Constituents of commercial Brazilian lantana oil

✍ Scribed by Peter Weyerstahl; Helga Marschall; Alexander Eckhardt; Christian Christiansen

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 245 KB
• Volume: 14
• Category: Article
• ISSN: 0882-5734
• DOI: 10.1002/(sici)1099-1026(199901/02)14:1<15::aid-ffj777>3.0.co;2-m

✦ Synopsis

The constituents of the commercial Brazilian lantana oil are mainly bisabolene derivatives, altogether about 65%. The following new natural compounds were characterized by their 1 H-NMR and partly 13 C-NMR data: 1,12-epoxycadina-3,11-dienes (37, 40), helifolen-15-als (38/39), acora-2,4(15)-dien-11-ol ( 44), (E)-sesquithujen-12-al ( 47) and -12-ol (54), italicen-15-al (2,11-cycloacor-3-en-15-al, 52), the 6,10-epoxybisabolen-12-als 49, 50, 53, 58, 60/61, ar-curcumen-15-al (62) and its 10,11-epoxides 76/77, epi-a-bisabolone (69), methyl (E)-trans-a-bergamota-2,10-dien-12-oate (74) and its 2,3-epoxide 80. The so-called helifolen-12-als 35, 36, 42, 43, which were trace constituents of the Iranian Pulicaria gnaphalodes oil, belong to the main constituents (together 7.2%) of the Lantana oil. NaBH 4 reduction of 35, 36, 42, 43 yielded the helifolen-12-ols A±D. Their structure was elucidated by NOED and HMBC experiments and an X-ray analysis of the p-bromobenzenesulphonate of helifolen-12-ol D. The helifolen-12-ols A±D are racemates. Therefore, a biogenetic pathway via a bisaboladienyl and an acorenyl cation to the helifolen-12- (35, 36, 42, 43) and -15-als (38/39) is proposed.