Amide Type Research Articles

Chitosan, a Natural Polymer, is an Excellent Sustained-Release Carrier for Amide Local Anesthetics.

Local anesthetics, particularly amide types, play a crucial role in perioperative anesthesia to alleviate pain and manage chronic, long-term pain, with their brief effect period remaining a universal challenge that needs resolution. There is a high anticipation for creating materials that maintain prolonged effectiveness of local anesthetics through a straightforward administration technique. Chitosan is the most typical natural amino polymer, which is highly reactive and easy to modify. It has been widely and deeply used in the field of medicine. At present, it is mainly used in tissue regeneration and repair, hemostasis and wound healing, antibacterial and anti-infection, disease diagnosis and treatment detection, and drug delivery. In the field of anesthesia, chitosan is regarded as a potential perfect carrier for the sustained release of amide local anesthetics. This document aims to analyze the current application of chitosan as a prolonged-release substance in amide-type local anesthetics, encapsulate the associated research advancements, and subsequently investigate the practicality and prospects of its medical uses.

Spectroscopic characterization of black N- and P-doped zeolite templated carbons

The incorporation of heteroatoms (X) into the zeolite-templated carbon (ZTC) structure is a widely used technique to tailor its properties for specific applications such as gas adsorption, methane and hydrogen storage, and catalysis. However, the literature lacks sufficient data on Fourier-transform infrared spectroscopy (FTIR) analysis of ZTCs due to the challenge in obtaining high-quality FTIR spectra required for accurate assignment of the C–X bands, primarily caused by the black mass effect. In this work we prepared nitrogen (N) and phosphorus (P) doped ZTC samples using FAU type zeolite as a template and furfuryl alcohol as a carbon precursor. The Raman results confirmed the presence of medium-sized aromatic structures and also showed that doping these structures with N and P leads to some defects, although the overall conformation remains structurally intact. The FTIR spectra of the ZTC materials were obtained by controlling the preparation procedure and humidity, enabling clear analysis of the black samples. A Density Functional Theory (DFT) model based on the dimeric buckybowl structure was developed and complemented by experimental results obtained from X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR), and FTIR. The proposed DFT model was then used for deconvolution and precise band assignment of the experimental FTIR spectra. The FTIR deconvolution study also supported the incorporation of N and P into the ZTC as well as the presence of primarily two types of nitrogen species, amide (primary and secondary) and pyridine-like, while P was mainly incorporated as triphenylphosphine oxide and phosphonic acid.

Principles of the pharmacology of local anesthetics

The development of local anesthetics revolutionized the performance of painful interventions. Local anesthetics have an effect on voltage-gated sodium channels in nerve fibers and modulate the conduction of impulses. With respect to the chemical structure, local anesthetics can be divided into amide and ester types. The structural differences of local anesthetics have an influence on the duration of action, the degradation pathways and specific side effects. Severe adverse events include cardiotoxicity and neurotoxicity. In addition to basic measures, such as the monitoring and securing of vital parameters, lipid infusion represents a treatment option in cases of intoxication. The recent developments of local anesthetics are particularly concerned with the reduction of toxicity and prolonging the duration of action.

Comparing Similarity And Difference between Two Local Anesthetics, Lidocaine And Procaine

Amide type lidocaine and lipid type procaine are important anesthetics. In fact, they not only solve the problem of overused opioids, but also stimulate the invention of local anesthetic operations, which both declines the time of surgery and limits the possible damage of general anesthetics to patients’ bodies. But these two anesthetics also have their different target diseases, mechanisms, and side effects. For example, lidocaine is not only used for analgesic in dental and skin surgery operations, but also maintain the welfare of patients, who stay in the hospital waiting for recovery, by limiting the pain they could feel from their chronic illness. Actually, procaine has antiatherogenic effects, also multiple target sites which could provide some protection for the old while using. Besides, based on the fact that these chemicals come from different groups, amide type and lipid type, their mechanisms causing anesthetic effects could also be different, which would be introduced in the following context.

