Pergamon

PII: s0305-1978(96)00118-9

Biochemical Systernatics and Ecology, Vot. 25, No. 3, pp. 269-270,1997 O 1997 Elsevier Science Ltd

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Flavonoid Aglycones and Triterpenoids from the Leaf Exudate of Lantana camara and Lantana montevidensis

ECKHARD WOLLENWEBER,*§ MARION DORR,* R. MUNIAPPAN1- and KARSTEN SIEMS$ *lnstitut for Botanik der Technischen Hochschule, Schnittspahnstrasse 3, D-64287 Darmstadt, Germany;

tAgricultural Experiment Station, University of Guam, Mangilao, Guam 96923, U.S.A.; tAnalytiCon Gesellschaft for Chemische Analytik und Consulting, Gustav-Meyer-Allee 25, D-13356 Berlin,

Germany

Key Word Index--Lantana camara; L. montevidensis; Verbenaceae; leaf and stem exudate; flavonoid agly- cones; triterpene acids; 13C-NMR of lantadene A and icterogenin.

Subject and Source Lantana camara is native to tropical America, but was introduced throughout the tropics as well as in the U.S. from Florida to Texas. In Europe it is cultivated as an ornamental plant. L. montevidensis originates from Brazil and Uruguay; it was likewise introduced in the U.S. from Florida to Texas (Zander, 1993). An infusion of the aromatic leaves of Lantana camara is sometimes used in home remedies as a tonic and stimulant (Uphof, 1968).

Aerial parts of Lantana camara Cav. were collected on 9 August 1995 by R. Muniappan in Mangilao, Guam. A voucher (-7~ 27127) is kept in the herbarium at the Biology Department of the University of Guam at Man- gilao. Some twigs of Lantana montevidensis (Spreng.) Briq. were taken from a shrub cultivated in the Botanical Garden at Darmstadt.

Previous Work From aerial parts of Lantana achyranthifolia Desf., the flavonoids penduletin and chrysosplenetin were isolated, along with 13-sitosterol (Dominguez et al., 1983). 5-Hydroxy-6,7,3',4',5'-pentamethoxy flavone ( 'umuhen- gerin") has been reported previously as an antimicrobially active compound from Lantana trifolia L. (Rwangabo et al., 1988). From aerial parts of Lantana camara, triterpenoid esters have been isolated since the 1940s (lan- taden A, lantaden B, icterogenin) (cf. Hegnauer, 1973), and further triterpenoid esters and acids were reported between 1972 and 1985 (lantinic acid, lantanolic acid, lantanilic acid, lantaninilic acid, lantoic acid) (cf. Hegnauer, 1990; for a survey see table p. 746). Begum et al. (1995) recently identified two new triterpenoid esters from the same species, called camarilic acid and camaricinic acid. None of these publications mentions the external accumulation of any of these compounds.

Present Study In the acetone wash of Lantana camara, we identified Qu-3-Me, Qu-3,7-diMe and Qu-3,7,4'-triMe. The leaf wash of L. montevidensis exhibits Lut, Lut-7,3'-diMe, and Lut-7,3',4'-triMe. Some minor flavonoids have not yet been identified, due to lack of material. Coloudess crystalline material obtained from the terpenoid fraction of L. camara was found to be a mixture of lantadene A (1) and its 24-hydroxy derivative (icterogenin, 2), which could easily be separated by prep. TIC. The structures of lantadene A (1) and icterogenin (2) were deduced from 1 H- N M R, 13C_ N M R and mass spectra and comparison with literature data (Hart et al., 1976; Johns et al., 1983). To the best of our knowledge, ~3C-NMR data of lantadene A and icterogenin are reported here for the first time (Table 1 ). Further triterpene constituents present have not been analyzed in this study. We assume that previously reported flavonoid aglycones and triterpenoids from Lantana spp. are also accumulated exter- nally on aerial parts.

§Corresponding author.

(Received 18 October 1996; accepted 25 November 1996)

269

270 E. WOLLENWEBER ETAL

TABLE 1.13C-NMR DATA FOR LANTADENE A (1) AND ITS 24-HYDROXY DERIVATIVE ICTEROGENIN (2)

Carbon 1 2 Carbon 1 2

1 38.87 38.28 t 16 23.29 23.50 t 2 33.93 34.05 t 17 50.39 50.34 s 3 217.59 220.47 s 18 38.25 38.57 d 4 4723 50.44 s 19 47.77 45.89 t 5 55.03 55.40 d 20 29.84 29.84 s 6 1 9,26 18.98 t 21 37.58 37.73 t 7 31 96 32.17 t 22 75.73 75.72 d 8 38.96 38.93 s 23 25.98 21 95 q 9 46.65 46.25 d 24 21.26 65.41 q/t

1 0 36.55 36.32 s 25 15.48 1 5.83 q 11 23.99 23.96 t 26 16.62 1 6.46 q 12 122.10 121.94 d 27 25.62 25.49 q 1 3 143.06 143.19 s 28 179.67 177.11 s 14 41.75 4184 s 29 33.53 33.53 q 1 5 27.35 27.50 t 30 26.23 25.97 q 1' 166.24 1 66.42 s 2' 1 27.45 127.68 s 3' 1 38.77 138.24 d 4' 1 4.90 15.38 q 5' 20.43 20.31 q

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