Simple phenols in tropical woods determined by UHPLC-PDA and their antioxidant capacities: an experimental design for Randall extraction using environmentally friendly solvents

Abstract

A comprehensive experimental design was developed to determine suitable conditions (volume, percentage of solvent, extraction temperature) for the ethanol extraction of phenolic compounds from ten tropical woody plants. Wenge, angelim vermelho, zebrano, merbau, tigerwood, angelim pedra, jatoba, angelim amargoso, massaranduba, and doussie woods were used in experiments. The effects of three independent variables and their interactions on the yields of cinnamic and benzoic acid derivates were analyzed using UHPLC-PDA. The most significant parameters were found to be solvent percentage, extraction volume, and extraction temperature. Optimal conditions for the extraction of phenolic compound contents were an 80 °C extraction temperature, a 30 mL extraction volume, and the use of pure water as the extraction solvent. The tested species of woods contained mainly cinnamic acid derivates. Water extracts after hydrolysis contained greater amounts of cinnamic acid derivates than those extracts from non-hydrolyzed material. The total phenolics content was highest in water extracts of tigerwood, wenge and merbau; however, the extract of merbau wood was a stronger radical scavenger in ABTS^+· assays: 34.11 ± 0.02 mM Trolox equivalents per g of dry extract. The main compounds possessing antioxidant activity in the extracts of vermelho wood assessed by UHPLC analysis were hydroxycinnamic acids.

Keywords

Phenolic compounds / Tropical woods / Ultrahigh-performance liquid chromatography / Antioxidant capacity

References

[1] Aadil KR, Barapatre A, Sahu S, Jha H, Tiwary BN. Free radical scavenging activity and reducing power of Acacia nilotica wood lignin. Int J Biol Macromol, 2014, 67: 220-227.

[2] Aspé E, Fernández K. Comparison of phenolic extracts obtained of Pinus radiata bark from pulp and paper industry and sawmill industry. Rev Esp Cien Tec Ali, 2011, 13(3): 243-252.

[3] Baar J, Tippner J, Gryc V. The influence of wood density on longitudinal wave velocity determined by the ultrasound method in comparison to the resonance longitudinal method. Eur J Wood Prod, 2012, 70: 767-769.

[4] Baar J, Tippner J, Gryc V. Wood anatomy and acoustic properties of selected tropical hardwoods. IAWA J, 2016, 37(1): 69-83.

[5] Bursal E, Köksal E. Evaluation of reducing power and radical scavenging activities of water and ethanol extracts from sumac (Rhus coriaria L.). Food Res Int, 2011, 44(7): 2217-2221.

[6] Celhay C, Mathieu CE, Candy L, Vilarem G, Rigal L. Aqueous extraction of polyphenols and antiradicals from wood by-products by a twin-screw extractor: feasibility study. C R Chim, 2014, 17: 204-211.

[7] Dvorackova E, Snoblova M, Chromcova L, Hrdlicka P. Effects of extraction methods on the phenolic compounds contents and antioxidant capacities of cinnamon extracts. Food Sci Biotechnol, 2015, 24(4): 1201-1207.

[8] Fengel D, Wegener G. Wood. Chemistry, ultrastructure, reactions, 1984, Berlin: Walter de Gruyter 613

[9] Gironi F, Piemonte V. Temperature and solvent effects on polyphenol extraction process from chestnut tree wood. Chem Eng Res Des, 2011, 89(7): 857-862.

[10] Häkkinen S (2000) Flavonols and phenolic acids in berries and berry products. Dissertation, Kuopio University Publications D. Medical Sciences 221, Finland, pp 1–90

[11] Hertog MGL, Feskens EJM, Hollman PCH, Katan MB, Kromhout D. Dietary antioxidant flavonoids and cancer risk in the Zutphen elderly study. Nutr Cancer, 2000, 22(2): 175-184.

[12] Inbaraj BS, Lu H, Kao TH, Chen BH. Simultaneous determination of phenolic acids and flavonoids in Lycium barbarum Linnaeus by HPLC–DAD–ESI-MS. J Pharm Biomed Anal, 2010, 51(3): 549-556.

[13] Japon-Lujan R, Luque-Rodriguez JM, de Castro MDL. Dynamic ultrasound-assisted extraction of oleuropein and related biophenols from olive leaves. J Chromatogr A, 2006, 1108(1): 76-82.

[14] Kougan GB, Tabopda T, Kuete V, Verpoorte R. Kuete V. Simple phenols, phenolic acids, and related esters from the medicinal plants of Africa. Medicinal plant research in Africa: pharmacology and chemistry, 2013 1 Amsterdam: Elsevier 225 249

[15] Lamounier KC, Cunha LCS, de Morais SAL, de Aquino FJT, Chang R, de Nascimento EA, de Souza MGM, Martins CHG, Cunha WR. Chemical analysis and study of phenolics, antioxidant activity, and antibacterial effect of the wood and bark of Maclura tinctoria (L.) D. Don ex Steud. Evid Based Complement Altern Med, 2012, 2012: 451039.

[16] Markom M, Hasan M, Ramli W, Daud W, Singh S, Jahim JM. Extraction of hydrolysable tannins from Phyllanthus niruri Linn. Effect of solvents and extraction methods. Sep Purif Technol, 2007, 52(3): 487-496.

[17] Mattila P, Kumpulainen J. Determination of free and total phenolic acids in plant-derived foods by HPLC with diode-array detection. J Agric Food Chem, 2002, 50(13): 3660-3667.

[18] Medina MB. Simple and rapid method for the analysis of phenolic compounds in beverages and grains. J Agric Food Chem, 2011, 59(5): 1565-1571.

[19] Nenkova S, Radoykova T, Stanulov K. Preparation and antioxidant properties of biomass low molecular phenolic compounds (review). J Chem Technol Metall, 2011, 46(2): 109-120.

[20] Paulova H, Bochrakova H, Taborska E. In vitro methods for estimation of the antioxidant activity of natural compounds. Chem Listy, 2004, 98: 174-179.

[21] Prasad NK, Chun Y, En Y, Zhao M, Jiang Y. Effects of high pressure on the extraction yield, total phenolic content and antioxidant activity of longan fruit pericarp. Innov Food Sci Emerg, 2009, 10(2): 155-159.

[22] Re R, Pellegrini N, Proteggente A. Antioxidant activity applying an improved ABTS radical cation decolorization assay. Free Radic Bio Med, 1999, 26(9–10): 1231-1237.

[23] Robards K, Antolovich M. Analytical chemistry of fruit bioflavonoids: a review. Analyst, 1997, 122(2): 11-34.

[24] Rostagno MA, Palma M, Barroso CG. Ultrasound-assisted extraction of isoflavones from soy beverages blended with fruit juices. Anal Chim Acta, 2007, 597(2): 265-272.

[25] Šliumpaitė I, Venskutonis PR, Murkovic M, Ragažinskienė O. Antioxidant properties and phenolic composition of wood betony (Betonica officinalis L., syn. Stachys officinalis L.). Ind Crop Prod, 2013, 50: 715-722.

[26] Strack D. Dey PM, Harborne JB. Phenolic metabolism. Plant biochemistry, 1997, London: Academic Press 387 416

[27] Wallace G, Fry SC. Phenolic components of the plant cell wall. Int Rev Cytol, 1994, 151: 229-267.