A simple, sensitive and rapid method for the analysis of jasminoidin in rabbit plasma by liquid chromatography coupled to tandem mass spectrometry was developed. Detection was by positive ion electrospray ionization in multiple reactions monitoring mode. The method included a chromatographic run of 5.0 min using a C18 analytical column and the calibration curve was linear over the concentration range of 0.5–2,000 ng mL−1 with a correlation coefficient R of 0.998 or better. The intra- and inter-day precision ranged from 3.4 to 5.6% and 4.3 to 8.2%. The intra- and inter-day assay accuracy was between −7.4 and 8.6%. The method was successfully applied for the pharmacokinetic study on jasminoidin in rabbit after a single dose oral administration of Gardenia jasminoides Ellis (Gardenia) and Gardenia coupling Coptis chinensis Franch (Coptidis) extracts.
In recent years, β-amino acids and their derivatives have attracted considerable attention due to their occurrence in biologically active natural products, such as dolastatins,cyclohexylnorstatine and Taxol. β-Amino acids also find application in the synthesis of β-lactams,piperidines, indolizidines. Moreover, the peptides consisting of β-amino acids, the so-called β-peptides, have been extensively studied recently. Consequently, considerable efforts have been directed to the synthesis of β-amino acids and their derivatives1. In particular, stereoselective synthesis of β-amino acids has been a challenging project, and there are only limited methods available. In this presentation, we report our efforts in this area. 相似文献
Interest in piezochromic luminescence has increased in recent decades, even though it is mostly limited to pure organic compounds and fluorescence. In this work, a Cu3Pz3 (Cu3, Pz: pyrazolate) cyclic trinuclear complex (CTC) with two different crystalline polymorphs, namely 1a and 1b, was synthesized. The CTC consists of two functional moieties: carbazole (Cz) chromophore and Cu3 units. In crystals of 1a, discrete Cz–Cu3–Cu3–Cz stacking was found, showing abnormal pressure-induced phosphorescence enhancement (PIPE), which was 12 times stronger at 2.23 GPa compared to under ambient conditions. This novel observation is ascribed to cooperation between heavy-atom effects (i.e., from Cu atoms) and metal–ligand charge-transfer promotion. The infinite π–π stacking of Cz motifs was observed in 1b and it exhibited good piezochromism as the pressure increased. This work demonstrates a new concept in the design of piezochromic materials to achieve PIPE via combining organic chromophores and metal–organic phosphorescence emitters.One molecule, two response mechanisms: a pair of newly-designed cyclic trinuclear Cu(i) complex crystalline polymorphs are engineered, which show excellent luminescent piezochromism and pressure-induced phosphorescence enhancement, respectively.相似文献
Asymmetric synthesis of irnigaine was achieved starting from an enantiopure β-amino ester 5 using the condensation of amino al-cohol 2 with acetylacetone and the subsequent intramolecular cycllzation as the key steps. 相似文献
A new triterpenoid saponin, 3-O-β-D-glucopyranosyl 16-oxo-platycodigenin 28-O-β-D-apiofuranosyl-(1→3)-β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyra-nosyl ester, was isolated from the roots of Platycodon grandiflorum, together with three known saponins, including platycodin D, deapio platycoside E and platycoside E. The structure of the new compound, named 16-oxo-platycodin D, was elucidated on the basis of spectroscopic data. 相似文献
The reductive deoxygenation of aldehydes and ketones into the corresponding alkanes is accomplished by LiAlH4, in the presence of Lewis acid InBr3. It provides a convenient method to complete the transformation from carbonyl compounds to alkanes. 相似文献
The hydroxyl group was directly converted into the trichloroacetylamino group by reacting beta-hydroxy alpha-diazo carbonyl compounds with Cl(3)CCN and NaH. Rh(II)-catalyzed reactions of the beta-amino alpha-diazo carbonyl compounds were discussed. [reaction: see text] 相似文献