Cyclohexanol Derivatives Research Articles

Malva neglecta seed polysaccharide mucilage coating enriched by the Lactobacillus brevis TD4 postbiotics: A promising strategy to promote the shelf life of fresh beef

The need for bioactive-incorporated biodegradable packaging products is growing due to the desire to achieve food goods that have a longer shelf life and enhanced safety. The current study set out to create an edible coating using Malva neglecta seed polysaccharide mucilage (MNSM) containing Lactobacillus brevis TD4-derived postbiotics (PLB), and assess how well the PLB-MNSM edible coating preserved beef slices over a 12-day period of refrigeration. PLB was rich in fatty acids, organic heteropolycyclic compounds, monoterpene and cyclohexanol derivative, prenol lipids, ester compounds, and alpha-CH2-containing aldehyde with significant antimicrobial and antioxidant activities. By adding it to the edible coating at 0, 5, 10, and 15 % v/v, it successfully prevented the proliferation of microbial agents (total viable count, psychrotrophic count, Staphylococcus aureus, Escherichia coli, total coliform bacteria count, and fungi) as well as the oxidation of lipids (thiobarbituric and peroxide values) in beef samples. The samples' pH value, hardness, and moisture content were all more successfully sustained when PLB preparation was applied to the coating solution (P < 0.05). The edible coating consisting of PLB effectively maintained the meat color (L*, a*, b*) and sensory properties. Additionally, the bioactive edible coating comprised of MNSM and PLB, specifically MNSM-15 % PLB, significantly prevented the quality deterioration of beef samples and prolonged the shelf-life of the meat to over 12 days. The outcomes indicated that the MNSM-PLB edible coating has the capacity to be utilized as an antibacterial and antioxidant-rich packing material, hence enhancing the shelf life of meat-based goods.

Undescribed polyketides from endophytes associated with the critically endangered conifer Abies beshanzuensis

Four undescribed polyketides, beshanzones A (1) and B (2) as well as beshanhexanols A (3) and B (4), along with three known ones (5–7) were isolated from the rice fermentation of two endophytic fungi associated with the critically endangered Chinese endemic conifer Abies beshanzuensis. γ-Butyrolactone derivatives 1, 2, and 5 were isolated from Phomopsis sp. BSZ-AZ-2, an interesting strain that drawn our attention this time. The cyclohexanol derivatives 3, 4, 6, and 7 were obtained during a follow-up investigation on Penicillium commune BSZ-P-4-1. The chemical structures including absolute configurations of compounds 1–4 were determined by spectroscopic methods, Mo2(OAc)4 induced electronic circular dichroism (IECD), GIAO NMR calculations and DP4+ probability analyses. In particular, compound 2 contains a novel 5/5 bicyclic ring system, which might be biogenetically derived from the known compound 5 through hydrolysis followed by an Aldol reaction. All isolates were evaluated for their antimicrobial activities against a small panel of bacterial and fungal pathogens. Compounds 6 and 7 showed moderate inhibitory activities against Candida albicans, with MIC values of 16 and 32 μg/mL, respectively.

Chemical characterization of different parts of Forsythia suspensa and α-glucosidase and pancreatic lipase inhibitors screening based on UPLC-QTOF-MS/MS and plant metabolomics analysis

Forsythia suspensa (Thunb.) Vahl (FS) is an important plant with high edible and medicinal values. The edible fruit of FS is a common traditional medicine in China, Japan and Korea. Compared to the research on the phytochemistry and pharmacology of the fruits, study on the other parts of FS, such as leaves and flowers is still limited. In this study, an integrated strategy based on ultra-performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC-QTOF-MS/MS), plant metabolomics and correlation analysis was established for comprehensively chemical characterization of fruits, leaves and flowers of FS, and discovery of α-glucosidase and pancreatic lipase inhibitory metabolites. The plant metabolic profiling of fruits, leaves and flowers of FS was performed by UPLC-QTOF-MS/MS, and a total of 74 secondary metabolites, including 15 phenylethanoid glycosides, 20 lignans, 10 cyclohexanol derivatives, 11 organic acids, 9 flavonoids, 3 triterpenes, and 10 other compounds were identified. Then, 29 differential secondary metabolites that responsible to distinguish the fruits, leaves and flowers of FS were further screened out by multivariate statistical analysis. Meanwhile, the α-glucosidase and pancreatic lipase inhibition of different parts of FS were evaluated and compared by in vitro experiments. The results demonstrated that the leaves of FS showed the highest inhibition on α-glucosidase and pancreatic lipase with IC50 of 0.17 ± 0.04 mg/mL and 0.56 ± 0.33 mg/mL, respectively. Then, the correlation between differential metabolites and enzyme inhibitory activities were investigated by Pearson correlation analysis, and 12 potential α-glucosidase and pancreatic lipase inhibitors were screen out. Additionally, the α-glucosidase and pancreatic lipase inhibitory activities of five potential enzyme inhibitory components, including quercitrin, rutin, kaempferol-3-O-rutinoside, pinoresinol-4-O-glucoside and phillyrin were further validated by in vitro assays and molecular docking analysis. The results showed that all the five potential inhibitors showed good inhibitory effects on α-glucosidase and pancreatic lipase, and the binding of the five inhibitors to enzymes mainly through hydrogen bonding, hydrophobic force, and ionic bonding. This study provided a feasible strategy for comparison and discrimination of different parts of medicinal plant and discovery of bioactive components, and also provided useful information for future utilization of different parts of FS.

