Curcumaromins A, B, and C, Three Novel Curcuminoids from Curcuma aromatica

Three novel curcuminoids, curcumaromins A–C ( 1 – 3 , resp.), along with a known compound, longiferone B ( 4 ) were isolated from Curcuma aromatica Salisb . The structures of the new compounds were elucidated as (1 E ,4 Z ,6 E )‐5‐hydroxy‐7‐{4‐hydroxy‐3‐[(1 R* ,6 R* )‐3‐methyl‐6‐(propan‐2‐yl)cyclohex‐2‐en‐1‐yl)phenyl}‐1‐(4‐hydroxyphenyl)hepta‐1,4,6‐trien‐3‐one ( 1 ), 2,3‐dihydro‐2‐(4‐hydroxyphenyl)‐6‐[( E )‐2‐(4‐hydroxyphenyl)ethenyl]‐5‐[(1 R* ,6 R* )‐3‐methyl‐6‐(propan‐2‐yl)cyclohex‐2‐en‐1‐yl]‐4 H ‐pyran‐4‐one ( 2 ), and (1 E ,6 E )‐1,7‐bis(4‐hydroxyphenyl)‐4‐[(1 R* ,6 R* )‐3‐methyl‐6‐(propan‐2‐yl)cyclohex‐2‐en‐1‐yl]hepta‐1,6‐diene‐3,5‐dione ( 3 ) on the basis of spectroscopic analysis. Curcumaromins A–C ( 1 – 3 ) represented the first examples of menthane monoterpene‐coupled curcuminoids. The known compound, longiferone B ( 4 ), was the first daucane sesquiterpene isolated from the genus Curcuma.