Determination of cefodizime in biological materials by high-performance liquid chromatography

Cefodizime (THR-221) is a new semi-synthetic cephalosporin. A high-performance liquid chromatographic method has been developed for the determination of cefodizime in biological materials. A plasma or serum sample was deproteinized with methanol and the resulting methanol eluate was concentrated to a volume of 0.5 ml. Urine and bile samples were diluted with buffer and each diluted sample was filtered. Faeces samples were homogenized and the supernate obtained after centrifugation was filtered. Visceral tissue samples were homogenized, the centrifuged supernate was deproteinized with methanol, and the methanol eluate was concentrated to a volume of 0.5 ml. Aliquots of each preparation were chromatographed on a reversed-phase column with an ion-pair chromatographic technique on a high-performance liquid chromatograph equipped with an UV detector set at 264 nm. The detection limits for cefodizime were 0.1 microgram/ml in plasma or serum, 0.3 microgram/ml in bile, and 0.5 microgram/ml in urine, 0.5 microgram/g in faeces and visceral tissue. This precise and sensitive assay for the determination of cefodizime is described, and its stability in several media is reported.     

Synthesis of cyclodextrin‐based radial polycatenane cyclized by amide bond and subsequent fabrication of water‐soluble derivatives

Journal of Inclusion Phenomena and Macrocyclic Chemistry - In recent years, functional materials using cyclodextrin (CD)-based polyrotaxanes have attracted considerable attention, and...     

Mass spectra of 5-fluorouracil derivatives. N-1-substituted sulfonyl derivatives

The electron impact mass spectra of 1-sulfonyl substituted derivatives of 5-fluorouracil were investigated. The substituents were CH₃SO₂ (compound I), CH₃(CH₂)₃SO₂ (II), C₆H₅SO₂ (III) and p-CH₃C₆H₄SO₂ (IV).     

The effect of folate-appended methyl-β-cyclodextrin increases on survival rates in a peritoneal dissemination mouse models of human ovarian cancer

Journal of Inclusion Phenomena and Macrocyclic Chemistry - Among gynaecological cancers, ovarian cancer is known to be highly sensitive to chemotherapy. However, it is often detected at an advanced...     

Design and evaluation of folate-appended methyl-��-cyclodextrin as a new antitumor agent

Methyl-??-cyclodextrin (M-??-CyD) is widely used as a raft disrupting agent through extraction of cholesterol from lipid rafts which are highly expressed in cell membranes of tumor cells, but it does not have tumor cell-selective action. Meanwhile, the widespread use of folic acid (FA) as a tumor-targeting ligand has been known, because folate receptor (FR) overexpresses in various kinds of epithelial tumor cells. In the present study, in order to obtain more tumor cell-selectivity and antitumor activity of M-??-CyD, we designed folate-appended M-??-CyD (FA-M-??-CyD), and evaluated its physicochemical properties and antitumor activity. The ¹H-NMR study demonstrated that FA-M-??-CyD having average degree of substitution of FA (DSF) of 1.0 was prepared. In addition, FA-M-??-CyD (DSF 1.0) was found to be amorphous in a solid state and surface-active. Importantly, FA-M-??-CyD (DSF 1.0) had potent cytotoxicity, compared to M-??-CyD in KB cells, but not in A549 cells. These results suggest that FA-M-??-CyD (DSF 1.0) has the potential as a novel antitumor agent.     

A new binding motif of sterically demanding thiolates on a gold cluster

A gold cluster, Au(41)(S-Eind)(12), was synthesized by ligating the bulky arenethiol 1,1,3,3,5,5,7,7-octaethyl-s-hydrindacene-4-thiol (Eind-SH) to preformed Au clusters. Extended X-ray absorption fine structure, X-ray photoelectron spectroscopy, and the fragmentation pattern in the mass spectrometry analysis indicated that formation of gold-thiolate oligomers at the interface was suppressed, in sharp contrast to conventional thiolate-protected Au clusters.     

C-F?HO hydrogen bond in 8-fluoro-4-methyl-1-naphthol

The 8-fluoro-4-methyl-1-naphthol forms the intermolecular bifurcated HB, OH?(F, HO) in the crystal. This is quite contrasting to the reported results of the ab initio calculations. On the contrary, the intramolecular hydrogen bond in solution was confirmed by ¹H, ¹³C, and ¹⁹F NMR spectra.     

Exceeding Metal Capacity in Sandwich Complexes: Ligand‐Unsupported Docking of Extra Metal Moieties at Edges of a Metal Sheet Sandwich Complex

The ligand‐unsupported accommodation of extra metal moieties in a sandwich complex is reported. Although it has been considered that the metal‐capacity of a metal sheet sandwich complex is strictly limited by the size of cyclic unsaturated hydrocarbon ligands, the M?M edge bonds in a metal sheet sandwich complex provide a ligand‐unsupported docking site for extra metal moieties, allowing expansion of metal‐capacity in sandwich complexes. The metal sheet sandwich complex [Pd₄(μ₄‐C₈H₈)(μ₄‐C₉H₉)]⁺, in which the ligand‐based metal capacity is full in terms of the usage of all C=C moieties of the smaller carbocyclic ligand C₈H₈ in coordination, can accommodate extra M⁰{P(OPh)₃}₂ (M=Pd, Pt) moieties without coordinative assistance by either the C₉H₉ or the C₈H₈ ligand.     

基于集群方法(ER)的近红外光谱转移集优化法

近红外光谱因为具有小成本、易操作、低耗时等优点,所以广泛用于食品领域。作为一种间接的检测方法,近红外光谱检测需要建立光谱和浓度之间的统计模型。但是,一种条件下建立的模型在另一种检测条件下会失效。针对此问题,重新建模可以加以解决,但是重新建立光谱与浓度之间的模型非常繁琐耗时。此时,模型转移可以在避免重新建模的情况下,通过光谱校正,保证预测精度。在模型转移中,已经建立好模型的光谱称为主光谱(A),不用建立模型,而只用主光谱模型预测的光谱称为从光谱 (B)。模型转移方法的步骤是,先在校正集中选择一些样本作为主光谱的转移集(A_t),然后选择从光谱中浓度和A_t相同的光谱,以此作为从光谱的转移集(B_t)。通过A_t和B_t构建模型转移矩阵。最后将需要校正的从光谱(B_v)乘以上述的转移矩阵中,即可获得校正后的从光谱(B_new)。此时,B_new就可以用主光谱的模型来直接预测。在模型转移中,转移集样本的选择对模型校正至关重要。目前,转移集的样本通常从光谱之间的距离而非模型转移误差获得。但是,转移误差对模型转移结果的验证至关重要,故该研究出了基于集群分析的集群优化法(ER)并将其用于优化KS方法产生的转移集样本。ER先用随机方法建立转移集的多个子集合,并计算每个子集合的转移误差。然后,对某一个样本,计算包含这个样本的子集合转移误差均值。最后,选择转移误差均值较低的样本作为新转移集样本进行模型转移。以玉米数据测试了ER算法。结果显示,对于典型相关分析-有信息成分提取法(CCA-ICE)、直接校正法(DS)、分段直接校正法(PDS)、光谱空间转化法(SST)这些常见的模型转移方法,相比于KS样本选择方法,ER方法可以找出重要的转移集样本,进而显著降低模型转移误差。