Synthesis and characterization of a new natural product analog, 132-173-bacteriochlorophyllone a

2014 ◽  
Vol 18 (03) ◽  
pp. 188-199 ◽  
Author(s):  
Áron Roxin ◽  
Thomas D. MacDonald ◽  
Gang Zheng

Here we show the facile synthesis of 132-173-bacteriochlorophyllone a (12), with a distinct seven-membered exocyclic F-ring formed by 132-173-cyclization of bacteriopheophorbide a(16). This is the latest reported bacteriochlorin with such an exocyclic F-ring since 1975 (132-173 cyclobacteriopheophorbide a-enol, 11), and is an analog of previously described natural exocyclic F-ring-containing porphyrins (1–4) and chlorins (5–10). The structure of 12 was confirmed using a combination of 1D 1 H NMR, 2D COSY 1 H NMR, Jmod 13 C NMR and HRMS analysis. The biological activity of 12 was explored, and we found that this compound does not possess strong antioxidant activity like its natural product counterparts, but is a capable photosensitizer for photodynamic therapy.

2019 ◽  
Vol 23 (11n12) ◽  
pp. 1542-1550
Author(s):  
Nagihan Kocaağa ◽  
Öznur Dülger Kutlu ◽  
Ali Erdoğmuş

In this study, the synthesis and characterization of mono-(phthalocyaninato) lutetium(III) (1-Cl and 1-F) [Lu[Formula: see text](AcO)(Pc)] (Pc [Formula: see text] phthalocyaninato, AcO [Formula: see text] acetate) and bis-(phthalocyaninato) lutetium(III) (2-Cl and 2-Br) [Lu[Formula: see text]Pc[Formula: see text]] bearing halogenated (F, Cl and Br) phenoxy–phenoxy groups are described and verified by IR, [Formula: see text]H-NMR, UV-vis and mass spectrometry. Photochemical and photophysical properties of 1-F, 1-Cl 2-Cl and 2-Br in DMSO are also presented. A comparison between photophysical and photochemical parameters of mono and bis derivatives showed that mono phthalocyanines are better photosensitizers than bis phthalocyanines. Photophysical and photochemical properties of phthalocyanines are very useful for photodynamic therapy applications. Singlet oxygen quantum yields [Formula: see text] give an indication of the potential of the complexes as photosensitizers in photodynamic therapy applications. The chloro, fluoro, bromo-phenoxy–phenoxy substituted mono-(phthalocyaninato) lutetium(III) complexes (1-Cl and 1-F) gave good singlet oxygen quantum yields (from 0.86 to 0.80) in DMSO. Thus, these complexes show potential as Type II photosensitizers for PDT of cancer.


2014 ◽  
Vol 618 ◽  
pp. 170-174
Author(s):  
Hong Qi Li ◽  
Xiu Juan Tian ◽  
Zhen Chen ◽  
Ding Xiao ◽  
Ning Fang ◽  
...  

A new coumarin-1,2,3-triazole diad was designed and synthesized by Pechmann-Duisberg reaction and click chemistry. The three-step synthetic route to the target compound afforded an overall yield of 56%. The structures of the synthesized compounds were characterized by 1H NMR, 13C NMR, IR and mass spectrum. The click chemistry provided an ideal approach for synthesis under mild conditions of coumarin-1,2,3-triazole diads which may exhibit excellent biological activities such as antitubercular activity.


2015 ◽  
Vol 21 (5) ◽  
pp. 269-272 ◽  
Author(s):  
Snehal A. Chavan ◽  
Avinash G. Ulhe ◽  
Baliram N. Berad

AbstractNew 4,7-bis(arylamino)-2-tetra-O-acetyl-β-d-glucopyranosylimino-1,3,5,6-dithiadiazepines were synthesized via reaction of N-tetra-O-acetyl-β-d-glucopyranosyl isocyanodichloride with 1,6-diaryl-2,5-dithio-bis-ureas without using any catalyst. Thus, the synthesis of 7-membered heterocycles containing two sulfur and two nitrogen atoms through carbon-sulfur bond formation was explored. The chemical structures of these new compounds were elucidated by IR, 1H NMR, 13C NMR, mass spectral, and elemental analyses.


2014 ◽  
Vol 92 (9) ◽  
pp. 838-848 ◽  
Author(s):  
Vanessa Renee Little ◽  
Keith Vaughan

Five series of a novel class of 4-acyl-1-[2-aryl-1-diazenyl]piperazines have been synthesized and characterized: the 4-acetyl-1-[2-aryl-1-diazenyl]piperazines [series 1]; the 4-cyclohexylcarbonyl-1-[2-aryl-1-diazenyl]piperazines [series 2]; the 4-benzoyl-1-[2-aryl-1-diazenyl]piperazines [series 3]; the benzyl 4-[2-aryl-1-diazenyl]-1-piperazinecarboxylates [series 4]; and the t-butyl 4-[2-aryl-1-diazenyl]-1-piperazinecarboxylates [series 5]. The compounds were synthesized by diazotization of a primary aromatic amine and subsequent coupling to an appropriate secondary amine: 1-acetylpiperazine [series 1]; 1-(cyclohexylcarbonyl)-piperaizine [series 2]; 1-benzoylpiperazine [series 3]; benzyl 1-piperazinecarboxylate [series 4]; and t-butyl piperazine-1-carboxylate (1-BOC-piperazine) [series 5]. The compounds of series 1–5 were characterized by 1H NMR, 13C NMR, high-resolution MS and IR spectroscopy. The model compounds 1,4-di[2-aryl-1-diazenyl]piperazines, and ethyl 4-[2-aryl-1-diazenyl]-1-piperazinecarboxylates were used to facilitate the assignment of the chemical shifts specific to the piperazine ring carbons. HSQC spectra of select compounds established the correlation between proton and carbon resonance signals.