Hydrogenation of lignin-derived feedstocks and bio-oil using active and stable ruthenium catalyst

Value addition of lignin-derived phenols into high-value chemicals and fuels is highly desirable and beneficial for bio-refineries owing to their broad applications in chemical and polymer industries. Here we present selective hydrogenation of various lignin-derived phenols into cyclohexanol and its derivatives using SiO2-Al2O3 supported stable and reusable Ru nanoparticles (Ru-NC/SiO2-Al2O3) in a green and sustainable manner. The Ru-NC/SiO2-Al2O3 nanocatalyst is prepared by simple impregnation followed by the pyrolysis method. The Ru-NC/SiO2-Al2O3 nanocatalyst shows excellent activity for the hydrogenation of lignin-derived functional phenols, including o, p, m-cresols, catechol, 4-n-propylphenol, diphenyl ether, guaiacol, eugenol, and others. In addition, hemicelluloses-derived furfural and furfuryl alcohol were also transformed into their hydrogenated products. Further, this transformation is also used for the hydrogenation of alkali lignin bio-oil, which is selectively transformed into corresponding cyclohexanol derivatives. HR-TEM, XPS, powder-XRD, N2 adsorption-desorption, and NH3-TPD analyses were used to examine the physicochemical properties of both fresh and spent Ru-NC/SiO2-Al2O3 nanocatalysts. Furthermore, the Ru-NC/SiO2-Al2O3 nanocatalyst is recycled and reused four times with no loss of any catalytic activity.

SYNTHESIS OF AMINOMETHOXY DERIVATIVES OF CYCLOHEXANOL AND STUDYING THEM AS BACTERICIDE INHIBITORS

Based on cyclohexanol, cyclic amines (piperidine, morpholine, hexamethyleneimine), and formaldehyde, new Mannich bases have been synthesized. The reaction was carried out at a temperature of 78–800C for 4–5 h in a benzene solution at an equimolar ratio of the starting components. The yield of compounds was 69–75%. The physicochemical data of the synthesized compounds were determined. The composition and structure of the target products were confirmed by elemental analysis, IR, 1H and 13C NMR spectroscopy, and mass spectrometry. Their effect on the vital activity of sulfate-reducing bacteria of the "Desulfovibrio desulfuricans" type at three concentrations (25; 50; 100 mg/l) was studied. The obtained compounds showed high bactericidal properties, 1% solutions of these compounds in isopropyl alcohol at a concentration of 100 mg/l showed 100% bactericidal effect. A 1% solution of the compound with a fragment of morpholine already at a concentration of 50 mg/l exhibits a 100% bactericidal effect. Compounds with a fragment of piperidine and hexamethyleneimine at a concentration of 50 mg/l showed 96.2 and 98% bactericidal effects, respectively. And at a concentration of 25 mg/l, the bactericidal effect of all three compounds was 16.4%, 36.4%, and 58.2%, respectively. The results obtained show that the synthesized compounds showed more bactericidal properties compared to the industrially used bactericide-inhibitors АМДОР ИК-7 and АМДОР ИК-10 taken as a standard. Established, that these aminomethoxy derivatives of cyclohexanol affect bacteria at very low concentrations, they can be proposed as effective inhibitors against sulfate-reducing bacteria

