Abstract: Azadirachta indica A. Juss. (neem) is a source of several bioactive components, however only Azadirachtins have been commercially exploited. A quantitative HPLC analysis of the components present in an aqueous extract of powdered neem leaves prepared in the traditional manner was undertaken. This study indicate that aqueous extracts contain Azadirachtin A, B, D, H, I, Desacetylnimbin, Azadiradione, Nimbin, Salanin, Azadirone, Nimbolin, Nimbinene, Nimbolide. Neem leaves extract have been used for pesticide, fertilizer, corrosion inhibition and biosorbent for dyes.
INTRODUCTION
Neem (Azadirachta indica A. Juss.) plant has been used extensively in Asian and African subcontinent mainly to tap its medicinal and agrochemical properties since ancient times (srivastava and Prakash, 2006).
Neem (Azadirachta indica A. Juss) is a large, evergreen, hardy tree, native to the Indian sub-continent (Usher, 1984; Chari, 1996; Gajalakshmi, 2002). It grows easily and survives even on dry, nutrient-lean soils (Pundt, 2000). It has been popular, even revered, in the Indian sub-continent. It is friendly to other vegetation but repels insects (Arora, 1996; Kumar, 2002). Its leaves and fruit-both exceedingly bitter-are known to possess fungicidal and nematicidal properties (Schmutterer, 1995; Parveen and Alam, 1996; Pundt, 2000). In recent years, neem has attracted global attention due to its potential as a source of natural drugs and also environment-friendly pesticides (Schmutterer, 1995; Agarwal, 1996; Alam, 1996; Randhawa and Parmar, 1996; Mulla and Su, 1999; Joshi and Lockwood, 2000; Daniel, 2000; Kumar, 2002; Gajalakshmi and Abbasi, 2004). But, one major problem is what does the compounds in neem leaves extraction?
The present study was initiated to investigate quantitative triterpenoids composition of neem.
MATERIALS AND METHODS
The leaves of Azadirachta indica were collected in June 2006 from Lar, Iran and identified by assistant professor Dr. F. Mortazaienezhad, Department of Horticulture, Azad University, Khorasgan Branch.
Powdered neem leaves (5 kg) were taken in a cotton cloth bag, placed in a vessel containing (10 L) water and soaked overnight. The water layer was decanted and the bag was completely squeezed in a hand press to give the aqueous extract and then soaked in MeOH overnight. The MeOH extract was filtered and solvent removed to yield a viscous liquid the extract subjected to HPLC analysis for the estimation of components.
RESULTS AND DISCUSSION
Results in Table 1 indicate that aqueous extract of neem
leaves contain bioactive compounds for insect control, antioxidant activity,
biosorbent for dyes, fertilizer and corrosion inhibition. The major bioactive
compounds in neem leaves extracts are Salanin, Nimbin, Azadirone and Azadirachtins.
There was no correlation of either Nimbin or Salanin to Azadirachtin concentration
(Behl et al., 2004). All of compounds in Table 1 are
active as insect control but the most active ones are Azadirachtin A, Azadirachtin
B and Salanin.
| Table 1: | Components in the aqueous extract of neem leaves |