共查询到20条相似文献,搜索用时 15 毫秒
1.
Rajendra Prasad Nandi Dr. Pagidi Sudhakar Dr. Neena K. Kalluvettukuzhy Prof. Pakkirisamy Thilagar 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(69):16306-16317
Herein, the design, synthesis, optical properties, and mechanofluorochromism characteristics of a series of conjugates having covalently linked triarylborane (TAB) and anil/boranil units (TAB-anil: 1 a – 3 a and TAB-boranil: 1 – 3 ) are reported. The electronic interactions between TAB and anil/boranil in 1 a – 3 a and 1 – 3 were fine-tuned by changing the boryl moiety's position on the phenyl spacer connecting the BMes2 (Mes=mesityl) and anil/boranil units. A boryl moiety at the meta position ( 1 a ) of the phenyl spacer stabilizes the enolic form (E-OH), whereas a boryl moiety at the para position ( 2 a and 3 a ) stabilizes the keto form (Z-NH) in the solid state. However, in solution 1 a , 2 a , and 3 a exhibit keto–enol tautomerism in both ground and excited states. Compounds 1 a – 3 a and 1 – 3 show red-shifted absorption compared with 4 a and 4 , which are devoid of TAB moieties, which indicate effective participation of an empty p orbital on the boron center in 1 a – 3 a and 1 – 3 . Compounds 1 and 2 showed fluorescence variations in response to external stimuli such as mechanical grinding. Long phosphorescence lifetimes of 18–46 ms were observed for compounds 1 – 3 . The observed optical properties of 1 a – 3 a and 1 – 3 are rationalized in the context of quantum mechanical calculations. 相似文献
2.
JPC – Journal of Planar Chromatography – Modern TLC - Asensitive, selective, and precise high-performance thin-layer chromatography (HPTLC) method was developed for simultaneous... 相似文献
3.
MarcS. Robillard BartA.J. Jansen Martin Lochner Herv Geneste Yi Li Jaap Brouwer Manfred Hesse Jan Reedijk 《Helvetica chimica acta》2001,84(10):3023-3030
The synthesis of three bis[(tert‐butoxy)carbonyl]‐protected (tetramine)dichloroplatinum complexes 2a – c of formula cis‐[PtCl2(LL)] and of their cationic deprotected analogs 3a – c and their evaluation with respect to in vitro cytotoxicity, intramolecular stability, DNA binding, and cellular uptake is reported. The synthesis comprises the complexation of K2[PtCl4] with di‐N‐protected tetramines 1a – c to give 2a – c and subsequent acidolysis, yielding 3a – c . The cytotoxicity of the complexes is in direct relation to the length of the polyamine. Complexes 3a – c display a significant higher affinity for CT DNA as well as for cellular DNA in A2780 cells than cisplatin. 相似文献
4.
Quazi Ahmed Theodor Wagner-Jauregg Ernst Pretsch Josef Seibl 《Helvetica chimica acta》1973,56(5):1646-1655
The N-substituted 1-benzimidazolyl-succinimides 6a – v (Scheme 1, Table 1 and 2) have been prepared by the reaction of benzimidazole and its derivatives with maleimides. Reduction of the N-cyclohexyl and N-cyclo-octyl substituted 1-benzimidazolyl-succinimides 6i – k with lithium aluminium hydride gives the normally expected substituted (N-alkyl-3-pyrrolidinyl)benzimidazoles 14i – k . However by LiAlH4-reduction of the N-phenyl substituted 1-benzimidazolylsuccinimides 6a – h mainly the 1-aryl-9-alkyl-2, 3, 3a, 4, 9, 9a-hexahydro-1H-pyrrolo[2, 3-b]quinoxalines 7a – h are obtained. The mechanism of this unusual reduction has been elucidated. 相似文献
5.
JPC – Journal of Planar Chromatography – Modern TLC - A chromatographic–densitometric method has been established for identification and quantification of... 相似文献
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JPC – Journal of Planar Chromatography – Modern TLC - 相似文献
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JPC – Journal of Planar Chromatography – Modern TLC - Aegle marmelos (Rutaceae) has gained traditional therapeutic importance owing to their coumarins (umbelliferone, psoralene, marmin,... 相似文献
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JPC – Journal of Planar Chromatography – Modern TLC - 相似文献
9.
