This article was downloaded by: [University of Hong Kong Libraries] On: 12 March 2013, At: 05:59 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK Natural Product Research: Formerly Natural Product Letters Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/gnpl20 Comparison of antifungal activities of Vietnamese citrus essential oils a a Pham Van Hung , Pham Thi Lan Chi & Nguyen Thi Lan Phi b a School of Biotechnology, International University, Vietnam National University, HoChiMinh City, Vietnam b Faculty of Chemical Engineering, HoChiMinh City University of Technology, HoChiMinh City, Vietnam Version of record first published: 16 Jul 2012 To cite this article: Pham Van Hung , Pham Thi Lan Chi & Nguyen Thi Lan Phi (2013): Comparison of antifungal activities of Vietnamese citrus essential oils, 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material Natural Product Natural ProductResearch, Research2013 Vol 27, Nos 4–5, 506–508, http://dx.doi.org/10.1080/14786419.2012.706293 2012, 1–3, iFirst SHORT COMMUNICATION Comparison of antifungal activities of Vietnamese citrus essential oilsy Pham Van Hunga*, Pham Thi Lan Chia and Nguyen Thi Lan Phib a Downloaded by [University of Hong Kong Libraries] at 05:59 12 March 2013 School of Biotechnology, International University, Vietnam National University, HoChiMinh City, Vietnam; bFaculty of Chemical Engineering, HoChiMinh City University of Technology, HoChiMinh City, Vietnam (Received 11 January 2012; final version received 12 June 2012) Citrus essential oils (EOs) are volatile compounds from citrus peels and widely used in perfumes, cosmetics, soaps and aromatherapy In this study, inhibition of citrus EOs extracted from Vietnamese orange (Citrus sinensis), mandarin (Citrus reticulata Blanco), pomelo (Citrus grandis Osbeck) and lime (Citrus aurantifolia Swingle) on the growth of plant pathogenic fungi, Mucor hiemalis, Penicillium expansum and Fusarium proliferatum was investigated The EOs of the citrus peels were obtained by cold-pressing method and the antifungal activity of EOs was evaluated using the agar dilution method The results show that the EOs had significant antifungal activity Lime EO was the best inhibitor of M hiemalis and F proliferatum while pomelo EO was the most effective against P expansum These results indicate that citrus EOs can be used as antifungal natural products in the food, pharmaceutical and cosmetic industries Keywords: citrus essential oils; antifungal activity; cold-pressing extraction; plant pathogenic fungi Introduction Citrus fruits grown in Vietnam are diversified and each citrus crop varies with the agroecological region Orange (Citrus sinensis), mandarin (Citrus reticulata Blanco), pomelo (Citrus grandis Osbeck) and lime (Citrus aurantifolia Swingle) are found to be the most popular varieties harvested all over the country (Lan-Phi, 2010) Citrus varieties contain large amounts of essential oils (EOs), which exist especially in peel, flowers and leaves EOs are now widely used in many fields because they posses a wide spectrum of biological activity The antimicrobial abilities of citrus EOs are also shown to be a particularly interesting field for applications within the food and cosmetic industries (Caccioni, Guizzardi, Biondi, Renda, & Ruberto, 1998) The application of citrus EOs for skincare products and for acne control was also investigated (Lertsatitthanakorn, Taweechaisupapang, Aromdee, & Khunkitti, 2006) Although antifungal activities of citrus oils have been widely done all over the world, the variation of antifungal activities of citrus EOs grown in different locations has been observed because of the variation of chemical components in the oils (Caccioni et al., 1998; Kirbaslar, Tavman, Dulger, & Turker, 2009; Viuda-Martos, Ruiz-Navajas, Fernandez-Lopez, & Perez-Alvarez, 2008) Therefore, the objective of this study is to investigate the antifungal activity of EOs *Corresponding author Email: pvhung@hcmiu.edu.vn yThis article is a contribution for the special issue on the 70th birthday of Prof Dr Atta-ur-Rahman *Corresponding author Email: pvhung@hcmiu.edu.vn † ISSN 1478–6427 