Identification of metabolites of Danggui Buxue Tang in rat urine by liquid chromatography coupled with electrospray ionization time‐of‐flight mass spectrometry

A method coupling liquid chromatography with electrospray ionization time‐of‐flight mass spectrometry (LC/ESI‐TOF/MS) has been developed for rapid and sensitive analysis of rat urinary metabolite profile of Danggui Buxue Tang (DBT), a well‐known Chinese herbal formula. After oral administration of DBT, urine samples were collected during 0–24 h, and then pretreated by solid‐phase extraction. A total of 68 compounds including 13 parent compounds and 55 metabolites were detected in the drug‐containing urines compared with blank urines. The total analytical time was less than 20 min. Metabolites of DBT were identified using dynamic adjustment of the fragmentor voltage to produce structure‐relevant fragment ions. By using this approach, the mass accuracy of precursor and fragment ions was typically within ±5 ppm of the theoretical values, and enabled the identification of 43 metabolites including 27 isoflavanoid and 16 phthalide metabolites. Our results indicated that glucuronidation and sulfation were the major metabolic pathways of isoflavonoids, while glutathione conjugation, glucuronidation and sulfation were the main metabolic pathways of phthalides. No saponin‐related metabolites were detected. The results of the present study provided important structural information relating to the metabolism of DBT. Furthermore, this work demonstrated the potential of the LC/ESI‐TOF/MS approach for identification of metabolites from Chinese herbal medicines in urine. Copyright © 2009 John Wiley & Sons, Ltd.     

Two novel fluorescent calix[4]arene derivatives with benzoazole units in 1,3-alternate conformation for selective recognition to Fe~(3+) and Cr~(3+)

Two novel fluorescent calix[4]arene derivatives 1a and 1b with benzoxazole or benzothiazole units in 1,3-alternate conformation have been synthesized and characterized by IR,~1H NMR,~(13)C NMR and MS.Their complexation properties to different heavy and transition metal ions have been studied by UV-vis spectroscopy and fluorescence spectrometer.Compounds 1a and 1b show selective recognition to Fe~(3+) and Cr~(3+).     

A new macrolide and glycosides from the stem of Sargentodoxa cuneata

A new macrolide glycoside,cuneataside F was isolated from the n-butanol extract of the stem of Sargentodoxa cuneata. The structure was elucidated on the basis of extensive 1D and 2D NMR as well as HRESI-MS spectroscopic analysis.     

New Sesquiterpenes from the Roots and Stems of Aristolochia Mollissima

Two new sesquiterpenes, madolins Y ( 1 ) and Z ( 2 ) were isolated from the dried roots and stems of Aristolochia mollissima, and their structures were determined by spectroscopic methods.     

Eigenspaces of symmetric graphs are not typically irreducible

We construct rich families of Schrödinger operators on symmetric graphs, both quantum and combinatorial, whose spectral degeneracies are persistently larger than the maximal dimension of an irreducible representation of the symmetry group.     

铈对16Mn钢中夹杂物和组织的影响

在高温钼丝炉内向16Mn钢中加入不同含量的铈进行脱氧,分析了钢中夹杂物和组织的变化,并探讨了含铈夹杂物诱发晶内铁素体形核的机制.结果表明:随钢中铈含量的增加,夹杂物依次转变为CeAlO3,Ce2O2S和Ce2S3.经铈处理后,钢液在1873 K时保温300 s,夹杂物最为细小弥散.钢中晶内铁素体随铈含量的增加而增加,但最佳的铈含量约为0.032%(质量分数).钢中Ce2O2S和Ce2S3夹杂与α-Fe相之间的错配度分别只有1.2%和0.5%,均可作为IGF非常有效的形核核心,促进其形成.