Biotransformation of betulinic and betulonic acids by fungi.

Betulinic acid (1), a triterpenoid found in many plant species, has attracted attention due to its important pharmacological properties, such as anti-cancer and anti-HIV activities. The closely related, betulonic acid (2) also has similar properties. In order to obtain derivatives potentially useful for detailed pharmacological studies, both compounds were submitted to incubations with selected microorganisms.

Determination of the diterpenoid, kaurenoic acid, in Annona glabra by HPLC.

The isolation of ent-kaur-16-en-19-oic acid (1) from the leaves and bark of Annona glabra and its determination by reversed-phase HPLC with a photodiode array detector is described. The results indicate that 1 accumulates in the bark of the plant with only very low concentrations in the leaves. Levels of 1 varied throughout the year being highest for bark and leaves in the autumn (5.