Free radical scavenging capacity as related to antioxidant activity and ginsenoside composition of Asian and North American ginseng extracts

Different Panax species derived from Asia (Panax ginseng C.A. Meyer) and North America (Panax quinquefolium L.) were extracted by methanol and evaluated for relative ginsenoside composition and antioxidant activities. Ginseng root contained a greater proportion of total ginsenoside compared to ginseng hair analyzed by high-performance liquid chromatography. North American ginseng root was characterized with undetectable ginsenoside Rf and greater Rb₁/Rb₂ than Asian ginseng root. Panax quinquefolium exhibited a relatively higher (P<0.05) affinity to scavenge free radical than panax ginseng using the 2,2-azobis (3-ethylbenzothine-6-thine-6-surfonic acid) radical model. In a bilayer lamella suspension oxidation model induced by peroxyl radicals, ginseng samples exhibited notable antioxidant activity. Specifically, however, the P. quinquefolium extracts delayed lipid peroxidation longer (P<0.05) than the P. ginseng extracts. Ginseng extracts from both Panax species protected human low-density lipoprotein against cupric ion-mediated oxidation. Similar protection was observed against peroxyl radical-induced supercoiled DNA breakage. A pure ginsenoside standard (e.g., Rb₁) produced similar results. The antioxidant activities of different ginseng species and specific plant parts include free radical scavenging and may be related to ginsenoside Rb₁/Rb₂ content.     

适合酿酒葡萄果实、果皮及种子的蛋白质提取方法

制备高质量的蛋白质样品是进行蛋白免疫印迹(Western blot)分析的前提.酿酒葡萄果实中含有大量的多酚和多糖等物质,给蛋白质的提取带来了因难.本研究比较了不同聚乙烯聚吡咯烷酮(PVPP)浓度和料液比对赤霞珠葡萄果实、果皮和种子中粗蛋白提取的影响.结果表明,采用10%PVPP及1:2料液比对果实、5%PVPP及1:3料液比对果皮或10%PVPP及1:3料液比对种子的蛋白进行提取,可获得较好的SDS-PAGE图谱;对花色素还原酶(ANR)的蛋白免疫印迹分析显示,ANR在果实、果皮和种子中均有表达,分子量约为43kDa.     

响应面试验优化超临界CO2萃取人参挥发油的工艺

以生晒参为原料,响应面分析法优化超临界CO2提取挥发油的工艺。采用自动质谱退卷积定性系统和保留指数方法对挥发油化学成分定性。结果表明：最佳工艺条件为萃取压力38 MPa、萃取温度55 ℃、静态萃取时间2 h、动态萃取时间1 h,此条件下挥发油提取率达1.12%。气相色谱-质谱法结果显示分离出35 个色谱峰,鉴定出29 种化学成分,相对含量占挥发性物质的96.69%。     

Accumulation of potassium and calcium by ripening berries on field vines of Vitis vinifera (L) cv. Shiraz

Ripening berries of Vitis vinifera (L) cv. Shiraz can show pre-harvest weight loss at sub-optimal sugar content (shrinkage). This later-age decline in berry weight implies that water loss from mature berries has begun to exceed water inflow from the parent grapevine. Such decrease in net inflow has been attributed to a cessation of xylem flow subsequent to veraison, followed by a cessation of phloem flow into berries during later stages of ripening. We address this issue in this present paper, and show a continuing increase in berry content of both potassium and calcium throughout ripening. We measured changes in berry fresh weight and berry content of potassium (phloem mobile) and calcium (phloem immobile) in fruit on field vines sampled from set to harvest. Berry fresh weight reached a plateau between 81 and 95 days after flowering, then declined to 75% of maximum fresh weight by 115 days. Dry weight maximum occurred 14 days after the onset of the fresh weight plateau. Potassium accumulation was slow pre-veraison, increased 3.5-fold post-veraison, and continued during berry shrinkage. Calcium content per berry also showed a linear increase throughout fruit enlargement and ripening phases. Assuming both potassium and calcium were entering berries via vascular conduits, our results imply a continuing connection between parent grapevine and ripening berries. Moreover, an abrupt change (increase) in the ratio of potassium/calcium content per berry subsequent to veraison implies that phloem inflow has increased relative to xylem inflow during post-veraison enlargement.     

Impacts of crop level,soil and irrigation management in grape berries of cv ‘Trincadeira’ (Vitis vinifera L.)

Berry size and crop yield are widely recognized as important factors that contribute to wine quality. The final berry size indirectly affects the phenolic concentration of the wine due to skin surface-to-berry volume ratio. The effects of different irrigation levels, soil management and plant crop level on growth of ‘Trincadeira’ berries were studied. In order to test the influence of different irrigation levels (rainfed, pre-veraison and post-veraison), different soil management (tillage and natural cover crops) and different plant crop levels (8 and 16 clusters per vine), leaf water potential, skin anthocyanin, polyphenols, berry skin and seed fresh weight were measured in fruits. The segregation of berries into three different berry classes: small, medium and large, allowed to identify different levels of contribution of soil management and irrigation level into berry, skin and seeds ratios. As expected, higher water availability due to irrigation and soil tillage management during berry development induced an increase in berry flesh weight and this was more evident in larger berries; however, berry skin and seed fresh weight remained unchanged. Also, anthocyanins did not show significant differences.     

高产人参皂甙β—葡萄糖苷酶菌种的筛选

选取８种菌,筛选了能水解人参皂甙β－葡萄糖苷键的β－葡萄糖苷酶的高产菌株,研究了酶法改变人参皂甙糖基、以去掉人参皂甙Ｒｇ３上的一个葡萄糖基变成高抗癌Ｒｈ２皂甙的可能性,结果,８种菌所产的酶,均有纤维素外切酶的对硝基七酚基－β－葡萄糖苷（ｐＮＰＧ）酶活力,但其中２种菌所产的酶不具有水解人参皂甙－β－葡萄糖键的酶活,只有３种菌所产的酶水解人参皂甙－β－葡萄糖键的酶活高,证明了纤维素外切酶和人参皂甙－β     

Ginsenoside Composition and Antiproliferative Activities of Explosively Puffed Ginseng (Panax ginseng C.A. Meyer)

ABSTRACT: The puffing process was evaluated as an alternative to the steaming process for producing a biologically more active ginseng product, like red ginseng, from raw ginseng. A puffing treatment of dried raw ginseng roots induced an overall increase in crude saponin content. As puffing pressure increased, the content of ginsenoside Re, Rg1, Rb1, Rc, and Rb2 decreased, while ginsenoside Rg3 increased significantly as compared to raw ginseng. The content of ginsenoside Rg3 in puffed ginseng at a pressure of 490 kPa was similar to that of red ginseng. Cancer cell lines (HeLa, MCF-7, and HepG2) showed that antiproliferative effects of saponin extract of puffed ginseng increased with an increase in puffing pressure. Ginseng explosively puffed at 490 kPa had similar saponin constituents and antiproliferative effects as those of red ginseng. Practical Application: The puffing process could provide an alternative mean to produce functional ginseng products, along with a reduction in processing time as compared to traditional red ginseng processing by steam.