红紫素-18二酰亚胺的羟(酰)基化及其叶绿素类二氢卟吩衍生物的合成

以红紫素-18甲酯为起始原料,通过外接环的胺解反应转化成氮上连有含羟基或者酰基取代结构的红紫素-18二酰亚胺,利用其周环上的活性反应区域,通过氧化、空气氧化、游离基取代和亲核取代反应,在3-,12-和20-meso-位上分别引进了羟基、酰基或者带有相应官能结构的取代基团,完成了12个未见报道的具有红紫素-18二酰亚胺的叶绿素类二氢卟吩衍生物的合成,其化学结构均经UV,IR,1H NMR及元素分析予以证实;同时也讨论了不同位置的羟基化和酰基化对四吡咯大环所形成的不同影响.     

红紫素-18的化学修饰及其叶绿素类二氢卟吩衍生物的合成

以红紫素-18甲酯及其N-甲氧基二酰亚胺甲酯为起始原料,以氧化苯甲腈或者甲亚胺作为1,3-偶极体,与红紫素-18的3-位乙烯基进行偶极环加成反应,在周环上建立了不同的五元杂环结构;选择芳胺和芳醛缩合而成的含氮二烯与红紫素-18二酰亚胺C(3)-双键实施杂Diels-Alder反应(Povarov反应),得到了3-位芳酰基或者芳烷基取代的开环重排产物;利用20-meso-氢和C(12)-甲基的反应活性,在红紫素-18的二氢卟吩色基上分别完成了亲电取代、空气氧化和类羟醛缩合反应,并在周环的12-和20-位上引进了不同的取代基团,合成了一系列未见报道的叶绿素类二氢卟吩衍生物.其化学结构均经UV,IR,1H NMR,MS及元素分析予以证实.同时,对所涉及的反应机理也进行了相应的讨论.     

红紫素-18的卤化反应及其二氢卟吩类衍生物的合成

从红紫素-18甲酯开始,通过对其3-位乙烯基和20-meso-位的亲电加成和亲电取代反应,区域选择性地给出相应的氯代或者溴代产物.红紫素-18甲酯与重氮甲烷的1,3偶极环加成反应生成C(3)-吡唑啉基取代的红紫素-18,继续与N-溴代丁二酰亚胺(NBS)和N-氯代丁二酰亚胺(NCS)进行亲电取代反应,生成相应的卤代吡唑啉基取代二氢卟吩.3-吡唑啉基红紫素-18热裂解后的卤代反应则给出3-环丙基-20-卤代二氢卟吩.选择脱镁叶绿酸-a甲酯为另一起始反应物,通过C(3)-乙烯基和E-环结构的一系列化学转换和20-meso-位的溴代反应,区域选择性地得到20-溴代红紫素-18衍生物.新报道的标题化合物均经UV,IR,1H NMR及元素分析证明其结构.     

红紫素-18二酰亚胺的化学反应及其叶绿素类二氢卟吩衍生物的合成

以N-甲氧基红紫素-18二酰亚胺甲酯为起始原料,利用其二氢卟吩大环上的活性反应区域,分别进行了3-位乙烯基的亲电加成和1,3-偶极环加成反应、20-meso-位的亲电取代反应、12-位甲基的空气氧化和亲核取代反应的研究,在红紫素-18二酰亚胺周环上的C(3)-,C(12)-和C(20)-meso-位上构建和引进不同的化学结构和取代基团,完成了11个未见报道的叶绿素类二氢卟吩衍生物的合成,其化学结构均经UV,1H NMR,IR及元素分析予以证实;对相应的化学反应也提出了可能的反应机理     

红紫素-18的胺解反应及其叶绿素类二氢卟吩衍生物的合成

以红紫素-18甲酯为原料,与脂肪胺或者苯胺在加热回流和微波促进的条件下进行胺解反应,分别得到单酰胺化、双酰胺化和羰基亚胺化产物;同时,沿着N21-N23轴向对所得红紫素-18酰亚胺实施化学修饰,分别得到难以分离的具有阻旋异构和差向异构特征的红紫素-18酰亚胺混合物.新的二氢卟吩类衍生物均经UV,IR,1H NMR光谱、质谱及元素分析证明其结构,并对相应的胺解反应提出了可能的反应机理.     

