Biological evaluation of a phosphate ester prodrug of 10-methyl-aplog-1, a simplified analog of aplysiatoxin, as a possible latency-reversing agent for HIV reactivation.

10-Methyl-aplog-1 (10MA-1), a simplified analog of aplysiatoxin, exhibits a high binding affinity for protein kinase C (PKC) isozymes with minimal tumor-promoting and pro-inflammatory activities. A recent study suggests that 10MA-1 could reactivate latent human immunodeficiency virus (HIV) in vitro for HIV eradication strategy. However, further in vivo studies were abandoned by a dose limit caused by the minimal water solubility of 10MA-1. To overcome this problem, we synthesized a phosphate ester of 10MA-1, 18-O-phospho-10-methyl-aplog-1 (phos-10MA-1), to improve water solubility for in vivo studies. The solubility, PKC binding affinity, and biological activity of phos-10MA-1 were examined in vitro, and the biological activity was comparable with 10MA-1. The pharmacokinetic studies in vivo were also examined, which suggest that further optimization for improving metabolic stability is required in the future.

AI and computational chemistry-accelerated development of an alotaketal analogue with conventional PKC selectivity.

The protein kinase C (PKC) family consists of ten isozymes and is a potential target for treating cancer, Alzheimer's disease, and HIV infection. Since known natural PKC agonists have little selectivity among the PKC isozymes, a new scaffold is needed to develop PKC ligands with remarkable isozyme selectivity. Taking advantage of machine-learning and computational chemistry approaches, we screened the PubChem database to select sesterterpenoids alotaketals as potential PKC ligands, then designed and synthesized alotaketal analogues with a different ring system and stereochemistry from the natural products. The analogue exhibited a one-order higher affinity for PKCα-C1A than for the PKCδ-C1B domain. Thus, this compound is expected to serve as the basis for developing PKC ligands with isozyme selectivity.