory activity against germination of radish seeds. The percent growth inhibition of radish seeds by different fractions are being reported in this paper. I. Introduction The use of botanicals for the control of insects, pests and weeds has recently advanced to a new stage. The recent frontier has moved from study of synthetic chemicals to study of the thousands of phytochemicals that may have important physiological effects. There is a broad and growing consensus that many phytochemicals found may provide a plant protection umbrella to the crops and versatile protection for human beings . Natural plant products are easily degradable, less persistent in the environment and eco-friendly. The search of plant products is unanimous choice to manage different diseases and to control the development of several herbaceous plants or weeds. Ageratum conyzoides L. (Family Asteraceae) - with common name Ajgandha, Ghandhari, Sahadevi - is an annual herb with a long history of traditional medicinal used in many countries in the world, especially in the tropical and subtropical regions (I). The plant has been used as purgative, febrifuge, treatment of ulcers and wound dressing (2). In addition to its popular use for skin diseases and wound healing, a decoction of the plant is taken to treat diarrohea and to relieve pain associated with the navel in children (3). The secondary metabolites of A. conyzoides include flavonoids, alkaloids, coumarins, essential oils and tannins. Many of these are biologically active (4). These compounds have been shown to affect insect development, as anti juvenile hormones, resulting in sterile adults (5). The research was carried out on A. conyzoides leaves in a search for new botanicals possessing good biological activity. II. Materials And Methods 1. Extraction and Isolation: Plants were collected from Landscape, CCSHAU, Hisar, in the month of March -April 2008. The plant material was washed with tap water and separated into different parts (roots, leaves and stems). The dried leaves (2.5Kg) were chopped into small pieces and put into a round bottom flask (5 L). The extraction was done by boiling with methanol (3 L) by heating the flask on a water bath. After six hours, methanol was removed and the leaves were again boiled with methanol. The procedure was repeated thrice. The methanolic extract was concentrated using distillation over a water bath under reduced pressure. The crude extract was sun dried and divided into two parts. One part (250g) was mixed with silica gel (60 - 120 mesh), again dried on a water bath and subjected to silica gel (60 - 120 mesh) column chromatography. The other part (100g) was fractionated with different solvents of increasing polarity viz. hexane, benzene and ethyl acetate. Fractions so obtained were concentrated over a water bath under reduced pressure. The obtained viscous mass was dried in sunlight for several hours and the completely dried material was used for determining the plant growth inhibitory activity against germination of radish seeds. The elution of the column was done with solvents of increasing polarity. The eluotropic series with increasing polarity comprising of petroleum ether, benzene, ethyl acetate, methanol and their mixtures were used to isolate the compounds. The column chromatography afforded six compounds labeled as L1 - L6. The characterization of compounds was done with the help of their melting point, recorded at the Ganson Electrical melting point, 1 HNMR spectra, recorded on Bruker AC-300F 300MHz NMR spectrometer in CDCl3 and DSMO-d6 using TMS as internal standard, IR spectra recorded on Hitachi 570 infrared spectrophotometer using KBr, and Mass spectra, recorded on VG-70S 11-250J GC-MS-DS mass spectrometer.
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Apr 30, 2024
Dr. Kavita Krishnamoorti 
Open Access