AMINOMETHOXY DERIVATIVES OF CYCLOHEXANOL AS BIOCORROSION INHIBITORS

Based on cyclohexanol, aliphatic amines (diethylamine, dipropylamine, dibutylamine, dihexylamine), and formaldehyde, new Mannich bases have been synthesized. The reaction was carried out at a temperature of 78–80°C for 4–5 h in a benzene solution at an equimolar ratio of the starting components. The yield of compounds was 63–80%. The physicochemical data of the synthesized compounds were determined. The composition and structure of the target products were confirmed by elemental analysis, IR, 1H and 13C NMR spectroscopy. Their influence on the vital activity of sulfate-reducing bacteria (SRB) of the "Desulfovibrio desulfuricans" type at three concentrations (25; 50; 100 mg/l) was studied. The resulting compounds showed high bactericidal properties. 1% solutions of these compounds in isopropyl alcohol at a concentration of 100 mg/l showed a 100% bactericidal effect. Given that these aminomethoxy derivatives of cyclohexanol affect bacteria at very low concentrations, they can be proposed as effective inhibitors against sulfate reducing bacteria. Keywords: cyclohexanol, aliphatic amines, Mannich bases, sulfatereducing bacteria, inhibitor-bactericides, biocorrosion.

Pt Nanoparticles Confined in Hollow Mesoporous Silica Nanoreactors for Phenol Selective Hydrogenation to Cyclohexanol

Pt nanoparticles confined in hollow mesoporous nanoreactors (Pt@HMSNs) are prepared by using Pt ion containing polymer micelles as templates. The unique hollow mesoporous nanostructures result in the greatly improved catalytic performance for deep hydrogenations of phenolic compounds to the corresponding cyclohexanol derivatives under mild reaction conditions.

Trans-2-(Azaarylsulfanyl)cyclohexanol derivatives as potential pH-triggered conformational switches

A series of trans-2-(azaarylsulfanyl)cyclohexanol derivatives, structurally similar to previously studied trans-2-amino-cyclohexanols, were synthesized through epoxide ring opening under basic conditions with sodium tetraborate as a catalyst. 1H NMR spectroscopy was used to elucidate the conformational equilibrium in various solvents and its acid-induced change due to stabilization of the conformer with the azaarylsulfanyl and hydroxy groups in equatorial position by an intramolecular hydrogen bond and electrostatic interactions.

Synthesis of Terpyridines: Simple Reactions-What Could Possibly Go Wrong?

The preparation of 24-functionalized 12,22:26,32-terpyridines (4′-functionalized 3,2:6′,3″-terpyridines) by the reaction of three 4-alkoxybenzaldehydes with 3-acetylpyridine and ammonia was investigated; under identical reaction conditions, two (R =nC4H9, C2H5) gave the expected products whereas a third (R = nC3H7) gave only a cyclohexanol derivative derived from the condensation of three molecules of 3-acetylpyridine with two of 4-(n-propoxy)benzaldehyde. A comprehensive survey of “unexpected” products from reactions of ArCOCH3 derivatives with aromatic aldehydes is presented. Three different types of alternative product are identified.

L‐Proline‐Catalyzed One‐Pot Diastereoselective Synthesis of Cyclohexanols from β‐Aryl‐γ‐nitroketones and α,β‐Unsaturated Aldehydes: A New Route to 2,3,4,6‐Tetrasubstituted Phenols

AbstractA wide array of densely functionalized cyclohexanol derivatives having five contiguous chiral centers were efficiently achieved in good to high yields with high diastereoselectivities. The double C−C bonds forming reaction proceeds via a domino nitro‐Michael/aldol reaction between several β‐aryl‐substituted‐γ‐nitroketones and a range of β‐aryl‐substituted acroleins as Michael acceptors catalyzed by L‐proline as a naturally available, non‐toxic, cheap organocatalyst. Several important features of this strategy include 100% atom‐economical, high‐efficiency, operational simplicity, and broad functional‐group tolerance. Gratifyingly, one‐pot conversion of cyclohexanols to a novel class of 2,3,4,6‐tetrasubstituted phenols under metal‐free conditions has been demonstrated.

Hydrogen Atom Transfer from Alkanols and Alkanediols to the Cumyloxyl Radical: Kinetic Evaluation of the Contribution of α-C-H Activation and β-C-H Deactivation.

