Characterisation of volatile sulphur-containing compounds generated in crushed leaves of Chinese chive (Allium tuberosum Rottler)

To characterise the composition of sulphur-containing constituents in Chinese chive (Allium tuberosum Rottler), GC–MS and HPLC analyses were carried out, using 12 varieties of Chinese origin, 4 varieties of Japanese origin and 6 commercially available cultivars. Five disulphides (dimethyl, allyl methyl, methyl 1-(E)-propenyl, diallyl, and allyl 1-(E)-propenyl), two trisulphides (dimethyl and allyl methyl), and two vinyldithiins (3-vinyl-[4H]-1,2- and 2-vinyl-[4H]-1,3-) were identified on the basis of their mass spectral and GC-retention data. Among the detected sulphur compounds, sulphides with a methyl group predominated over those with an allyl group. This was supported by the HPLC estimations, suggesting that all cultivars examined had much greater amounts of methiin than alliin. Also, two novel compounds were tentatively identified as [3H,4H]-1,2-dithiin and [2H,4H]-1,3-dithiin on the basis of their mass spectral features, GC-retention data, and some experimental results on their formation in reaction mixtures with different proportions of methiin and alliin. Their formation mechanism was proposed.     

细香葱提取物对人胃癌细胞SGC7901抑制作用

通过四甲基偶氮唑蓝比色法和流式细胞术研究不同细香葱提取物对人胃癌细胞SGC7901增殖的抑制作用及其对细胞周期、凋亡率的影响。结果显示,细香葱抗胃癌活性成分主要集中在75%乙醇提取部位,同一区域不同品种细香葱抑制胃癌细胞增殖作用存在显著性差异(P0.05),其中3号细香葱75%乙醇提取物的抑制作用最强,其24、48、72 h时IC50值分别为(0.88±0.07)、(0.45±0.08)、(0.21±0.03)mg/m L;SGC7901细胞经1.0、2.0 mg/m L的细香葱75%乙醇提取物处理48 h后,S期细胞所占比例显著增多(P0.05),细香葱75%乙醇提取物阻碍人胃癌细胞SGC7901由S期向G2期的转化,将细胞周期阻滞于S期;同时,实验组细胞相比对照组凋亡率显著上升(P0.05),存在量效关系。综上,细香葱75%乙醇提取物能够阻滞人胃癌细胞SGC7901由S期向G2期转化、促进其凋亡并抑制细胞增殖,细香葱具有开发成为抗胃癌功能食品的潜力。     

Search for potent attractants of onion flies

Of various chopped vegetables tested,Allium spp. high in propyl-containing alkyl sulfides (e.g.,cepa group) caught the most onion flies in trapping tests in the field. Fly catches to chopped onion increased with bait quantity. Attractancy of chopped onion changed dramatically during aging in the field; catch increased over the first few days, peaked at ca. fivefold over fresh material by 3–5 days, and then declined sharply. This age-dependent increase in attraction was not seen for garlic (known to have antimicrobial properties) nor with chopped onion mixed with chopped garlic. These data suggested that attraction of onion flies to onions was strongly influenced by microbial activity associated with decomposing onions. The bacteriumKlebsiella pneumoniae was identified as a major colonizer of onions maximally attractive to onion flies. This increased attraction is not due to the previously reported microbially produced volatiles ethyl acetate and tetramethyl pyrazine.Diptera: Anthomyiidae.Paper No. 11047 of the Michigan State University Agricultural Experiment Station.     

Phytochemicals in Chinese Chive (Allium tuberosum) Induce the Skeletal Muscle Cell Proliferation via PI3K/Akt/mTOR and Smad Pathways in C2C12 Cells

Chinese chive (Allium tuberosum) is a medicinal food that is cultivated and consumed mainly in Asian countries. Its various phytochemicals and physiological effects have been reported, but only a few phytochemicals are available for skeletal muscle cell proliferation. Herein, we isolated a new compound, kaempferol-3-O-(6″-feruloyl)-sophoroside (1), along with one known flavonoid glycoside (2) and six amino acid (3–8) compounds from the water-soluble fraction of the shoot of the Chinese chive. The isolated compounds were identified using extensive spectroscopic methods, including 1D and 2D NMR, and evaluated for their proliferation activity on skeletal muscle cells. Among the tested compounds, newly isolated flavonoid (1) and 5-aminouridine (7) up-regulated PI3K/Akt/mTOR pathways, which implies a positive effect on skeletal muscle growth and differentiation. In particular, compound 1 down-regulated the Smad pathways, which are negative regulators of skeletal muscle growth. Collectively, we suggest that major constituents of Chinese chive, flavonoids and amino acids, might be used in dietary supplements that aid skeletal muscle growth.     

