基于光氧化反应的1-苯甲酰基-3,4-二氢异喹啉类生物碱Nelumstemine和Longifolonine的首次全合成

研究了1-苯甲酰基-3,4-二氢异喹啉生物碱的一条新的合成路线.以3,4-二甲氧基苯甲醛为起始原料,通过6步反应,以50%的总收率首次全合成得到生物碱Nelumstemine;另外,以香兰醛为起始原料,通过9步反应,以35%的总收率首次全合成得到生物碱Longifolonine.上述全合成的关键步骤为,可见光照射下1-苄基-3,4-二氢异喹啉在室温下被空气氧化为1-苯甲酰基-3,4-二氢异喹啉的反应,并对此温和的光化学反应进行了详细研究.     

1 - 烃基异喹啉Reissert Compounds 的合成及其氢化研究

1-苄基异喹啉Reissertcompound经RaneyNi(w-2)催化氢化,分离得到二个未见报道的氢化产物,经化学和波谱分析推定其结构为:1-亚氨基-1-苄基-2-苯甲酰基-1,2-二氢异喹啉(4)和3-苯基-10b-苄基-1,10b-二氢咪唑骈[5,1-a]异喹啉(5)。据此提出了一条1-苄基异喹啉Reissertcompound高压催化氢化的途径,并对异喹啉eissertcompound高压催化氢化反应中酰基转位进行了讨论。试图以环已基溴作为烷化剂,在氢化钠条件下,与异喹啉Reissertcompound作用来制备1-环已基异喹啉Reissertcompound,结果只得到了1-氰基异喹啉,产率达75%,为制备1-氰基异喹啉提供了一个新方法。     

延胡索素乙有关化合物的合成 Ⅲ.2,3,9,11-四甲氧基-5,6,13,13a-四氢-8H-二苯并[a,g]喹诺里嗪的合成

β-(3,4-二甲氧基苯基)乙胺(Ⅲ)与3,5-二甲氧基-α-重氮苯乙酮(Ⅳ)在氧化银存在下作用,生成N-(3',5'-二甲氧基苯乙酰基)-β-(3,4-二甲氧基苯基)乙胺(Ⅴ).以磷酰氯行Bischler-Napieralski反应,得1-(3',5'-二甲氧基苄基)-6,7-二甲氧基-3,4-二氢异喹啉(Ⅵ),再用锌粉与盐酸还原,生成1-(3',5'-二甲氧基苄基)-6,7-二甲氧基-1,2,3,4-匹氢异喹啉(Ⅶ),用甲醛行Pictet-Spengler反应得2,3,9,11-四甲氧基-5,6,13,13 a-匹氢-8 H-二苯并[a,g]喹诺里嗪(Ⅷ).     

5-羟基-3,4-二氢异喹啉-1-酮的合成

以异喹啉为起始原料,经成盐、磺化得异喹啉-5-磺酸(3),3与熔融的氢氧化钠和氢氧化钾反应得1,5-二羟基异喹啉(4),以5%Pd-C为催化剂还原4得5-羟基-3,4-二氢异喹啉-1-酮(1),总收率47.6%。1的结构经1H NMR和MS确证。     

亮点介绍

铱催化3,4-二取代异喹啉的不对称氢化Angew.Chem.Int.Ed.2012,51,8286～8289手性四氢异喹啉骨架是生物碱和手性药物分子中的重要结构单元.对异喹啉化合物进行不对称氢化是得到手性四氢异喹啉化合物最直接有效的途径.但是由于存在底物活性低和底物和氢化产物对催化剂具有抑制作用,异喹啉的不对称氢化是一个未能很好解决的难题.     

