Cytotoxic Evaluation of Pungencine: A New Tropane Alkaloid from the Roots of Erythroxylum pungens O. E. Schulz

A new tropane alkaloid as well as a new substitution group, (3‐endo,8‐anti)‐8‐methyl‐8‐azabicyclo[3.2.1]oct‐3‐yl 4‐hydroxy‐3,5‐dimethoxybenzoate, called pungencine ( 1 ), was isolated from the roots of Erythroxylum pungens O. E. Schulz . The structure was elucidated by spectral analyses, including ¹H‐ and ¹³C‐NMR and 2D‐NMR techniques (¹H,¹H‐COSY, NOESY, DEPT, HMQC, and HMBC) and HR‐ESI‐MS. Furthermore, compound 1 was tested for cytotoxicity against several cell lines (Jurkat, HL‐60, U937, K562, KG‐1, and U266) and was determined not to inhibit cell viability at 10 μM .     

Structural elucidation and NMR assignments of a new pyrrolizidine alkaloid from Crotalaria vitellina Ker Gawl

A new pyrrolizidine alkaloid, named crotavitelin, was isolated from fruits of Crotalaria vitellina, Fabaceae (Papilionoideae). The structure was established by spectroscopic techniques such as one‐dimensional and two‐dimensional NMR, IR, and MS. Copyright © 2013 John Wiley & Sons, Ltd.     

Quantitative Determination and Variation Trends of Six Alkaloids in Crude and Processed Corydalis Yanhusuo

A convenient, sensitive, and accurate analytical method using reversed-phase high-performance liquid chromatography coupled with ultraviolet-visible detection was investigated for the determination of 6 alkaloids (tetrahydrocoptisine, protopine, tetrahydropalmatine, coptisine, corydaline, and palmatine) in crude and processed samples of corydalis yanhusuo. The results revealed that the content of the alkaloids in crude corydalis yanhusuo samples varied from those of the processed samples. The concentrations of tetrahydrocoptisine, protopine, tetrahydropalmatine, coptisine, and corydaline were reduced after processing; however, the concentration of palmatine increased after processing. This method was established using a C₁₈ column (250 mm × 4.6 mm, 5 µm). The mobile phase, a mixture (19:81) of acetonitrile and a 0.6% solution of acetic acid (pH 3.5, adjusted using triethylamine), was used to elute the target compounds in the isocratic elution mode. The solvent flow rate was 1.0 mL/min, the column temperature was 35°C, and the detection wavelength was 280 nm. All of the calibration curves exhibited good linearity with R >0.9999. The inter- and intra-day precisions for all of the investigated components ranged from 0.10–2.64% RSD, and the recoveries were in the range of 97.3–102.5%. The validated method provides a new solution for analyzing the contents of crude and processed samples of corydalis yanhusuo.     

Determination of Indole Alkaloids by High-Performance Liquid Chromatography with Resonance Rayleigh Scattering Detection

A novel resonance Rayleigh scattering (RRS) detection approach combined with high–performance liquid chromatography (HPLC) was developed for the determination of reserpine, deserpidine, and ajmalicine. The resonance Rayleigh scattering signal increased when the analytes were bound to diiodofluorescein in Britton–Robinson buffer (pH 4.2). Separation was performed using a C18 column with a mobile phase consisting of acetonitrile–5 millimolar ammonium acetate buffer at pH 4.2 (44:56, volume by volume). Resonance Rayleigh scattering was measured at excitation and emission wavelengths of 320 nanometers. The experimental parameters affecting the separation and the scattering intensity were carefully optimized. Possible mechanisms for the resonance Rayleigh scattering enhancement of the indole alkaloid–diiodofluorescein system were explored by scanning electron microscopy, nuclear magnetic resonance, and ultraviolet-visible absorption spectroscopy. The method was employed for the determination of the analytes in human urine and pharmaceutical tablets.     

