ORIGINALS ORIGINALARBEITEN Influence of different extraction temperatures and methanol solvent percentages on the total phenols and total flavonoids from the heartwood and bark of Acacia auriculiformis Mun Wai Tham • Kang Chiang Liew Received: 28 March 2013 Ó Springer-Verlag Berlin Heidelberg 2013 Abstract Acacia auriculiformis heartwood and bark were obtained, dried under shelter for 2 weeks and pulverized into powdered form to be extracted with the following extraction temperatures of 35, 55 and 75 °C and methanol solvent percentages of 55, 65 and 75 % for 3 h in a water bath. The material ratio used was 1:20 (pulverized samples: solvent). The total phenolics and flavonoids yield was determined by using a Thermo Scientific Genesys 10 UV– Visible Spectrophotometer. The optimum total phenolics and flavonoids yield were achieved by extraction with an extraction temperature of 75 °C and a methanol solvent percentage of 75 % for both the heartwood [75.44 % (total phenolics) and 36.64 % (total flavonoids)] and bark [87.18 % (total phenolics) and 99.10 % (total flavonoids)] of A. auriculiformis trees. Einfluss verschiedener Extraktionstemperaturen und Methanolkonzentrationen auf die gesamte Phenol- und Flavonoidausbeute aus Acacia auriculiformis Kernholz und Rinde Zusammenfassung Fu ¨r eine Dauer von 2 Wochen unter Dach getrocknetes und zu Pulverform gemahlenes Kernholz und Rinde von A. auriculiformis wurden bei Temperaturen von 35, 55 und 75 °C und einer Methanol- konzentration von 55, 65 und 75 % in einem Wasserbad fu ¨r eine Dauer von 3 Stunden extrahiert. Das Verha ¨ltnis von pulverisierter Probe zu Lo ¨sungsmittel betrug 1:20. Die gesamte Phenol- und Flavonoidausbeute wurde mit einem Thermo Scientific Genesys 10 UV-Visible Spectrophotometer bestimmt. Die optimale Ausbeute an Phenolen und Flavonoiden aus A. auriculiformis Ba ¨umen wurde bei einer Extraktionstemperatur von 75 °C und einer Methanolkonzentration von 75% sowohl fu ¨r Kernholz (75.44 % Phenole, 36.64 % Flavonoide) als auch fu ¨r Rinde (87.18 % Phenole und 99.10 % Flavonoide) erzielt. 1 Introduction Acacia auriculiformis of Leguminosae plant family are also known as Auri, earleaf acacia, earpod wattle, northern black wattle or tan wattle (PIER (Pacific Islands Ecosys- tems at Risk) 2002). This tree species is native to Australia, Papua New Guinea and Indonesia, was brought into Sabah, and is widely grown in plantations as a raw material for the production of pulp and paper as well as wood composites due to its fast growing nature and its capability of growing up to 30 m in height. Besides that, this tree species were also planted as ornamental (Gilman and Watson 1993) and shade trees. Studies have shown that A. auriculiformis trees contain a large amount of natural products including phenolics, flavones and flavonols, flavanones as well as flavonoids such as 3,4 0 ,7,8-tetrahydroxyflavanone, teracacidin (Mihara et al. 2005), auriculoside, Oritin-4b-ol and 4,2 0 ,3 0 ,4 0 -tetra- hydroxychalcone (Harborne and Baxter 1999) and all of these chemicals are known to possess both antioxidant and antifungal properties (Barry et al. 2005). The chemical compounds mentioned above also possess other potential usages such as anti-inflammatory (Garcia-Lafuente et al. 2009), antidepressant (Nisar et al. 2010), anticancer (Zhang et al. 2005), sweeteners (Kinghorn et al. 2010) and anti- feedant property of natural origin (Drijfhout and Morgan 2010). M. W. Tham (&) Á K. C. Liew School of International Tropical Forestry, University Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia e-mail: thammunwai@gmail.com 123 Eur. J. Wood Prod. DOI 10.1007/s00107-013-0743-y