取代二氢异喹啉基苯基甲基酮的合成新方法

以3,4-二甲氧基苯乙酸为原料,经氯化亚砜酰氯化、3,4-二甲氧基苯乙胺氨解得到了N-(3,4-二甲氧基苯乙基)-2-(3,4-二甲氧基苯基)乙酰胺,经Bischler-Napieraski反应环化同时氧化,合成了Lamellarin重要中间体(6,7-二甲氧基-3,4-二氢异喹啉-1-基)(3,4-二甲氧基苯基)甲基酮,优化了环化的反应条件,其总收率为56%。此方法未见文献报道。产物用1H NMR、13C NMR、MS、IR进行了表征。     

基于UHPLC-Q-TOF MS结合分子网络技术快速分析荷叶中生物碱类成分

该研究采用超高效液相色谱-四极杆-飞行时间串联质谱（UHPLC-Q-TOF MS）和分子网络整合技术,快速分析和鉴定了荷叶中的生物碱类化学成分。采用Acquity UPLC HSS T3色谱柱（100 mm×2.1 mm,1.8μm）,以0.1%甲酸水和0.1%甲酸乙腈溶液为流动相进行梯度洗脱,流速为0.3 mL/min,在正离子模式下采集质谱数据信息。将经格式转换后的荷叶提取物二级质谱数据上传至全球天然产物社会分子网络（GNPS）平台计算分析,借助Cytoscape 3.6. 1软件构建可视化分子网络,获得了单苄基异喹啉类、双苄基异喹啉类和阿朴啡类生物碱类型的粒子簇。根据对照品、色谱保留时间、特征碎片离子、MS/MS裂解规律和文献报道等信息,从荷叶中共鉴定和推测57种生物碱类成分,包括27个单苄基异喹啉类、2个双苄基异喹啉类、25个阿朴啡类和3个其他类生物碱,其中19个成分为潜在新化合物,30个成分在荷叶中首次报道。该方法快速、准确,可为荷叶的药效物质基础研究提供参考,为中药化学成分的快速定性分析提供借鉴。     

基于UPLC-Q-Orbitrap-HRMS技术鉴定护心胆中异喹啉类生物碱成分

应用超高效液相色谱-四极杆静电场轨道阱高分辨质谱法（UPLC-Q-Orbitrap-HRMS）分析并鉴定了护心胆（Corydalis suaveolens Hance）块根中的异喹啉类生物碱。护心胆甲醇提取物经Poroshell RRHD C18(150 mm×2.1 mm,1.8μm)色谱柱分离,以乙腈-0.1%甲酸水为流动相进行梯度洗脱。在正离子模式下使用加热电喷雾离子源进行数据采集得到总离子流图。通过对色谱图中各色谱峰的精确质量数进行识别,结合对照品数据及相关文献分析二级高分辨质谱信息。在护心胆甲醇提取物中共鉴定出62个异喹啉类生物碱,包括15个原小檗碱型生物碱、15个四氢小檗碱类生物碱、14个苄基异喹啉类生物碱、3个阿朴菲类生物碱、6个普罗托品类生物碱、7个苯并菲啶类生物碱、2个二氢苯并菲啶类生物碱。该研究对护心胆中异喹啉类生物碱成分进行了较为全面系统的解析,可为后续药效物质基础研究及应用开发奠定基础。     

均相体系中铱催化2-取代-1,2-二氢喹啉类化合物的脱氢芳构化

 采用原位制备的铱双膦(或膦氮)配合物在碘存在下催化2-取代-1,2-二氢喹啉、2-甲基-2,3-二氢吲哚、1,4-二氢吡啶及3,4-二氢异喹啉等化合物的脱氢芳构化反应, 并考察了不同金属前体、配体、催化剂用量、溶剂和碘等因素对反应速率和选择性的影响. 结果表明,原位制备的［Ir(COD)Cl］2/(±)-MeO-Biphep在碘的存在下催化2-取代-1,2-二氢喹啉的脱氢芳构化反应速率快, 选择性好,催化剂的用量少; 对1,4-二氢吡啶和2,3-二氢吲哚的催化脱氢芳构化反应则须在高温下进行; 而对 3,4-二氢异喹啉, 即使在加热回流条件下也只有不到5%的转化率. 催化体系中碘的存在可以明显提高反应速率.     