online This1478–6419 article is print/ISSN a contribution for the special issue on the 70th birthday of Prof Dr Atta-ur-Rahman *Corresponding author Email: xxxxxxxxxxxxxx � 2012 Taylor & Francis © 2013 Taylor & Francis http://dx.doi.org/10.1080/14786419.2012.706293 http://www.tandfonline.com © 2013 Taylor & Francis Natural Product Research 507 P Van Hung et al extracted from the peels of Vietnamese citrus including C sinensis, C reticulata Blanco, C grandis Osbeck and C aurantifolia Swingle on the growth of Mucor hiemalis, Penicillium expansum and Fusarium proliferatum Results and discussion Downloaded by [University of Hong Kong Libraries] at 05:59 12 March 2013 2.1 Results Vietnamese C sinensis EO mainly comprised of monoterpene hydrocarbons with limonene, myrcene, sabinene and �-pinene (90.42%, 2.81%, 0.99% and 0.81%, respectively) as the major components (Table S1) The largest component found in the C reticulata Blanco EO was limonene (91.58%) and other main constituents included the monoterpene group including myrcene (2.79%), �-pinene (0.93%), �-pinene (0.60%), �-phellandrene (0.53%) and sabinene (0.33%) Limonene was only 70.46% of the total EO of C grandis Osbeck In addition, �-terpinene of this fruit accounted for 11.09%, higher than that of C sinensis and C reticulata Blanco EOs (occupied lower than 0.01%) Limonene (41.40%) was found as the largest compound of C aurantifolia Swingle EO, but significantly lower than in other citrus fruits �-pinene (18.54%), �-terpinene (7.13%), sabinene (4.52%), �-pinene (2.87%) and myrcene (1.21%) were also major components of C aurantifolia Swingle EO In addition, geranial (2.92%) and neral (1.87%) were found to be high contents of the aldehyde group in C aurantifolia Swingle EO The Vietnamese citrus EOs were found to have high activity in inhibition of the growth of fungi (Table 1) After days of culturing, the growth of the tested fungi decreased, associated with increase of EO concentration Citrus aurantifolia Swingle EO had the greatest reduction in mycelial growth of M hiemalis at a concentration of 2000 ppm (100% inhibition) The second most effective EO on M hiemalis was from C grandis Osbeck (42.1% inhibition), followed by the EOs of C sinensis and C reticulata Blanco (36.5% and 37.1%, respectively) Citrus grandis Osbeck and C aurantifolia Swingle EOs were found to be the most effective in reducing mycelium growth of P expansum (53.8% and 52.0% inhibition, respectively) The C sinensis and C reticulata Blanco EOs showed significantly lower reduction than did the C grandis Osbeck and C aurantifolia Swingle (34.9% and 39.3% inhibition) The highest reduction of mycelial growth of F proliferatum was recorded in C aurantifolia Swingle EO (91.5% inhibition) Other citrus EOs also exhibited the high activity on the inhibition of the growth of F proliferatum as the inhibition percentages were 59.5%, 50.9% and 63.0% inhibition for C sinensis, C reticulata Blanco and C grandis Osbeck, respectively As a result, the significant differences in the inhibition of the tested fungi of Vietnamese citrus EOs were clearly observed in this study Table Inhibition (%) of Vietnamese citrus EOs (at 2000 ppm) on the growth of M hiemalis, P expansum and F proliferatum Fungi Citrus variety Citrus Citrus Citrus Citrus sinensis reticulata Blanco grandis Osbeck aurantifolia Swingle Mucor hiemalis Penicillium expansum Fusarium proliferatum 36.5 � 0.2a 37.1 � 0.5a 42.1 � 0.4b 100 � 0.0c 34.9 � 1.4a 39.3 � 0.7b 53.8 � 0.9c 52.0 � 1.0c 59.5 � 1.6b 50.9 � 1.6a 63.0 � 1.0c 91.5 � 2.4 d Note: Values are means of triplicate measurements The same letters in the same column are not significantly different (p 0.05) 508 P Van Hung et al Natural Product Research Downloaded by [University of Hong Kong Libraries] at 05:59 12 March 2013 2.2 Discussion The EOs of Citrus varieties show significant ability against fungi The antifungal activity of EOs was due to the presence of terpenes existing in the EOs This component passes the cell membranes, penetrates into the interior of the cell and interacts with critical intracellular sites (Cristani et al., 2007) Several studies