Home
Giới thiệu
Tài khoản
Đăng nhập
Quên mật khẩu
Đổi mật khẩu
Đăng ký tạo tài khoản
Liệt kê
Công trình khoa học
Bài báo trong nước
Bài báo quốc tế
Sách và giáo trình
Thống kê
Công trình khoa học
Bài báo khoa học
Sách và giáo trình
Giáo sư
Phó giáo sư
Tiến sĩ
Thạc sĩ
Lĩnh vực nghiên cứu
Tìm kiếm
Cá nhân
Nội dung
Góp ý
Hiệu chỉnh lý lịch
Thông tin chung
English
Đề tài NC khoa học
Bài báo, báo cáo khoa học
Hướng dẫn Sau đại học
Sách và giáo trình
Các học phần và môn giảng dạy
Giải thưởng khoa học, Phát minh, sáng chế
Khen thưởng
Thông tin khác
Tài liệu tham khảo
Hiệu chỉnh
Số người truy cập: 107,005,108
Is Vitamin A an Antioxidant or a Prooxidant? (SCIE)
Tác giả hoặc Nhóm tác giả:
Duy Quang Dao
1,*
, Thi Chinh Ngo
1
, Nguyen Minh Thong
2
, Pham Cam Nam
3
Nơi đăng:
J. Phys. Chem. B;
S
ố:
121 (40);
Từ->đến trang
: 9348–9357;
Năm:
2017
Lĩnh vực:
Tự nhiên;
Loại:
Bài báo khoa học;
Thể loại:
Quốc tế
TÓM TẮT
Antioxidant efficiency of all-
trans
-retinol has been studied on the basis of characteristic thermochemical properties using density functional theory. The influence of the solvent polarity has also been evaluated. It is found that retinol may act in parallel as an effective antioxidant via H-atom donating as well as a prooxidant in yielding reactive hydroxyl radical. In fact, the lowest values of bond dissociation enthalpy were found at C18-H and C18-OH positions. Retinol was also determined as good electron donor but bad acceptor in the single electron transfer (ET) reaction with hydroperoxyl (HOO
●
) radical. In addition, potential energy surfaces of H-atom transfer (HAT) and radical adduct formation (RAF) reactions between retinol and HOO
●
radical were also investigated in the gas phase and in the solvent. The results demonstrated that RAF mechanism was generally more predominant than ET and HAT ones. The most favored radical addition position was found at C2=C3 double bond in cyclohexenyl ring. Moreover, the radical scavenging reactivity via RAF reactions was strongly exergonic and thermodynamically feasible while the ET one was endergonic. Natural bond orbital analysis showed that the lone pairs of electron on oxygen atom of the HOO
•
radical were donated to unoccupied antibonding orbital of transferred H-atom in HAT reactions. In contrast, in the case of RAF reactions, strong interactions between
2p
orbitals on oxygen atoms of the radical and p-orbital of double bond on retinol molecule were recognized. The results obtained in this work were in agreement with previous experimental observations.
ABSTRACT
Antioxidant efficiency of all-
trans
-retinol has been studied on the basis of characteristic thermochemical properties using density functional theory. The influence of the solvent polarity has also been evaluated. It is found that retinol may act in parallel as an effective antioxidant via H-atom donating as well as a prooxidant in yielding reactive hydroxyl radical. In fact, the lowest values of bond dissociation enthalpy were found at C18-H and C18-OH positions. Retinol was also determined as good electron donor but bad acceptor in the single electron transfer (ET) reaction with hydroperoxyl (HOO
●
) radical. In addition, potential energy surfaces of H-atom transfer (HAT) and radical adduct formation (RAF) reactions between retinol and HOO
●
radical were also investigated in the gas phase and in the solvent. The results demonstrated that RAF mechanism was generally more predominant than ET and HAT ones. The most favored radical addition position was found at C2=C3 double bond in cyclohexenyl ring. Moreover, the radical scavenging reactivity via RAF reactions was strongly exergonic and thermodynamically feasible while the ET one was endergonic. Natural bond orbital analysis showed that the lone pairs of electron on oxygen atom of the HOO
•
radical were donated to unoccupied antibonding orbital of transferred H-atom in HAT reactions. In contrast, in the case of RAF reactions, strong interactions between
2p
orbitals on oxygen atoms of the radical and p-orbital of double bond on retinol molecule were recognized. The results obtained in this work were in agreement with previous experimental observations.
[
acs.jpcb.7b07065.pdf
]
© Đại học Đà Nẵng
Địa chỉ: 41 Lê Duẩn Thành phố Đà Nẵng
Điện thoại: (84) 0236 3822 041 ; Email: dhdn@ac.udn.vn