Flavanones from the Flower of Macaranga triloba

Macaranga triloba belongs to the family of Euphorbiaceae. Investigation on the dichloromethane extract of flower of Macaranga triloba collected at Hulu Terengganu, Malaysia has yielded four flavanone compounds known as 6-prenyl-3’-methoxy-eriodictyol (1), nymphaeol-B (2), nymphaeol-C (3) and 6-farnesyl3’,4’,5,7-tetrahydroxyflavanone (4). The structures of these compounds were elucidated based on spectroscopic methods including nuclear magnetic resonance (NMR-1D and 2D), UV, IR as well as mass spectrometry. This is the first report of 6-prenyl-3’-methoxy-eriodictyol(1) and 6-farnesyl-3’,4’,5,7-tetrahydroxyflavanone (4) from the genus of Macaranga. Key word: Euphorbiaceae Macaranga Flavonoids Prenyl Geranyl Farnesyl NMR INTRODUCTION Experimental The genus Macaranga is one of the largest genera of the Euphorbiaceae, with approximately 300 species [1]. Macaranga triloba locally known as “Mahang merah” is a tree endemic to Southeast Asia at forest margins and its water extract is used as pain relief for stomach trouble in Java [2]. A previous phytochemical investigation on the leaves of this plant has resulted in the isolation of geranylated flavanones, 2’-hydroxy-macarangaflavanone A and 4’,7-dihydroxy-8-methylflavan [3]. A phytochemical study by Jang and co-researchers on the chemical constituents of the leaves of Macaranga triloba collected from West Kalimantan, Indonesia has led to the isolation of a new rotenoid, 4,5-dihydro-5’ -hydroxy-4’ methoxy-6a,12a-dehydro-toxicarol, together with 12 known compounds namely, (+)-clovan-2 , 9 -diol, ferulic acid, 3,7,3’,4’,tetramethylquercetin, 3,7,3’trimethylquercetin, 3,7-dimethylquercetin, abscisic acid, 1 ,6 -dihydroxy-4(15)-eudesmene, 3 -hydroxy-24ethylcholest-5-en-7-one, loliolide, scopoletin, taraxerol and 3-epi-taraxerol [4]. Besides that, the triterpene constituents of the apicuticular wax blooms obtained from the stems on M. triloba have been analyzed by GC-MS [5]. This paper reports on the isolation of flavanone compounds from the flower of Macaranga triloba which has not been reported before. General Procedures: The H-NMR and C-NMR were 1 13 recorded in acetone-D and chloroform-D on Bruker 300 Ultrashield NMR spectrometer measured at 300 and 75 MHz. Chemical shifts are reported in ppm and and the coupling constants are given in Hz. Melting point was taken on a hot stage Gallen Kamp melting point apparatus with microscope and was uncorrected. The infrared (IR) was recorded on the Perkin Elmer spectrum one FT-IR spectrometer. The ultraviolet (UV) spectra were recorded on Shimadzu UV-Vis 160i. The mass spectra were measured on Perkin Elmer Clarus 600T spectrometer 70 eV. Vacuum liquid chromatography (VLC) used Silica gel 60, 70-230 mesh ASTM (Merk 1.07747), Radial chromatography used Si-gel 60 PF (Merck catalog 254 number: 1.07749). Aluminum supported silica gel 60 F254 was used for thin layer chromatography, while glass supported silica gel 60 F was used for preparative thin 254 layer chromatography. Plant Material: The flowers of Macaranga triloba were collected from Pasir Raja, Hulu Terengganu, Malaysia and a voucher specimen (UiTM17/09) was deposited at the Herbarium of Universiti Teknologi MARA, Malaysia. Extraction and Isolation: The flowers (1.5 kg) of M. triloba were air dried, ground and soaked successively with hexane, dichloromethane and methanol for 72 hours. World Appl. Sci. J., 9 (9): 1003-1007, 201