Abstract
Theaflavins, the orange-red pigments contained in black tea, have attracted attention as a result of their health-promoting effects. However, their synthetic preparation, in which the enzymatic oxidation of catechol-type catechin is followed by the quinone-induced oxidative dimerization of selectively combined catechol- and pyrogallol-type catechins, provides only a low yield. In the present study, we found that a 1-octanol/buffer biphasic system improved the yield of theaflavin 3-gallate in a tyrosinase-catalyzed synthetic reaction with (-)-epicatechin and (-)-epigallocatechin gallate. When the enzymatic reaction proceeded in a buffer solution, oxidized (-)-epigallocatechin gallate was preferentially used for self-dimerization. However, self-dimerization was suppressed in the octanol phase, allowing oxidized (-)-epigallocatechin gallate to participate in coupling with (-)-epicatechin quinone, leading to effective production of theaflavin 3-gallate. Furthermore, the preferential localization of theaflavin 3-gallate in the octanol phase prevented (-)-epicatechin-quinone-induced degradation.
| Original language | English |
|---|---|
| Pages (from-to) | 13464-13472 |
| Number of pages | 9 |
| Journal | Journal of Agricultural and Food Chemistry |
| Volume | 66 |
| Issue number | 51 |
| DOIs | |
| Publication status | Published - 2018 Dec 26 |
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Keywords
- 1-octanol
- biphasic system
- enzymatic synthesis
- theaflavin
- tyrosinase
ASJC Scopus subject areas
- Chemistry(all)
- Agricultural and Biological Sciences(all)
Cite this
Efficient Synthesis of Theaflavin 3-Gallate by a Tyrosinase-Catalyzed Reaction with (-)-Epicatechin and (-)-Epigallocatechin Gallate in a 1-Octanol/Buffer Biphasic System. / Narai-Kanayama, Asako; Uekusa, Yoshinori; Kiuchi, Fumiyuki; Nakayama, Tsutomu.
In: Journal of Agricultural and Food Chemistry, Vol. 66, No. 51, 26.12.2018, p. 13464-13472.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Efficient Synthesis of Theaflavin 3-Gallate by a Tyrosinase-Catalyzed Reaction with (-)-Epicatechin and (-)-Epigallocatechin Gallate in a 1-Octanol/Buffer Biphasic System
AU - Narai-Kanayama, Asako
AU - Uekusa, Yoshinori
AU - Kiuchi, Fumiyuki
AU - Nakayama, Tsutomu
PY - 2018/12/26
Y1 - 2018/12/26
N2 - Theaflavins, the orange-red pigments contained in black tea, have attracted attention as a result of their health-promoting effects. However, their synthetic preparation, in which the enzymatic oxidation of catechol-type catechin is followed by the quinone-induced oxidative dimerization of selectively combined catechol- and pyrogallol-type catechins, provides only a low yield. In the present study, we found that a 1-octanol/buffer biphasic system improved the yield of theaflavin 3-gallate in a tyrosinase-catalyzed synthetic reaction with (-)-epicatechin and (-)-epigallocatechin gallate. When the enzymatic reaction proceeded in a buffer solution, oxidized (-)-epigallocatechin gallate was preferentially used for self-dimerization. However, self-dimerization was suppressed in the octanol phase, allowing oxidized (-)-epigallocatechin gallate to participate in coupling with (-)-epicatechin quinone, leading to effective production of theaflavin 3-gallate. Furthermore, the preferential localization of theaflavin 3-gallate in the octanol phase prevented (-)-epicatechin-quinone-induced degradation.
AB - Theaflavins, the orange-red pigments contained in black tea, have attracted attention as a result of their health-promoting effects. However, their synthetic preparation, in which the enzymatic oxidation of catechol-type catechin is followed by the quinone-induced oxidative dimerization of selectively combined catechol- and pyrogallol-type catechins, provides only a low yield. In the present study, we found that a 1-octanol/buffer biphasic system improved the yield of theaflavin 3-gallate in a tyrosinase-catalyzed synthetic reaction with (-)-epicatechin and (-)-epigallocatechin gallate. When the enzymatic reaction proceeded in a buffer solution, oxidized (-)-epigallocatechin gallate was preferentially used for self-dimerization. However, self-dimerization was suppressed in the octanol phase, allowing oxidized (-)-epigallocatechin gallate to participate in coupling with (-)-epicatechin quinone, leading to effective production of theaflavin 3-gallate. Furthermore, the preferential localization of theaflavin 3-gallate in the octanol phase prevented (-)-epicatechin-quinone-induced degradation.
KW - 1-octanol
KW - biphasic system
KW - enzymatic synthesis
KW - theaflavin
KW - tyrosinase
UR - http://www.scopus.com/inward/record.url?scp=85059534559&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85059534559&partnerID=8YFLogxK
U2 - 10.1021/acs.jafc.8b05971
DO - 10.1021/acs.jafc.8b05971
M3 - Article
C2 - 30482011
AN - SCOPUS:85059534559
VL - 66
SP - 13464
EP - 13472
JO - Journal of Agricultural and Food Chemistry
JF - Journal of Agricultural and Food Chemistry
SN - 0021-8561
IS - 51
ER -