title: Bioconversion of Capsaicin by Aspergillus oryzae.
abstract: This study identified metabolites of capsaicin bioconverted by Aspergillus oryzae, which is generally used for mass production of gochujang prepared by fermenting red pepper powder in Korea. A. oryzae was incubated with capsaicin in potato dextrose broth. Capsaicin decreased depending on the incubation period, but new metabolites increased. Five capsaicin metabolites purified from the ethyl acetate fraction of the capsaicin culture were identified as N-vanillylcarbamoylbutyric acid, N-vanillyl-9-hydroxy-8-methyloctanamide, ω-hydroxycapsaicin, 8-methyl-N-vanillylcarbamoyl-6(E)-octenoic acid, and 2-methyl-N-vanillylcarbamoyl-6(Z)-octenoic acid by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The capsaicin metabolites in gochujang were confirmed and quantitated by selective multiple reaction monitoring detection after liquid chromatography electrospray ionization MS using the isolated compounds as external standards. On the basis of the structures of the capsaicin metabolites, it is proposed that capsaicin metabolites were converted by A. oryzae by ω-hydroxylation, alcohol oxidation, hydrogenation, isomerization, and α- and/or β-oxidation.
authors.forename: Minji
authors.initials: M
authors.lastname: Lee
authors.forename: Jeong-Yong
authors.initials: JY
authors.lastname: Cho
authors.forename: Yu Geon
authors.initials: YG
authors.lastname: Lee
authors.forename: Hyoung Jae
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: §Division of Nutrition and Metabolism Research, Korea Food Research Institute, Baekhyun-Dong, Bundang-Ku, Sungnam-Si, Gyeonggi-Do 463-746, Republic of Korea.
authors.forename: Seong-Il
authors.initials: SI
authors.lastname: Lim
authors.affiliation: §Division of Nutrition and Metabolism Research, Korea Food Research Institute, Baekhyun-Dong, Bundang-Ku, Sungnam-Si, Gyeonggi-Do 463-746, Republic of Korea.
authors.forename: So-Lim
authors.initials: SL
authors.lastname: Park
authors.forename: Jae-Hak
authors.initials: JH
authors.lastname: Moon
mesh_terms: D001236:Aspergillus oryzae / Q000378:metabolism*; D001711:Biotransformation; D002211:Capsaicin / Q000737:chemistry / Q000378:metabolism*; D002212:Capsicum / Q000737:chemistry / Q000378:metabolism / Q000382:microbiology*; D005285:Fermentation; D006865:Hydrogenation; D006900:Hydroxylation; D007536:Isomerism; D013058:Mass Spectrometry; D015394:Molecular Structure; D056910:Republic of Korea
chemical_list: D002211:Capsaicin
keywords: Aspergillus oryzae; capsaicin; gochujang; hot pepper; secondary metabolites