Synthesis, antiproliferative and antiplasmodial evaluation of new chloroquine and mefloquine-based harmiquins.

Here we present the synthesis and evaluation of the biological activity of new hybrid compounds, ureido-type (UT) harmiquins, based on chloroquine (CQ) or mefloquine (MQ) scaffolds and β-carboline alkaloid harmine against cancer cell lines and Plasmodium falciparum. The hybrids were prepared from the corresponding amines by 1,1'-carbonyldiimidazole (CDI)-mediated synthesis. In vitro evaluation of the biological activity of the title compounds revealed two hit compounds. Testing of the antiproliferative activity of the new UT harmiquins, and previously prepared triazole-(TT) and amide-type (AT) CQ-based harmiquins, against a panel of human cell lines, revealed TT harmiquine 16 as the most promising compound, as it showed pronounced and selective activity against the tumor cell line HepG2 (IC 50 = 5.48 ± 3.35 μmol L-1). Screening of the antiplasmodial activities of UT harmiquins against erythrocytic stages of the Plasmodium life cycle identified CQ-based UT harmiquine 12 as a novel antiplasmodial hit because it displayed low IC 50 values in the submicromolar range against CQ-sensitive and resistant strains (IC 50 0.06 ± 0.01, and 0.19 ± 0.02 μmol L-1, respectively), and exhibited high selectivity against Plasmodium, compared to mammalian cells (SI = 92).

Synthesis, crystal structure and Hirshfeld surface analysis of the tetra-kis complex NaNdPyr4(i-PrOH)2·i-PrOH with a carbacyl-amido-phosphate of the amide type.

The tetra-kis complex of neodymium(III), tetra-kis-{μ-N-[bis-(pyrrolidin-1-yl)phos-phor-yl]acet-am-id-ato}bis(pro-pan-2-ol)neodymiumsodium pro-pan-2-ol monosol-vate, [NaNd(C10H16Cl3N3O2)4(C3H8O)2]·C3H8O or NaNdPyr4(i-PrOH)2·i-PrOH, with the amide type CAPh ligand bis(N,N-tetra-methylene)(tri-chloro-acetyl)phos-phoric acid tri-amide (HPyr), has been synthesized, crystallized and characterized by X-ray diffraction. The complex does not have the tetra-kis-(CAPh)lanthanide anion, which is typical for ester-type CAPh-based coordin-ation compounds. Instead, the NdO8 polyhedron is formed by one oxygen atom of a 2-propanol mol-ecule and seven oxygen atoms of CAPh ligands in the title compound. Three CAPh ligands are coordinated in a bidentate chelating manner to the NdIII ion and simultaneously binding the sodium cation by μ2-bridging PO and CO groups while the fourth CAPh ligand is coordinated to the sodium cation in a bidentate chelating manner and, due to the μ2-bridging function of the PO group, also binds the neodymium ion.

Principles of the pharmacology of local anesthetics

The development of local anesthetics revolutionized the performance of painful interventions. Local anesthetics have an effect on voltage-gated sodium channels in nerve fibers and modulate the conduction of impulses. With respect to the chemical structure, local anesthetics can be divided into amide and ester types. The structural differences of local anesthetics have an influence on the duration of action, the degradation pathways and specific side effects. Severe adverse events include cardiotoxicity and neurotoxicity. In addition to basic measures, such as the monitoring and securing of vital parameters, lipid infusion represents a treatment option in cases of intoxication. The recent developments of local anesthetics are particularly concerned with the reduction of toxicity and prolonging the duration of action.