可见光促进的酰胺氮自由基参与的分子内氢胺化反应

报道了可见光促进的邻烯基取代苯甲酰胺的分子内自由基氢胺化反应.在该反应中,通过脱质子光致电子转移策略实现了氮-氢键的直接催化活化来产生氮自由基,随后通过氮自由基与烯烃的加成来实现氢胺化反应.该反应以优异的收率合成了一系列具有潜在生理活性的3,4-二氢异喹啉酮衍生物.该反应体系利用有机染料催化剂EosinY Na作为光氧化还原催化剂、廉价易得的NaOH作为碱试剂、反应条件温和、操作简单、且官能团兼容性好.另外,该反应在放大量到克级规模、或者利用太阳光作为光源,均能以优异的收率得到相应目标化合物.因此,这类反应为3,4-二氢异喹啉酮的合成提供了一个简便有效的方法.     

Enzymatic biosynthesis of benzylisoquinoline alkaloid glycosides via promiscuous glycosyltransferases from Carthamus tinctorius

Three new GTs (UGT84A33, UGT71AE1 and UGT90A14) from Carthamus tinctorius exhibited robust catalytic promiscuity to benzylisoquinoline alkaloids, and were used as enzymatic tools for the synthesis of diverse benzylisoquinoline alkaloid glycosides.     

Establishment of a search library about benzylisoquinoline alkaloids based on selective separation on the binaphthyl column and standard analysis on C18 column

A search library about benzylisoquinoline alkaloids was established based on preparation of alkaloid fractions from Rhizoma coptidis, Cortex phellodendri, and Rhizoma corydalis. In this work, two alkaloid fractions from each herbal medicine were first prepared based on selective separation on the “click” binaphthyl column. And then these alkaloid fractions were analyzed on C18 column by liquid chromatography coupled with tandem mass spectrometry. Many structure‐related compounds were included in these alkaloids fractions, which led to easy separation and good MS response in further work. Therefore, a search library of 52 benzylisoquinoline alkaloids was established, which included eight aporphine, 19 tetrahydroprotoberberine, two protopine, two benzyltetrahydroisoquinoline, and 21 protoberberine alkaloids. The information of the search library contained compound names, structures, retention times, accurate masses, fragmentation pathways of benzylisoquionline alkaloids, and their sources from three herbal medicines. Using such a library, the alkaloids, especially those trace and unknown components in some herbal medicine could be accurately and quickly identified. In addition, the distribution of benzylisoquinoline alkaloids in the herbal medicines could be also summarized by searching the source samples in the library.     

Identification and metabolite profiling of alkaloids in aerial parts of Papaver rhoeas by liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry

Papaver plants can produce diverse bioactive alkaloids. Papaver rhoeas Linnaeus (common poppy or corn poppy) is an annual flowering medicinal plant used for treating cough, sleep disorder, and as a sedative, pain reliever, and food. It contains various powerful alkaloids like rhoeadine, benzylisoquinoline, and proaporphine. To investigate and identify alkaloids in the aerial parts of P. rhoeas, samples were collected at different growth stages and analyzed using liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry. A liquid chromatography with mass spectrometry method was developed for the identification and metabolite profiling of alkaloids for P. rhoeas by comparing with Papaver somniferum. Eighteen alkaloids involved in benzylisoquinoline alkaloid biosynthesis were used to optimize the liquid chromatography gradient and mass spectrometry conditions. Fifty‐five alkaloids, including protoberberine, benzylisoquinoline, aporphine, benzophenanthridine, and rhoeadine‐type alkaloids, were identified authentically or tentatively by liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry in samples taken during various growth stages. Rhoeadine alkaloids were observed only in P. rhoeas samples, and codeine and morphine were tentatively identified in P. somniferum. The liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry method can be a powerful tool for the identification of diverse metabolites in the genus Papaver. These results may help understand the biosynthesis of alkaloids in P. rhoeas and evaluate the quality of this plant for possible medicinal applications.     

Mass spectra of methines of the benzylisoquinoline alkaloids

Mass spectra of the stilbene type methines of the benzylisoquinoline alkaloids exhibit high melecular peaks and show structurally characteristic fragmentation patterns.     

