Structure-guided optimization of a series of C-5 alkyl substituents led to the discovery of a potent nicotinic acid receptor agonist SCH 900271 (33) with an EC₅₀ of 2 nM in the hu-GPR109a assay. Compound 33 demonstrated good oral bioavailability in all species. Compound 33 exhibited dose-dependent inhibition of plasma free fatty acid (FFA) with 50% FFA reduction at 1.0 mg/kg in fasted male beagle dogs. Compound 33 had no overt signs of flushing at doses up to 10 mg/kg with an improved therapeutic window to flushing as compared to nicotinic acid. Compound 33 was evaluated in human clinical trials.

中文翻译：

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发现 SCH 900271，一种用于治疗血脂异常的强效烟酸受体激动剂

一系列 C-5 烷基取代基的结构引导优化导致在 hu-GPR109a 测定中发现了有效的烟酸受体激动剂 SCH 900271 ( 33 )，其 EC ₅₀为 2 nM。化合物33在所有物种中均表现出良好的口服生物利用度。在禁食的雄性比格犬中，化合物33在 1.0 mg/kg 时表现出对血浆游离脂肪酸 (FFA) 的剂量依赖性抑制，FFA 减少 50%。化合物33在高达10mg/kg的剂量下没有明显的潮红迹象，与烟酸相比具有改善的潮红治疗窗。在人体临床试验中评估了化合物33。