Design, synthesis and antiplasmodial evaluation of new amide-, carbamate-, and ureido-type harmicines

Malaria, one of the oldest parasitic diseases, remains a global health threat, and the increasing resistance of the malaria parasite to current antimalarials is forcing the discovery of new, effective drugs. Harmicines, hybrid compounds in which harmine/β-carboline alkaloids and cinnamic acid derivatives are linked via an amide bond or a triazole ring, represent new antiplasmodial agents. In this work, we used a multiple linear regression technique to build a linear quantitative structure–activity relationship (QSAR) model, based on a group of 40 previously prepared amide-type (AT) harmicines and their antiplasmodial activities against erythrocytic stage of chloroquine-sensitive strain of P. falciparum (Pf3D7). After analysing the QSAR model, new harmicines were designed and synthesized: six amide-type, eleven carbamate-type and two ureido-type harmicines at the N-9 position of the β-carboline core. Subsequently, we evaluated the antiplasmodial activity of the new harmicines against the erythrocytic and hepatic stages of the Plasmodium life cycle in vitro and their antiproliferative activity against HepG2 cells. UT harmicine (E)-1-(2-(7-methoxy-1-methyl-9H-pyrido[3,4–b]indol-9-yl)ethyl)-3-(3-(3-(trifluoromethyl)phenyl)allyl)urea at the N-9 position of the β-carboline ring exhibited pronounced antiplasmodial activity against both the erythrocytic and the hepatic stages of the Plasmodium life cycle, accompanied by good selectivity towards Plasmodium.

Bio-based monomers for amide-containing sustainable polymers.

The field of sustainable polymers from renewable feedstocks is a fast-reviving field after the decades-long domination of petroleum-based polymers. Amide-containing polymers exhibit a wide range of properties depending on the type of amide (primary, secondary, and tertiary), amide density, and other molecular structural parameters (co-existing groups, molecular weight, and topology). Engineering amide groups into sustainable polymers via the "monomer approach" is an industrially proven strategy, while bio-based monomers are of enormous importance to bridge the gap between renewable sources and amide-containing sustainable polymers (AmSPs). This feature article aims at conceptualizing the monomer-design philosophy behind most of the reported AmSPs and is organized by discussing di-functional monomers for step-growth polymerization, cyclic monomers for ring-opening polymerization and amide-containing monomers for chain-growth polymerization. We also give a perspective on AmSPs with respect to monomer design and performance enhancement.

Axially chiral N-alkyl-N-cinnamoyl amide type P,olefin ligands for Pd-catalyzed reactions.

We synthesized N-alkyl-N-cinnamoyl amide type phosphine-olefin compounds 1 and found axial chirality in a C(aryl)-N(amide) bond in compounds 1 by HPLC analysis using a chiral stationary phase column. We successfully obtained enantiomeric isomers of 1 and demonstrated the use of (-)-1 for chiral ligands in Pd-catalyzed asymmetric allylic substitution reactions of allylic esters with indoles (up to 97% ee).

Prenylated sulfonyl amides from the leaves of Glycosmis pentaphylla and their potential anti-proliferative and anti-inflammatory activities

Six previously undescribed sulfur-containing amides were isolated from the leaves of Glycosmis pentaphylla. Their structures were delineated by HRESIMS, 1D and 2D NMR, electronic circular dichroism (ECD) calculations, and DP4+ analyses based on gauge-independent atomic orbital (GIAO) NMR calculations. Compounds 1–4 belong to the type of methylsulfonylpropenoic acid amides. Through different cyclization pathways of geranyloxy, compounds 1 and 2 carry uncommon cyclohexane-1, 3-diol and cyclohex-3-en-1-ol moiety, respectively. Compound 3 is the oxidation product of the double bond Δ6′′(7′′) of geranyloxy. Compound 5 is elucidated as the type of methylsulfonylpropanoic acid amide. Compound 6 represents a rare sulfur-containing amide possessing a morpholin-3-one moiety. All isolated compounds were evaluated for their anti-inflammatory and anti-proliferative activities. Compound 4 significantly inhibited lipopolysaccharide-induced nitric oxide (NO) production in mouse macrophage RAW 264.7 cells with the IC50 value of 0.55 µM. Moreover, compounds 3 and 4 exhibited different anti-proliferative activities against HepG-2 with IC50 values ​​of 11.52 and 9.41 µM, respectively.

