Medicinal plants of the Plectranthus genus (Lamiaceae) are well known for their ethnomedicinal applications. Plectranthus madagascariensis, which is native to South Africa, is traditionally used in the treatment of respiratory conditions, scabies, and cutaneous wounds. The phytochemical studies of P. madagascariensis led to the isolation of five known royleanone abietanes, namely, 6β,7α-dihydroxyroyleanone (1), 7α-acetoxy-6β-hydroxyroyleanone (2), horminone (3), coleon U quinone (4), and carnosolon (5). The relative configuration of compound 2 was established by X-ray analysis. Compounds 1–4 showed antimycobacterial activity (Minimum inhibitory concentration for 90% inhibition, MIC₉₀ = 5.61–179.60 μM) against Mycobacterium tuberculosis H₃₇Rv. Compound 4 and 5 showed comparable toxicity (Concentration for 50% inhibition, IC₅₀ 98.49 μM and 79.77 μM) to tamoxifen (IC₅₀ 22.00 μg/mL) against HaCaT cells. Compounds 1–5 showed antioxidant activity through single-electron transfer (SET) and/or hydrogen-atom transfer (HAT) with compound 5 being the most active antioxidant agent. Compounds 3 and 5 were isolated for the first time from P. madagascariensis. The observed results suggest P. madagascariensis as an important ethnomedicinal plant and as a promising source of diterpenoids with potential use in the treatment of tuberculosis and psoriasis.

中文翻译：

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喜洋甘菊分离的Abietane二萜类化合物的抗分枝杆菌，细胞毒性和抗氧化活性。

Plectranthus属（唇形科）的药用植物因其人种医学应用而闻名。南非原产的Plectranthus madagascariensis传统上用于治疗呼吸道疾病，sc疮和皮肤伤口。马达加斯加疟原虫的植物化学研究导致分离出五种已知的丙酮酸双氢苯丙胺酮，即6β，7α-二羟基royleanone（1），7α-乙酰氧基-6β - hydroxyroyleanone（2），激素（3），coleon U醌（4） ，和carnosolon（5）。通过X射线分析确定化合物2的相对构型。化合物1– 4对结核分枝杆菌H ₃₇ Rv具有抗分枝杆菌活性（抑制90％的最低抑菌浓度，MIC ₉₀ = 5.61–179.60μM）。化合物4和5对他莫昔芬（IC ₅₀ 22.00μg / mL）表现出对HaCaT细胞可比的毒性（50％抑制浓度，IC ₅₀ 98.49μM和79.77μM）。化合物1 - 5通过单电子转移显示抗氧化活性（SET）和/或氢原子转移（HAT）与化合物5是最活跃的抗氧化剂。化合物3和5首次从马达加斯加疟原虫中分离得到。观察到的结果表明，马达加斯加疟原虫是一种重要的民族药用植物，也是一种有希望的二萜类来源，可潜在地用于治疗结核病和牛皮癣。