have mentioned that a single major compound or the synergistic or antagonistic of various compounds of citrus EOs may produce antifungal activity (Deba, Xuan, Yasuda, & Tawata, 2007) Other authors reported that the presence of components such as D-limonene, linalool or citral causes the antifungal capacity of citrus EOs (Alma et al., 2004) Citral can form a charge transfer complex with an electron donor to fungal cells, which results in fungal death (Kurita, Miyaji, Kurane, & Takahara, 1981) In addition, other researchers reported that the formation of hydrogen bonds between the hydroxyl group of oil phenolics and active sites of target enzymes induces the antifungal activity of EOs (Daferera, Ziogas, & Polissiou, 2000) Thus, the different antifungal activity observed in this study is due to the different chemical composition existing in the EOs of citrus varieties Conclusions The EOs of C sinensis, C reticulata Blanco, C grandis Osbeck and C aurantifolia Swingle showed significant antifungal activities against M hiemalis, P expansum and F proliferatum Citrus aurantifolia Swingle EO is the most effective against M hiemalis and F proliferatum, whereas C grandis Osbeck EO is the best inhibitor of P expansum Supplementary material Experimental details relating to this article are available online, alongside Table S1 References Alma, M.H., Nitz, S., Kollmannsberger, H., Digrak, M., Efe, F.T., & Yilmaz, N (2004) Chemical composition and antimicrobial activity of the essential oils from the gum of Turkish Pistachio (Pistacia vera L.) Journal of Agricultural and Food Chemistry, 52, 3911–3914 Caccioni, D.R.L., Guizzardi, M., Biondi, D.M., Renda, A., & Ruberto, G (1998) Relationship between volatile components of citrus fruit essential oils and antimicrobial action on Penicillium digitatum and Penicillium italicum International Journal of Food Microbiology, 43, 73–79 Cristani, M., D’Arrigo, M., Mandalari, G., Castelli, F., Sarpietro, M.G., Micieli, D., Trombetta, D (2007) Interaction of four monoterpenes contained in essential oils with model membranes: Implications for their antibacterial activity Journal of Agricultural and Food Chemistry, 55, 6300–6308 Daferera, D.J., Ziogas, B.N., & Polissiou, M.G (2000) GC–MS analysis of essential oils from some Greek aromatic plants and their fungitoxicity on Penicillium digitatum Journal of Agricultural and Food Chemistry, 48, 2576–2581 Deba, F., Xuan, T.D., Yasuda, M., & Tawata, S (2007) Chemical composition and antioxidant, antibacterial and antifungal activities of the essential oils from Bidens pilosa Food Control, 19, 346–352 Kirbaslar, F.G., Tavman, A., Dulger, B., & Turker, G (2009) Antimicrobial activity of Turkish citrus peel oils Pakistan Journal of Botany, 41, 3207–3212 Kurita, N., Miyaji, M., Kurane, R., & Takahara, Y (1981) Antifungal activity of components of essential oils Agricultural and Biological Chemistry, 45, 945–952 Lan-Phi, N.T (2010) Composition analysis: Vietnam In M Sawamura (Ed.), Citrus essential oils – Flavor and Fragrance (pp 132–145) Hoboken, NJ: John Wiley & Sons Lertsatitthanakorn, P., Taweechaisupapong, S., Aromdee, C., & Khunkitti, W (2006) In vitro bioactivities of essential oils used for acne control International Journal of Aromatherapy, 16, 43–49 Viuda-Martos, M., Ruiz-Navajas, Y., Fernandez-Lopez, J., & Perez-Alvarez, J (2008) Antifungal activity of lemon (Citrus lemon L.), mandarin (Citrus reticulata L.), grapefruit (Citrus paradisi L.) and orange (Citrus sinensis L.) essential oils Food Control, 19, 1130–1138 ... Inhibition (%) of Vietnamese citrus EOs (at 2000 ppm) on the growth of M hiemalis, P expansum and F proliferatum Fungi Citrus variety Citrus Citrus Citrus Citrus sinensis reticulata Blanco grandis... of citrus oils have been widely done all over the world, the variation of antifungal activities of citrus EOs grown in different locations has been observed because of the variation of chemical... 2012) Citrus essential oils (EOs) are volatile compounds from citrus peels and widely used in perfumes, cosmetics, soaps and aromatherapy In this study, inhibition of citrus EOs extracted from Vietnamese