Synthetic and mechanistic investigations of analogues of bryostatin 1

Bryostatin 1 is a potent anti-cancer natural product capable of eliciting other favorable responses, such as cell differentiation, immune system stimulation, synergy with other therapeutic agents, and radioprotection. These effects can likely be attributed to the extraordinary, nanomolar binding affinity of bryostatin 1 to proteins containing C1 domains, such as protein kinase C (PKC). The supply of the bryostatins and their derivatives for the purposes of mechanistic and therapeutic investigations is hampered by their low natural abundance and structural complexity, which renders their synthesis lengthy and inefficient. Moreover, bryostatin 1 was not fundamentally designed by nature as an anti-cancer drug, and thus is unoptimized for use in humans. It would, therefore, be preferable to achieve efficient and flexible access to analogues of bryostatin 1, whose structures could be optimized for therapeutic performance.; The synthesis of a second-generation analogue of this type is described. This analogue outperformed the natural product in binding and cellular assays. In addition, the access of this analogue is more efficient and more cost effective than access of the natural product. Next, the synthesis of a novel class of bryostatin macrolactam analogues was undertaken in an effort to enable systematic steric and electronic optimization of analogue performance and to facilitate clinical development. A concise and flexible approach to these analogues was developed, however, these analogues were ultimately found to be inactive in binding assays, and in one case, unstable. Additionally, a translocation assay of fluorescently tagged PKC isotypes as a rapid screen for bryostatin analogues was developed. Significantly, it was found that the functionality and steric bulk present in the spacer domain of the bryostatins and their analogues influence the isotype selectivity and rate of PKC translocation. Finally, progress toward a dimeric bryostatin analogue whose design was guided by the results of this translocation assay is discussed. This project was progressed to a very advanced stage and enabled the development of a novel coupling strategy.; The results from these synthetic and mechanistic investigations should be useful in the design and development of future analogues.