ALOE PLANTS ACCUMULATE ANTHRONE-TYPE ANTHRANOIDS IN INFLORESCENCE ANDLEAVES, AND TETRAHYDROANTHRACENES IN ROOTS

The accumulation and distribution of characteristic secondary products in the different organs of an Aloe plant (A. succotrina Lam.) were st udied by high performance liquid chromatography for the first time. In the leaves of the Aloe plant, only anthrone-C-glycosyls of the 7-hydr oxyaloin type and, for the first time in plant material, the free anth raquinone 7-hydroxyaloeemodin were found. In contrast to previous repo rts on the distribution of secondary products in Aloe plants, anthrone -C-glycosyls were also detected in flowers, bracts and the inflorescen ce axis of the species examined. Aloesaponol I, a tetrahydroanthracene aglycone, was only present in the underground organs and in the stem. The 2-alkylchromone-C-glucosyl aloeresin B showed no specific occurre nce as it was found in every type of organ. Based on these results and the findings of recent studies on Aloe roots and flowers, a distribut ion scheme of polyketide types in the Aloe plant was established. It s uggests a separate and independent anthranoid metabolism for undergrou nd Aloe organs and stem on the one hand, and for leaves and infloresce nce organs on the other hand. In the latter structures anthranoid meta bolism seems to be additionally compartmentalized as the anthranoid pr ofiles of inflorescence organs and leaves differ in two points relevan t to anthranoid biosynthesis: firstly, the occurrence of anthrone agly cones and secondly, the individual content of corresponding anthrone-C -glucosyl diastereomers.