Multisite Occupancy and Multidimensional Optimization: Design and Evaluation of Piperazine-Thioureidobenzamide Derivatives as Potent HBV Capsid Assembly Modulators

Hepatitis B virus (HBV) capsid assembly modulators are
a promising
class of agents for chronic HBV infection. Thioureidobenzamide compound 17i exhibits potent anti-HBV activity but suffers from poor
water solubility, high cytotoxicity, and limited drug-like properties.
Herein, we report the design of piperazine-thioureidobenzamide derivatives
via multisite occupancy and multidimensional optimization strategies.
The representative compound 35a exhibited potent anti-HBV
activity and low cytotoxicity in HepAD38 cells (EC50 =
0.020 μM, CC50 > 100 μM) and HLCZ01 cells
(EC50 = 0.024 μM, CC50 > 100 μM).
Molecular
dynamics simulations revealed that 35a retained critical
hydrogen bonds with Trp-102, Thr-128, and Leu-140, while forming new
hydrogen bonds with Ser-106, Thr-142, and Asn-136. Multidimensional
optimization endowed 35a with improved solubility, ideal
LogP and high plasma stability. In HBV carrier mouse models, 35a inhibited viral replication more effectively than 17i, highlighting its potential as a promising candidate drug
for further development.