ABSTRACT
Buxrugulosides A-E, four lignan glycosides (1-4) and a protocatechuate derivative (5) featuring a rare (N, N-diethyl)methyl amino group at aromatic rings, were obtained from the aerial parts of Buxus rugulosa, which is famous for treating coronary heart disease. Their structures including absolute configurations were elucidated by HRMS, 1D and 2D NMR, and by comparing their CD data with previous reports. Compound 1 was a rare sesquilignan, and all of these compounds were the first example of lignans with (N, N-diethyl)methyl amino group.
ABSTRACT
Objective • To investigate the effect of content changes of neurotransmitters on multiple physiological and pathophysiological processes in mammals, and explore simultaneous sensitive quantification of these metabolites. Methods • An efficient and sensitive method for simultaneous quantification of 20 amino neurotransmitters was achieved through pre-column N-ethylation of neurotransmitters with acetaldehyde and NaBH3CN followed with quantitative analysis using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). And NaBH3CN and NaBD3CN were used as a pair of stable isotope labeling reagents together with natural isotopic standards to achieve accurate quantification. Results • The analysis showed all 20 neurotransmitters had excellent linearity with R2 over 0.991 0 and sensitivity with the limits of detection (LOD) in the range of 0.5-10 fmol except for histidine with an LOD of 36.5 fmol. The result also showed good robustness with the interday and intraday RSD (relative standard deviation) below 15%. The method was further applied to human urine, serum and saliva samples for validation, in which 14, 10 and 8 neurotransmitters were detected, respectively. Conclusion • The method is of high sensitivity and precision. Compared to previous ones, this method is of great applicability in different matrices, with mild reaction and straightforward procedures. Besides, the reaction reagents are easy to be removed by simple quenching thus avoiding interference in the subsequent analysis.
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OBJECTIVE: To prepare amino-modified ordered mesoporous silica (NH2-OMS) as a drug carrier and test the loading and release properties of poorly water soluble drug carried by it. METHODS: OMS was first prepared using cetyltrimethyl ammonium bromide as the template and then modified by 3-aminopropyl trimethoxy silane to prepare NH2-OMS. N2 adsorption-desorption, X-ray diffraction and thermogravimetric analysis were used to characterize the NH2-OMS. Quercetin was loaded onto NH2-OMS in order to explore the drug loading properties of NH2-OMS. RESULTS: The drug loading and entrapment efficiency of quercetin-NH2-OMS were about 21.0% and 58.2%, respectively, when the concentration of quercetin was 4 mmol·L-1, the reaction time was 24 h and the temperature was set at 50°C. The in vitro release test demonstrated that quercetin-NH2-OMS could form supersaturated solution in simulated intestinal fluid and gastric fluid at concentrations of 13-fold and 27-fold of the thermodynamic solubility of quercetion. CONCLUSION: NH2-OMS, as the carrier for quercetin, can significantly increase its water solubility and release rate in intestinal and gastric fluids.
ABSTRACT
OBJECTIVE: To design and synthesize a series of novel amino acid-modified ursolic acid derivatives containing primary amino-group and to investigate their antitumor activities against gastric carcinama in vitro. METHODS: 1, 2-Ethylenediamine was added to the C28 site of ursolic acid(UA) and the resulting intermediates were conjugated to amino acid to get the amino acid-modified ursolic acid derivatives. The effects of these UA derivatives on the growth of BGC823 cells and AGS cells were assessed by MTT assay. Meanwhile, Annexin V/PI dual staining and cell cycle analysis were performed to investigate the anti-tumor mechanism. RESULTS: Most of the derivatives exhibited more powerful cytotoxicity than UA against these two gastric cancer cell lines. The apoptosis of BGC823 cells incubated with compound 3 or compound 4 were observed. Cell cycle analysis showed that compound 3-6 triggered 44.69% -92.64% of the treated AGS cells into apoptotic status. CONCLUSION: Potent anticancer abilities of these UA derivatives bearing primary amido are achieved by inducing apoptosis. Introducing primary amino group to UA is an effective way to develop new UA derivatives with enhanced anti-proliferative activities. Copyright 2012 by the Chinese Pharmaceutical Association.