The acetogenin containing members of the Annonaceae family Annona squamosa L., Annona reticulata L., and Annona muricata L are known insecticidals. The antifungal potency of these three well studied plants along with a fourth acetogenin containing member, Uvaria narum L. were put to test against the fungus Colletotrichum gloeosporioides that causes post harvest anthracnose disease in many tropical fruits. Preliminary screening formed the first part of the study where the leaves and seeds of all the four plants were extracted sequentially by soxhelet extraction in four different solvents, viz. (PE) Petroleum ether, (highly non polar), (Chl) Chloroform and (Ac) Acetone, (both medium polar) and (CH3OH) Methanol (highly polar). The obtained extracts were subjected to antifungal test by paper disc method. None of the plant extracts showed any appreciable activity except the PE and Chl extracts of Uvaria narum. Hence this plant was subjected to individual soxhelet extractions in the four above mentioned solvents. Both the above mentioned type of extracts (i.e. sequential and individual) were then subjected to inhibition studies against the same fungus using Poison food technique, in PDA (Potato Dextrose Agar Medium) and the diameter of the hyphal growth measured, to know the inhibition percentage of each extract. It was found that the chloroform and acetone extracts of Uvaria narum obtained by individual soxhelet extraction showed a 100% inhibition to the growth of fungus. The effect of the acetone extract on the fungal hyphae and spores was noted by the Scanning Electron Microscope (SEM). It revealed membrane disruptions by pore formations and putative lysis causing cytoplasmic spilling and empty hyphae.
