Evaluation of antifungal and DNA-damaging activities of alkaloids from branches of Porcelia macrocarpa.

Bioactivity-guided fractionation of the alkaloidal fractions of the CH2Cl2 extract from branches of Porcelia macrocarpa using mutant yeast strains of Saccharomyces cerevisiae and fungi Cladosporium cladosporioides and C. sphaerospermum led to the isolation of bioactive alkaloids: two tetrahydrobenzylisoquinolines (1 and 2), two aporphines (3 and 4), one proaporphine (5), one oxoaporphine (6), four azantraquinones (7-10) and four azafluorenones (11-14). The alkaloids cleistopholine (7) and 6-methoxycleistopholine (8) showed the highest fungitoxic activity while the mixture of 6- and 7-methoxyonychine (12+13) and 6,7-dimethoxyonychine (14) showed a weak DNA-damaging potential.