Antagonists for the serotonin receptor 2B (5-HT_2B) have clinical applications towards migraine, anxiety, irritable bowl syndrome, and MDMA abuse; however, few selective 5-HT_2B antagonists have been identified. Previous studies from these labs identified a natural product, 5-hydroxy-2-(2-phenylethyl)chromone (5-HPEC, 2) as the first non-nitrogenous ligand for the 5-HT_2B receptor. Studies on 5-HPEC optimization led to the identification of 5-hydroxy-2-(3-phenylpropyl)chromone (5-HPPC, 3), which showed a tenfold improvement in binding affinity over 2 at 5-HT_2B. This study aimed to further improve receptor pharmacology of this unique scaffold. Guided by molecular modeling studies modifications at the C-3′ and C-4′ positions of 3 were made to probe their effects on ligand binding affinity and efficacy. Among the derivatives synthesized 5-hydroxy-2-(3-(3-cyanophenyl)propyl)chromone (5-HCPC, 3d) showed the most promise with a multifold improvement in binding affinity (pK_i = 7.1 ± 0.07) over 3 with retained antagonism.

血清素2B（5-HT _2B）拮抗剂在偏头痛，焦虑症，易怒性碗综合征和MDMA滥用方面具有临床应用；然而，几乎没有发现选择性的5-HT _2B拮抗剂。这些实验室的先前研究确定了天然产物5-羟基-2-（2-苯乙基）色酮（5-HPEC，2）作为5-HT _2B受体的第一个非氮配体。对5-HPEC优化的研究导致鉴定了5-羟基-2-（3-苯基丙基）色酮（5-HPPC，3），在5-HT _2B上结合亲和力比2提高了十倍。这项研究旨在进一步改善这种独特支架的受体药理学。通过分子建模研究修改在C-3'和C-4'的位置的引导3作了探讨其对配体结合亲和力和效力的影响。在合成的衍生物中，5-羟基-2-（3-（3-氰基苯基）丙基）发色酮（5-HCPC，3d）表现出最有希望的结合亲和力（pK _i  = 7.1±0.07）的提高超过3倍。保留对抗性。