Distribution of aloin-A in different leaves of Aloe

Aloe (Aloe barbadensis Mill.) is one of the most important herbs used in medicinal and cosmetic preparations. Aloin-A is the major active compound in aloe exudates. It is present in the rind of leaves and is commercially used in several drug preparations. A study was conducted to find out the relationship between leaf age and quality parameters such as aloin-A content, weights of leaf exudates, fresh leaf, rind and gel with a view to find out optimum stage for harvesting of leaves. The aloin-A content was estimated by HPLC method and expressed as per cent on dry weight basis. Aloin yield and weight of exudates had very high and significant correlation (r = 0.983). Highest aloin-A content was recorded in the younger leaves (20.12% in 2^nd leaf) which declined with leaf age.Weight of leaf exudates increased from 46.43 ± 5.41 to 460.88 ± 18.18 mg along with increase in leaf age. Maximum yield of the exudates (460.88 ± 18.18 mg) was obtained in the fully matured leaves (9–12 month-old). Hence, for obtaining the maximum yield of aloin-A, harvesting of leaves should be done when the leaves attain maturity, i.e. of about 9–12 month-old.