Relevance of phenolic diterpene constituents to antioxidant activity of supercritical CO(2) extract from the leaves of rosemary.
Isolation of phenolic diterpene constituents from the freeze-dried leaves of Rosmarinus officinalis has been obtained by supercritical extraction with carbon dioxide. To determine the ideal conditions for the maximum yield of extract, nine different conditions using three levels of pressures (3000, 4000 and 5000 psi) in combination with three temperatures at 40, 60 and 80 degrees C, respectively, in combination with the analyses of the corresponding antioxidant activities and constituents which existed in extracts has been investigated. The antioxidant activity of each obtained extract was determined by using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals test. GC/MS method was used as an alternative to conventional HPLC method for the determination of the principal antioxidant constituents in extract, including phenolic diterpenes carnosic acid (CA) and carnosol (CAL). The confirmation of CA and CAL in extract was forward performed by subjecting HPLC isolates from extract into an ion trap mass spectrometer through an electrospray ionization (ESI) interface for MS/MS analysis. These results indicate that an ideal extraction process was obtained at 5000 psi and 80 degrees C with an extraction yield of 4.27% (w/w) and rich in phenolic antioxidants CA and CAL as contents of 35.23 and 0.46 mg g(-1) in extract, respectively.
Chang
Chi-Huang
CH
Research Institute of Biotechnology, Hungkuang University, Taichung Hsien, Taiwan. ROC.
Chyau
Charng-Cherng
CC
Hsieh
Chiu-Lan
CL
Wu
Yen-Ying
YY
Ker
Yaw-Bee
YB
Tsen
Hau-Yang
HY
Peng
Robert Y
RY
D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology; D002245:Carbon Dioxide / Q000737:chemistry*; D004224:Diterpenes / Q000737:chemistry*; D015394:Molecular Structure; D010636:Phenols / Q000032:analysis / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D027542:Rosmarinus / Q000737:chemistry*
D000975:Antioxidants; D004224:Diterpenes; D010636:Phenols; D010936:Plant Extracts; D002245:Carbon Dioxide