Synthesis of the partially protected fragment 1-16 of salmon calcitonin by using the phenylhydrazide protecting 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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Effects of Teriparatide versus Salmon Calcitonin Therapy for the Treat-ment of Osteoporosis in Asia: A Meta-analysis of Randomized Controlled Trials

Endocrine Metabolic & Immune Disorders - Drug Targets ◽

10.2174/1871530320999200817114817 ◽

2020 ◽

Vol 20 ◽

Author(s):

Changjun Chen ◽

Mohammed Alqwbani ◽

Jie Chen ◽

Ruitong Yang ◽

Songgang Wang ◽

...

Keyword(s):

Femoral Neck ◽

Adverse Events ◽

Randomized Controlled Trials ◽

Salmon Calcitonin ◽

Bone Markers ◽

Meta Analysis ◽

Controlled Trials ◽

Randomized Controlled ◽

Asian Patients ◽

Teriparatide Treatment

Objective: The objective of this meta-analysis was to compare the efficacy and safety of teriparatide versus salmon calcitonin for the treatment of osteoporosis in Asian patients and to investigate whether the results of global studies could be applicable to Asian patients. Methods: PubMed, OVID, Cochrane Central Register of Controlled Trials (CENTRAL) and EMBASE up to December 2018 were searched. Eligible randomized controlled trials (RCTs) that compared teriparatide versus salmon calcitonin in Asian osteoporosis popula-tion were included. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used for data synthe-sis, and Cochrane Collaboration software Review Manager 5.3 was used to analyze the pooled data. Results: Three RCTs involving 529 patients were included (mean age 68.7 yr; 93.4% females; mean follow-up 6 months); outcome measures included bone mineral density (BMD) of the femoral neck, total hip and lumbar spine; bone markers and adverse events. We found that the period of 6-months of teriparatide treatment was helpful for the improvement of the BMD of lumbar vertebra, however, the improvement of BMD was not significant in femoral neck and total hip join. There was a positive correlation between bone-specific alka-line phosphatase (BSAP) and osteocalcin (OCN) and the response of Asian patients to subcutaneous injection of 20 micrograms per day of teriparatide. And the proportion of the occurrence of adverse effect was more obvious in teriparatide group compared with salmon calciton-in, but there was no significant difference. Conclusion: Results suggested that the use of teriparatide could improve the lumbar BMD by short-term (six months) application in Asian osteoporosis patients, which is beneficial to the patients who cannot tolerate adverse events of long-term treatment. The BSAP and OCN bone markers could be useful to monitor the responses of Asian osteoporosis patients to teriparatide treatment. Finally, both of teriparatide and salmon calcitonin were well tolerated by Asian patients.

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

Synthesis ◽

10.1055/a-1464-2473 ◽

2021 ◽

Author(s):

Michio Kurosu ◽

Katsuhiko Mitachi ◽

David Mingle

Keyword(s):

Chemical Transformation ◽

Relative Stability ◽

Protecting Group

Abstract(4,4′-Bisfluorophenyl)methoxymethyl (BFPM) group of uridine ureido nitrogen shows good relative stability in a variety of chemical transformation reactions for uridine. The BFPM group can be cleaved by 2% of TFA in CH2Cl2 without affecting the Boc group.

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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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