红紫素-18酰亚胺衍生物的化学修饰

以脱镁叶绿酸-a甲酯为原料, 通过对其3-位乙烯基的氧化, 得到了3-甲酰基脱镁叶绿酸甲酯, 利用Wittig反应合成了对应的3-(2-取代的乙烯基)脱镁叶绿酸甲酯. 结合E环的改造, 将其转变成酸酐环进而转变成N-取代的酰亚胺环. 目标化合物具有亲水区和疏水区两部分, 吸收波长明显向红位移. 合成得到的红紫素-18酰亚胺衍生物有可能成为光动力疗癌的理想光敏剂. 合成的新化合物均由核磁共振、红外光谱、元素分析和质谱予以证实.     

б-(甲酰乙烯基)二氢卟吩衍生物的合成

以脱镁叶绿酸-a甲酯为原料,利用Vilsmeier反应合成б-(甲酰乙烯基)二氢卟吩衍生物.镍(II)脱镁叶绿酸-a甲酯和镍(II)红紫素-18与Vilsmeier试剂作用,生成了E环被打开的镍(II)б-(甲酰乙烯基)红紫素-7-三甲酯和镍(II)б-(甲酰乙烯基)二氢卟吩P6三甲酯.镍(II)N-乙酰氧基红紫素-18-酰亚胺和Vilsmeier试剂作用,生成了镍(II)б-(甲酰乙烯基)-N-_乙酰氧基红紫素-18-酰亚胺.当这些化合物脱去镍离子后,吸收波长明显红移,б-(甲酰乙烯基)-N-乙酰氧基红紫素-18-酰亚胺的吸收波长达到742 nm.同时保留了对б-位再进行化学修饰的可能性.合成的新化合物均由核磁共振、红外光谱、元素分析和质谱予以证实.     

δ-（甲酰乙烯基）二氢卟吩衍生物的合成

以脱镁叶绿酸-a甲酯为原料,利用Vilsmeier反应合成δ-(甲酰乙烯基)二氢卟吩衍生物.镍(II)脱镁叶绿酸-a甲酯和镍(II)红紫素-18与Vilsmeier试剂作用,生成了E环被打开的镍(II)δ-(甲酰乙烯基)红紫素-7-三甲酯和镍(II)δ-(甲酰乙烯基)二氢卟吩P6三甲酯.镍(II)N-乙酰氧基红紫素-18-酰亚胺和Vilsmeier试剂作用,生成了镍(II)δ-(甲酰乙烯基)-N-乙酰氧基红紫素-18-酰亚胺.当这些化合物脱去镍离子后,吸收波长明显红移,δ-(甲酰乙烯基)-N-乙酰氧基红紫素-18-酰亚胺的吸收波长达到742nm.同时保留了对δ-位再进行化学修饰的可能性.合成的新化合物均由核磁共振、红外光谱、元素分析和质谱予以证实.     

脱镁叶绿酸-a甲酯的多阶降解与罗多二氢卟吩衍生物的合成

从脱镁叶绿酸-a甲酯开始,经过一系列降解反应完成罗多二氢卟吩的合成.以N-氯代丁二酰亚胺(NCS)或者硝酸作为亲电试剂,对罗多二氢卟吩实施亲电取代反应;选择氧化对氯苯甲腈和重氮甲烷作为l,3-偶极体,与罗多二氢卟吩进行1,3-偶极环加成反应,分别在二氢卟吩色基上构建了吡唑啉和异噁唑啉环系;继续对吡唑啉基取代的二氢卟吩实施热裂解反应,在3-位上形成环丙基结构;在酸性条件下,罗多二氢卟吩可以水解成相应的单酯衍生物.在红紫素-7的20-meso-位上引进氯原子后,再经脱羧反应去除15-位上的取代基团,区域选择性地完成罗多二氢卟吩的单一氯原子的引入.所合成的新化合物均经UV,IR,1H NMR及元素分析证明其结构.与此同时,对相应的空气氧化和重排反应提出了可能的反应机理.     

具有叶绿素基本碳架的C-3-异噁唑啉基二氢卟吩类衍生物的合成

以脱镁叶绿酸-a甲酯为起始原料,通过3-位乙烯基与氧化苯甲腈和4-取代氧化苯甲腈的1,3-偶极环加成反应,分别得到3-位异噁唑基取代的二氢卟吩衍生物以及其他形式的加成产物,对其脱镁叶绿酸的E-环结构修饰则转换成相应的二氢卟吩-p6衍生物;脱镁叶绿酸-a甲酯经空气氧化和重排反应形成了红紫素-18-内酰胺,再与4-取代氧化苯甲腈进行相同的环加成反应,也以理想的产率生成标题化合物.所得新的二氢卟吩衍生物的化学结构均经UV,IR,1H NMR 及元素分析得以证实,并对相应的反应提出可能的反应机理.     

