76) in HMBC spectrum indicated that prenyl group
was located at C-4 of A ring.
The only difference between the chemical structure of 3-isomangostin and those of [alpha]-mangostin and [beta]-mangostin is the cyclization of the prenyl group
at the position-two carbon.
The cyclization of the C-2 prenyl group of [alpha]-mangostin to the C-2 and C-3 substituted chromene ring as seen in mangostanol and 3-isomangostin significantly reduced the AChE (p < 0.
In addition, a hydrogen bond was formed between the prenyl group at C-8 of garcinone C and His 440 of the AChE catalytic site.
These results lead to a hypothesis that prenyl group might be crucial to exhibit the activity.
The difference is isobavachin has a prenyl group at C-8, while bavachin at C-6.
SAR, involved in various biological activities, depends on the number and position of different side chains and functional groups (such as prenyl group
, hydroxyl groups and methoxy groups).
The formation of the furan ring with the prenyl group
at C-2 or C-4 gives linear or angular dihydrofuroquinolines or pyranoquino-lines (Gray 1993; Mester 1983).
In contrast, in bitucarpin A both positions 3 and 9 are methoxylated, while there is just a single prenyl group at position 4.
2002) and to the presence and arrangement of hydroxyl/methoxyl and prenyl group substituents on ring A and B of the molecules (Miranda et al.
50] value displayed is dependent of prenyl groups and phenolic hydroxyls number, and inversely proportional to the hydrophobicity.
Thus, the compound (1), the more lipophylic compound was the more active on both forms of protozoan Leishmania, due to the presence of four prenyl groups.