Assembly of Platinum Nanoparticles and Single-atom Bismuth for Selective Oxidation of Glycerol

2021 ◽  
Author(s):  
Ning Huang ◽  
Zihao Zhang ◽  
Yubing Lu ◽  
Jinshu Tian ◽  
Dong Jiang ◽  
...  
Keyword(s):  
Selective Oxidation ◽  
Platinum Nanoparticles ◽  
Single Atom ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Main Difficulty ◽  
Secondary Hydroxyl

Selective oxidation of the secondary hydroxyl group of glycerol to dihydroxyacetone (DHA) is an extremely challenging yet important reaction. The main difficulty is that three hydroxyl groups in glycerol are...

scholarly journals SYNTHESIS OF 1,2;3,4-DI-O-ISOPROPYLIDENE-6- O-[4-(1H-AZOL-1-YLMETHYL) PHENYL]- ¯-D-GALACTOPYRANOSE AND 1,2,3,4-TETRA-O-ACETYL-6- O-[4-(1H-AZOL-1- YLMETHYL)PHENYL]-¯-D-GLUCOPYRANOSE

2017 ◽  
Vol 17 (5) ◽  
pp. 122-128
Author(s):  
Z.P. Belousova ◽  
P.P. Purygin ◽  
A.P. Tyurin
Keyword(s):  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Secondary Hydroxyl ◽  
Primary Hydroxyl ◽  
Derivatives Of

Derivatives of D-galactose and D-glucose substituted for the primary hydroxyl group, which contain an aglycone azolylmethylphenyl fragments (for imidazole, 1,2,4-triazole, benzimidazole and benzotriazole) has been synthesized. Toprotect the secondary hydroxyl groups of monosaccharides acetyl and isopropylidene groups were used.

scholarly journals Characteristics and Kinetics Study of Glycerolabietate from Glycerol and Abietic Acid from Rosin

2021 ◽  
Vol 15 (2) ◽  
pp. 170
Author(s):  
Danang Tri Hartanto
Keyword(s):  
Abietic Acid ◽  
Ester Group ◽  
Acid Number ◽  
Hydroxyl Group ◽  
Esterification Reaction ◽  
Hydroxyl Groups ◽  
Carboxylic Group ◽  
Secondary Hydroxyl ◽  
Reaction Rate Constants ◽  
Natural Resin

Rosin is a natural resin from the coniferous tree sap, which separated from its oil content (terpenes). Rosin is brittle. Therefore modifications are needed to improve its mechanical properties. The main content of rosin is abietic acid which has a carboxylic group, so it can form an ester group when reacted with polyhydric alcohol (polyalcohol) such as glycerol. The research aimed to study the kinetics of the esterification reaction between the hydroxyl group in glycerol and the carboxylic group in abietic acid from rosin at various reaction temperatures and reactant compositions. This reaction is carried out in a three-neck flask at atmospheric pressure without a catalyst. The reaction temperatures used were 180˚C, 200˚C, and 220˚C, and the ratio of rosin and glycerol was 1:1, 1:3, and 1:5. The reaction kinetics calculations were analyzed with acid number data over the reaction time using three different models. The calculations showed that this reaction involves positioning a hydroxyl group on glycerol, which the primary and secondary hydroxyl groups contribute to forming a rosin ester (glycerolabietate). The rate of reaction constants of primary hydroxyl of glycerol and abietic acid were in the range 6.25x10-4 - 3.90x10-3 g/(mgeq.min), while reaction rate constants of secondary hydroxyl and abietic acid were in the range 1.06x10-5 - 1.15x10-4 g/(mgeq.min). FTIR analysis showed a change in the hydroxyl, carboxylate, and ester groups which were assigned by a shift of wavenumber and a difference of intensity at 3200-3570 cm-1, 1697.36 cm-1, and 1273.02 cm-1.

