pubs.acs.org/JAFC Published on Web 02/16/2010 © 2010 American Chemical Society J. Agric. Food Chem. 2010, 58, 3393–3398 3393 DOI:10.1021/jf9039759 Chemical Assessment and in Vitro Antioxidant Capacity of Ficus carica Latex ANDREIA P. OLIVEIRA, † LUI ´ S R. SILVA, † FEDERICO FERRERES, ‡ PAULA GUEDES DE PINHO,* ,§ PATRI ´ CIA VALENTA ˜ O, † BRANCA M. SILVA, †, ) JOSE ´ A. PEREIRA, ^ and PAULA B. ANDRADE* ,† † REQUIMTE/Department of Pharmacognosy, Faculty of Pharmacy, Porto University, R. Anı´bal Cunha, 164, 4050-047 Porto, Portugal, ‡ Research Group on Quality, Safety and Bioactivity of Plant Foods, Department of Food Science and Technology, CEBAS (CSIC) P.O. Box 164, 30100 Campus University Espinardo, Murcia, Spain, § REQUIMTE/Department of Toxicology, Faculty of Pharmacy, Porto University, R. Anı´bal Cunha, 164, 4050-047 Porto, Portugal, ) CEBIMED/Faculdade de Ci ^ encias da Sa ude, Universidade Fernando Pessoa, R. Carlos da Maia, 296, 4200-150 Porto, Portugal, and ^ CIMO/Escola Superior Agr aria, Instituto Polite´ cnico de Braganc -a, Campus de Santa Apol onia, Apartado 1172, 5301-855 Braganc -a, Portugal Ficus species possess latex-like material within their vasculatures, affording protection and self- healing from physical attacks. In this work, metabolite profiling was performed on Ficus carica latex. Volatiles profile was determined by HS-SPME/GC-IT-MS, with 34 compounds being identified, distributed by distinct chemical classes: 5 aldehydes, 7 alcohols, 1 ketone, 9 monoterpenes, 9 sesquiterpenes and 3 other compounds. Sesquiterpenes constituted the most abundant class in latex (ca. 91% of total identified compounds). Organic acids composition was also characterized, by HPLC-UV, and oxalic, citric, malic, quinic, shikimic and fumaric acids were determined. Malic and shikimic acids were present in higher amounts (ca. 26%, each). The antioxidant potential of this material was checked by distinct in vitro chemical assays. A concentration-dependent activity was noticed against DPPH, nitric oxide and superoxide radicals. Additionally, acetylcholinesterase inhibitory capacity was evaluated, but a weak effect was found. KEYWORDS: Ficus carica latex; volatiles; organic acids; antioxidant potential; acetylcholinesterase inhibition INTRODUCTION Latex is widely distributed in plants and consists of cytoplasmatic fluid of laticiferous tissues that contain the usual organelles of plant cells, such as nucleus, mitochondria, vacuoles and ribossomes, among others ( 1 ). This material contains various secondary meta- bolites, like terpenoids and phenolics, and proteins, namely, cysteine proteases ( 2 , 3 ). Many of these compounds provide resistance to hervibores via toxic or antinutritive effects, whereas others are involved in the stickiness that can mire insect hervibores ( 2 ). Ficus carica L., the common fig, is a species of great commer- cial importance, comprising numerous varieties with significant genetic diversity. All Ficus species possess latex-like material within their vasculatures. F. carica latex has been traditionally used in the treatment of gout, ulcers and warts, among other situations ( 4 , 5 ), given its proteolytic and keratolytic effects, associated with its viscosity ( 6 ). Plants show a constitutive emission of volatile compounds that are released from the surface of the leaf and/or accumulated in storage sites. Terpenes, as the largest class of plant secondary metabolites ( 7 ), have many volatile representatives. Monoterpenes (C 10 ), sesquiterpenes (C 15 ), and even some diterpenes (C 20 ), have high enough vapor pressures at normal atmospheric conditions to allow significant release into the air ( 8 ). These compounds play different roles in herbivore elimination, either by attraction of parasitoids that increase herbivore mortality (indirect defense) or by directly reducing herbivores ( 7 ). Organic acids are primary metabolites, which can be found in great amounts in all plants, especially in the fruits. The type and content of organic acids found are extremely variable between species, developmental stages and tissues types, additionally playing an important role in pH regulation ( 9 ). These compounds also exert a protective role against various diseases, due to their antioxidant activity ( 10 ). Antioxidant compounds, such as phenolics, organic acids, vitamin E and carotenoids, protect against oxidation, or cellular damage caused by reactive species, preventing the initiation of several diseases, like many types of cancer, heart disesase, diabetes and neurodegenerative illnesses ( 11 ). Antioxidant activ- ities have also been observed for volatile compounds, which are found in many plants, as well as in foods and beverages ( 12 ). Recently, several studies have been developed to assess the ability of natural compounds for inhibiting acetylcholinesterase activity, since this is the first approach for the treatment of neurological disorders, such as Alzheimer’s disease, senile de- mentia and ataxia ( 13 ). Few studies have been reported in F. carica latex, to describe the presence of 6-O-acyl-β-D-glucosyl-β-sitosterols and their *Corresponding authors. Tel: þ 351 222078934. Fax: þ351 222003977. E-mail: pandrade@ff.up.pt (P.B.A.), pguedes@ff.up.pt (P.G.P.).