UPLC-MS/MS结合多探针底物方法研究刺五加叶中黄酮苷类成分对CYP450活性的影响

利用超高效液相色谱-串联质谱联用(UPLC-MS/MS)的多反应监测(MRM)技术结合多探针底物方法, 研究了刺五加叶中的主要黄酮苷类化合物槲皮苷、金丝桃苷及芦丁对肝细胞色素P450酶(CYP450)亚型CYP1A2, CYP2C, CYP2E1, CYP2D和CYP3A活性的影响. 结果表明, 3种化合物对各CYP亚型酶均有抑制作用, 其中金丝桃苷和槲皮苷对CYP1A2催化的非那西丁的O-脱乙基反应抑制的IC₅₀值分别为46.53和49.75 μmol/L, 金丝桃苷和芦丁对CYP2E1催化的氯唑沙宗的6-羟基化反应抑制的IC₅₀值分别为99.87和86.36 μmol/L. 机理性抑制实验结果表明, 3种化合物对2种亚型酶的抑制作用是随着预孵时间延长而增强的机理性抑制.     

南雄银杏叶中银杏黄酮含量的H PLC测定

用高效液相色谱法测定在广东省南雄市不同采摘时间、不同树龄的银杏叶中总黄酮含量;采用Kromasil C18柱,流动相为V（甲醇）：V（4g/L磷酸水溶液）=55:45体系,检测波长254nm,外标法定量;结果表明南雄银杏叶中总黄酮平均含量为0.55%(w,干叶计）,每年6月为最佳摘叶时间。     

香桂叶油合成胡椒基丁醚

胡椒基丁醚 (ＰＢ)是一种可用于贮藏粮食的除虫菊酯类农药的杀虫增效剂[1 ] 。它通过抑制昆虫的多功能氧化酶 ,防止昆虫产生抗药性 ,从而增加杀虫效果。ＰＢ的市场需求量每年约 2 0 0 0吨左右。为了生产绿色农产品 ,用于农田害虫防治 ,单是国内每年就需要ＰＢ数万吨。国外用黄樟油催化加氢制成二氢黄樟油素 (ＤＨＳ) ,再氯甲基化生产氯甲基二氢黄樟油素 (ＣＭＤＨＳ) ,醚化生成ＰＢ。以黄樟树根为原料生产黄樟油严重破坏植被和资源 ,造成自然生态环境的恶化。以黄樟树根为原料生产的黄樟油已经面临全球性的资源枯竭。重庆嘉顿公司 (四川省日…     

肉桂中有机锗的分光光度法测定

本文对肉桂中有机锗进行了分光光度法研究，研究表明，肉桂中含有丰富的有机锗，本方法简便可靠，可获得满意的分析结果。     

Surface-enhanced raman scattering from silver-cyanide and silver-thiocyanate vibrations and the importance of adatoms

Surface-enhanced Raman scattering (SERS) has been studied for silver-cyanide and 3-thiocyanate vibrations at 221 and 2111 cm^?1 and at 218 and 2132 cm^?1, respectively. We report evidence that besides large-scale surface roughness the presence of adatoms is mandatory in order to obtain SERS.     

南雄银杏叶中内酯的高效液相色谱法测定

用高效液相法分析了广东省南雄市不同采收时间，不同树龄的银杏叶中的银杏内酯含量；采用Kromasil C18柱、甲醇－水－四氢呋喃流动相、流速1mL/min、差示折光检测器、柱温35℃、外标法定量，样品用聚酰胺柱纯化，获得了满意的分离效果；结果表明银杏内酯含量随树龄不同，采收时间不同而不同，南雄银杏叶内酯平均含量为0．23％（w）。     

辽东楤木叶中皂苷Congmuyenoside B(2)的分离与鉴定

本研究实现了对辽东楤木叶中Congmuyenoside B(2)的分离与鉴定。研究中采用大孔吸附树脂提取法和硅胶柱层析法对其分离,应用HPLC色谱法和薄层色谱法对纯度进行分析,利用电喷雾多级串联质谱结合核磁共振和红外光谱对该化合物的结构进行分析鉴定。本提取分离法操作简便,提高了分离化合物的纯度。HPLC色谱法灵敏度高,结果准确、减少了质谱及其它色谱中的杂质峰对化合物鉴定的干扰,结构准确,可靠。     

Triterpene Acids from the Leaves of Planchonella Duclitan (Blanco) Bakhuizan

From the methanolic extract of the leaves of Planchonella duclitan, 2α,3α,19α,23‐tetrahydroxy‐13,27‐cyclours‐11‐en‐28‐oic acid (1), myrianthic acid (2), 2‐hydroxyursolic acid (3), ursolic acid (4), pomolic acid (5), rotundic acid (6), and jacoumaric acid (7) were isolated, and their structures were elucidated on the basis of their spectroscopic analysis. Among them, compound 1 was a new cyclopropyl ursane‐type triterpene acid. Additionally, compounds 4 and 7 showed significant cytotoxicity toward human colorectal carcinoma cell line HT29 and human breast carcinoma cell line MCF‐7 with IC₅₀ values ranging from 5.8 ± 1.4 to 6.5 ± 1.9 μM.     

银杏叶中微量元素Cu、Mn和Ti的溶出特性及其化学形态研究

本文以正辛醇-水分配体系模拟银杏叶水煎液中的微量元素在人体胃肠中的分配情况，采用阳离子交换色谱／ICP-AES研究其水煎液中微量元素Cu、Mn和Ti的含量、分布及其在不同溶剂中的溶出特性和化学形态，得到了一些有一定指导意义的规律性。这些结果对银杏叶的综合研究有参考价值。     

Phytochemical study,an evaluation of the antioxidant potential and the antimicrobial activity of Inga semialata (Vell.) C. Mart. hydroalcohol extract

Abstract

Inga semialata (Vell.) C. Mart. belongs to the family Fabaceae. It is known for its therapeutic properties, highlighting its antimicrobial and antioxidant potential. The objective of the present work was to obtain crude extract leaves of Inga semialata, to identify and quantify active compounds, to evaluate the antioxidant potential of the crude extract in vitro, as well as to determine its antimicrobial activity. The crude extract was obtained by the maceration process. The identified and quantified of compounds present in the crude extract of Inga semialata was performed by high performance liquid chromatography. The evaluation of the antioxidant potential of the extract was realized by in vitro tests (DPPH, diacetate dichlorofluorescein test and nitric oxide test) and the evaluation of the antimicrobial activity was carried out using the minimum inhibitory concentration methodology.