Boost Up the Mechanical and Electrical Property of CNT Fibers by Governing Lyotropic Liquid Crystalline Mesophases with Aramid Polymers for Robust Lightweight Wiring Applications

Monofilament type of polyaromatic amide (PA) and carbon nanotube (CNT) composite fibers is presented. A concept of a lyotropic liquid crystal (LLC) constructed via a spontaneous self-assembly is introduced to mitigate the extremely low compatibility between PA and CNT. These approaches provide an effective co-processing route of PA and CNT simultaneously to fabricate the uniform, continuous, and reliable composite fibers through a wet-spinning. Interestingly, the addition of a small amount PA into the dope solution of CNT governs the LLC mesophase not only in a spinneret stage but also in a coagulant region. Thus, the developed PA/CNT composite fibers have the high uniaxial orientational order and the close interfacial packing compared to the pure CNT fibers. The PA/CNT composite fibers achieve the outstanding tensile strength, electrical conductivity, and electrochemical response, while maintaining a lightweight. They also exhibit the chemical, mechanical, and thermal robustness. All of these advantages can make flexible, sewable, and washable PA/CNT composite fibers ideal nanocomposite materials for use in next-generation information and energy transporting system by replacing conventional metal electrical conductors.Graphical The lyotropic liquid crystal self-assembly governed by doping the aramid polymers shows the ability to construct mechanically strong and continuous carbon nanotube-based composite fibers that can be used in the lightweight and robust electrical wiring for extreme environmental applications.

Tribological mechanisms of the synergistic effect between sulfur- and phosphorus-free organic molybdenum and ZDDP

In this work, three environmentally friendly sulfur- and phosphorus-free organic molybdenums, MODE (amide type), MGMO (ester type) and MGME (ether type) with different structures were prepared, and the relationship between molecular structure and tribological properties was investigated. Furthermore, the tribological properties and mechanisms after compounding with conventional zinc dialkyldithiophosphate (ZDDP) were also investigated, indicating that the synergistic effect on antiwear and antifriction properties has the following order: MODE+ZDDP > MGMO+ZDDP > MGME+ZDDP. We further explored the tribological mechanisms through the in-depth surface and cross-sectional analyses, which manifests that the formation of homogeneous and compact tribofilm composed of molybdenum disulfide, molybdenum oxide, sulfate, phosphate, and polyphosphate with the thickness of 50–200 nm is contributed to the excellent synergistic effect.

Indolizin-1-ols with Charged Electron Acceptors: A Direct Way to 3H-Indolizinium-1-olates with Donor Functions.

The reaction of cyclopropenones with pyridines, having an attached integer-charged electron-withdrawing group (pyridinium, imidazolium, and phosphonium) was discovered to afford novel indolizin-1-ol derivatives in high yields with no chromatographic purification required. While being stable as solids, these indolizin-1-ols have a limited lifetime in solution. The study of reasons for such instability uncovered an aerobic oxidative pathway, eventually resulting in indolizine-1,7-dione dimers. The exploration of N-(1-hydroxyindolizin-7-yl)pyridinium salts' chemistry led to a reaction discovery, affording a new type of rare pseudo-cross-conjugated mesomeric betaines (3H-indolizin-4-ium-1-olates with an electron-donating function at C7 position) inaccessible by other means. In this reaction, a sequential introduction of nucleophiles takes place: the first one (Nu1) is represented by simple anilines, whereas Nu2 extends to primary, secondary, aliphatic, aromatic amines, and phenols. For the obtained betaines having unsymmetrical aliphatic amino groups at C7 position an increased order of the C7-Nu2 bond resulting in existence of amide type E/Z-forms (∼1:1 at room temperature) was demonstrated. For aryl amino groups, with typically reduced nitrogen's lone-pair donation, the barrier of rotation around the C7-Nu2 bond was lower, and for the C7-oxy betaines, no such E/Z-isomerism was revealed. Although primary amines (as Nu2) introduce a hydrogen atom in the conjugated betaine system, allowing prototropic tautomerism in this way, non-zwitterionic tautomers (3-amino-7-iminoindolizin-1-ones) were rejected by nuclear Overhauser effect spectroscopy experiments.