Diazotised 4-Nitroaniline as a Chromogenic Reagent for the Determination of Indole Derivatives in Certain Pharmaceutical Preparations

Abstract

A sensitive colorimetric method has been devised for microdetermination of six indole derivatives; ergotamine tartrate, methylergometrine maleate, dihydroergocornine methanesulphonate, dihydroergocristine methanesulphonate, dihydroergocryptine methanesulphonate and pindolol, both in pure form and in pharmaceutical preparations. The method is based on the reaction of indole moiety with diazotised 4-nitroaniline in buffer solution of pH 6 to produce a stable yellow monoazo dye. Beer's law is obeyed over final concentration ranges 8–32 μgm1^?1 for ergotamine tartrate, 4–48 μgml^?1 for methylergometrine maleate, 8–56 μgml^?1 for dihydro-ergot alkaloids and 1–10 μgml^?1 for Pindolol with apparent molar absorptivity range (7.62 × 10³?2.61 × 10⁴) 1.mole^?1.cm^?1. A study has been made to determine the optimum conditions of the colour reaction.     

A New Diterpenoid Alkaloid from the Roots of a White‐Flowering Aconitum orientale Sample

From the roots of a white‐flowering Aconitum orientale Miller sample, collected in Artvin‐?av?at, Turkey, a new diterpenoid alkaloid named aconitorientaline ( 1 ) was isolated, along with the known diterpenoid alkaloids septentiriodine, lappaconitine, finaconitine, ranaconitine, puberanidine and delstaphinine (Fig.). The structure of 1 was established on the basis of ¹H‐ and ¹³C‐NMR, DEPT, ¹H,¹H‐COSY, NOESY, HSQC, and HMBC studies. All the known compounds were identified by comparison of their ¹H‐ and ¹³C‐NMR data and co‐TLC behavior with those of authentic samples.     

聚偏二氯乙烯负载金鸡纳碱催化剂的合成及其对不对称Michael反应的催化性能

将天然的金鸡纳碱——辛可宁与聚偏二氯乙烯进行接枝反应,制备了聚偏二氯乙烯负载辛可宁的催化剂.将制备的催化剂用于催化不对称Michael反应,并探索了溶剂、催化剂用量、温度、底物等不同条件对其催化性能的影响.结果表明,该催化剂在甲苯中有很高的催化活性和较好的立体选择性,Michael反应中部分产率达到80%以上,e.e值达到72%,且该催化剂具有一定的重复使用性能.     

AChE抑制剂类抗AD药物的研究进展

阿尔茨海默病(AD)是常见的一种神经退行性疾病,胆碱能神经传递缺陷是该病的主要病因。AD可以通过使用能抑制乙酰胆碱酯酶(AchE)的制剂来治疗。抑制乙酰胆碱酯酶的关键作用一是增强AD患者的胆碱在大脑中的运输,二是减少患者大脑中β-样淀粉蛋白的聚集和神经纤维的形成。目前对AChE抑制剂的研究主要集中在他克林、多奈哌齐、加兰他敏、石杉碱甲等已有药物及其衍生物,以及天然产物(尤其是植物、微生物来源的)及其衍生物。     

Qualitative and quantitative analysis of aconitine-type and lipo-alkaloids of Aconitum carmichaelii roots

By optimizing the extraction and analytical conditions, a reliable and precise HPLC method coupled with photodiode array detection (HPLC–DAD) has been developed for the identification and quantification of three major aconitine-type alkaloids (aconitine, mesaconitine, hypaconitine) in the roots of Aconitum carmichaelii Debeaux. The qualitative analysis of the plant material was carried out by LC-APCI-MSⁿ. By means of this method, 26 lipo-alkaloids were also identified from the roots of A. carmichaelii. The effect of processing on aconitine-type alkaloids, lipo-alkaloids and pure aconitine was studied. As part of our investigation, two lipo-alkaloids, 14-benzoylaconine-8-palmitate and 14-benzoylaconine-8-linoleate were produced semisynthetically. The COX-1, COX-2 and LTB₄ formation inhibitory activity of aconite root extracts and different types of diterpene alkaloids and the toxicity of lipo-alkaloids were also investigated.