Short and flexible route to 3,4-diarylpyrrole marine alkaloids: syntheses of permethyl storniamide A, ningalin B, and lamellarin G trimethyl ether

A highly efficient route to 3,4-diarylpyrrole marine alkaloids has been developed using Hinsberg-type pyrrole synthesis and palladium-catalyzed Suzuki cross-coupling of the 3,4-dihydroxypyrrole bis-triflate derivatives as key reactions. Based on this approach, formal syntheses of permethyl storniamide A and ningalin B, and a total synthesis of lamellarin G trimethyl ether have been achieved.     

Nomenclature of benzylisoquinoline and related alkaloids

A classification of the bisbenzylisoquinoline, benzylisoquinoline, and related alkaloids is proposed which is based on the biogenetic characteristics of these alkaloids.All-Union Research Institute of Medicinal Plants, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 25–29, January–February, 1981.     

Development of an indirect competitive ELISA for the determination of papaverine

Papaverine (1-(3,4-dimethoxybenzyl)-6,7-dimethoxyisoquinoline, PAP) is a member of the benzylisoquinoline sub-group of the opium alkaloids. It has been widely used for treating diseases like pulmonary arterial embolism and renal or biliary colic. In this paper, a specific conjugate of mono-demethylated papaverine-O-carboxylmethyl ether (MDMPAP-O-CME) and bovine serum albumin (BSA) was synthesized and used as the complete antigen (PAP-BSA), with which we successfully obtained a high-titer anti-PAP polyclonal antibody (pAb) by immunization of rabbits. The anti-PAP pAb showed high affinity to papaverine with an affinity constant (K_aff) of 7.3 × 10⁷ L/mol. With this antibody, we established a sensitive immunochemical method for the determination of papaverine based on indirect competitive enzyme-linked immunosorbent assay (ELISA). The optimal concentrations of the coated antigen (PAP-OVA) and purified pAb used in the ELISA were 5 and 1.2 μg/mL, respectively. The cross reactivity of other benzylisoquinoline derived substances, including 1-(3,4-dihydroxybenzyl)-7-hydroxy-6-methoxy-isoquinoline (6-methoxy-papaveroline, MPAPO), morphine (MP) and codeine (CD) were all lower than 1%. The linear range of the calibration curve was 0.1-1000 ng/mL. Normal human serum samples were spiked with known amount of papaverine and measured by the ELISA. Recoveries were between 102% and 105%. Papaverine content in a commercial papaverine hydrochloride injection sample was also determined using the established ELISA. Compared with the results given by the control experiment of HPLC, the recoveries of ELISA to detect injection samples were 102-110%. The limits of detection for synthetic serum samples and injection samples of papaverine hydrochloride were 0.25 and 0.06 ng/mL, respectively.     

Two new benzylisoquinoline alkaloids from Papaver triniifolium

From the aerial parts of Papaver triniifolium Boiss. (Papaveraceae) collected from Erzincan (Eastern Anatolia), two new benzylisoquinoline alkaloids, miltanthoridine and miltanthoridinone were isolated. Their structures were established through the use of UV, EIMS, and NMR techniques.     

Asymmetric synthesis of isoquinoline alkaloids

The use of chiral formamidines affixed to variously substituted tetrahydroisoquinolines, allows asymmetric C-C bond forming reactions to occur α- to the amino group. In this manner, a wide variety of (S)-1-alkyl-1,2,3,4-tetrahydroisoquinolines were constructed in > 90% enantiomeric excess. Choosing the proper substituents and skeletal features, an efficient entry into the benzylisoquinoline, tetrahydroprotoberberine, aporphine, and isopavine class of alkaloids was achieved.     

A new benzylisoquinoline alkaloid from stems of Nelumbo nucifera

A new benzylisoquinoline alkaloid, named nelumstemine （1）, 1-（4＇-hydroxybenzoyl）-6,7-dimethoxy-3,4-dihydroisoquinoline, was isolated from the stems of Nelumbo nucifera Geartn. Its structure was established on the basis of spectral analysis.