Preparation of prednisolone‐appended α‐, β‐ and γ‐cyclodextrins: Substitution at secondary hydroxyl groups and in vitro hydrolysis behavior

2001 ◽  
Vol 90 (4) ◽  
pp. 493-503
Author(s):  
Hideki Yano ◽  
Fumitoshi Hirayama ◽  
Hidetoshi Arima ◽  
Kaneto Uekama
Keyword(s):  
Hydroxyl Groups ◽  
Secondary Hydroxyl ◽  
In Vitro Hydrolysis

scholarly journals Reactivity of Aliphatic and Phenolic Hydroxyl Groups in Kraft Lignin towards 4,4′ MDI

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2131
Author(s):  
Leonardo Dalseno Antonino ◽  
Júlia Rocha Gouveia ◽  
Rogério Ramos de Sousa Júnior ◽  
Guilherme Elias Saltarelli Garcia ◽  
Luara Carneiro Gobbo ◽  
...  
Keyword(s):  
Experimental Work ◽  
Chemical Structure ◽  
31P Nmr ◽  
Kraft Lignin ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Diphenylmethane Diisocyanate ◽  
Complex Chemical ◽  
Heterogeneous Reactivity ◽  
Phenolic Hydroxyl Groups

Several efforts have been dedicated to the development of lignin-based polyurethanes (PU) in recent years. The low and heterogeneous reactivity of lignin hydroxyl groups towards diisocyanates, arising from their highly complex chemical structure, limits the application of this biopolymer in PU synthesis. Besides the well-known differences in the reactivity of aliphatic and aromatic hydroxyl groups, experimental work in which the reactivity of both types of hydroxyl, especially the aromatic ones present in syringyl (S-unit), guaiacyl (G-unit), and p-hydroxyphenyl (H-unit) building units are considered and compared, is still lacking in the literature. In this work, the hydroxyl reactivity of two kraft lignin grades towards 4,4′-diphenylmethane diisocyanate (MDI) was investigated. 31P NMR allowed the monitoring of the reactivity of each hydroxyl group in the lignin structure. FTIR spectra revealed the evolution of peaks related to hydroxyl consumption and urethane formation. These results might support new PU developments, including the use of unmodified lignin and the synthesis of MDI-functionalized biopolymers or prepolymers.

scholarly journals Enhancement of Antioxidant and Hydrophobic Properties of Alginate via Aromatic Derivatization: Preparation, Characterization, and Evaluation

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2575
Author(s):  
Smaher M. Elbayomi ◽  
Haili Wang ◽  
Tamer M. Tamer ◽  
Yezi You
Keyword(s):  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Benzoyl Group ◽  
Antioxidant Evaluation ◽  
Thermo Stability

The preparation of bioactive polymeric molecules requires the attention of scientists as it has a potential function in biomedical applications. In the current study, functional substitution of alginate with a benzoyl group was prepared via coupling its hydroxyl group with benzoyl chloride. Fourier transform infrared spectroscopy indicated the characteristic peaks of aromatic C=C in alginate derivative at 1431 cm−1. HNMR analysis demonstrated the aromatic protons at 7.5 ppm assigned to benzoyl groups attached to alginate hydroxyl groups. Wetting analysis showed a decrease in hydrophilicity in the new alginate derivative. Differential scanning calorimetry and thermal gravimetric analysis showed that the designed aromatic alginate derivative demonstrated higher thermo-stability than alginates. The aromatic alginate derivative displayed high anti-inflammatory properties compared to alginate. Finally, the in vitro antioxidant evaluation of the aromatic alginate derivative showed a significant increase in free radical scavenging activity compared to neat alginate against DPPH (2,2-diphenyll-picrylhydrazyl) and ABTS free radicals. The obtained results proposed that the new alginate derivative could be employed for gene and drug delivery applications.

Halosugar nucleosides. II. Iodination of secondary hydroxyl groups of nucleosides with methyltriphenoxyphosphonium iodide

1970 ◽  
Vol 35 (9) ◽  
pp. 2868-2877 ◽  
Author(s):  
Julien P. H. Verheyden ◽  
John G. Moffatt
Keyword(s):  
Hydroxyl Groups ◽  
Secondary Hydroxyl

Bisquaternary ammonium salts derived from 3α,12α-Diamino-5β-cholane and 3α,12α-Diamino-24-nor-5β-cholane

1971 ◽  
Vol 24 (3) ◽  
pp. 521 ◽  
Author(s):  
S Ahmed ◽  
M Alauddin ◽  
B Caddy ◽  
M Martin-Smith ◽  
WTL Sidwell ◽  
...  
Keyword(s):  
Deoxycholic Acid ◽  
Ammonium Salts ◽  
Hydroxyl Group ◽  
Amino Compound ◽  
Hydroxyl Groups ◽  
Lithium Aluminium Hydride ◽  
Lithium Aluminium ◽  
Polyhydric Alcohols ◽  
Methane Sulphonate ◽  
Methylene Group

The preparation of 3α,12α-bisdimethylamino-5β-cholane dimethiodide, 3α,12α-bisdimethylamino-5β-cholane dimethiodide, 3α,12α- bisdimethylamino-24-nor-5β-cholanedimethiodide, and 3α,12α- bisdimethylamino-24-nor-5β-cholanediethiodide, from deoxycholic acid are described. During this work it was found that attempted copper- quinoline decarboxylation of dehydrocholic acid gives rise to lactol formation, and that what had previously been considered to be 3α,12α- dihydroxy-5β-cholane is a mixture of this compound and 12α,24- dihydroxy-5β-cholane. Comparable selectivity of attack by methanesulphonyl chloride and toluene-p-sulphonyl chloride occurs with various polyhydric alcohols derived from bile acids, as evidenced from the products of reduction of the sulphonates with lithium aluminium hydride. With both 5α- and 5β-cholane derivatives, a C 3 equatorial hydroxyl group exhibits comparable reactivity to the terminal primary hydroxyl group, generated from the bile acid carboxylic group, towards both sulphonyl chlorides. With axial hydroxyl groups at C 7 and C 12, toluene-p-sulphonate formation is much more difficult than methane- sulphonate formation. Reduction by means of lithium aluminium hydride of equatorial sulphonate esters at C 7 and C 12 gives rise to a methylene group, but the axial sulphonates under the same conditions give the axial alcohol. The same clear distinction between equatorial and axial sulphonate esters is not observed at C 3 and C 6, but 17α- methanesulphonyloxy-5α-androstane gives 5α-androstane and the 17β- ester gives 17β-hydroxy-5α-androstane. Reduction of 12-oximino groups in both 5α- and 5β-cholanes with sodium and ethanol, hydrogen in the presence of a catalyst, or lithium aluminium hydride gives solely the 12α-amino compound.

Regioselectivity among six secondary hydroxyl groups: selective acylation of the least reactive hydroxyl groups of inositol

2012 ◽  
Vol 48 (18) ◽  
pp. 2448 ◽  
Author(s):  
Amol M. Vibhute ◽  
Adiyala Vidyasagar ◽  
Saritha Sarala ◽  
Kana M. Sureshan
Keyword(s):  
Hydroxyl Groups ◽  
Secondary Hydroxyl ◽  
Selective Acylation

scholarly journals Zn(II) and Ag(I) complexes of N-allythioamides of pyrimidinyl (cyclohexenyl) carboxylic acids and products their proton- and iodocyclization

2019 ◽  
Vol 85 (3) ◽  
pp. 3-19
Author(s):  
Polina Borovyk ◽  
Mariia Litvinchuk ◽  
Anton Bentya ◽  
Svitlana Orysyk ◽  
Yurii Zborovskiy ◽  
...  
Keyword(s):  
Carboxylic Acids ◽  
Metal Ion ◽  
Polymer Chains ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Polymer Complexes ◽  
Vis Spectroscopy ◽  
Polynuclear Coordination Compounds ◽  
Complexation Reactions ◽  
Oxygen Atoms

