A Convenient Protecting Group for Uridine Ureido Nitrogen: (4,4′-Bisfluorophenyl)methoxymethyl Group

A practical and concise total synthesis of tricyclic ketone 7 (CDE ring), a valuable intermediate for the synthesis of racemic camptothecin and analogs, was described (8 chemical steps and 29% overall yield). The synthesis starts with two inexpensive, readily available materials and is operationally simple to perform. It is worth mentioning that the reported protecting group-free synthesis, with advantages of a short route, would be helpful for the future development of industry-scale syntheses of camptothecin-family alkaloids.

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Fluoroquinolone-3-carboxamide Amino Acid Conjugates: Synthesis, Antibacterial Properties And Molecular Modeling Studies

Medicinal Chemistry ◽

10.2174/1573406415666190904143852 ◽

2020 ◽

Vol 17 (1) ◽

pp. 71-84

Author(s):

Riham M. Bokhtia ◽

Siva S. Panda ◽

Adel S. Girgis ◽

Hitesh H. Honkanadavar ◽

Tarek S. Ibrahim ◽

...

Keyword(s):

Experimental Data ◽

Antibacterial Activity ◽

Amino Acid ◽

Bacterial Infections ◽

Antibacterial Agents ◽

Antibacterial Properties ◽

Computational Studies ◽

Protecting Group ◽

Amino Acid Conjugates ◽

Molecular Modeling Studies

Background: Bacterial infections are considered as one of the major global health threats, so it is very essential to design and develop new antibacterial agents to overcome the drawbacks of existing antibacterial agents. Method: The aim of this work is to synthesize a series of new fluoroquinolone-3-carboxamide amino acid conjugates by molecular hybridization. We utilized benzotriazole chemistry to synthesize the desired hybrid conjugates. Result: All the conjugates were synthesized in good yields, characterized, evaluated for their antibacterial activity. The compounds were screened for their antibacterial activity using methods adapted from the Clinical and Laboratory Standards Institute. Synthesized conjugates were tested for activity against medically relevant pathogens; Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27856) Staphylococcus aureus (ATCC 25923) and Enterococcus faecalis (ATCC 19433). Conclusion: The observed antibacterial experimental data indicates the selectivity of our synthesized conjugates against E.Coli. The protecting group on amino acids decreases the antibacterial activity. The synthesized conjugates are non-toxic to the normal cell lines. The experimental data were supported by computational studies.

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Synthesis of (15E)-17β-hydroxy-5α-androstane-3,15-dione 15-[O-(Carboxymethyl)]oxime, New Hapten for Dihydrotestosterone (17β-hydroxy-5α-androstan-3-one)

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19971642 ◽

1997 ◽

Vol 62 (10) ◽

pp. 1642-1649 ◽

Cited By ~ 2

Author(s):

Ivan Černý ◽

Tereza Slavíková ◽

Vladimír Pouzar

Keyword(s):

Hydroxy Group ◽

Carboxy Group ◽

Title Compound ◽

Oxidative Cleavage ◽

Hydroxy Derivative ◽

Borohydride Reduction ◽

Protecting Group ◽

Free Hydroxy Group

Addition of 4-methoxybenzyl alcohol to 3β-hydroxy-5α-androst-15-en-17-one gave the mixture of isomeric 15-(4-methoxyphenyl)methoxy derivatives from which, after acetylation and chromatography, the major 15β isomer was separated. Borohydride reduction gave 17β-hydroxy derivative which was protected as methoxymethyl ether. Oxidative cleavage of protecting group at position 15 and the subsequent Jones oxidation afforded corresponding 15-ketone. Its oximation with O-(carboxymethyl)hydroxylamine, deacetylation and methylation with diazomethane gave protected O-(carboxymethyl)oxime derivative with free hydroxy group at position 3. Its oxidation afforded dihydrotestosterone derivative and successive deprotection of position 17 and of carboxy group led to final (15E)-17β-hydroxy-5α-androstane-3,15-dione 15-[O-(carboxymethyl)]oxime. The title compound was designed as dihydrotestosterone hapten for heterologous radioimmunoassays.

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Equilibrium Studies of Binary and Ternary Complexes of Palladium(II) Involving Amino Acids

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19931103 ◽

1993 ◽

Vol 58 (5) ◽

pp. 1103-1108 ◽

Cited By ~ 4

Author(s):

Mohamed M. Shoukry ◽

Eman M. Shoukry

Keyword(s):

Amino Acids ◽

Relative Stability ◽

Ternary Complex ◽

Formation Constants ◽

Ternary Complexes ◽

Conductivity Measurements ◽

Equilibrium Studies ◽

Binary And Ternary Complexes ◽

Binary Complexes

The formation constants of the binary and ternary complexes of palladium(II) with diethylenetriamine and amino acids as ligands have been determined potentiometrically at 25 °C in 0.1 M NaNO3 solution. The relative stability of each ternary complex was compared with that of the corresponding binary complexes in terms of ∆logK values. The mode of chelation was ascertained by conductivity measurements.