A kinetic study on the reactions of the cumyloxyl radical (CumO•) with a series of alkanols and alkanediols has been carried out. Predominant hydrogen atom transfer (HAT) from the α-C-H bonds of these substrates, activated by the presence of the OH group, is observed. The comparable kH values measured for ethanol and 1-propanol and the increase in kH measured upon going from 1,2-diols to structurally related 1,3- and 1,4-diols is indicative of β-C-H deactivation toward HAT to the electrophilic CumO•, determined by the electron-withdrawing character of the OH group. No analogous deactivation is observed for the corresponding diamines, in agreement with the weaker electron-withdrawing character of the NH2 group. The significantly lower kH values measured for reaction of CumO• with densely oxygenated methyl pyranosides as compared to cyclohexanol derivatives highlights the role of β-C-H deactivation. The contribution of torsional effects on reactivity is evidenced by the ∼2-fold increase in kH observed upon going from the trans isomers of 4- tert-butylcyclohexanol and 1,2- and 1,4-cyclohexanediol to the corresponding cis isomers. These results provide an evaluation of the role of electronic and torsional effects on HAT reactions from alcohols and diols to CumO•, uncovering moreover β-C-H deactivation as a relevant contributor in defining site selectivity.

Synthesis, Characterization, Stereochemistry and Biological Evaluation of Novel Cyclohexanol Derivatives

Synthesis, Characterization, Stereochemistry and Biological Evaluation of Novel Cyclohexanol Derivatives

Alkenyl cyclohexanone derivatives from Lannea rivae and Lannea schweinfurthii

Phytochemical investigation of the CH2Cl2/MeOH (1:1) extract of the roots of Lannea rivae (Chiov) Sacleux (Anacardiaceae) led to the isolation of a new alkenyl cyclohexenone derivative: (4R,6S)-4,6-dihydroxy-6-((Z)-nonadec-14′-en-1-yl)cyclohex-2-en-1-one (1), and a new alkenyl cyclohexanol derivative: (2S*,4R*,5S*)-2,4,5-trihydroxy-2-((Z)-nonadec-14′-en-1-yl)cyclohexanone (2) along with four known compounds, namely epicatechin gallate, taraxerol, taraxerone and β-sitosterol; while the stem bark afforded two known compounds, daucosterol and lupeol. Similar investigation of the roots of Lannea schweinfurthii (Engl.) Engl. led to the isolation of four known compounds: 3-((E)-nonadec-16′-enyl)phenol, 1-((E)-heptadec-14′-enyl)cyclohex-4-ene-1,3-diol, catechin, and 1-((E)-pentadec-12′-enyl)cyclohex-4-ene-1,3-diol. The structures of the isolated compounds were determined by NMR spectroscopy and mass spectrometry. The absolute configuration of compound 1 was established by quantum chemical ECD calculations. In an antibacterial activity assay using the microbroth kinetic method, compound 1 showed moderate activity against Escherichia coli while compound 2 exhibited moderate activity against Staphylococcus aureus. Compound 1 also showed moderate activity against E. coli using the disc diffusion method. The roots extract of L. rivae was notably cytotoxic against both the DU-145 prostate cancer cell line and the Vero mammalian cell line (CC50=5.24 and 5.20μg/mL, respectively). Compound 1 was also strongly cytotoxic against the DU-145 cell line (CC50=0.55μg/mL) but showed no observable cytotoxicity (CC50>100μg/mL) against the Vero cell line. The roots extract of L. rivae and L. schweinfurthii, epicatechin gallate as well as compound 1 exhibited inhibition of carageenan-induced inflammation.

Total Synthesis of (+)-Antrocin and Its Diastereomer and Clarification of the Absolute Stereochemistry of (-)-Antrocin.

Using 2,2-dimethyl cyclohexanone as the starting compound, (+)-antrocin and its diastereomer have been synthesized. The absolute stereochemistry of (-)-antrocin, a natural sesqui-terpenoid and an antagonist in some types of cancer cells, was clarified using the character data of (+)-antrocin. The synthetic procedure involved two key steps: (1) the reaction of vinyl magnesium bromide with 2,2-dimethyl-6-t-butyl-dimethyl-silyoxy-methyl-1-cyclo-hexanone to give a vinyl cyclohexanol derivative and (2) a highly stereoselective intramolecular Diels-Alder (IMDA) reaction of the camphanate-containing triene intermediate. The relative energy levels of the possible transition states of the IMDA reaction of the camphanate-containing triene were obtained from density functional theory calculations, proving the stereospecific formation of the target molecule.

