Extraction and isolation of diphenylheptanes and flavonoids from Alpinia officinarum Hance using supercritical fluid extraction followed by supercritical fluid chromatography.

In this paper, an off-line combination method of supercritical fluid extraction and supercritical fluid chromatography was developed for the selective extraction and isolation of diphenylheptanes and flavonoids from Alpinia officinarum Hance. The enrichment of target components was successfully achieved using supercritical fluid extraction with the following conditions (8% ethanol as co-solvent at 45°C and 30 MPa for 30 min). Taking full advantage of the complementarity of supercritical fluid chromatography stationary phases, a two-step preparative supercritical fluid chromatography strategy was constructed. The extract was firstly divided into seven fractions on a Diol column (250 × 20 mm internal diameter, 10 µm) within 8 min by gradient elution increasing from 5% to 20% modifier (methanol) at 55 ml/min and 15 MPa. Then the seven fractions were separated by using a 1-AA or a DEA column (250 × 19 mm internal diameter, 5 µm) at 50 ml/min and 13.5 MPa. This two-step strategy showed superior separation ability for structural analogs. As a result, seven compounds, including four diphenylheptanes and three flavonoids with high purity, were successfully obtained. The developed method is also helpful for the extraction and isolation of other structural analogs of traditional Chinese medicines.

Neuroprotective and Anti-Inflammatory Effects of Diphenylheptanes from the Fruits of Amomum tsaoko, a Chinese Spice.

Two novel diphenylheptanes, 2,3- dihydro-2 - (4' - hydroxy-phenylethyl) - 6 - [(3″,4″ - dihydroxy-5" - methoxy) phenyl] -4 - pyrone (CG-A) and 4 - dihydro-2 - (4' - hydroxy-phenylmethyl) -6 - [(3",4″ - dihydroxy-5″ - methoxyphenyl) methylene]-pyran-3, 5 - dione (CG-B), were isolated from the dried fruits of Amomum tsaoko, a commercially important spice. This study was designed to investigate their protective effects against H2O2-induced nerve injury, using PC-12 cells to determine the cell cytotoxicity and cell viability. The inhibitory effect on (nitric oxide) NO production was also determined in (lipopolysaccharide) LPS-stimulated macrophage RAW 264.7 cells. The results showed that CG-A and CG-B displayed significant neuroprotective effect and exhibited anti-inflammatory activity in a dose-dependent manner. These findings suggest that CG-A and CG-B are very important nutritional ingredients responsible for the neuroprotective and anti-inflammatory health benefits of A. tsaoko.