Nucleic acid related compounds. 25. Syntheses of arabino, xylo, and lyxo-anhydro sugar nucleosides from tubercidin ribo-epoxide

1977 ◽  
Vol 55 (7) ◽  
pp. 1260-1267 ◽  
Author(s):  
Morris J. Robins ◽  
Yves Fouron ◽  
Wolfgang H. Muhs
Keyword(s):  
Nucleic Acid ◽  
Intramolecular Cyclization ◽  
Sodium Benzoate ◽  
Chemical Properties ◽  
Biologically Active ◽  
Isopropylidene Derivative ◽  
Ion Formation ◽  
Related Compounds ◽  
And Chemical Properties

Treatment of the trans iodohydrin acetate, 4-amino-7-(3-iodo-3-deoxy-2-O-acetyl-5-O-[2,5,5-trimethyl-1,3-dioxolan-4-on-2-yl]-β-D-xylofuranosyl)pyrrolo[2,3-d]pyrimidine (2) with metha-nolic ammonia gave 2′,3′-anhydrotubercidin (3) in 96% yield. N4,N4,O5′-Tribenzoylation of 3 gave 4, which is stabilized against intramolecular cyclization. Treatment of 4 with boron tri-fluoride etherate (3′,5′-benzoxonium ion formation) followed by deblocking gave 4-amino-7-β-D-xylofuranosylpyrrolo[2,3-d]pyrimidine (5) in 91% overall yield from tubercidin (1). The 3′,5′-O-isopropylidene derivative (6a) of 5 was mesylated to give 6b which was deprotected in acid and the resulting trans hydroxy mesylate was treated with base to give 4-amino-7-(2,3-anhydro-β-D-lyxofuranosyl)pyrrolo[2,3-d]pyrimidine (7). This lyxo epoxide was treated with sodium benzoate in DMF to give 4-amino-7-β-D-arabinofuranosylpyrrolo[2,3-d]pyrimidine (8). Biochemical, spectroscopic, and chemical properties of these semisynthetic antibiotic analogues of biologically active adenine nucleosides are discussed.

The Nature of S-N Bonding in Sulfonamides and Related Compounds: Insights into π-Bonding Contributions from Sulfur K-Edge XAS

2020 ◽  
Author(s):  
Tulin Okbinoglu ◽  
Pierre Kennepohl
Keyword(s):  
Density Functional ◽  
Chemical Properties ◽  
Functional Theory ◽  
Rotational Barriers ◽  
Td Dft ◽  
Nitrogen Bonds ◽  
X Ray Absorption ◽  
Related Compounds ◽  
And Chemical Properties

Molecules containing sulfur-nitrogen bonds, like sulfonamides, have long been of interest due to their many uses and chemical properties. Understanding the factors that cause sulfonamide reactivity is important, yet their continues to be controversy regarding the relevance of S-N π bonding in describing these species. In this paper, we use sulfur K-edge x-ray absorption spectroscopy (XAS) in conjunction with density functional theory (DFT) to explore the role of S<sub>3p</sub> contributions to π-bonding in sulfonamides, sulfinamides and sulfenamides. We explore the nature of electron distribution of the sulfur atom and its nearest neighbors and extend the scope to explore the effects on rotational barriers along the sulfur-nitrogen axis. The experimental XAS data together with TD-DFT calculations confirm that sulfonamides, and the other sulfinated amides in this series, have essentially no S-N π bonding involving S<sub>3p</sub> contributions and that electron repulsion and is the dominant force that affect rotational barriers.

Synthesis and chemical properties of adamantylated nucleic bases and related compounds

2013 ◽  
Vol 47 (5) ◽  
pp. 264-280 ◽  
Author(s):  
E. A. Shokova ◽  
V. V. Kovalev
Keyword(s):  
Chemical Properties ◽  
Nucleic Bases ◽  
Related Compounds ◽  
And Chemical Properties

scholarly journals Dendrimers: A New Race of Pharmaceutical Nanocarriers

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Pooja Mittal ◽  
Anjali Saharan ◽  
Ravinder Verma ◽  
Farag M. A. Altalbawy ◽  
Mohammed A. Alfaidi ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Chemical Properties ◽  
Biologically Active ◽  
Dimensional Structure ◽  
Synthesis Mechanism ◽  
Drug Conjugates ◽  
Wide Range ◽  
New Race ◽  
Physical And Chemical ◽  
And Chemical Properties

Dendrimers are nanosized, symmetrical molecules in which a small atom or group of atoms is surrounded by the symmetric branches known as dendrons. The structure of dendrimers possesses the greatest impact on their physical and chemical properties. They grow outwards from the core-shell which further reacts with monomers having one reactive or two dormant molecules. Dendrimers’ unique characteristics such as hyperbranching, well-defined spherical structure, and high compatibility with the biological systems are responsible for their wide range of applications including medical and biomedical areas. Particularly, the dendrimers’ three-dimensional structure can incorporate a wide variety of drugs to form biologically active drug conjugates. In this review, we focus on the synthesis, mechanism of drug encapsulations in dendrimers, and their wide applications in drug delivery.

