高压处理种子对西瓜生长发育的影响

以8个汴梁西瓜品种(京引21、花皮88、圳板、郭牟、金玫黑、金小兰、日本瓜和蜜玫绿)为实验材料,采用样本率的显著性检验t、检验及单因素方差分析方法,研究了26~28 MPa的高氮气压及50~150 MPa的高静水压处理种子对西瓜出苗率、叶绿素含量、过氧化物酶活性、单瓜重、含糖量等生长特性的影响。结果表明:高压处理会显著(P0.05)或极显著(P0.01)地降低西瓜的出苗率和幼苗期叶片的类胡萝卜素含量,提高幼苗期叶片的叶绿素a含量和过氧化物酶的活性。高压处理种子对于含糖量和单瓜重这两个农艺性状的影响,品种间存在较大差异。其中,在50~150 MPa高压下处理种子20 min主要影响日本瓜(P0.001)和金小兰(P0.092)的单瓜重以及郭牟的含糖量(P0.064)。     

Enhanced sugar-binding ability of deprotonated calix[4]resorcarene in water: Balance of CH-π interaction and hydrophobic effect

The complexation of calix[4]resorcarene as host and sugar (fucose) as guest in water can be significantly facilitated upon deprotonation of the OH groups of the host. The enhanced sugar-binding ability of the resulting anionic host having a more electron-rich and less hydrophobic aromatic cavity seems to result from a better sugar-host CH-π interaction.     

鲜辣椒中糖份和维生素C含量的近红外光谱非破坏性测定

用近红外光谱法非破坏测定鲜辣椒中可溶性糖和维生素C含量，可溶性糖含量的化学值与近红外预测值之间的相关系数为0．9024，校正集标准差(SEP)为1．23％，RSD9．3％；VC含量的化学值与近红外预测之间的相关系数为0．9122，校正集标准差(SEP)为24．17，RSD为9．5％，辣椒鲜果中可溶性糖和VC含量与近红外光谱有显著的相关关系。     

蜂蜜中糖的薄层展开剂的研究与应用

 建立了蜂蜜中糖的薄层色谱分析法。色谱条件:冰醋酸-氯仿-95%乙醇(体积比为21∶23∶15)为流动相,固定相为涂布于薄层板上的硅胶G-0.2 mol/L 醋酸钠溶液。对多个蜂蜜样品和果糖、葡萄糖、蔗糖标准品进行上行展开,并用苯胺-二苯胺-磷酸显色剂显色。结果表明:真蜜图谱上出现5个色斑,其中果糖呈火红色,葡萄糖呈纯蓝色,蔗糖呈紫色,麦芽糖和多聚葡萄糖呈蓝色。将样品色斑的颜色、深浅度和Rf值与标准糖进行比较,能判断蜂蜜中的还原糖总含量和蔗糖含量,同时也能了解其他少量多糖的存在情况。通过与真蜜图谱比较,     

毛细管电泳—激光诱导荧光—增强型电荷耦合器件检测痕量氨基糖

利用毛细管电泳－激光诱导荧光－增强型电荷耦合器件系统，高灵敏度检测了痕量氨基糖。以异硫氰酸荧光素为荧光衍生试剂，氨基葡萄糖，氨基半乳糖及氨基葡萄酸为模型化合物，具体考察了缓冲溶液，ＰＨ值等多种因素对荧光衍生反应和电泳分离的影响。     

DETERMINATION OF THERMODYNAMIC AND KINETIC PARAMETERS OF LARGE SCALE CHROMATOGRAPHIC SEPARATION OF SUGAR AND REDUCING SUGAR

ＤＥＴＥＲＭＩＮＡＴＩＯＮＯＦＴＨＥＲＭＯＤＹＮＡＭＩＣＡＮＤＫＩＮＥＴＩＣＰＡＲＡＭＥＴＥＲＳＯＦＬＡＲＧＥＳＣＡＬＥＣＨＲＯＭＡＴＯＧＲＡＰＨＩＣＳＥＰＡＲＡＴＩＯＮＯＦＳＵＧＡＲＡＮＤＲＥＤＵＣＩＮＧＳＵＧＡＲＬｉＺｈｏｎｇ；ＳｈｕＷｅｎｌｉ；...     

Multigram scale synthesis of formyl tetra-O-benzyl-β-d-C-glucopyranoside using benzothiazole as a formyl group equivalent

The addition of 2-lithiobenzothiazole to d-gluconolactone followed by deoxygenation of the resulting ketose affords a mixture of benzothiazolyl α- and β-d-glucopyranoside; treatment of this mixture with sodium methoxide gives the β-anomer from which the title aldehyde is obtained in a pure form by transformation of the benzothiazole ring into the formyl group.     

An efficient synthesis of novel deoxy phospha sugar pyrimidine nucleosides

An efficient method is described in the synthesis of several novel deoxy phospha sugar pyrimidine nucleosides in racemic form, analogs of normal sugar nucleosides, in high yields by treatment of (±)-2-aminophospholane 1-oxide with several, α-cyano-, -acetyl-, -ethoxycarbonyl-β-ethoxy-N-ethoxycarbonylacrylamides.     

离子液体中糖酯类化合物的酶法合成

糖酯作为一种非离子型表面活性剂, 由于特殊的两亲结构, 已广泛应用于医药、食品及化妆品工业. 除作为表面活性剂外, 一些糖酯及其衍生物还具有抗菌及抗肿瘤等生物活性. 酶法合成糖酯反应条件温和, 选择性高. 有机介质中酶促糖酯合成的困难在于糖类化合物的低溶解度. 离子液体作为新型绿色反应介质, 用于糖酯类化合物的酶法合成具有许多优点. 综述了近年来该领域的研究进展.     

A new synthetic approach to mycobacterial cell wall α-(1→5)-d-arabinofuranosyl C-oligosaccharides

Three designed arabinofuranose building blocks allowed the diastereoselective synthesis of a C-disaccharide and a C-trisaccharide by Wittig olefination. The latter compound represents the first example of all-carbon linked arabinofuranotriose analogue.