e-Polymers ◽  
2017 ◽  
Vol 17 (5) ◽  
pp. 439-448 ◽  
Author(s):  
Djamal Eddine Kherroub ◽  
Mohammed Belbachir ◽  
Saad Lamouri

AbstractThe present work is devoted to the synthesis and characterization of vinylsiloxane polymers produced by the use of an activated natural catalyst known as Maghnite-H+. The cationic ring opening polymerization of pentavinylpentamethylcyclopentasiloxane (V5D5) made it possible to obtain the desired polymeric materials. Through this study, we have adapted a new strategy of synthesis of a siloxane polymer with relatively high molecular mass, using a solid initiator activated by sulfuric acid, which has enabled us to combine the ecological aspect of synthesis and the effectiveness of the catalyst in this kind of reaction. Structural [infrared (IR), proton and carbon nuclear magnetic resonance (1H NMR and 13C NMR)], thermal differential scanning (DSC) and chromatographic (GPC) characterization methods have allowed the products obtained to be identified and their various properties to be focused on. The kinetic study was made to determine the order of the reaction. The proposed reaction mechanism shows the advantages of Maghnite-H+.


2014 ◽  
Vol 937 ◽  
pp. 80-85 ◽  
Author(s):  
Haroon A.M. Saeed ◽  
Yassir A. Eltahir ◽  
Yu Min Xia ◽  
Yi Min Wang

Hydroxyl-terminated hyperbranched polyesters (HBPET) with aromatic-aliphatic structure were synthesized by melt polycondensation of isophthalic acid and pentaerythritol via A2+ B4 approach, at three different monomer mole ratios (A2/B4 =1:1, 1.5:1, 2:1, respectively). Fourier transform infrared (FTIR) spectroscopy indicated that the expected HBPET. The degree of branching of the HBPET was estimated to be between 0.39–0.45 by 1H-NMR and 13C-NMR measurement. The thermogravimetric analysis ( TGA ) measurement revealed that HBPET had a 10 % weight-loss at 350°C in N2.


2014 ◽  
Vol 33 (2) ◽  
pp. 189 ◽  
Author(s):  
Mustafa Er ◽  
Ayşe Şahin ◽  
Hakan Tahtacı

<p>Thiosemicarbazone derivatives <strong>3a–e</strong> were synthesized by the reaction of various aldehydes<strong> 1a–e</strong> with 4-methyl thiosemicarbazide <strong>2</strong> in 78% to 90% yield. Then, the thiazole moieties of the target materials <strong>5a–e</strong> were obtained in high yields (71–93%) using the Hantzsch reaction utilizing thiosemicarbazone derivatives <strong>3a–e</strong> with ethyl-2-chloroacetoacetic ester. The substituted nitrile derivatives <strong>7a–e</strong> were obtained in moderate to high yield (58–84%) from the reaction of compounds <strong>5a–e</strong> with chloroacetonitrile by the nucleophilic aliphatic substitution reaction in the presence of anhydrous potassium carbonate. Finally, substituted 2-amino-1,3,4-thiadiazole compounds <strong>9a–e</strong> were obtained in moderate to good yields (51–62%) from the reaction of thiosemicarbazide with substituted nitrile derivatives <strong>7a–e</strong>. As a result, compounds that all share a high disposition for biological activities were obtained. The structures of the newly synthesized compounds were confirmed by IR, <sup>1</sup>H NMR, <sup>13</sup>C NMR, elemental analysis, and mass spectrometric techniques.</p>


Author(s):  
A.M. Shah ◽  
A.J. Rojivadiya

An efficient protocol for the synthesis of imidazo [1,2-a] pyrimidine was developed by using three component one-pot Biginelli synthesis. The synthesized compounds were characterized by spectroscopic techniques like FT-IR, 1H NMR, 13C NMR, and mass spectroscopy.


2009 ◽  
Vol 13 (02) ◽  
pp. 215-222 ◽  
Author(s):  
Motoki Toganoh ◽  
Takayoshi Hihara ◽  
Kentaro Yonekura ◽  
Yuichi Ishikawa ◽  
Hiroyuki Furuta

A unique class of azo porphyrin, 5,10,15,20-tetraphenyl-21-phenylazo-(2-aza-21-carbaporphyrin 1, in which an azophenyl group is embedded in N -confused porphyrin, was synthesized and characterized by 1 H NMR, 13 C NMR, UV-vis absorption, MS, and X-ray crystallographic analysis. Synthesis of 1 was achieved through a coupling reaction of 21-amino N -confused tetraphenylporphyrin with nitrosobenzene and subsequent deoxygenation of resulting azoxy derivative with a trioxo rhenium(VII) N -fused porphyrinato catalyst. The azo-conjugate molecule was exclusively obtained as a trans-isomer and no isomerization to the cis-isomer was observed under thermal or photoirradiation. The absorption spectrum of 1 shows a moderate red-shift due to the effective interaction between the porphyrinic π-system and the connecting azophenyl group. Upon protonation, this effect is essentially lost as a result of removing degeneracy of LUMO and LUMO+1.


2015 ◽  
Vol 1094 ◽  
pp. 37-40
Author(s):  
Hai Xin Ding ◽  
Zhi Zhong Ruan ◽  
Qiang Xiao ◽  
Xiao Jun Wang

A novel galactoside derivative (1) incorporatingp-nitroaniline (p-NA) as chromophore has been synthesized and used as a cascaded chromogenic enzyme substrate for the detection of β-D-galactosidase, which was characterized using UV,1H NMR,13C NMR and MS spectra. A plausible mechanism for the release ofp-NPA from the enzyme substrate 1 was proposed.


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