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Cleavage of the Epimines of 1,6-Anhydrohexoses with Fluoride Anion

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20052075 ◽

2005 ◽

Vol 70 (12) ◽

pp. 2075-2085 ◽

Cited By ~ 5

Author(s):

Jiří Kroutil ◽

Klára Jeništová

Keyword(s):

Fluoride Anion ◽

Ring Cleavage ◽

Protecting Group ◽

Reaction Conditions ◽

Aziridine Ring ◽

Cleavage Reactions ◽

Derivatives Of ◽

Fluoro Derivatives

Aziridine ring cleavage reactions of five N-nosylepimines (2-6) having D-talo, D-galacto, D-manno, and D-allo configurations with potassium hydrogendifluoride under various reaction conditions have been performed. The cleavage regioselectively afforded diaxial isomers of vicinal amino-fluoro derivatives of 1,6-anhydro-β-D-gluco- and mannopyranose 7-11 in 51-94% yields. Removal of 2-nitrobenzenesulfonyl protecting group with benzenethiol has been attempted in the case of compound 10.

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ChemInform Abstract: Studies on the Chemical Transformation of Rotenoids. Part 2. Reactions of Rotenone and Rotenonone with Primary Amines.

Chemischer Informationsdienst ◽

10.1002/chin.198643168 ◽

1986 ◽

Vol 17 (43) ◽

Author(s):

J. SAKAKIBARA ◽

S. NAGAI ◽

T. AKIYAMA ◽

T. UEDA ◽

N. ODA

Keyword(s):

Chemical Transformation ◽

Primary Amines

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A Novel Index (RI) to Evaluate the Relative Stability of Soils Using Ultrasonic Agitation

Sustainability ◽

10.3390/su13084229 ◽

2021 ◽

Vol 13 (8) ◽

pp. 4229

Author(s):

Fakher Abbas ◽

Fang Lin ◽

Zhaolong Zhu ◽

Shaoshan An

Keyword(s):

Relative Stability ◽

Characteristic Curve ◽

Geometric Mean ◽

Relative Strength ◽

Soil Stability ◽

Dispersion Energy ◽

Ultrasonic Agitation ◽

Mean Weight Diameter ◽

Change In Mean ◽

Wet Sieving

As soil stability is a complex phenomenon, various methods and indexes were introduced to assess the strength of soils. Because of the limitations of different stability methods and indexes (including wet sieving-based), we aimed to presents a relative stability index (RI) that was based on the estimated components of the soil overall disruptive characteristic curve (SODC): (1) soil disruption constant (Ki, that is based upon dispersion energy of soils); (2) resulting change in mean weight diameter (ΔMWD). To evaluate the effectiveness and limitations of RI as well as to compare it with classical soil stability indexes of mean weight diameter (MWD) and geometric mean diameter (GMD). Ultrasonic agitation (UA) along with a wet sieving method (followed by dry sieving) was applied against four different soils named on the basis of sample location, Qingling soil (QL), Guanzhong soil (GZ), Ansai soil (AS), and Jingbian soil (JB). To evaluate the relative strength of soils at different applied energies (increase in sonication duration usually resulted in increased input energy and temperature of soil–water suspension), soils were subjected to six sonication durations (0, 30, 60, 120, 210, and 300 s) with a fixed (and exact) initial amplitude and temperature. Output energy was calculated based on the amplitude and temperature of the suspension, vessel, and system. The most abrupt and maximum disruption of soil aggregates was observed at a dispersion energy level of 0–200 J g−1. The MWD value of surface and subsurface ranged between 0.58 to 0.15 mm and 0.37 to 0.17 mm, respectively, while GMD was ranged from 0.14 to 0.33 mm overall. The results for MWD and GMD showed a similar trend. MWD and GMD showed more strong associations with physicochemical characteristics of soil than RI. A non-significant correlation was found between RI and MWD/GMD. Contrary to MWD and GMD, RI was significantly positively correlated with sand content; this finding indicated the influential role of sand in assessing the soil’s relative strength. The results indicated that JB soil possessed the least MWD and GMD but proved to be relatively stable because of having the highest RI value.

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Synthesis and Antiproliferative Evaluation of 2-Deoxy-N-glycosylbenzotriazoles/imidazoles

Molecules ◽

10.3390/molecules26123742 ◽

2021 ◽

Vol 26 (12) ◽

pp. 3742

Author(s):

Caleigh S. Garton ◽

Noelle K. DeRose ◽

Dylan Dominguez ◽

Maria L. Turbi-Henderson ◽

Ashley L. Lehr ◽

...

Keyword(s):

Cell Lines ◽

Cancer Cell ◽

Addition Reaction ◽

Protecting Group ◽

Human Breast ◽

Lung Cancer Cell ◽

Subsequent Removal ◽

Anticancer Properties ◽

Tributyltin Hydride ◽

High Yields

A series of 2-deoxy-2-iodo-α-d-mannopyranosylbenzotriazoles was synthesized using the benzyl, 4,6-benzylidene and acetyl protected D-glucal in the presence of N-iodosuccinimide (NIS). Subsequent removal of the iodine at the C-2 position using tributyltin hydride under free radical conditions afforded the 2-deoxy-α-d-glucopyranosylbenzotriazoles in moderate to high yields. This method was extended to the preparation of substituted 2-deoxy-β-d-glucopyranosylimidazoles as well. The stereoselectivity of the addition reaction and the effect of the protecting group and temperature on anomer distribution of the benzotriazole series were also investigated. The anticancer properties of the newly synthesized compounds were evaluated in a series of viability studies using HeLa (human cervical adenocarcinoma), human breast and lung cancer cell lines. The N-[3,4,6-tri-O-benzyl-2-deoxy-α-d-glucopyranosyl]-1H-benzotriazole and the N-[3,4,6-tri-O-acetyl-2-deoxy-α-d-glucopyranosyl]-2H-benzotriazole were found to be the most potent cancer cell inhibitors at 20 µM concentrations across all four cell lines.

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