To increase the tumor uptake of Val-Gly-Gly (VGG), adenine was introduced into the peptide. N-mercaptoacetyl-VGG-adenine (MAVGG-adenine)
and MAVGG were labeled with 99mTc using a solution of SnCl2 and tartaric acid as reducing agent. Biodistribution in mice bearing the S180 tumor was measured and γ imaging was performed.
Compared with MAVGG, adenine conjugated MAVGG had higher tumor uptake and tumor to normal tissue ratios, which suggested that
the tumor uptake property of a peptide may be improved by introducing a nucleotide base. The high contrasted tumor images
of 99mTc-MAVGG-adenine also suggested its potential utility as tumor imaging agent.