Abstract
Seasonal variations of strychnine and brucine in different vegetative parts of Strychnos nux-vomica were determined by HPLC. Root bark and stem bark are rich in these two alkaloids. Root wood, stem wood, and twigs are poor sources of strychnine and brucine. In the stem bark, stem wood, and leaves, the alkaloids gradually decrease in amount up to December (winter). In the root bark, there is a tendency towards a gradual increase in these alkaloids up to December.