溶剂萃取/溶剂辅助风味蒸发-气相色谱/质谱联用分析野韭菜花挥发性成分

以乙醚为溶剂,采用溶剂萃取/溶剂辅助风味蒸发法(solvent extraction/solvent-assisted flavor evaporation,SE/SAFE)提取新鲜野韭菜花精油,采用气相色谱-质谱联用(gas chromatography/mass spectrometry,GC-MS)法结合双柱(RTX-5色谱柱和DB-WAX色谱柱)保留指数(retention index,RI)定性分析精油中的挥发性成分。结果共鉴定出47种挥发性成分,其中包括含硫化合物28种、醛类4种、醇类3种、酮类3种、烃类化合物9种。含硫化合物数量多且含量大,是新鲜野韭菜花中的主要挥发性成分。     

Chemical characterization of Chinese chive seed (Allium tuberosum Rottl.)

Chinese chive seeds (Allium tuberosum Rottl.) (grown in China) were investigated. Density, thousand-grain weight, and hectolitre weight of seeds were 1.27 g/cm³, 4.9 g, and 71 kg/100 l, respectively. The results showed that Chinese chive seeds contained high amounts of oil (15.8%), dietary fibre (18.2%) and crude protein (12.3%). Oil of seeds was composed of 10.1% saturated and 90.0% unsaturated fatty acids. Linoleic(69.1%) and palmitic (7.0%) were the most abundant unsaturated and saturated fatty acids, respectively. Chinese chive seeds contained 4.5 mg/kg of thiamin, 2.8 mg/kg of riboflavin and 55.1 mg/kg of niacin. The mineral contents of the seed of A. tuberosum, for iron, calcium and zinc, were 580 mg/kg, 1328 and 80.8 mg/kg, respectively. Analysis of the amino acid content of Chinese chive seed revealed that it was a rich source of the essential amino acids, isoleucine, tryptophan and lysine. The study revealed that Chinese chive seeds had high levels of nutritionally important components, such as oil, minerals and essential amino acids.     

蔬菜发酵机理探讨

以韭菜为原料,通过不同加糖量、温度、加盐量和菌种量对韭菜的发酵条件进行了研究。结果表明,糖是发酵的基础物质,正常的发酵条件为温度25℃,糖3%,盐6%。     

响应面法优化超声辅助提取韭菜根不溶性膳食纤维

以韭菜根为原料,用超声处理法辅助提取韭菜根不溶性膳食纤维(insoluble dietary fiber,IDF),探讨液料比、超声温度、超声功率强度和超声时间对IDF得率的影响;用Box-Behnken中心组合原理建立数学模型,通过响应面优化提取工艺参数;最后进行红外光谱分析、热重分析和扫描电镜观察。最佳提取工艺为:液料比25 mL/g,超声温度56℃,超声时间48 min、超声功率强度60%,在此条件下得率达32.92%,与理论值33.87%相比,相对误差2.80%;IDF持水力为11.90 g/g,膨胀性8.23 mL/g,持油力7.63 g/g;韭菜根IDF化学组成具有典型膳食纤维特性,热稳定性良好且具有典型网状结构。以上结果表明,韭菜根是优质膳食纤维的良好来源,通过响应面优化可有效提高IDF得率,该研究将为韭菜根IDF的提取、改良和推广应用提供数据支撑。     

成都市春季市售韭菜中农药残留量的初步调查

为了解食物中农药污染的现状,对成都市售韭菜中农药残留进行了调查.对2004年春季成都市11个菜市场市售韭菜中甲基对硫磷农药的残留量进行测定:蔬菜试样采用乙腈提取、再浓缩有机相,然后直接用气相色谱/质谱(GC/MS)的选择离子监测(SIM)方式测定甲基对硫磷含量.韭菜中甲基对硫磷的标准添加回收率为83.5%,可满足这种杀虫剂在蔬菜中残留量检测的要求.结果表明,在当前防治蔬菜病虫害中仍在使用高毒有机磷农药杀虫剂甲基对硫磷,对蔬菜等食品的安全性应给予充分重视.     

超声波和臭氧在鲜切韭薹保鲜中的应用

采用超声波、臭氧以及2者结合处理的方法对鲜切韭薹进行清洗。结果表明,4℃冷藏货架下,采用超声波和臭氧处理鲜切韭薹可以有效抑制韭薹的呼吸强度,减少鲜重的损失,对叶绿素的VC也有很好的保护作用,对其表面的细菌增殖也有较好的抑制作用,较好的保持鲜切韭薹的品质。尤其是2者结合处理,可将韭薹的货架期延长至11d。