Preparation of polyamides containing tetraphenyl-imidazolyl units from 1,2-bis(4-iodophenyl)-4,5-diphenyl-1H-imidazole via C–N coupling reaction and their characterization

A new aromatic diiodide compound, 1,2-bis(4-iodophenyl)-4,5-diphenyl-1H -imidazole was synthesized by a one-pot sequential diazotization-iodination reaction using 1,2-bis(4-aminophenyl)-4,5-diphenyl-1H -imidazole as the starting material in a KI/NaNO2/p -TsOH/CH3CN system at room temperature. A series of aromatic polyamides (PAs) containing tetraphenyl-imidazolyl units were prepared in good yields via a Pd(PPh3)2Cl2 catalyzed carbonylation polymerization of this diiodide, diamines and carbon monoxide in DMAc in the presence of PPh3 and 1,8-diazabicyclo[5,4,0]-7-undecene. These new PAs with inherent viscosities of 0.63–0.72 dL/g were amorphous and easily soluble in amide type aprotic solvents such as N -methyl-2-pyrrolidone (NMP), N,N’-dimethylacetamide (DMAc), N,N′-dimethylformamide (DMF), dimethyl sulfoxide (DMSO) and pyridine at room temperature. Thermal analyses data of the resulting PAs up to 800 °C in nitrogen showed their high thermal behavior with 5% weight loss temperature of 425–517 °C and char yield of 43–58%. The present PAs could be classified as “self-extinguishing polymers” based on the limiting oxygen index in the 34.7–40.7 range. Such attractive properties make these PAs promising as a new type of processable heat-resistant polymer materials.

New fluorinated poly(pyridine amide)s derived from 2,6-bis(4-iodophenyl)-4-(4-trifluoromethylphenyl)pyridine by C–N coupling reaction

2,6-Bis(4-iodophenyl)-4-(4-trifluoromethylphenyl)pyridine, as a new aromatic diiodide compound, was synthesized through a one-pot protocol by the sequential diazotization-iodination of 2,6-bis(4-aminophenyl)-4-(4-trifluoromethylphenyl)pyridine with KI/NaNO2/ p-TsOH in acetonitrile at room temperature. A number of new aromatic fluorinated poly(pyridine amide)s containing 2,6-diphenyl-4-(4-trifluoromethylphenyl)pyridine units were prepared via a Pd(PPh3)2Cl2 catalyzed carbonylation polymerization of this diiodide, diamines and carbon monoxide in DMAc in the presence of PPh3 and 1,8-diazabicyclo[5,4,0]-7-undecene. These new polyamides with inherent viscosities of 0.63–0.72 dL/g were amorphous and easily soluble in amide type aprotic solvents such as NMP, DMAc, DMF and dimethyl sulfoxide at room temperature. Thermal analysis data up to 800°C in nitrogen showed their high thermal behavior with 5% weight loss temperature of 428–498°C and char yield of 62–69%. Their limiting oxygen index of 42.3–45.1 showed that the resulting poly(pyridine amide)s could be classified as “self-extinguishing polymers”. Also, their thin films exhibited high optical transparency with a cut-off wavelength of 324–373 nm.

A Simple and Efficient Acylation Reaction Over Zinc Triflate as a New Catalyst

The amide containing structure is found chemistry and related science. As a consequence, methods for the N-acylation of amines occupies a large place in organic chemistry. In this study, Zinc triflate acylation between aniline derivatives and furan-2-carbonyl chloride was investigated under mild conditions. Also, different types of amides was obtained in very good yields at room temperature and purity after a simple workup. This newly developed method is presented as a new method in organic synthesis.