《Journal of heterocyclic chemistry》2017,54(6):3342-3349
New series of chromenes 2 – 4 , pyridines 5 – 8 , and pyranopyrazoles 9a,b were synthesized via one‐pot multicomponent reaction of 4‐tosyloxybenzaldehyde ( 1 ) and malononitrile with phenols, amines or hydrazines, and ethyl acetoacetate, respectively. Compound 9a was reacted with acetic anhydride, formic acid, or formamide to afford N ‐acetyl derivative 10 and pyrazolopyranopyrimidines 11 – 13 , respectively. Imidazole derivatives 14 and 15a – d were obtained by multicomponent reaction between compound 1 with ammonium acetate and benzil or aromatic amines in (1:2:1) or (1:1:1:1) ratio, respectively. The structures of new compounds were elucidated by elemental and spectral analyses. 相似文献
10.
JPC – Journal of Planar Chromatography – Modern TLC - Athin-layer chromatographic (TLC) method was used for the quantification of four dominant flavonoids (rutin, narcissin,... 相似文献
11.
JPC – Journal of Planar Chromatography – Modern TLC - A simple, precise, and rapid HPTLC method has been established for quantitative determination of the bioactive marker compound... 相似文献
12.
JPC – Journal of Planar Chromatography – Modern TLC - We report improved separation of the highly toxic contact herbicides paraquat, diquat, difenzoquat, mepiquat, and chloromequat by... 相似文献
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JPC – Journal of Planar Chromatography – Modern TLC - A new, simple, accurate, and rapid high-performance thin-layer chromatographic method has been developed for the determination of... 相似文献
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JPC – Journal of Planar Chromatography – Modern TLC - 相似文献
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JPC – Journal of Planar Chromatography – Modern TLC - 相似文献
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Agbaba Danica Novovic Dragana Karljiković-Rajić Katarina Marinković Valentina 《平面色谱法杂志一现代薄层色谱法》2004,17(3):169-172
JPC – Journal of Planar Chromatography – Modern TLC - A method has been developed for separation of omeprazole and pantoprazole, and their impurities omeprazole sulfone and... 相似文献
17.
Khabiya Rakhi Upadhyay Dilawar Srivastava Anshu Anandjiwala Sheetal 《平面色谱法杂志一现代薄层色谱法》2014,27(4):281-286
JPC – Journal of Planar Chromatography – Modern TLC - Phyllanthus amarus, a well-known drug of the Indian Systems of Medicine, possesses a wide variety of pharmacological activities... 相似文献
18.
Dayanand Patagar Raviraj Kusanur Nikum D. Sitwala Manjunath D. Ghate Shanmugasundar Saravanakumar Sharanappa Nembenna Piyush A. Gediya 《Journal of heterocyclic chemistry》2019,56(10):2761-2771
Coumarins are the important class of naturally occurring heterocyclic compounds. Activities like antioxidant, antibacterial, anti‐inflammatory, and anticancer have been reported for coumarin derivatives. Present work details the synthesis of substituted coumarin‐4‐pyrrolones as well as coumarin‐4‐acetyl amino acids and their DHODH inhibitory activity, which is a dual target for malaria and cancer. Coumarin‐4‐acetic acids ( 2a – c ) were coupled with different methyl esters of α‐amino acids ( 3 ) giving rise to corresponding coumarin‐4‐acetyl amino acid methyl esters ( 4a – o ), which on hydrolysis under basic condition underwent cyclization forming substituted dihydropyrrole‐2‐ones ( 5a – i ), dihydroindolizine‐3‐ones ( 5j – l ), and dihydropyrrolizin‐3‐one ( 5m – o ). Acidic hydrolysis of the compounds ( 4a – o ) yielded corresponding coumarin‐4‐acetyl amino acids ( 6a – f ). The docking study was performed with the protein 4IGH (obtained from PDB) using Surflex–Dock module. The newly synthesized compounds were tested for DHODH inhibitory activity using Brequinar as the standard. Compound 6b showed remarkable inhibition compared with the standard, and the other compounds with terminal COOH showed moderate inhibition. 相似文献
19.
Six new apotirucallane‐type triterpenoids, chisiamols A – F ( 1 – 6 ), along with two known compounds, were isolated from the twigs of Chisocheton siamensis. The structures of compounds 1 – 6 were established on the basis of spectroscopic and chemical methods. 相似文献
20.
JPC – Journal of Planar Chromatography – Modern TLC - A 2D-separation of 16 polyaromatic hydrocarbons (PAHs) according to the Environmental Protecting Agency (EPA) standard was... 相似文献