利用脱镁叶绿酸甲酯的化学修饰合成红紫素酰亚胺衍生物

A series of novel purpurin-18 imide derivatives exhibiting long wavelength absorption and amphiphilicity wereobtained from methyl pheophorbide-a(MPa)by modification of the peripheral functional groups.The vinyl groupat 3-position was oxidized with OsO_4 and NaIO_4 to form the formyl group and the Grignard reaction of this alde-hyde with the alkyl magnesium bromide was carried out to give the corresponding 3-(1-hydroxylalkyl)pheophor-bide-a.The E-ring of these chlorines was converted into anhydride ring to give purpurin derivatives by air oxidation.The trans-3~2-alkyl purpurin derivatives were obtained by dehydration of hydroxyl group at 3~1-position.TheN-hydroxyl purpurin imide was generated by treatment of the anhydride ring with bydroxylamine hydrochloride.The 3~1-alkylacyl-N-hydroxyl purpurin imides were obtained by oxidation of hydroxyl group at 3~1-position.Theacylation of N-hydroxyl group was completed to afford N-acyloxy purpurin imides.The photocytoxicity of severalcompounds in vitro were tested.     

（焦）脱镁叶绿酸－a甲酯的N~(21)N~(23)轴向化学结构修饰及其对可见光吸收的影响

以脱镁叶绿酸－a甲酯和焦脱镁叶绿酸-a甲酯为起始原料，通过3－位乙烯基和 13~1-位环上基的化学反应，改变二氢中卟吩母环上N~(21)-N~(23)轴向的化学结构 ，完成了（焦）脱镁叶绿酸－a甲酯衍生物2～15的合成，并对其可见光谱的变化进 行了讨论。所合成的新叶绿酸衍生物均经UV，IR，~1H NMR及元素分析证明其结构 。     

焦脱镁叶绿酸-a甲酯的E-环格氏反应及其脱氧衍生物的合成

以焦脱镁叶绿酸-a甲酯及其3-甲酰甲基为起始原料,通过与直链烷基溴化镁或者环烷基溴化镁进行格氏反应,将131-位羰基转化为烷羟基,经脱水在E-环形成环外碳碳双键,完成单(双)烷亚甲基取代的131-脱氧焦脱镁叶绿酸衍生物的合成,并且讨论了格氏反应的立体化学.所合成的新化合物均经UV,IR,1H NMR及元素分析证明其结构.     

Studies on the Photodynamic Mechanism of Tetrapyrrole Compounds by Laser Flash Photolysis

Photodynamic therapy (PDT) is a promising new treatment technique which can potentially destroy unwanted and malignant tissues, such as those of cancer. The photodynamic mechanisms of three tetrapyrrole compounds: Mg‐purpurin‐18, tetra(meso‐chlorophenyl)porphyrin (m‐TCPP) and 2,7,12,18‐tetramethyl‐3,8‐di[(1‐isobutoxyl)‐ ethyl]‐13,17‐bis[3‐di(2‐chloroethyl)aminopropyl]porphyrin (TDBP) in acetonitrile were investigated by 355 nm laser flash photolysis. It was found that after laser flash photolysis (LFP), the excited states of TDBP and Mg‐purpurin‐18 could react with O₂ and ¹O₂ was produced, which proved that TDBP and Mg‐purpurin‐18 took effects through type II mechanism in PDT. This suggested that TDBP and Mg‐purpurin‐18 should be suitable for target tissues containing enough O₂. Mg‐purpurin‐18 has two extra absorptions at 550 and 700 nm, which means it has broad choices of laser wavelength in PDT. It was also found that m‐TCPP could be photoionized when excited with 355 nm laser under N₂‐saturated condition. It could also react with O₂ to produce reactive oxygen species such as superoxide and the peroxide anions, but not ¹O₂. These were known as the Type I mechanism. So m‐TCPP could be used even at low oxygen concentration or more polar environments with good behavior in PDT. From the above studies on the three different tetrapyrrole compounds it could be concluded that the structure of porphin ring takes a main role in PDT. And there was important impact on the photodynamic mechanism for the functional group directly connecting with porphin ring, while little influence for the functional group indirectly connecting with porphin ring. These will be of great value in the discovery of new PDT drugs.     