Advantages of spinal anesthesia in orthopedic surgery

Introduction. Spinal anesthesia is one of the oldest and most commonly used regional anesthesia techniques. It is based on the injection of a local anesthetic into the subarachnoid space, during which there is a transient interruption of impulse conduction in the spinal nerve roots. Application of spinal anesthesia. The use of spinal anesthesia depends on the following factors: the site of the surgical procedure, the type and duration of the surgical procedure, the degree of necessary surgical relaxation, and presence of accompanying diseases. Local anesthetics used in spinal anesthesia. There are two types local anesthetics used in spinal anesthesia. These are local anesthetics of the ester and amide type. Most frequently applied local anesthetics are those of the amide type. Orthopedic procedures under spinal anesthesia. The most common surgical procedures in orthopedic surgery performed under spinal anesthesia are hip, knee and ankle surgeries. Complications of spinal anesthesia. The most common complications of spinal anesthesia are hypotension, bradycardia, urinary retention, and postpuncture headache. Conclusion. The advantages of spinal over general anesthesia in orthopedic surgery include lower incidence of respiratory and myocardial depression, better peripheral tissue perfusion, minimal coagulation system disorders and prolonged postoperative analgesia.

Natural inspired ligustrazine-based SLC-0111 analogues as novel carbonic anhydrase inhibitors

Ligustrazine is the principle bioactive alkaloid in the widely-used Chinese herb Chuan Xiong rhizome. Herein, a series of novel derivatives has been designed as human carbonic anhydrases inhibitors (hCAIs) starting from the natural product Ligustrazine inserted as a tail instead of the 4-fluorophenyl tail of SLC-0111, a front-runner selective hCA IX inhibitor currently in clinical trials as antitumor/antimetastatic agent. Other derivatives were designed via incorporation of different linkers, of amide and ester type, or incorporation of different zinc anchoring groups such as secondary sulfamoyl and carboxylic acid functionalities. The newly designed molecules were prepared following different synthetic pathways, and were assessed for their inhibitory actions against four isoforms: the widespread cytosolic (hCA I and II), and the transmembrane tumor-related (hCA IX and XII). The primary sulfonamides efficiently inhibited the target hCA IX and hCA XII in the nanomolar range (KIs: 6.2–951.5 nM and 3.3–869.3 nM, respectively). The most selective hCA IX inhibitors 6c and 18 were assessed for their potential anticancer effects, and displayed anti-proliferative activity against MCF-7 cancer cell line with IC50s of 11.9 and 36.7 μM, respectively. Molecular modelling studies unveiled the relationship between structural features and inhibitory profiles against the off-target hCA II and the target, tumor-related isoforms hCA IX and XII.

Comparison of Efficacy of 4% Articaine and 0.5% Bupivacaine and 2% Lignocaine Anaesthetic agents in Orthodontic Extractions-A Prospective Randomised Controlled Study

Aim: Articaine, bupivacaine, lignocaine are amide type of local anesthetic agents, which are of almost equal potency. However, lidocaine is considered the gold standard and is the most widely used anesthetic agent because of its potency, safety, and efficiency. Articaine is fast acting and bupivacaine is long lasting local anaesthesia. The aim of this clinical study was to evaluate and compare the clinical anesthetic efficacy of 4% articaine and 0.5% bupivacaine and 2% lignocaine in therapeutic orthodontic extractions.
 Materials and Methods: A 150 healthy patients, requiring Maxillary premolars extraction for orthodontic reasons were included. Patients were categorized into three groups (4% articaine and 0.5% bupivacaine, 2% lignocaine) in a crossover manner. Subjective and objective observations recorded that include age, gender, and pain score using visual analog scale. At the first appointment, both upper premolars were extracted on one or two sides of the jaws. Each patient was evaluated using a visual analogue scale.
 Results: The results showed that 0.5% Bupivacaine had significantly faster onset of action and lower visual analogue scores when compared with articaine and lignocaine. However, the duration of analgesia and need of first rescue analgesic medication was longer in the bupivacaine group.
 Conclusion: Within the limitations of study we found that Bupivacaine has the best anaesthetic effect with low pain scores followed by Articaine and followed by Lignocaine. Bupivacaine is an alternative local anaesthetic drug for performing therapeutic orthodontic extractions.