P-methoxybenzoic Acid Research Articles

Dimerization and Dissociation: The Rate-Controlling steps of molecular Self-Assembly during solution nucleation determined by variation of gas media

To further probe into the link between solution chemistry and nucleation processes experimental and computational data are presented on unsaturated, saturated, and supersaturated solutions and in situ monitoring of nucleation chemistry of p-chlorobenzoic acid (PCBA), p-methoxybenzoic acid (PMBA) and p-nitrobenzoic acid (PNBA), three benzoic acid derivatives with different properties of para-substituents. By variation of the gas media, we were able to establish that hydrogen-bonded dimers (HD) are the basic building unite in solution for clusters and nucleuses despite of the gases and solvents, and there is a strong link between the supersaturated solution chemistry and the intrinsic supersaturation ratio, and the nucleation kinetics. Two different molecular self-assembly pathways and the rate-controlling steps were discussed, which paves new aspects for understanding the role of solution chemistry in directing nucleation processes.

Insight into the Nucleation Mechanism of p-Methoxybenzoic Acid in Ethanol-Water System from Metastable Zone Width.

The metastable zone width (MSZW) of p-methoxybenzoic acid (PMBA) in an ethanol-water system was measured using the polythermal method. The nucleation order m obtained by the Nývlt’s model indicates the nucleation of PMBA following a progressive nucleation mechanism at low saturation temperature (m = 3.18–7.50) and an instantaneous nucleation mechanism at high saturation temperature (m = 1.46–2.55). Then, combined with the metastable zone experiment and the Sangwal model, we found that the MSZW and the interfacial energy reached the maximum when the mass fraction of ethanol was 0.8, which resulted in the smallest crystal product size. Meanwhile, the maximum and obtained based on the modified Sangwal model indicating the PMBA needs to overcome a higher nucleation barrier in the ethanol mass fraction of 0.8. Finally, we proposed a preferential strategy for adjusting MSZW by correlating the interfacial energy with the change in ethanol mass fraction, saturation temperature, and cooling rate, respectively.

Steric, Activation Method and Solvent Effects on the Structure of Paddlewheel Diruthenium Complexes

Conventional heating and solvothermal synthetic methods (with or without microwave activation) have been used to study the reaction of o-, m- and p-methoxybenzoic acid with [Ru2Cl(μ-O2CMe)4]. The tetrasubstituted series [Ru2Cl(µ-O2CC6H4-R)4], with R = o-OMe, m-OMe and p-OMe, has been prepared by the three procedures. Depending on the synthetic method and the experimental conditions, three compounds have been isolated (1a, 1b, 1c) with the o-methoxybenzoate ligand. However, with the m- and p-methoxybenzoate ligands, only the complexes 2 and 3 have been obtained, respectively. Compound 1a, with stoichiometry [Ru2Cl(µ-O2CC6H4-o-OMe)4]n, shows a polymeric structure with the chloride ions bridging the diruthenium units to form linear chains. Compounds 2 and 3, with the same stoichiometry, predictably form zig-zag chains in accordance with their insolubility and their magnetic measurements. Compound 1b, [Ru2Cl(µ-O2CC6H4-o-OMe)4(EtOH)], is a discrete molecular species with a chloride ion and one ethanol molecule occupying the axial positions of the dimetallic unit. Compound 1c is a cation-anion complex, [Ru2(µ-O2CC6H4-o-OMe)4(MeOH)2][Ru2Cl2(µ-O2CC6H4-o-OMe)4]. The cationic complex has two solvent molecules at the axial positions whereas the anionic complex has two chloride ligands at these positions. Complexes have been characterized by elemental analyses, mass spectrometry and IR and UV-vis-NIR spectroscopies. A magnetic study of complexes 1a, 1b, 2 and 3 have also been carried out. The crystal structure of compounds 1b and 1c have been solved by single X-ray crystal methods.

In situ Chemical Synthesis of PANI by Using Aromatic Carboxylic Acid as Dopant for Detection of Ammonia at Room Temperature

In this work, polyaniline (PANI) film was successfully synthesized by in situ chemical polymerization technique by using aromatic carboxylic acids like benzoic acid, p-methoxybenzoic acid and p-nitrobenzoic acid, doped in presence of ammonium persulphate as an oxidant. Electric conductivity study of doped polyaniline has been studied concerning temperature. Surface composition morphology and structure of synthesized carboxylic acid doped polyaniline were characterized via different methods such as the electrical conductivity by two probes, UV-vis spectroscopy, FTIR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The PANI based ammonia gas sensor was synthesized by using, benzoic acid, p-methoxybenzoic acid and p-nitrobenzoic acid as dopant which has excellent selectivity towards NH3 and 28, 426 and 327% response of ammonia gas at 100 ppm concentration, respectively at room temperature.

