New triterpenoids from Lantana camara: Isomerisation of the angeloyl moiety of lantadene A during catalytic hydrogenation

lndian Institute of Chemical Biology, 4 RajaS. C. Mullick Road, Jadavpur, Calcutta-700 032, India

lndian Veterinary Research Institute, Regional Station, Palampur-176 061, India

Schering Plough Research Institute, 20 I 5 Galloping Hill Road, Kenilworth, New Jersey 07033-0539, U.S.A.

Manuscript received 12 October 1999

Two new triterpenes, 22β-tigloyloxylantanolic acid (5) and 22β-dimethylacryloyloxylantic acid (6) have been isolated along with 22β-angeloyloxylantanolic acid (4) and 24-hydroxy-3-oxoolean-12-en-28-oic acid (7) from the leaves of the Common Pink variety of Lαntαnα cαmαrα var. αculeαtα and their structures elucidated by spectroscopic methods. 13C NMR spectral data assignments of lantadenes A, Band Cisolated from the red variety of the plant and isomerization of the angeloyl moiety of lantadene A to tigloyl moiety to yield a new product 22β-tigloyloxy-3-oxoolean-12-en-28-oic acid (10) during catalytic hydrogenation are also reported.