Extraction of nobiletin from Citrus Unshiu peels by supercritical fluid and its CRE-mediated transcriptional activity.
BACKGROUND
Polymethoxyflavone (PMF) is one of bioactive compounds in Citrus Unshiu and included mainly in the peels rather than the fruits, seeds and leaves.


OBJECTIVE
Supercritical CO2extraction is one candidate for selective extraction of polymethoxyflavone and in this study, supercritical CO2extraction with/without ethanol entrainer from Citrus Unshiu peels was examined at a temperature of 333K and a pressure of 30MPa.


METHODS
CRE (cyclic AMP response element)-mediated transcriptional assay was examined by using the extracts from supercritical fluid extraction.


RESULTS
The results showed that extracts including nobiletin increased with increasing ethanol concentration in supercritical CO2and the elapsed extraction time. Extracts at ethanol concentration of 5 mol% showed high CRE-mediated transcription activity. This can be caused by activity of the extract including nobiletin in addition to the other methoxylated flavonoid species such as tangeretin. Extracts at ethanol concentration of 50% showed the highest CRE-mediated transcription activity, which can be attributed to flavonoid glycoside such as hesperidin. From our investigations, flavonoid glycoside can be one of promoters of CRE-mediated transcription activity.
Research Center of Supercritical Fluid Technology, Tohoku University, 6-6-11-403, Aoba, Aramaki, Aoba-ku, Sendai, 980-8579, Japan.
Chisato
C
Oba
Research Center of Supercritical Fluid Technology, Tohoku University, 6-6-11-403, Aoba, Aramaki, Aoba-ku, Sendai, 980-8579, Japan. Electronic address: masa@scf.che.tohoku.ac.jp.
Masaki
M
Ota
Research Center of Supercritical Fluid Technology, Tohoku University, 6-6-11-403, Aoba, Aramaki, Aoba-ku, Sendai, 980-8579, Japan.
Koichiro
K
Nomura
Research Center of Supercritical Fluid Technology, Tohoku University, 6-6-11-403, Aoba, Aramaki, Aoba-ku, Sendai, 980-8579, Japan.
Hironori
H
Fujiwara
Research Center of Supercritical Fluid Technology, Tohoku University, 6-6-11-403, Aoba, Aramaki, Aoba-ku, Sendai, 980-8579, Japan.
Jiro
J
Takito
Research Center of Supercritical Fluid Technology, Tohoku University, 6-6-11-403, Aoba, Aramaki, Aoba-ku, Sendai, 980-8579, Japan.
Yoshiyuki
Y
Sato
Research Center of Supercritical Fluid Technology, Tohoku University, 6-6-11-403, Aoba, Aramaki, Aoba-ku, Sendai, 980-8579, Japan.
Yasushi
Y
Ohizumi
Research Center of Supercritical Fluid Technology, Tohoku University, 6-6-11-403, Aoba, Aramaki, Aoba-ku, Sendai, 980-8579, Japan.
Hiroshi
H
Inomata
D002957:Citrus / Q000737:chemistry*; D017362:Cyclic AMP Response Element-Binding Protein / Q000187:drug effects* / Q000378:metabolism*; D047309:Flavones / Q000032:analysis* / Q000494:pharmacology*; D005638:Fruit / Q000737:chemistry*; D007564:Japan; D010936:Plant Extracts / Q000032:analysis / Q000494:pharmacology*
D017362:Cyclic AMP Response Element-Binding Protein; D047309:Flavones; D010936:Plant Extracts
CO(2); Pharmacological activity; Supercritical fluid extraction