| Ginger (Zingiber officinale Roscoe) rhizome contains the volatile essential oil responsible for the distinct aroma and the nonvolatile pungent compounds responsible for the pungent aroma and mainly pharmacologically active components in ginger. In order to promote the development and utilization of ginger oil, this paper studied the histochemical localization method of ginger essential oil and pungent compounds; the GC/MS analytical method for the determination of the chemical compositions of ginger oil; a novel HSCCC method for the separation and purification of major gingerols reference substances from ginger and effects of the growing development of ginger, cultivars, cultivated factors, different organs on the content and chemical compositions of ginger oil. The main results were as follows:1. NADI reagent can be used for histochemical localization staining of essential oils and gingerols by comparing the number of stains. And the essential oil was stained red brown, but gingerols was stained azure by NADI reagent. The essential oil and gingerols existed in the same type of oil cells and the number of points in the rhizomeby light microscope and transmission electron microscopy. They both were stored and accumulated in parenchyma cells of phloem and xylem.2. GC / MS technology can be applied to determinate the chemical compositions of the volatile essential oil and non-volatile gingerols in ginger oil without derivatization. The analysis resulted in 77 compounds in ginger oil from Zingiber officinale Rosc. var. Laiwudajiang, in which contained non-volatile ginger pungent compounds (40.69%) and abundant volatile compounds (59.31%). The volatile compounds were mainlyα- zingiberene (22.29%),β-sesquiphellandrene (8.58%),α-farnesene(3.93%),β-bisobolene (3.87%),α-curcumene (2.63%), which was mostly consisted of sesquiterpene hydrocarbons (50.15%). The pungent compounds of ginger were mainly 6-gingerol (9.38%), 6-shogaols (7.59%), zingerone (9.24%) produced by thermal degradation of the gingerols or shogaols. This analysis resulted in the detection of 3 hitherto unknown natural compounds from ginger var. Laiwudajiang, which were 6-isogingerol, Z-10-isoshogaol and E-10-isoshogaol, respectively.3. There were significant differences in ginger oil extraction rate and chemical components among different extraction methods. The ginger oil extraction rate by steam distillation, ethanol leaching and supercritical carbon dioxide was 0.95%,3.75% and 4.67%,respectively. The ginger essential oil obtained by steam distillation was mainly the sesquiterpenoids (63.46%) and the monoterpenoids (34.91%) responsible for the distinct aroma; The ginger concrete obtained by ethanol leaching was mainly the pungent compounds (86.41%) responsible for the pungent aroma, 6-gingerol (16.86%), 6-shogaol (16.58%) and zingerone (17.68%) among them; The ginger oleoresin obtained from supercritical carbon dioxide contained abundant non-volatile ginger pungent compounds (40.69%) and abundant volatile aromatic compounds (59.31%), and presented intensely the aroma and pungency of ginger.4. Ginger oil content of seed-ginger were more higher than that of fresh ginger. And the chemical components in both were the same, however, the relative content of chemical components was a significant difference. The relative content ofα-curcumene and pungent principles in seed-ginger was 3.60%, 3.89% higher than that in fresh ginger, respectively. The seed-ginger had a lighter fragrance than fresh ginger, but had a strong pungent taste and higher value of nutition and health care.5. Root, ligament, xylem and periderm contained abundant ginger oil, and the content of ginger oil was 2.1±0.1%, 4.64±0.13%, 4.6 2±0.17%, 0.94±0.04%, respectively. Ginger oil can be extracted without peeling ginger in processing. Extracts with SEF-CO2 from stem and leaf have little chemical compounds of ginger oil and can make use of little value from extrating ginger oil.6. There were non-significant differences between different ginger cultivars. However, the relative content of chemical composition was significant differences. The following ginger cultivars were contained more higher the content of ginger oil and the relative content of pungent principles: laiwedajiang, ribendajiang, shannongyihao, shannongrehao, anqiudajiang. The following ginger cultivars were contained more lower the content of ginger oil and the relative content of pungent principles: fangzhoujiang, jingshijiang, anqiuxiaojiang.7. There were non-significant differences between chemical compounds of ginger oil during different growth times. But the relative content of chemical composition was significant differences. The content of ginger oil and the relative content of pungent priciples were a gradual upward trend from 1.86±0.09% and 32.7% to 4.56±0.15% and 40.11% from germinating stage to harvesting stage, espectively. The results indicated that the second metabolites (ginger oil) were continuously synthesized and stored in the rhizomes of ginger.8. Green film, red film and white film in ginger cultivation had non-significant effect on the content of ginger oil and chemical components of ginger oil, and can be applied to ginger cultivation. However, blue film was unsuitable for ginger cultivation due to making ginger oil content (3.85±0.11%) and the relative content of pungent priciples (33.68%) a significant decrease.9. High-speed counter-current chromatography can be applied to the separation and purification of 6-gingerol,8-gingerol and 10-gingerol from a crude extract of ginger. The experiment yielded 30.2 mg of 6-gingerol, 40.5 mg of 8-gingerol, 50.5 mg of 10-gingerol from 200mg of crude extract in one-step separation. And the purity of these compounds was 99.9%, 99.9% and 99.2%, respectively, as determined by high-performance liquid chromatography (HPLC). Gingerols may be used for in vitro and in vivo studies and as reference substances for analytical purposes...
|
PDF Full Text Request