ABIETANE DITERPENES FROM CLERODENDRON-CYRTOPHYLLUM

Two novel abietane derivatives, cyrtophyllones A (1) and B (2), togeth er with six known compounds, teuvincenone F (3), uncinatone (4), sugio l (5), friedelin (6), clerodolone (7), stigmasta-5,22,25-trien-3beta-o l (8) and clerosterol (9), were isolated from the stem of Clerodendron cyrtophyllum. One of the abietane diterpenes, cyrtophyllone A, posses ses a rearranged-abietane skeleton which contains a 17(15-16)-abeo-abi etane framework. The stereo-structure proposed for 1 was characterized as hoxy-17(15-16)-abeo-abieta-5,8,11,13-tetraen-7-one on the basis of spectral analysis (UV, IR, MS, two dimensional (2D) NMR and CD) and X -ray diffraction. The structure of 2 was also characterized as (+)-11, 12.16-trihydroxy-abieta-8,11,13-trien-7-one by a combination of spectr oscopic comparison with sugiol.