Sesquiterpenoids from Costus Root Oil (Saussurea lappa CLARKE)

Apart from the well‐known constituents (+)‐β‐selinene ( 2 ), (−)‐β‐elemene ( 4 ), (+)‐β‐costol ( 7 ), (−)‐caryophyllene ( 17 ), and (−)‐elemol ( 19 ) the following sesquiterpenoids have been isolated for the first time from costus root oil ( Saussurea lappa C LARKE ): (−)‐α‐selinene ( 1 ), (+)‐selina‐4, 11‐diene ( 3 ), (−)‐α‐ trans ‐bergamotene ( 5 ), (−)‐α‐costol ( 6 ), (+)‐γ‐costol ( 8 ), (−)‐elema‐1,3,11 (13)‐trien‐12‐ol ( 9 ), (−)‐α‐costal ( 11 ), (+)‐γ‐costal ( 12 ), (+)‐γ‐costal ( 13 ), (−)‐elema‐1,3,11 (13)‐trien‐12‐al (elemenal, 14 ), (−)‐( E )‐ trans ‐bergamota‐2, 12‐dien‐14‐al ( 15 ), (−)‐ ar ‐curcumene ( 16 ), and (−)‐caryophyllene oxide ( 18 ). Compounds 6 , 8 , 9 , and 13 are new sesquiterpenoids. IR. and NMR. spectra of 12 sesquiterpenoids are reproduced.