scholarly journals Bromobenzoylation of Methyl α-D-Mannopyranoside: Synthesis and Spectral Characterization

Author(s):  
Farhana Yasmin ◽  
Md. R. Amin ◽  
Anowar Hosen ◽  
M.A. Kawsar Sarkar

The widening importance of carbohydrate derivatives as unrivaled potential antimicrobial and therapeutic drugs has attracted attentionto the synthesis of mannopyranoside derivatives. In the present study, regioselective 3-bromobenzoylation of methyl α-D-mannopyranoside (1) was carried out using the direct method and gave the corresponding 6-O-(3-bromobenzoyl) derivative (2) in excellent yield. A number of 2,3,4-tri-O-acyl derivatives (3–10) of this 6-substitution product using a wide variety of acylating agents were also prepared in order to obtain newer derivatives of synthetic and biological importance. The chemical structures of the newly synthesized compounds were ascertained by analyzing their physicochemical, elemental, and spectroscopic data. Additionally, the X-ray powder diffraction (XRD) of these acylated products was studiedfor quantitatively identifying crystalline compounds.Therefore, due to the importance of carbohydrates, it might be useful to develop a good method for the synthesis of carbohydrate-based drugs of the current global situation for health and disease

Marine Drugs ◽  
2019 ◽  
Vol 17 (7) ◽  
pp. 384 ◽  
Author(s):  
Qinxue Jing ◽  
Xu Hu ◽  
Yanzi Ma ◽  
Jiahui Mu ◽  
Weiwei Liu ◽  
...  

Marine natural products are considered to be valuable resources that are furnished with diverse chemical structures and various bioactivities. To date, there are seven compounds derived from marine natural products which have been approved as therapeutic drugs by the U.S. Food and Drug Administration. Numerous bromotyrosine derivatives have been isolated as a type of marine natural products. Among them, psammaplin A, including the oxime groups and carbon–sulfur bonds, was the first identified symmetrical bromotyrosine-derived disulfide dimer. It has been found to have a broad bioactive spectrum, especially in terms of antimicrobial and antiproliferative activities. The highest potential indole-derived psammaplin A derivative, UVI5008, is used as an epigenetic modulator with multiple enzyme inhibitory activities. Inspired by these reasons, psammaplin A has gradually become a research focus for pharmacologists and chemists. To the best of our knowledge, there is no systematic review about the biological activity and structural modification of psammaplin A. In this review, the pharmacological effects, total synthesis, and synthesized derivatives of psammaplin A are summarized.


2007 ◽  
Vol 62 (4) ◽  
pp. 519-522 ◽  
Author(s):  
Anvarhusen K. Bilakhiya ◽  
Frank W. Heinemann ◽  
Andreas Grohmann

The reaction of four equivalents of phenyl or tert-butyl isocyanate with the pyridine-derived tetraamine 2,6-C3H3N[CMe(CH2NH2)2]2 in toluene gives high yields of the quadruply ureido substituted products 2,6-C5H3N[CMe(CH2R)2]2 [R = -NH(CO)NHPh and -NH(CO)NHtBu]. Full spectroscopic data for both compounds are given. A single crystal X-ray structure determination of the phenyl derivative reveals an intricate network of both intra- and intermolecular hydrogen bonds involving the C=O and both NH functionalities in all ureido groups.


1996 ◽  
Vol 51 (6) ◽  
pp. 832-837 ◽  
Author(s):  
Konstantin V. Domasevitch ◽  
Victor V. Skopenko ◽  
Eduard B. Rusanov

Abstract Diphenyltellurium(IV) derivatives of the types Ph2Te{ACO}2 (1), Ph4Te2O{ACO}2 (2) and Ph6Te3O2{ACO} (3) (ACO = nitrosocarbamylcyanmethanide -ONC(CN)C(O)NH2) have been prepared. The IR spectroscopic data reveal that the ambidentate ligands are coordinated to the tellurium(IV) atom in a monodentate manner via the nitroso oxygen atom. The crystal and molecular structure of 3 has been determined from X-ray diffraction data (triclinic, space group P1̅ with a = 12.382(2), 6=13.100(2), c = 14.944(3) Å, a = 87.74( 1), β = 85.04(2), 7 = 66.29( 1)°, V = 2211.0 A , Z = 2, R = 0.040). The structure is made up of unsymmetric molecules, in which the tellurium atoms are linked by oxo bridges to form chains Te-O-Te-O-Te (d(Te-O) ca. 1.94-2.09 A). The Te-0 (nitroso group) bond lengths are in the range 2.33 - 2.36 Å


