https://doi.org/10.17113/ftb.57.03.19.6022


Influence of D-Amino Acids in Beer on Formation of Uric Acid


Yuhe Kan^1§, Zhikun Zhang^1§, Kunhao Yang¹, Mengru Ti¹, Yongqi Ke¹, Li Wu^1,2*, Jingkui Yang¹* and Yujian He^1,2*


¹School of Chemical Sciences, University of Chinese Academy of Sciences, No.380 Huaibei Zhuang, Huairou District, 100049 Beijing, PR China
²State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Peking University,
 100191 Beijing, PR China




Article history:
Received: 4 September 2018
Accepted: 10 May 2019





Key words:
uric acid, beer, D-amino acid, hydroxyl radicals, DNA damage




Summary:
Excessive intake of beer could increase serum uric acid levels, leading to high risk of gout, which was previously attributed to high purine content in beer. Recent reports that purine-rich vegetables and bean products do not cause higher uric acid levels do not support this theory. Why excessive intake of beer could increase a high risk of gout has been unclear. Other factors affecting the accumulation of uric acid in the blood have been explored. Beer contains relatively high levels of D-amino acids due to the racemization of L-amino acids induced by food processing. D-amino acid was catalyzed by D-amino acid oxidase to produce H₂O₂, which is further oxidized in the presence of Fe²⁺ to produce hydroxyl radicals, resulting in DNA damage and formation of a large amount of purine bases, which are oxidized to uric acid by a series of enzymes. Some food ingredients, such as vitamins and I^–, prompt D-amino acids to form uric acid. d-amino acids in beer are one of the key factors responsible for the increase in uric acid levels. The biological response of D-amino acids could explain gout occurrence in beer drinkers.






*Corresponding author:    +8615010119766
                                              wuli@ucas.ac.cn (Li W)
                                            +8613693049534
                                             jkyang@ucas.ac.cn (Yang J)
                                            +8613691472876
                                             heyujian@ucas.ac.cn (He Y)

^§These authors contributed equally to this work