Studies on the Indian Rutaceae. Chemical Investigation of Limonia alata and Evodia lunu-ankenda

Abstract

As part of our systematic chemical investigation of some of the members of the Rutaceae which are used in folk medicine, we report the isolation of several natural compounds from Limonia alata W. & A. (1) and Evodia lunu-ankenda Merr. (1).The petroleum ether extract of the bark of L. alata furnished the pyranocoumarins, xanthyletin (2) and xanthoxyletin (2), and the triterpene lupeol (3). From the fruits of the same species the pyranocoumarin, seselin (4), was isolated.Examination of the basic fraction of the bark extract of E. lunu-ankenda afforded the furoquinoline alkaloids, dictamnine (5), evolitrine (5), kokusaginine (5), and a rare N-methyl-4-methoxy-2-quinolone ( 6), along with marmesin (7), a furocoumarin. EXPERIMENTALPlant material.-Bark and fruits of L. alata were collected in the month of June 1982, from the Maruthamalai hills near Coimbatore (Tamil Nadu, India), and the bark of E. lunu-ankenda was collected from the Naduvattam and Kodanadu of Nilgris (Tamil Nadu). The herbarium specimens are maintained in the Department of Chemistry, Bharathiar University. Extraction and separation.-Air-dried bark material of L. alata (250 g) was extracted with petroleum ether (60-80°) in a Soxhlet apparatus, and the extract was concentrated. Column chromatography of the residue over silica gel using petrol-CgHg (1:1) as eluent yielded the triterpene, lupeol (150 mg), followed by xanthoxyletin (250 mg) and traces of xanthyletin. The air-dried fruits of L. alata (250 g) on similar workup gave seselin (500 mg).The dried and powdered bark of E. lunu-ankenda (2.5 kg) was exhaustively extracted with CH2C12.The concentrated extract was acidified with 10% HC1 and left for three days. The filtered solution was neutralized with NH3 and extracted with CH2C12 (3 x 500 ml). The gummy residue obtained, after evaporation of the solvent, was placed over a column of basic alumina in petrol and eluted with petrol-C6H6 (1:1) when dictamnine (75 mg) and evolitrine (125 mg) were obtained. Further elution of the column with CgH6 afforded kokusaginine (45 mg), N-methyl-4-methoxy-2-quinolone (40 mg), and traces of marmesin (3 mg).Hplc assay.-The above constituents were neatly separated by hplc (Jobin-Yuon Prep-10 model):Lichroprep Si 60, 15 µg-25 µg column, Uv detector at 298 nm; using petroleum ether-CHCl3 (Gradient elution), at flow rate of 18 ml/mn.Full details of the isolation and identification of the compounds are available on request to the senior author.

HIV Inhibitory Natural Products. 26. Quinoline Alkaloids from Euodia roxburghiana

“…The remaining two doublets at δ 7.05 (J ) 3.0 Hz) and δ 7.56 (J ) 3.0 Hz) were coupled to each other. These substitution patterns, combined with the fact that furoquinolines have been found in other Rutaceae, 12 strongly suggested the presence of a furoquinoline skeleton. Indeed, these aromatic proton resonances matched very well those of dictamnine.…”

Inhibition of hepatitis C virus replication by chalepin and pseudane IX isolated from Ruta angustifolia leaves

“…Plants of the genus Ruta have been commonly used in both ancient and modern medicine practices in the Mediterranean region to cure pulmonary diseases, rheumatic diseases and helminthic infections [15,27]. A large number of chemical constituents have been isolated from the genus Ruta, such as coumarins, alkaloids, benzoquinones, flavone glycosides, sterols, triterpenoids, acridone alkaloids, stigmasterol, lupeol, 5-methoxyarborinine, 5-hydroxyarborinine, ostruthin, bergapten, psoralen, xanthotoxin, limonoid obacunone, isopimpinellin, integriquinolone, kokusaginine, dictamnine, furoquinolin alkaloid, xanthyletin and xanthoxyletin [28,29]. It was also reported that coumarin compounds are the major constituents of the plants in the Rutaceae family, with about two hundred different coumarins being identified [30,31].…”

Phytochemical Constituents and Biological Activities of Melicope lunu-ankenda

“…Leptonol demonstrated good antipyretic and antioxidant activities, while both chromenes showed moderate analgesic and anti-inflammatory activities, rationalizing the use of M. lunu-ankenda in treating conditions such as fever and inflammation in folklore practices [ 8 ]. Furoquinoline alkaloids, dictamnine, evolitrine, kokusaginine, and N -methyl-4-methoxy-2-quinolone, along with marmesin, were also successfully isolated from the basic fraction of bark extract [ 25 ]. Furthermore, dictamnine (4-methoxyfuro[2,3-b]quinoline) and evolitrine (4,7-dimethoxyfuro[2,3- b ]quinoline), which were isolated from the bark of M. lunu-ankenda , were reported to have moderate antifeedant activity [ 26 ].…”