Plant Material.
The initial collection (SV0477) of the leaves and twigs of Vitex leptobotrys was made in July 1999 in the Bong Center of Cuc Phuong National Park, Ninh Binh Province, Vietnam (20°21′05″ N; 105°35′39″ E; 330 m alt), from a tree 10 m in height.
A larger amount of the plant sample (SVA0477), consisting of the same plant part (leaves and twigs) (3.6 kg), was re-collected from the same tree in March 2001, for the current isolation work.
Voucher specimens (Soejarto & Cuong 10947) are deposited at the Herbarium of Cuc Phuong National Park (CPNP) and at the Field Museum (F), Chicago, IL, USA.