• Archives of Pharmacal Research
• /
• v.23 no.2
• /
• pp.163-166
• /
• 2000

The effects of modifiers such as methanol, water diethylamine in methanol (10 v/v %), and diethylamine in water (10 v/v %) were investigated at three different concentrations (1, 5, and 10 v/v %) of the modifiers in supercritical $CO_2$ (SC-$CO_2$) in order to enhance the supercritical fluid extraction (SFE) efficiency of cephalotaxine from Cephalotaxus wilsoniana Leaves. Among the modifiers employed, methanol basified with diethylamine was found to greatly enhance the extraction efficiency relative to any other modifiers employed. The results suggest that cephalotaxine in plant matrices may be readily changed from SC-$CO_2$-insoluble salt to SC-$CO_2$-soluble free base by basified modifiers. In addition, SC-$CO_2$modified with basified methanol could enhance the extraction efficiency of cephalotaxine more than 30% when compared to the conventional organic solvent extraction.

• KSBB Journal
• /
• v.15 no.5
• /
• pp.434-437
• /
• 2000

The contents and composition of alkaloids homoharringtonine, harringtonine, and cephalotaxine were determined in Korean native plumyew tree (Cephalotaxus koreana) collected from 17 different sites in Korea. The alkaloid contents of C. koreana varied with locations and plant populations from 11.8 mg/g to 195.2 mg/g of dry weight while C. koreana in southern area had higher alkaloid contents. The alkaloid compositions in C. koreana were highest with homoharringtonine (40%) and followed harringtonine (32%) and cephalotaxine (28%). Total alkaloids and homoharringtonine contents in needles were higher than those of stem by 2 fold. Alkaloid contents of C. koreana were the highest in winter, and the lowest in summer. Comparison of alkaloid contents and composition with other species of Cephalotaxus revealed that C. koreana was different to C. harringtonia, and contents of homoharringtonine were higher than other species. C. koreana could be potential source for homoharringtonine and related alkaloids.

• Journal of Pharmaceutical Investigation
• /
• v.35 no.4
• /
• pp.249-254
• /
• 2005

Multidrug resistance (MDR) of cancer cells is, at least in part, associated with the overexpression of P-glycoprotein (P-gp). Many studies have demonstrated that natural compounds obtained from fruits, vegetables, teas and medicinal plants may modulate P-gp activity. The objective of the present investigation was to examine the effect of seven natural compounds on the P-gp activity in human uterine sarcoma cell line, MES-SA/DX5. Daunomycin uptake was significantly increased by biochanin A and silymarin (p<0.0001) whereas it was reduced by morin (p<0.01). The efflux of daunomycin from the cells was significantly inhibited by biochanin A, morin, cephalotaxine, berberine (p<0.05) and silymarin (p<0.0001). Biochanin A, berberine and silymarin significantly decreased $IC_{50}$ value of daunomycin (p<0.05) while morin increased it (p<0.05). These results suggest that some natural compounds such as biochanin A and silymarin may inhibit P-gp function and can be developed as MDR reversing agents to improve the efficacy of chemotherapeutic drugs when administered concomitantly.