A Facile Synthesis of substituted Trifluoromethyl piperidines with diversify functionalization

2021 ◽  
Vol 18 ◽  
Author(s):  
Wahid Bux Jatoi ◽  
Ashique Hussain Balouch ◽  
Mazhar Iqbal Khaskheli ◽  
Nafeesa Khatoon Shahani ◽  
Qurat-Ul-Ain Shaikh ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Biologically Active ◽  
Physical And Chemical Properties ◽  
Great Tendency ◽  
Facile Synthesis ◽  
Physical And Chemical ◽  
Derivatives Of ◽  
Aromatic Heterocyclic ◽  
Active Natural ◽  
And Chemical Properties

: Piperidine-based alkaloids are undoubtedly an important class of biologically active natural products. When a unique group like trifluoromethyl (Tfm) is added to an active compound, it significantly ameliorates its bioactivity, bioavailability, physical and chemical properties. Many fluorination and trifluoromethylation methods have been reported. In the present paper, we have shown that among all other trifluoromethylation pathways, Mannich reaction also has the great tendency to introduce a Tfm group in a saturated or aromatic heterocyclic compound. Applications of this reaction are elaborated in preparing several derivatives of piperidine base alkaloids with trifluoromethyl at α-position. Furthermore, the substitution at C-4 and C-6 was successfully achieved with variety of saturated and aromatic groups.

scholarly journals Multispark Discharge in Water as a Method of Environmental Sustainability Problems Solution

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
E. M. Barkhudarov ◽  
I. A. Kossyi ◽  
Yu. N. Kozlov ◽  
S. M. Temchin ◽  
M. I. Taktakishvili ◽  
...  
Keyword(s):  
Environmental Sustainability ◽  
Chemical Properties ◽  
Environmental Issues ◽  
Biologically Active ◽  
Gas Discharges ◽  
Water Cleaning ◽  
Sustainability Problems ◽  
Physical And Chemical ◽  
Water Purity ◽  
And Chemical Properties

Multispark discharge excited in water is described, and its useful physical and chemical properties are discussed in the light of some environmental issues. Discharge of such a type generates hot and dense plasmoids producing intense biologically active UV radiation and chemically active radicals, atoms, and molecules. Simultaneously, discharge creates strong hydrodynamic perturbations and cavitation bubbles. Particular attention is given to factors influencing on water purity with special reference to discharge application for effective sterilization of water and its cleaning of harmful chemicals. The gas discharges of this type show considerable promise as a means for solving some actual plasma-chemical problems. The above-mentioned discharge properties have been demonstrated in a series of laboratory experiments, which proved the efficiency of disinfection of potable and waste water, water cleaning of pesticide (herbicide) contaminations, and conversion (recovery) of natural methane.

scholarly journals Synthesis and structural features of 5-(4-(tert-butyl) phenyl)-4-((R)amino)-4H-1,2,4-triazole-3-thiols

2018 ◽  
pp. 60-65
Author(s):  
I. I. Aksyonova-Seliuk ◽  
O. I. Panasenko ◽  
E. G. Knysh
Keyword(s):  
Chemical Structure ◽  
Chemical Properties ◽  
Biologically Active ◽  
Physical And Chemical Properties ◽  
Tert Butyl ◽  
New Compounds ◽  
Physical And Chemical ◽  
Derivatives Of ◽  
Active Substances ◽  
And Chemical Properties

Chemistry of heterocyclic compounds is one of the most popular sector in organic chemistry. Scientists allocate among them a class of derivatives of 1,2,4-triazole. This class of compounds attracts attention his broad spectrum of biological activity. There are antiviral, anti-inflammatory, anti-tubercular, antimicrobial, antioxidant, actoprotective, anti-cancer and other activities. The derivatives of 1,2,4-triazole have one more important advantage. It is low toxicity. This properties do this class of derivatives promising for researches their chemical structure and biological activity and purposeful search of biologically active substances. The purpose of the work is synthesis of 5-(4-(tert-butyl)phenyl)-4-((R)amino)-4H-1,2,4-triazoles-3-thiols from appropriate ylidene derivatives of 4-amino-5-(4 (tert-butyl)phenyl)-4H-1,2,4-triazoles-3-thiol and research of their physical and chemical properties. The objects of research were 10 new compounds, derivatives of 4-amino-5-(4-(tert-butyl)phenyl)-4H-1,2,4-triazoles-3-thiol. These compounds are the crystal substances which are odorless, insoluble in water and soluble in organic solvents. Investigation of the physical and chemical properties of this compounds was carried out according to the methods listed in the State Pharmacopoeia of Ukraine. The melting temperature of synthesized compounds was determined by device OptiMelt Stanford Research Systems MPA100. The structure of the compound was confirmed by 1H-NMR spectroscopy (Mercury 400) and gas chromatography-mass spectrometry (Agilent 1260 Infinity HPLC). 10 new compounds, derivatives of 4-amino-5-(4-(tert-butyl)phenyl)-4H-1,2,4-triazoles-3-thiol, were synthesized in a study. The chemical structure of the new compounds was confirmed by modern instrumental methods of analysis. Results of the done work can be use in the future search of biologically active substances.

ChemInform Abstract: Synthesis and Chemical Properties of Adamantylated Nucleic Bases and Related Compounds

ChemInform ◽  
2013 ◽  
Vol 45 (2) ◽  
pp. no-no
Author(s):  
E. A. Shokova ◽  
V. V. Kovalev
Keyword(s):  
Chemical Properties ◽  
Nucleic Bases ◽  
Related Compounds ◽  
And Chemical Properties
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