Three new pentacyclic triterpenoids, camarin (1), lantacin (2), and camarinin (3) were isoA C H T U N G T R E N N U N G lated from the aerial parts of Lantana camara LINN., together with seven known compounds. The structures of the new constituents were elucidated by chemical transformation, HR-EI mass spectrometry, and NMR spectroscopy, including 1D ( 1 H-and 13 C-NMR) and 2D ( 1 H, 1 H-COSY, NOESY, 1 H, 1 H-TOCSY, Jresolved, HMQC, and HMBC) experiments.
Introduction. -Lantana camara LINN. (Verbenaceae) is a hairy shrub native to Tropical America. Different parts of this plant are used for the treatment of various human ailments such as itches, cuts, ulcers, swellings, bilious fever, catarrh, eczema, tetanus, malaria, tumors, and rheumatism [1] [2]. Phytochemical studies carried out by different research groups have resulted in the isolation of various terpenoids, steroids, and flavonoids [3 -5].
In the course of our investiA C H T U N G T R E N N U N G gations on the constituents of the aerial parts of L. camara, we herein report the three new pentacyclic triterpenoids camarin (= (7a)-7-hydroxy-3-oxoolean-12-en-28-oic acid; 1), lantacin (= (3b,19a,22b)-3,19-dihydroxy-22-[(3-methylbut-2-enoyl)oxy]urs-12-en-28-oic acid; 2), and camarinin (= (22b)-3b,25epoxy-3-hydroxy-22-[(3-methylbut-2-enoyl)oxy]-11-oxoolean-12-en-28-oic acid; 3). Their structures were elucidated on the basis of various 2D-NMR techniques, including 1 H, 1 H-COSY, NOESY, TOCSY, HMQC, and HMBC spectroscopy. In addition, seven known compounds were identified: oleanolic acid [6], ursolic acid [7], pomolic acid [8], lantanolic acid [9], camangeloyl acid [10], lantaninilic acid [11], and lantoic acid [12].
Results and Discussion. -Compound 1 did not show the molecular ion peak in EI-, HR-EI-, and FAB-MS experiments. The molecular formula, C 30 H 46 O 4 , was, thus, established through in-depth analysis of various mass fragment ions (Fig. 1) and 13 C-NMR (DEPT) data (Table 1). The IR spectrum of 1 showed absorption bands at 3420 -2610 (br., OH, COOH), 2920 and 2850 (CH), and 1700 cm À1 (acid and ketone C=O). The UV spectrum showed an absorption at 206 nm, indicating the lack of conjugation in the molecule. The 1 H-NMR spectrum of 1 (Table 1) showed seven Me singlets at d(H) 0.84, 0.90, 0.92, 1.03, 1.06, 1.07, and 1.38. It also displayed resonances for an olefinic H-atom at d(H) 5.30 (t, J = 3.5 Hz, HÀC( 12)) and a H-atom at 2.82 (dd, J = 13.8, 4.4 Hz) assigned to HÀC(18). These data, along with the characteristic 13 C-NMR chemical shifts of C(12) (d(C) 122.2) and C(13) (143.6) (Table 1) [13] suggested that 1 belongs to the D 12 -b-amyrin series of pentacyclic triterpenoids.