THRβ-Selective Agonist Compounds for Cardiac-Sparing Lipid Control

The patent applies local quality by designing compounds with specific structural features (substituents at positions 3 and 5 of the phenyl ring, specific heterocyclic groups) that confer selective binding to THRβ over other thyroid hormone receptors and off-target receptors. This localized structural modification enables the compound to interact preferentially with THRβ while minimizing interactions with other targets, thereby reducing side effects from thyroid axis inhibition.

The patent employs parameter changes by systematically varying chemical parameters such as the type of heterocyclic group (pyridazinone, triazinone, etc.), the nature of substituents (halogen atoms, alkyl groups, alkoxy groups), and their positions on the molecular structure. These parameter modifications allow optimization of THRβ selectivity while controlling potency and reducing off-target effects, resolving the contradiction between selectivity and side effect profile.

The patent applies the taking out principle by extracting and isolating the lipid metabolism-regulating function from the cardiac effects. By designing compounds that selectively activate THRβ (the receptor subtype primarily responsible for lipid metabolism regulation) while avoiding activation of THRα (the subtype primarily involved in cardiac function), the invention separates the beneficial lipid-lowering effect from the harmful cardiac side effects, effectively taking out the desired function while leaving the harmful effects behind.

The patent uses selective THRβ agonists as intermediaries to achieve lipid metabolism regulation without directly activating cardiac pathways. These compounds serve as selective mediators that transmit the therapeutic signal for lipid metabolism improvement while blocking or avoiding the pathway that leads to cardiac side effects, thus resolving the contradiction between efficacy and safety.