具有叶绿素-a基本碳架的氯代二氢卟吩衍生物的合成

选择脱镁叶绿酸-a甲酯为起始原料, 经过化学结构修饰转换成其他叶绿素-a衍生物. 以过氧化氢/盐酸、N-氯代丁二酰亚胺(NCS)、氯化氢(或者浓盐酸)为氯化剂, 根据3-乙烯基和20-meso-位的不同化学反应活性, 通过亲电加成和亲电取代反应, 在二氢卟吩环上选择性地引进氯原子, 完成8种未见报道的具有叶绿素-a基本碳架的氯代二氢卟吩衍生物的合成. 所合成的新化合物均经UV, IR, 1H NMR及元素分析证明其结构.     

Photoisomerizations of N4-hydroxycytosines

A series of N4-hydroxycytosines, unsubstituted or substituted with methyl groups at N3 or C5 atoms of the heterocyclic ring, was studied using the matrix-isolation method. Depending on the absence or presence of the methyl substituent at N3 or C5 atoms (or at both of them) the syn or anti form of the compounds (or a mixture of both forms) was trapped from the gas phase into a low-temperature matrix. Upon UV (lambda > 295 nm) irradiation of the matrixes the syn --> anti as well as the anti --> syn photoisomerization reactions were observed. The syn and anti isomers of N4-hydroxycytosines were identified by comparing their experimental IR spectra with the theoretical spectra calculated at the DFT(B3LYP)/6-31G(d,p) level. For the majority of the studied compounds, the UV induced reactions led to a photostationary state. The position of the final photostationary state was found to be a sensitive function of weak interactions of a studied N4-hydroxycytosine with the matrix environment: solid argon or solid nitrogen. However, not all of the studied photoisomerizations led to a classical photostationary state. For some of the investigated N4-hydroxycytosines, the position of the photostationary state was shifted very strongly in favor of the photoproduct, whereas for some others the position was shifted so strongly in favor of the starting isomer that no photoisomerization was observed. These experimental findings were elucidated by theoretical investigations of the potential energy surfaces of the ground (S0) and first excited (S1) electronic states of N4-hydroxycytosine. The crucial result of these calculations (carried out at the CASSCF level) was the localization of a conical intersection between S0 and S1 at a structure with perpendicular orientation of the hydroxylimino group with respect to the heterocyclic ring.     

多酯基取代的叶绿素类二氢卟吩衍生物的合成

以脱镁叶绿酸-a甲酯为起始原料,通过碱性条件下的水解开环、空气氧化和重排反应,分别合成了红紫素-7三甲酯和二氢卟吩-p6三甲酯.然后对其C(3)-乙烯基、20-meso-位、12-位甲基以及尾端酯基进行化学修饰,通过亲电加成、亲电取代、1,3-偶极环加成和氧化重排等反应,完成10种具未见报道的的叶绿素类二氢卟吩衍生物,其化学结构均经UV,IR,1H NMR光谱及元素分析予以表征.     

A Quantum-Chemical and Correlation Study of the Ionization of Purpurin

Anthraquinoid tautomers participate in the ionization of purpurin. The tautomerism takes place in both ground and excited states of the molecules; the excited state is more sensitive to the tautomerism. The solvation and ionization shift the tautomeric equilibria. In the experimental absorption spectra of purpurin, the major bands correspond to the 9,10-, 1,4-, and 1,10-anthraquinoid tautomers; anions with the 9,10-anthraquinoid structure are not detected. The position and intensity of the π,π* bands, and also the quantum-chemical parameters linearly correlate with the degree of ionization of purpurin.     

The use of microspectrofluorimetry for the characterization of lake pigments

In this paper, the potential of confocal microfluorescence spectroscopy is explored for the characterization of selected red lake pigments and paints based on alizarin, purpurin and eosin (weak, medium and strong emitters). The anthraquinone pigments have been used since ancient times by artists, and eosin lakes were used by impressionist painters. Reconstructions of artists paints based on 19th century recipes are examined. The paints were made using the lake pigments bound in a range of binding media including gum arabic, collagen, a vinyl emulsion and linseed oil. The acquisition of the spectra is rapid, with high spatial resolution and the data reliable and reproducible. Together with full emission spectra, it was possible to acquire well-resolved excitation spectra for purpurin, alizarin and eosin based colors. The present investigation suggests that micro-emission fluorescence can also be used as a semi-quantitative method for madder lake pigments, enabling the determination of purpurin lake ratio in a mixture of purpurin and alizarin, which is important for provenance studies. The data obtained with microfluorescence emission with those acquired with fiber-optic fluorimetry are compared. The spatial resolution used, 8microm, is appropriate for the analysis of individual pigments particles or aggregates in a paint film. Micro-emission molecular fluorescence proved to be a promising analytical tool to identify the presence of selected red lake pigments combined with a range of binding media.