Leaf exudate of A. marlothii (2 g) was taken up in
MeOH, which upon concentration gave 1.6 g of a yellow mixture. This was subjected to ¯ash CC over silica
gel eluting with EtOAc and MeOH gradients. The
polar frs were further puri®ed by prep. TLC which
resulted in the isolation of 1 (120 mg), 2 (95 mg) and 4
(50 mg).
The dried leaf exudate of A. rupestris (ca. 14 g) when
extracted with Me2CO yielded 6.6 g of acetone soluble
portion, 2.2 g of which was subjected to ¯ash CC over
silica gel, eluting with CH2Cl2 and MeOH gradients.
Monitoring the separation with TLC and combining the
frs in which a substance with R
f 0.2 (Solvent system I)
was the major component, and recrystalization from
MeOH gave 260 mg of colourless needle-shaped crystals
of 3. The last two frs were further puri®ed by prep. TLC
to yield compound 5 (100 mg).