Published: January 24, 2011 r2011 American Chemical Society 1363 dx.doi.org/10.1021/jf1032729 | J. Agric. Food Chem. 2011, 59, 1363–1369 ARTICLE pubs.acs.org/JAFC Identification of Proanthocyanidin Dimers and Trimers, Flavone C-Glycosides, and Antioxidants in Ficus deltoidea, a Malaysian Herbal Tea Maizatul Hasyima Omar, † William Mullen, and Alan Crozier* Plant Products and Human Nutrition Group, Graham Kerr Building, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom ABSTRACT: Phenolic compounds in an aqueous infusion of leaves of Ficus deltoidea (Moraceae), a well-known herbal tea in Malaysia, were analyzed by HPLC coupled to photodiode array and fluorescence detectors and an electrospray ionization tandem mass spectrometer. Following chromatography of extracts on a reversed phase C 12 column, 25 flavonoids were characterized and/or tentatively identified with the main constituents being flavan-3-ol monomers, proanthocyanidins, and C-linked flavone glycosides. The proanthocyanidins were dimers and trimers comprising (epi)catechin and (epi)afzelechin units. No higher molecular weight proanthocyanidin polymers were detected. The antioxidant activity of F. deltoidea extract was analyzed using HPLC with online antioxidant detection. This revealed that 85% of the total antioxidant activity of the aqueous F. deltoidea infusion was attributable to the flavan-3-ol monomers and the proanthocyanidins. KEYWORDS: Ficus deltoidea, flavan-3-ol monomers, dimers and trimers, flavone C-glycosides, HPLC-PDA-MS 2 , antioxidants ’ INTRODUCTION Ficus deltoidea (Moraceae) is a shrub commonly known as Mas cotek or Serapat angin in Malaysia, Tabat barito in Indonesia, and Kangkalibang in Africa. It is has been reported that F. deltoidea, consumed principally as a tea prepared by aqueous infusion of the leaves, possesses various medicinal effects including aphro- disiac activity and antihypertension, antidiabetic, and anticancer properties. 1 An aqueous extract of F. deltoidea fed to rats exhibited antidiabetic properties with no side effects. 2 Phyto- chemical studies on a wide number of Ficus spp., including F. carica, F. indica, and F. racemosa, have revealed that phenolics are major components. 3,4 Ficus spp. are also reported to have antioxidant activity that has been attributed to the presence of flavonoids as well as terpenoids, alkaloids, 5 and tannins. 6 How- ever, little is known about the actual phytochemical content, and, in particular, the flavonoid composition of F. deltoidea. Flavonoids are C 6 -C 3 -C 6 compounds that in recent years have attracted an enormous amount of interest due to their potential protective effects on human health. They have antioxidant, anticarcinogenic, anti-inflammatory, antiviral, hepatoprotective, and antiallergenic properties. 7,8 Flavan-3-ols are a subclass of flavonoids that can form oligomeric and polymeric proanthocya- nidins, which are also known as condensed tannins. Proantho- cyanidins consisting of (-)-epicatechin/(þ)-catechin units are called procyanidins and are the most abundant type of proantho- cyanidins in plants. The less common proanthocyanidins con- taining (-)-epiafzelechin/(þ)afzelechin and (-)epigallocatechin/ (þ)-gallocatechin subunits are called propelargonidins and pro- delphinidins, respectively. 9 Proanthocyanidins have been reported to be anticancer agents and to have antiatheroscleretic effects. 10-12 Flavones are another subgroup of flavonoids that are found in many herbs, typically as O- or C-linked glycosides. They are reported to have antioxidant, anti-inflammatory, antimutagenic, anticancer, and anti-HIV activities. 13 There is growing interest in the phytochemical content and potential beneficial effects of F. deltoidea consumption, which has gained increasing popularity among the general population in Malaysia. The dried leaves, which are widely available in local markets, are made into a tea. In addition to being served as a tea, F. deltoidea extracts are also sold commercially in capsule form as an herbal supplement. In the present study, HPLC-MS 2 -based methodology was used to analyze the flavonoid compounds in aqueous extracts of F. deltoidea. In addition, to identify specific compounds with antioxidant activity extracts were analyzed by HPLC with an online antioxidant detection system. 14 ’ MATERIALS AND METHODS Chemicals and Reagents. HPLC grade methanol was purchased from Rathburn (Walkerburn, U.K.). The flavonoid standards, (þ)-catechin, apigenin-8-C-glucoside (vitexin), apigenin-6-C-glucoside (isovitexin), and luteolin-6-C-glucoside (isoorientin), were obtained from Extrasynthese (Genay, France). Gallic acid and delphinidin-3-galactoside were supplied by AASC Ltd. (Southampton, U.K.). Procyanidin B 2 ,(-)-epicatechin, formic acid, phosphoric acid, metaphosphoric acid, Folin-Ciocalteu reagent, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), and 2,2 0 -azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) were purchased from Sigma-Aldrich (Dorset, U.K.). Other chemicals were supplied by Fisher Scientific (Leicestershire, U.K.). Plant Material. Dried leaves of F. deltoidea purchased from a local market in Pahang, Malaysia, were dried further for 2 days at 45 °C before Received: August 24, 2010 Accepted: December 21, 2010 Revised: December 21, 2010