RE:RE:RE:GBMTaken from an old discussion on transition metal complexes & PDT.
Considering the potency of TLD1633, it may seem odd that TLD1433 was selected instead. TLD1433 was prioritized over the other compound for a number of reasons, including: (1) there were more synthetic steps required for producing TLD1633, and those steps were low yielding (unoptimized at that time) and required expensive catalysts, (2) there was more batch-to-batch variability with TLD1633, (3) the theranostic capacity of TLD1433 was greater (i.e., its luminescence quantum yield was higher), and (4) we were relatively far along in our pre-clinical studies with TLD1433 by the time the synthesis of TLD1633 was optimized to produce the larger batches required for in vivo studies.