In situ catalytic hydrogenation of model compounds and biomass-derived phenolic compounds for bio-oil upgrading

The renewable phenolic compounds produced by directional liquefaction of biomass are a mixture of complete fragments decomposed from native lignin. These compounds are unstable and difficult to use directly as biofuel. Here, we report an efficient in situ catalytic hydrogenation method that can convert phenolic compounds into saturated cyclohexanes. The process has high potential for production of hydrocarbon transportation fuels. In the in situ catalytic hydrogenation system, phenolic compounds were converted into cyclohexanol derivatives (that can be efficiently converted into cyclohexane-hydrocarbon fuels by acid-catalyzed dehydration) with a conversion yield 98.22 wt% under mild conditions (220 °C for 7 h with Raney Ni). The in situ catalytic hydrogenation of phenolic compounds, using methanol as a liquid hydrogen donor, was found to be superior to traditional hydrogenation using external hydrogen gas. The in situ hydrogenation of phenolic compounds was coupled with aqueous-phase reforming of methanol. The conversion of guaiacol and target product yields were significantly higher than by traditional hydrogenation.

Synthesis of a new 1,2,3,4,5-pentasubstituted cyclohexanol and determining its stereochemistry by NMR spectroscopy and quantum-chemical calculations.

The presence of substituents in cyclohexane can influence to the ratio of conformers; for some cases, the boat form is preferable. The new six-membered cyclohexanol derivative 2 has been obtained by the synthesis of (E)-1-(bromophenyl)-3-phenylpropen-2-one (1). The NMR and quantum-chemical conformational analysis for the 2 have carried out, and its possible mechanism of formation was given. Copyright © 2015 John Wiley & Sons, Ltd.

ChemInform Abstract: C—H Alkenylations with Alkenyl Acetates, Phosphates, Carbonates, and Carbamates by Cobalt Catalysis at 23 °C.

AbstractThe regioselective C‐H alkenylation of N‐(2‐pyrimidyl) or N‐(2‐pyridyl) substituted indoles using a variety of O‐substituted cyclohexanol derivatives in the presence of CoI2 and a NHC‐carbene is presented.

Three closely-related cyclohexanols (C35H27X2N3O3; X = F, Cl or Br): similar molecular structures but different crystal structures.

Three highly-substituted cyclohexanol derivatives have been prepared from 2-acetylpyridine and 4-halogenobenzaldehydes under mild conditions. (1RS,2SR,3SR,4RS,5RS)-3,5-Bis(4-fluorophenyl)-2,4-bis(pyridine-2-carbonyl)-1-(pyridin-2-yl)cyclohexanol, C35H27F2N3O3, (I), (1RS,2SR,3SR,4RS,5RS)-3,5-bis(4-chlorophenyl)-2,4-bis(pyridine-2-carbonyl)-1-(pyridin-2-yl)cyclohexanol acetone 0.951-solvate, C35H27Cl2N3O3·0.951C3H6O, (II), and (1RS,2SR,3SR,4RS,5RS)-3,5-bis(4-bromophenyl)-2,4-bis(pyridine-2-carbonyl)-1-(pyridin-2-yl)cyclohexanol, C35H27Br2N3O3, (III), all crystallize in different space groups, viz. Pbca, Fdd2 and P1, respectively. In compound (II), the acetone molecule is disordered over two sets of atomic sites having occupancies of 0.690 (13) and 0.261 (13). Each of the cyclohexanol molecules contains an intramolecular O-H···N hydrogen bond and their overall molecular conformations are fairly similar. The molecules of (I) are linked by two independent C-H···O hydrogen bonds to form a C(5)C(10)[R2(2)(15)] chain of rings, and those of (III) are linked by a combination of C-H···O and C-H···N hydrogen bonds, forming a chain of alternating R2(2)(16) and R2(2)(18) rings. The cyclohexanol molecules in (II) are linked by a single C-H···N hydrogen bond to form simple C(4) chains and these chains are linked by a π-π stacking interaction to form sheets, to which the disordered acetone molecules are weakly linked via a number of C-H···O contacts.

Catalytic hydrogenation of aromatic rings catalyzed by Pd/NiO

A simple and efficient heterogeneous palladium catalyst was prepared for aromatic ring hydrogenation. The catalyst was prepared by a reduction-deposition method and exhibited high activity and selectivity for the hydrogenation of a variety of substituted aromatic compounds to the corresponding cyclohexane and cyclohexanol derivatives with up to 99% yields. The catalyst was characterized by BET, TEM, XRD, XPS and ICP. Meanwhile the reusability of the catalyst was investigated, and it can be reused for several runs without significant deactivation.

ChemInform Abstract: The Reactivity of Potassium Carbanions with Epoxides.

AbstractReaction of cyclohexene with butylpotassium does not give the expected cyclohexanol derivative but 2‐butylcyclohexanone.