In dead biological tissues such as human hair, the ability of antioxidants to minimise autoxidation is determined by their chemical reactions with reactive oxygen species. In order to improve our understanding of factors determining such antioxidant properties, the mechanistic chemistry of four phenolic antioxidants found in tea and rosemary extracts (epicatechin, epigallocatechin gallate, rosmarinic and carnosic acids) has been investigated. The degradation of N-acetyl alanine by photochemically generated hydroxyl radicals was used as a model system. A relatively high concentration of the antioxidants (0.1 equivalent with respect to the substrate) tested the ability of the antioxidants to intercept both initiating hydroxyl radicals (preventive action) and propagating peroxyl radicals (chain-breaking action). LC-MS data showed the formation of hydroxylated derivatives, quinones and hydroperoxides of the antioxidants. The structure of the assignment was aided by deuterium exchange experiments. Tea polyphenolics (epicatechin and epigallocatechin gallate) outperformed the rosemary compounds in preventing substrate degradation and were particularly effective in capturing the initiating radicals. Carnosic acid was suggested to act mostly as a chain-breaking antioxidant. All of the antioxidants except for rosmarinic acid generated hydroperoxides which was tentatively ascribed to the insufficient lability of the benzylic C-H bond of rosmarinic acid.
机构:Aligarh Muslim Univ, Fac Life Sci, Dept Biochem, Aligarh 202002, Uttar Pradesh, India
Azam, S
Hadi, N
论文数: 0引用数: 0
h-index: 0
机构:Aligarh Muslim Univ, Fac Life Sci, Dept Biochem, Aligarh 202002, Uttar Pradesh, India
Hadi, N
Khan, NU
论文数: 0引用数: 0
h-index: 0
机构:Aligarh Muslim Univ, Fac Life Sci, Dept Biochem, Aligarh 202002, Uttar Pradesh, India
Khan, NU
Hadi, SM
论文数: 0引用数: 0
h-index: 0
机构:
Aligarh Muslim Univ, Fac Life Sci, Dept Biochem, Aligarh 202002, Uttar Pradesh, IndiaAligarh Muslim Univ, Fac Life Sci, Dept Biochem, Aligarh 202002, Uttar Pradesh, India
机构:
Duy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Duy Tan Univ, Fac Nat Sci, Da Nang 550000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Dinh Hieu Truong
Thi Chinh Ngo
论文数: 0引用数: 0
h-index: 0
机构:
Duy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Duy Tan Univ, Fac Nat Sci, Da Nang 550000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Thi Chinh Ngo
Nguyen Thi Ai Nhung
论文数: 0引用数: 0
h-index: 0
机构:
Hue Univ, Univ Sci, Dept Chem, Hue 530000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Nguyen Thi Ai Nhung
Duong Tuan Quang
论文数: 0引用数: 0
h-index: 0
机构:
Hue Univ, Univ Sci, Dept Chem, Hue 530000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Duong Tuan Quang
Thi Le Anh Nguyen
论文数: 0引用数: 0
h-index: 0
机构:
Duy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Duy Tan Univ, Fac Nat Sci, Da Nang 550000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Thi Le Anh Nguyen
Khiri, Dorra
论文数: 0引用数: 0
h-index: 0
机构:
Hue Univ, Univ Educ, Dept Chem, Hue 530000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Khiri, Dorra
Taamalli, Sonia
论文数: 0引用数: 0
h-index: 0
机构:
Hue Univ, Univ Educ, Dept Chem, Hue 530000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Taamalli, Sonia
Louis, Florent
论文数: 0引用数: 0
h-index: 0
机构:
Hue Univ, Univ Educ, Dept Chem, Hue 530000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Louis, Florent
El Bakali, Abderrahman
论文数: 0引用数: 0
h-index: 0
机构:
Hue Univ, Univ Educ, Dept Chem, Hue 530000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
El Bakali, Abderrahman
Duy Quang Dao
论文数: 0引用数: 0
h-index: 0
机构:
Duy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Duy Tan Univ, Fac Nat Sci, Da Nang 550000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
机构:Aligarh Muslim Univ, Fac Life Sci, Dept Biochem, Aligarh 202002, Uttar Pradesh, India
Azam, S
Hadi, N
论文数: 0引用数: 0
h-index: 0
机构:Aligarh Muslim Univ, Fac Life Sci, Dept Biochem, Aligarh 202002, Uttar Pradesh, India
Hadi, N
Khan, NU
论文数: 0引用数: 0
h-index: 0
机构:Aligarh Muslim Univ, Fac Life Sci, Dept Biochem, Aligarh 202002, Uttar Pradesh, India
Khan, NU
Hadi, SM
论文数: 0引用数: 0
h-index: 0
机构:
Aligarh Muslim Univ, Fac Life Sci, Dept Biochem, Aligarh 202002, Uttar Pradesh, IndiaAligarh Muslim Univ, Fac Life Sci, Dept Biochem, Aligarh 202002, Uttar Pradesh, India
机构:
Duy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Duy Tan Univ, Fac Nat Sci, Da Nang 550000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Dinh Hieu Truong
Thi Chinh Ngo
论文数: 0引用数: 0
h-index: 0
机构:
Duy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Duy Tan Univ, Fac Nat Sci, Da Nang 550000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Thi Chinh Ngo
Nguyen Thi Ai Nhung
论文数: 0引用数: 0
h-index: 0
机构:
Hue Univ, Univ Sci, Dept Chem, Hue 530000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Nguyen Thi Ai Nhung
Duong Tuan Quang
论文数: 0引用数: 0
h-index: 0
机构:
Hue Univ, Univ Sci, Dept Chem, Hue 530000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Duong Tuan Quang
Thi Le Anh Nguyen
论文数: 0引用数: 0
h-index: 0
机构:
Duy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Duy Tan Univ, Fac Nat Sci, Da Nang 550000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Thi Le Anh Nguyen
Khiri, Dorra
论文数: 0引用数: 0
h-index: 0
机构:
Hue Univ, Univ Educ, Dept Chem, Hue 530000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Khiri, Dorra
Taamalli, Sonia
论文数: 0引用数: 0
h-index: 0
机构:
Hue Univ, Univ Educ, Dept Chem, Hue 530000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Taamalli, Sonia
Louis, Florent
论文数: 0引用数: 0
h-index: 0
机构:
Hue Univ, Univ Educ, Dept Chem, Hue 530000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Louis, Florent
El Bakali, Abderrahman
论文数: 0引用数: 0
h-index: 0
机构:
Hue Univ, Univ Educ, Dept Chem, Hue 530000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
El Bakali, Abderrahman
Duy Quang Dao
论文数: 0引用数: 0
h-index: 0
机构:
Duy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
Duy Tan Univ, Fac Nat Sci, Da Nang 550000, VietnamDuy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam