Lengthening of the Alkyl Chain in Steroid O-(ω-Carboxyalkyl)oximes by Wittig Reaction

1998 ◽  
Vol 63 (10) ◽  
pp. 1623-1634 ◽  
Author(s):  
Vladimír Pouzar ◽  
Tereza Slavíková ◽  
Ivan Černý
Keyword(s):  
Wittig Reaction ◽  
Alkyl Chain ◽  
Carbon Chain ◽  
Hydroxyl Groups ◽  
Unsaturated Esters ◽  
Alkyl Length

The steroid O-alkyloximes with various alkyl length (2-4 carbons) and with terminal hydroxyl groups were oxidized to aldehydes and their Wittig reaction with triethyl phosphonoacetate was studied. Oximes derived from 17-oxoandrost-5-en-3β-yl acetate and from 7-oxo and 19-oxocholest-5-en-3β-yl acetate were used. Except of 7- and 19-[O-(2-hydroxyethyl)]oximes, all the hydroxyalkyloximes gave successively aldehydes and corresponding unsaturated esters. The method is useful for the lengthening of the carbon chain in ω-substituted O-alkyloximes.

scholarly journals The structure of novel C35 pentacyclic terpenes from Acetobacter xylinum

1973 ◽  
Vol 135 (1) ◽  
pp. 133-143 ◽  
Author(s):  
Hans J. Förster ◽  
Klaus Biemann ◽  
W. Geoffrey Haigh ◽  
Neil H. Tattrie ◽  
J. Ross Colvin
Keyword(s):  
High Resolution ◽  
High Resolution Mass Spectrometry ◽  
Carbon Chain ◽  
Acetobacter Xylinum ◽  
Mass Spectrometric ◽  
Hydroxyl Groups ◽  
Mass Spectral Data ◽  
Mass Spectral ◽  
High Resolution Mass ◽  
Resolution Mass

A novel C35 terpene and its monounsaturated analogue were isolated from cultures of Acetobacter xylinum, together with traces of their C36 homologues. These substances were found to be hopane derivatives substituted by a five-carbon chain bearing four vicinal hydroxyl groups. For the parent hydrocarbon the term bacteriohopane is proposed. The elucidation of the structures utilized high-resolution mass spectrometry of the terpenes, degradation to C32 hydrocarbons and detailed mass-spectrometric comparison of these with C32 hydrocarbons synthesized from known pentacyclic triterpenes. High-resolution mass-spectral data of the terpenes are presented. N.m.r. data are in agreement with the proposed structures, which are further supported by the isolation from the same organism of 22-hydroxyhopane and derivative hopene(s).

Hydration States of Cholinium Phosphate-Type Ionic Liquids as a Function of Water Content

2019 ◽  
Vol 72 (5) ◽  
pp. 392 ◽  
Author(s):  
Yohsuke Nikawa ◽  
Seiji Tsuzuki ◽  
Hiroyuki Ohno ◽  
Kyoko Fujita
Keyword(s):  
Ionic Liquids ◽  
Water Content ◽  
Alkyl Chain ◽  
Hydroxyl Group ◽  
Water Molecules ◽  
Hydroxyl Groups ◽  
Ion Structure ◽  
Activity Measurements ◽  
Microscopic Interactions ◽  
Dynamics Simulations

We investigated the hydration states of cholinium phosphate-type ionic liquids (ILs) in relation to ion structure, focusing on the influence of the hydroxyl group of the cation and the alkyl chain length of the anion. Water activity measurements provided information on the macroscopic hydration states of the hydrated ILs, while NMR measurements and molecular dynamics simulations clearly showed the microscopic interactions and coordination of the water molecules. The hydrogen bonding networks in these ILs were influenced by the anion structure and water content, and the mobility of water molecules was influenced by the number of hydroxyl groups in the cation and anion.

scholarly journals Advanced Analytical Methods for Phenolics in Fruits

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Nesibe Ebru Kafkas ◽  
Müberra Kosar ◽  
Ayşe Tülin Öz ◽  
Alyson E. Mitchell
Keyword(s):  
Phenolic Compounds ◽  
Value Added ◽  
Biological Tissues ◽  
Carbon Chain ◽  
Polyphenolic Compounds ◽  
Hydroxyl Groups ◽  
Plant Metabolites ◽  
Secondary Plant Metabolites ◽  
Extraction Separation ◽  
Health Promoting

Phenolic compounds are a group of secondary plant metabolites, many with health-promoting properties that are present in all parts of plants. They have an aromatic structure, including either one or more hydroxyl groups giving them the ability to stabilize free radicals and protect biological tissues against damage related to reactive oxygen species. Phenolic compounds are concentrated in the fruit of plants, and therefore, the fruit can be an important dietary source of these phytochemicals, which exist as monomers, or bound to one another. Polyphenolic compounds are classified into different subclasses based upon the number of phenol ring systems that they contain, saturation, and length of the carbon chain that bind the rings to one another. The phenolic acids present in fruit tissues protect the plant against disease, infections, UV radiation, and insect damage. For this reason, the beneficiary effects of phenolic compounds are continually being investigated for their health-promoting properties and for meeting increased consumer demand for healthy nutritious food. Due to the functional properties of polyphenolic compounds, there is increased interest on improving extraction, separation, and quantification techniques of these valuable bioactive compounds, so they can be used as value-added ingredients in foods, pharmaceuticals, and cosmetics. This review provides information on the most advanced methods available for the analysis of phenolics in fruits.

scholarly journals Synthesis and Antioxidant Activity of Caffeic Acid Derivatives

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2199 ◽  
Author(s):  
Katarzyna Sidoryk ◽  
Anna Jaromin ◽  
Nina Filipczak ◽  
Piotr Cmoch ◽  
Marcin Cybulski
Keyword(s):  
Organic Chemistry ◽  
Antioxidant Activity ◽  
Caffeic Acid ◽  
Wittig Reaction ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Water Medium ◽  
One Pot ◽  
Safe Alternative ◽  
Caffeic Acid Derivatives

A series of caffeic acid derivatives were synthesized via a modified Wittig reaction which is a very important tool in organic chemistry for the construction of unsaturated carbon–carbon bonds. All reactions were performed in water medium at 90 °C. The aqueous Wittig reaction worked best when one unprotected hydroxyl group was present in the phenyl ring. The olefinations in the aqueous conditions were also conducted with good yields in the presence of two unprotected hydroxyl groups. When the number of the hydroxyl groups was increased to three, the reaction yields were worse, and the derivatives 12, 13, and 18 were obtained with 74%, 37%, and 70% yields, respectively. Nevertheless, the Wittig reaction using water as the essential medium is an elegant one-pot synthesis and a greener method, which can be a safe alternative for implementation in organic chemistry. The obtained compounds were tested for their antioxidant activity, and 12, 13, and 18 showed the highest activities. Moreover, all synthesized compounds displayed no cytotoxicity, and can therefore be used in the pharmaceutical or cosmetic industry.

scholarly journals Strategy for Designing Selective Lysosomal Acid α-Glucosidase Inhibitors: Binding Orientation and Influence on Selectivity

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2843 ◽  
Author(s):  
Atsushi Kato ◽  
Izumi Nakagome ◽  
Mizuki Hata ◽  
Robert J. Nash ◽  
George W. J. Fleet ◽  
...  
Keyword(s):  
Alkyl Chain ◽  
Hydrophobic Interactions ◽  
Antiviral Agents ◽  
Design Strategy ◽  
Docking Study ◽  
Piperidine Ring ◽  
Hydroxyl Groups ◽  
Storage Site ◽  
Molecular Docking Study ◽  
Lysosomal Acid

Deoxynojirimycin (DNJ) is the archetypal iminosugar, in which the configuration of the hydroxyl groups in the piperidine ring truly mimic those of d-glucopyranose; DNJ and derivatives have beneficial effects as therapeutic agents, such as anti-diabetic and antiviral agents, and pharmacological chaperones for genetic disorders, because they have been shown to inhibit α-glucosidases from various sources. However, attempts to design a better molecule based solely on structural similarity cannot produce selectivity between α-glucosidases that are localized in multiple organs and tissues, because the differences of each sugar-recognition site are very subtle. In this study, we provide the first example of a design strategy for selective lysosomal acid α-glucosidase (GAA) inhibitors focusing on the alkyl chain storage site. Our design of α-1-C-heptyl-1,4-dideoxy-1,4-imino-l-arabinitol (LAB) produced a potent inhibitor of the GAA, with an IC50 value of 0.44 µM. It displayed a remarkable selectivity toward GAA (selectivity index value of 168.2). A molecular dynamic simulation study revealed that the ligand-binding conformation stability gradually improved with increasing length of the α-1-C-alkyl chain. It is noteworthy that α-1-C-heptyl-LAB formed clearly different interactions from DNJ and had favored hydrophobic interactions with Trp481, Phe525, and Met519 at the alkyl chain storage pocket of GAA. Moreover, a molecular docking study revealed that endoplasmic reticulum (ER) α-glucosidase II does not have enough space to accommodate these alkyl chains. Therefore, the design strategy focusing on the shape and acceptability of long alkyl chain at each α-glucosidase may lead to the creation of more selective and practically useful inhibitors.

9,10-Bis(N-alkylindole-3-yl-vinyl-2)anthracenes as a new series of alkyl length-dependent piezofluorochromic aggregation-induced emission homologues

RSC Advances ◽  
2015 ◽  
Vol 5 (89) ◽  
pp. 73046-73050 ◽  
Author(s):  
Q. K. Sun ◽  
W. Liu ◽  
S. A. Ying ◽  
L. L. Wang ◽  
S. F. Xue ◽  
...  
Keyword(s):  
Alkyl Chain ◽  
Aggregation Induced Emission ◽  
Spectral Shifts ◽  
Chain Lengths ◽  
Alkyl Length

AIE active 9,10-bis(N-alkylindole-3-yl-vinyl-2)anthracene homologues (IACn) could be facilely prepared and exhibit alkyl length-dependent piezofluorochromic properties whose spectral shifts increase with the decrease of N-alkyl chain lengths.

Grafted organic derivatives of kaolinite: I. Synthesis, chemical and rheological characterization

Clay Minerals ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 537-546 ◽  
Author(s):  
J. E. F. C. Gardolinski ◽  
G. Lagaly
Keyword(s):  
Alkyl Chain ◽  
Hydroxyl Groups ◽  
Rheological Characterization ◽  
Aqueous Dispersions ◽  
X Ray ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups ◽  
Transmission Electron ◽  
Yield Value ◽  
Derivatives Of

AbstractSeveral new interlayer-grafted derivatives of kaolinite were synthesized by esterification of inner-surface hydroxyl groups with alkanols, diols and glycol mono-ethers starting with the dimethyl sulphoxide intercalate. The derivatives were characterized by X-ray powder diffractometry, thermal analysis, Fourier transform infrared spectroscopy and transmission electron microscopy. The grafted molecules are arranged in monolayers between the kaolinite layers, with typical basal spacings of ~11.3 Å. Rheological studies of aqueous dispersions of the modified kaolinites revealed an exponential increase of the yield value and apparent viscosity with increasing alkyl chain length of the grafted molecules.

scholarly journals Dissolution Behavior of Cellulose in IL + DMSO Solvent: Effect of Alkyl Length in Imidazolium Cation on Cellulose Dissolution

2015 ◽  
Vol 2015 ◽  
pp. 1-4 ◽  
Author(s):  
Airong Xu ◽  
Lili Cao ◽  
Bingjun Wang ◽  
Junying Ma
Keyword(s):  
Solvent Effect ◽  
Dimethyl Sulfoxide ◽  
Chain Length ◽  
Alkyl Chain ◽  
Alkyl Chain Length ◽  
Dissolution Behavior ◽  
Cellulose Dissolution ◽  
Imidazolium Cation ◽  
Cellulose Solvents ◽  
Alkyl Length

Four cellulose solvents including [C2mim][CH3COO] + DMSO, [C4mim][CH3COO] + DMSO, [C6mim][CH3COO] + DMSO, and [C8mim][CH3COO] + DMSO were prepared by adding dimethyl sulfoxide DMSO in 1-ethyl-3-methylimidazolium acetate [C2mim][CH3COO], 1-butyl-3-methylimidazolium acetate [C4mim][CH3COO], 1-hexyl-3-methylimidazolium acetate [C6mim][CH3COO], and 1-octyl-3-methylimidazolium acetate [C8mim][CH3COO], respectively. The solubilities of cellulose in these solvents were determined at 25°C. The effect of the alkyl chain length in imidazolium cation on cellulose solubility was investigated. With increasing alkyl chain length in imidazolium cation, the solubility of cellulose increases, but further increase in alkyl chain length results in decreases in cellulose.

One-pot Wittig reaction for the synthesis of α,β-unsaturated esters using highly basic magnesium/lanthanum mixed oxide

2010 ◽  
Vol 321 (1-2) ◽  
pp. 10-14 ◽  
Author(s):  
M. Lakshmi Kantam ◽  
K.B. Shiva Kumar ◽  
V. Balasubramanyam ◽  
G.T. Venkanna ◽  
F. Figueras
Keyword(s):  
Mixed Oxide ◽  
Wittig Reaction ◽  
One Pot ◽  
Unsaturated Esters
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