A New Lanostane Triterpene from Skimmia laureola

Skimmia laureola Hook (Rutaceae) is found in Kashmir and in the mountains of Northern Pakistan and is used in folklore medicine for the treatment of various ailments [1 – 3]. The quinoline alkaloids of this plant have demonstrated antifungal and immunomodulating properties [4, 5]. The ethanolic extracts of the aerial parts of S. laureola are active against the animal pathogen Microsporium canis and the plant pathogen Fusarium solani var. lycopersici (tomato) [5]. A number of coumarins, e. g. isogospherol (2) [6], heraclenol (3) [7], (+)7-methoxy-6-(2′R-methoxy-3′-hydroxy-3′-methyl butyl)coumarin (4) [1], 5,8-dimethoxy coumarin-2H1-benzopyran-2-one (5) [8], 7-methoxy-6-[2′-oxo-3′methyl butyl]coumarin (6) [9] and (+)-ulopterol (7) [10, 11], were isolated, in addition to various quinoline alkaloids, e. g. 4-methoxy-1-methyl-3-(2′S-acetoxy-3′-ene butyl)-2-quinolone (8) [12], 4-methoxy1-methyl-3-(2′S-acetoxy-3′-hydroxy butyl)-2-quinolone (9) [12], 3-hydroxy-2,2,6-trimethyl-3,4,5,6-tetrahydro-2H-pyrano[3,2-c]quinoline-5-one (10) [13], 4methoxy-1-methyl-3-(2′-oxo-3′-methyl butyl)-2-quinolone (11) [15], 4-methoxy-1-methyl-3-(2′S-hydroxy3′-ene butyl)-2-quinolone (12) [12], methyl isoplatydesmine (13) [2], ribalinin (14) [14] and dictamnine (15) [15 – 18]. Five known compounds, namely, O-methyl-cyclolaudenol, (R)-7-methoxy-6-(3′-hydroxy-2′R-methoxy3′-methyl butyl)coumarin, (+)-(S)-ψ-ribalinine, (R)(+)-ribalinine and methyl isoplatydesmine, previously isolated from this plant were subjected to enzymatic bioassays for the first time. Methyl cyclolaudenol and (R)-7-methoxy-6-(3′-hydroxy-2′R-methoxy-