2010 ◽  
Vol 6 (3) ◽  
pp. 297-303
Author(s):  
Jumina Jumina

Alkylation of 3-aryl-4,6-dimethoxyindole 3a and 3b with methyl and ethyl a-bromoacetates afforded good yields of indol-1-ylacetates 4. Treatment of these indoles 4 with the Vilsmeier formylation reagent gave formylindoles 5 in 54-81 % yield. These formylindole 5 underwent intramolecular aldol condensation when treated with sodium hydride in tetrahydrofuran to give pyrroloindole-4-carboxylates 6 in 30-60 % yield. Structural assignment based on spectroscopic data confirmed the structure of the synthesized pyrroloindoles. In the case of pyrroloindole 6c, the structure of this molecule was also proven by X-ray crystallography data.    Keywords: indole, pyrroloindole, aldol condensation, alkylation, and formylation


2020 ◽  
Vol 17 ◽  
Author(s):  
Rahele Bargebid ◽  
Ali Khalafi-Nezhad ◽  
Kamiar Zomorodian ◽  
Leila Zamani ◽  
Ali Ahmadinejad ◽  
...  

Introduction: Mannich reaction is a typical example of a three-component condensation reaction and the chemistry of Mannich bases has been the matter of search by researchers. Here an efficient procedure for the synthesis of some new Mannich derivatives of simple phenols is described. Methods: In this procedure a microwave-assisted and solvent less condensation were done between different phenols, secondary amines and paraformaldehyde. The reactions proceed in the presence of catalytic amount of nano ZnO and tetrabutylammonium bromide (TBAB) in excellent yields. 10 new compounds were synthesized (A1-A10). Chemical structures of all new compounds were confirmed by different spectroscopic methods. We optimized the chemical reactions in different conditions. Optimization reactions were done in the presence of different mineral oxides, different amount of TBAB and also different solvents. Nano ZnO and TBAB in catalytic amounts and solvent free conditions were the best conditions. All the synthesized compounds were screened for their antimicrobial activities. Antifungal and antibacterial activities of the synthesized compounds were evaluated against some Candida, filaments fungi, gram positive and gram negative bacteria by broth micro dilution method as recommended by CLSI. Results: The result showed that compounds A2, A3 and A4 against most of the tested Candida species and compounds A5 and A7 against C. parapsilosis and C. tropicalis, exhibited considerable antifungal activities. Also Compounds A8 and A10 showed desirable antifungal activities against C. neoformance and C. parapsilosis, respectively. The antibacterial activities of the synthesized compounds were also evaluated. Compounds A6 - A10 against E. Fecalis and compounds A5, A7, A9 and A10 against P. aeruginosa showed desirable antibacterial activities. Discussion: We have synthesized some new Mannich adducts of poly-hydroxyl phenols in the presence of nano-ZnO as a reusable catalyst, with the hope of discovering new lead compounds serving as potent antimicrobial agents. The advantages of this method are generality, high yields with short reaction times, simplicity, low cost and matching with green chemistry protocols. The antimicriobial studies of Mannich derivatives of phenols showed desirable results in vitro.


2019 ◽  
Vol 19 (4) ◽  
pp. 439-452 ◽  
Author(s):  
Mohamed R. Selim ◽  
Medhat A. Zahran ◽  
Amany Belal ◽  
Moustafa S. Abusaif ◽  
Said A. Shedid ◽  
...  

Objective: Conjugating quinolones with different bioactive pharmacophores to obtain potent anticancer active agents. Methods: Fused pyrazolopyrimidoquinolines 3a-d, Schiff bases 5, 6a-e, two hybridized systems: pyrazolochromenquinoline 7 and pyrazolothiazolidinquinoline 8, different substituted thiazoloquinolines 13-15 and thiazolo[3,2-a]pyridine derivatives 16a-c were synthesized. Their chemical structures were characterized through spectral and elemental analysis, cytotoxic activity on five cancer cell lines, caspase-3 activation, tubulin polymerization inhibition and cell cycle analysis were evaluated. Results: Four compounds 3b, 3d, 8 and 13 showed potent activity than doxorubicin on HCT116 and three compounds 3b, 3d and 8 on HEPG2. These promising derivatives showed increase in the level of caspase-3. The trifloromethylphenyl derivatives of pyrazolopyrimidoquinolines 3b and 3d showed considerable tubulin polymerization inhibitory activity. Both compounds arrested cell cycle at G2/M phase and induced apoptosis. Conclusion: Compounds 3b and 3d can be considered as promising anticancer active agents with 70% of colchicine activity on tubulin polymerization inhibition and represent hopeful leads that deserve further investigation and optimization.


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