A series of substituted 8,8-dimethyl-8H-pyrano[2,3-f]chromen-2-ones (chromeno-coumarin hybrids) was synthesized from scopoletin (11) as vasorelaxing agents. The synthesized compounds 21a-f, 22, 23a-e and scopoletin (11) were evaluated for vasorelaxation in endothelium intact rat main mesenteric artery (MMA). Compounds 11, 21a, 21c-f and 22 showed significant vasorelaxation in precontracted MMA within the range of EC₅₀ value 1.58-5.02 µM. These derivatives presented 29.40-70.89 fold increased sensitivity for experimental tissue compared to scopoletin (11), the parent molecule. Among others, 22 was found to be the most active compound which had EC₅₀ 1.58µM with 70.89 fold increased sensitivity. The mechanistic evaluation of 22 showed that it exerted vasorelaxation through Ca²⁺-activated K⁺ (BKca) channel and the effect was endothelium-independent.

从草素（11）作为血管舒张剂合成了一系列取代的8,8-二甲基-8 H-吡喃并[2,3- f ] chromen -2-ones（chromeno-coumarin hybrids）。评估了合成的化合物21a-f， 22、23a -e和scopoletin（11）在内皮完整的大鼠主肠系膜动脉（MMA）中的血管舒张作用。化合物11，21A，21C - ˚F和22 EC的范围内预收缩MMA表明显著血管舒张₅₀值1.58-5.02μM。与东pole碱相比，这些衍生物对实验组织的敏感性提高了29.40-70.89倍（11），母体分子。其中，发现22种化合物的活性最高，其EC _50为1.58µM，灵敏度提高70.89倍。对22种化合物的机械评价表明，它通过Ca ²⁺激活的K ⁺（BKca）通道发挥血管舒张作用，且其作用与内皮无关。