Twelve new grayanoids (1−12) along with five known compounds were isolated from flowers of Rhododendron molle. Their structures were fully characterized using a combination of spectroscopic analyses, computational calculations, and single crystal X-ray diffraction. Rhomollone A (1) possesses an unprecedented 5/6/6/5 tetra-cyclic ring system (B-nor grayanane) incorporating a cyclopentene-1,3-dione scaffold. Rhodomollein XLIII (2) is a dimeric grayanoid, containing a novel 14-membered heterocyclic ring with a C₂ symmetry axis. The antinociceptive activities of compounds 3, 4, 6, 7, and 12−17 were evaluated by an acetic acid-induced writhing test. Among them, compounds 3, 7, 12, 15 and 16 displayed significant antinociceptive activities at a dose of 20 mg/kg with inhibition rates ranging from 41.9% to 91.6%. Compounds 6 and 13 inhibited 46.0% and 39.4% of the acetic acid-induced writhes at a dose of 2 mg/kg, while compound 17 inhibited 34.3% of the writhes at a dose of 0.4 mg/kg.

十二新grayanoids（1 - 12）具有5种已知化合物一起被从花中分离杜鹃。结合光谱分析，计算计算和单晶X射线衍射对它们的结构进行了充分表征。Rhomollone A（1）具有史无前例的5/6/6/5四环系统（B-或灰烷），其中并入有环戊烯-1,3-二酮骨架。Rhodomollein XLIII（2）是一种二聚体灰度类化合物，含有一个具有C ₂对称轴的新颖的14元杂环。化合物的抗伤害活性3，4，6，7，和12 - 17由乙酸诱导的扭体试验进行评价。其中，化合物3，7，12，15和16在与抑制率从41.9％至91.6％的剂量的20mg / kg的显示显著镇痛活性。化合物6和13以2mg / kg的剂量抑制46.0％和39.4％的乙酸诱导的扭曲，而化合物17以0.4mg / kg的剂量抑制34.3％的扭曲。