Two flavonoids isolated from the leaves of Macaranga gigantea

Euphorbiaceae is known as one of the largest family of Angiosperms which comprises 300 genera and 8000 species widely distributed in several types of vegetations and habitats. Macaranga which is a large genus from Euphorbiaceae family comprises of 300 species commonly distributed in the forests as well as in disturbed areas. Among the species found in Malaysia are M. gigantea, M. heynei, M. hosei, M. lowii and M. triloba. Apart being exploited as plywood and match splints, this genus is well-known for its traditional remedies by the old folks. The roots have been used to treat fever and antitusive for coughing while the fresh leaves are good for wound healing. Due to the interesting medicinal properties of these species, a phytochemical study was conducted on the leaves of M. gigantea (Rchb.f. & Zoll.) Müll.Arg, which was collected from Gombak Forest Reserve, Gombak. The dried leaves of M. gigantea were ground to form powder, macerated in methanol and the extractive solution was concentrated to obtain a methanolic crude extract. The crude extract was dissolved in methanol:water (90:10) to give dissolved and undissolved crude. The dissolved crude was partitioned with hexane followed by ethyl acetate. The ethyl acetate extract was subjected to vacuum liquid chromatography in increasing polarity to give 23 fractions. Fractions C was further purified by column chromatography and preparative TLC to give compound 1. Fraction D was purified by using preparative TLC to afford compound 2. The structure of compound 1 and 2 were characterized by using spectroscopic analyses and comparison with the literature data. The isolation from the leaves of M. gigantea was found to contain a flavone namely luteolin [1] as well as a glycosyloxyflavone known as apigenin 7-O-glucoside [2]. This is the first report of these compounds in M. gigantea.

Acknowledgements: I would like to express my greatest appreciation to the Ministry of Higher Education, Malaysia for the financial support (RAGS/1/2014/SG01/UITM/4) as well as the Faculty of Applied Sciences, Universiti Teknologi MARA for providing the research facilities.

Keywords: Macaranga gigantea, apigenin 7-O-glucoside, luteolin.

References:

[1] Harborne JB, Mabry TJ. The flavonoids-Advances in research. London: Chapman & Hall, 1982; 19 – 40

[2] Secco RDS, Cordeiro I, De Senna-Vale L, De Sales MF, De Lima LR, Medeiros D, Haiad BDS, De Oliveira AS, Caruzo MBR, Carneiro-Torres D, Bigio NC. An overview of recent taxonomic studies on Euphorbiaceae s.l. in Brazil. Rodriguesia 2012; 63: 227 – 242

[3] Stochmal A, Piacente S, Pizza C, De Riccardis F, Leitz R, Oleszek W. Alfafa (Medigo sativa L.) flavonoids. 1. Apigenin and luteolin glycosides from aerial parts. J Agric Food Chem 2001; 753 – 758