The possibility of using N-allylcarbothioamide derivatives as well as products of their iodine- and proton-initiated electrophilic heterocyclizations as chelating agents in complexation reactions with Zn(II) and Ag(I) ions is shown. Processing of the obtained experimental data showed that N-allythioamides of pyrimidinyl (cyclohexenyl) carboxylic acids H2L1 – H2L3 and their proton- and iodo-cyclization products HL4, HL5 containing four nucleophilic reaction centers (two oxygen atoms of the carbonyl and hydroxyl groups and N-, S-carbothioamide groups or N-atoms of the dihydrothiazole moiety) are polydentate ligands capable of coordinating with metal ions to form stable six-membered chelate metallocycles. A series of new chelating mono-, bi- and polynuclear complexes Zn(II) and Ag (I) of the composition [Zn2L1,32]n, [Zn2(HL1-3)2(CH3COO)2], [Ag2(HL1,3)2]n, [Zn(HL1-3)2], [Ag(H2L3)2NO3], [Zn(HL4,5)2], K[Ag(HL4,5)2] were synthesized and isolated in solid state. Their molecular structure was established by methods of elemental chemical analysis, NMR 1H, IR and UV-Vis spectroscopy. At a ratio of M:L 1:2, complexes were isolated in which two ligand molecules H2L1 − H2L3 are coordinated to the metal ion by the sulfur atoms of the carbothioamide group and the oxygen of the mono-deprotonated hydroxyl group. It was established that the products of the proton-/iodocyclization HL4, HL5 in the complex formation pass into the thione tautomeric form with coordination through the oxygen atoms of the deprotonated hydroxyl group and nitrogen atoms of the dihydrothiazole heterocycle. At M:L 1:1, binuclear or polynuclear coordination compounds are formed. It was shown that polymerisation in complexes [Zn2L1,32]n and [Ag2(HL1,3)2]n is due to the formation of Zn−(O2SN)−Zn and Ag−O−Ag polymer chains. Investigation of the solubility of the resulting complexes showed that the polymer complexes are weakly soluble or insoluble in DMSO, DMF, while the mononuclear are soluble in methanol, as well as in water.

scholarly journals Synthesis and biotical activity of bacterial cellulose 6-(2-phthalimidoethanesulfonate)

2020 ◽  
Vol 61 (2) ◽  
pp. 29-36
Author(s):  
Zoya P. Belousova ◽  
Keyword(s):  
Bacterial Cellulose ◽  
Side Reaction ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Cellulose Derivatives ◽  
Wound Surface ◽  
Reaction Products ◽  
Absorption Bands ◽  
Hydroxymethyl Group ◽  
Antibacterial And Antifungal

Bacterial cellulose obtained by culturing Gluconacetobacter sucrofermentans in HS environment was converted to sulfonate derivatives using methane-, toluene- and 2-phthalimidoethanesulfonic acids in pyridine. When the ratio of the starting reagents is 1 : 1, the modification of bacterial cellulose according to the primary hydroxyl group of glucopyranose fragments is most likely. The formation of 6-substituted bacterial cellulose derivatives was observed in the reaction mixture. The IR spectra of the reaction products contain absorption bands, which are specific for (O–SO2) group in the region 1377-1338 cm−1 (as), 1178-1154 cm−1 (s), fragments of the corresponding sulfonic acids, as well as free hydroxyl groups of glucopyranose in the region 3495-3382 cm−1. Bacterial cellulose 2-phthalimidoethanesulfonate was dissolved in pyridine. After drying with a desiccant in a desiccator, it turned into a dense transparent film of brown color. The increased molecular film allows to explain the side reaction occurring between the oxo group and fragments of one of the chains of modified cellulose and the non-substituted hydroxymethyl group. The IR spectrum of bacterial cellulose 6-(2-phthalimidoethanesulfonate) contains absorption bands in the region 1711 cm−1, which are specific for (Ar–CO–O) group, and absorption bands in the region 1618 cm−1, which prove the presence of (CO–NH) group. In order to impart antibiotic properties to the bacterial cellulose 6-(2-phthalimido-ethanesulfonate) film, it was physically modified with clotrimazole. The obtained experimental data showed that the films subjected to treatment with a 1% solution of clotrimazole have antibacterial and antifungal effects and prevent the growth of pathogenic microbiota on the wound surface. The exit rates of clotrimazole from the bacterial cellulose 6-(2-phthalimidoethanesulfonate) film and from the pure bacterial cellulose film differed, but only slightly. 2-Phthalimidoethanesulfonate bacterial cellulose films can be used to form composites of effective wound covering, since in addition to the unique properties of bacterial cellulose itself (low allergenicity and adhesion to the wound surface, high hygroscopicity) they will have a regenerating effect.

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