The Barbaloin Content and Distribution in Aloe Arborescens Leaves According to the Leaf Part, Age, Position, and Season

Abstract

The distribution of the secondary phenolic compound, barbaloin, in Aloe arborescens leaves depends on the leaf part, age, and position of the leaf, as well as on seasonal influences. Young and old leaves of A. arborescens were cut from plants monthly and the exudate was immediately freeze-dried. The barbaloin levels were determined spectrophotometrically at λmax, 360–362 nm after separation by TLC. In all leaves the tissue of the basal third of the leaf had the lowest barbaloin content, the upper third contained the highest percentage, and the middle part contained the intermediate percentage. After cutting young leaves, the new basal part that grows after replanting has a higher barbaloin content after about five months when compared with the same part before cutting. In the 16 leaves of a cutting rooted two years before the experiment, the highest barbaloin content was found in the four upper young leaves (63%). In all the other leaves the barbaloin content was found to be only between 13 and 22%. There are also seasonal influences on the barbaloin content of young leaves. When old and young leaves were compared, the higher barbaloin content was found in the young leaves harvested at the same time.

Peripheral defence strategy: variation of barbaloin content in the succulent leaf parts of Aloe arborescens Miller (Liliaceae)

“…In previous studies it was found that in different Aloe species the barbaloin or homonataloin content was higher in younger than in older leaves (Birch & Donavan 1955;Takayulu & Toshifiumi, 1983;Nakagomi et al, 1985;Groom & Reynolds, 1987;Yamamoto et al, 1991;Chauser-Volfson & Gutterman, 1996, 1998. It has also been found that the terminal third of the leaves have the highest percentages of these secondary metabolites and the leaf base third, the lowest (Chauser-Volfson & Gutterman, 1996& Gutterman, , 1997& Gutterman, , 1998.…”

“…It has also been found that the terminal third of the leaves have the highest percentages of these secondary metabolites and the leaf base third, the lowest (Chauser-Volfson & Gutterman, 1996& Gutterman, , 1997& Gutterman, , 1998.…”

“…/zermensiS, anthrone C-glycosides in A. mutubilis and barbaloin in A. arborescens leaves. The distribution depends on the leaf part, age and position of the leaf on the plant, as well as on seasonal influences (ChauserVolfson & Gutterman, 1996& Gutterman, , 1997& Gutterman, , 1998.…”

The content of secondary phenol metabolites in pruned leaves of Aloe arborescens, a comparison between two methods: leaf exudates and leaf water extract

“…3. Squeezing the leaf tissues and freeze drying the exudates in order to separate the SPhMs from the exudates (since 1996 we as well as others have used this method in all our research) [3,5,13,15]. 4.…”

Barbaloin: A concise report of its pharmacological and analytical aspects

“…Its highest in the terminal third of the leaf, at its lowest in the basal third; higher in the terminal, adaxial, leaf margin and lower in the basal, abaxial, leaf centre [1] . The distribution of barbaloin, in Aloe arborescens leaves was shown to depend on the leaf part, age, and position of the leaf, as well as on seasonal influences [17] . Plants that are subjected to repeated leaf pruning respond by increasing the content of their secondary phenol metabolites (SPhMs).…”