Attraction of Chrysotropia ciliata (Neuroptera, Chrysopidae) Males to P-Anisaldehyde, a Compound with Presumed Pheromone Function

In a field-trapping experiment with plant volatiles, we observed notably high attraction of green lacewing (Chrysotropia ciliata) males to the compound p-anisaldehyde. Based on this finding, we initiated the present study to elucidate this phenomenon and to investigate the chemical ecology of C. ciliata. Scanning electron microscopy revealed elliptical glands abundantly distributed on the 2nd to 6th abdominal sternites of C. ciliata males, whereas females of the species completely lacked such glands. No p-anisaldehyde was found in extractions of body parts of C. ciliata. Methyl p-anisate and p-methoxybenzoic acid were identified exclusively in the extract from abdominal segments 2–8 of males. Field-trapping experiments revealed no attraction of C. ciliata to either methyl p-anisate or p-methoxybenzoic acid. In contrast, males showed marked attraction to p-anisaldehyde in the field and antennae showed strong responses to this compound. Headspace collections in the field from living insects in their natural environment and during their main daily activity period indicated that p-anisaldehyde was emitted exclusively by C. ciliata males. Our overall results suggest that p-anisaldehyde might serve as a male-produced pheromone that attracts conspecific C. ciliata males. Here, we discuss hypotheses regarding possible mechanisms involved in regulation of p-anisaldehyde production, including involvement of the compounds methyl p-anisate and p-methoxybenzoic acid, and the potential ecological function of p-anisaldehyde in C. ciliata.

Catalytic Asymmetric Iodoesterification of Simple Alkenes.

Catalytic asymmetric iodoesterification of simple alkenes was achieved using a dinuclear zinc-3,3'-(R,S,S)-bis(aminoimino)binaphthoxide (di-Zn) complex. For iodoesterification using p-methoxybenzoic acid, the N-iodonaphthalenimide (NIN)-I2 system was effective for producing iodoesters in a highly enantioselective manner. The synthetic utility of chiral iodo-p-methoxybenzoates was also demonstrated. The quartet of metal ionic bond, hydrogen bond, halogen bond, and π-π stacking is harmonized on the single reaction sphere of di-Zn catalyst for enabling the highly enantioselective catalytic asymmetric iodoesterification of simple alkenes for the first time.

Thermo-physical and spectroscopic studies of liquid mixtures containing p-methoxy benzoic acid

ABSTRACT The density and speed of sound were measured for p-Methoxy benzoic acid (P-MBA) with Aniline, N-Methylaniline (NMA) and N, N-dimethylaniline (NNDMA) from (303.15 K–313.15 K) with 5K interval temperatures using standard techniques. Thermo physical properties of molar volume (Vm ), acoustic impedance (Z), isentropic compressibility (κs ), surface tension (σ) and free length (Lf ) and their excess properties were intended from measured data. These excess parameters have been fitted to the Redlich–Kister type polynomial equation using the least square method. Obtained values of partial molar volumes ( , ) reflects the culminations were drawn from Vm E. Supplementary, to test the pertinent of different theoretical models of speed of sound by means of resoluted values. Finally, the formation of hydrogen bonding between molecules in composition was fetched from FTIR spectra.

Homo- and Heteroligand Copper(II) Complexes with Some Aromatic Acid Hydrazides and L-Histidine

The composition and stability constants of homo- and heteroligand copper(II) complexes with benzoic acid, p-methoxybenzoic acid, or o-hydroxybenzoic acid hydrazide and L-histidine have been determined by spectrophotometry and mathematical modeling methods in aqueous solution with 0.1 M KNO3 as background at 25.0°C. Structural features of some complexes formed in binary and ternary systems have been determined using IR spectroscopy and quantum-chemical calculations.

The solvent effect on the photodeprotection of anthraquinone protected carboxylic acid unravelled by time-resolved spectroscopic studies.

Time-resolved spectroscopy studies coupled with the results from density functional theory (DFT) computations were utilized to unravel the photodeprotection reaction mechanism(s) of AQ protected p-methoxybenzoic acid (1) and its influence on the solvent was examined. It has been found that in aprotic organic solvents such as acetonitrile only the triplet state species was seen, whereas a hydrogen atom transfer (HAT) reaction takes place in isopropanol (IPA) to yield the aromatic ketyl radical species for 1. Compound 1 undergoes HAT and a proton transfer process sequentially to accomplish the release of the leaving group in protic organic solvent MeOH and MeOH-H2O solutions and photodeprotection is more favourable in the latter solution due to the stronger proton mediation ability of the water molecules and this system also facilitates the potential application of 1 in biological systems. Although the released acid from photodeprotection reaction can also be seen in another aqueous solvent system of THF-H2O, the by-product of the AQ chromophore undergoes side recombination reaction, which means this the solvent is not preferred for the photodeprotection process. This mechanistic work will help in the future design and development of AQ-PPGs for particular applications.

Trianthema portulacastrum L. (giant pigweed): phytochemistry and pharmacological properties

Trianthema portulacastrum L. (Aizoaceae) commonly called as black pigweed or giant pigweed, which is a yearly herb, utilized as purgative, pain relieving, stomachic and provide as alternative heal for lung disease, cardiovascular disease, anemia and edema. In the Ayurvedic system of medicine, the plant is used in the treatment of inflammation in the peripheral organs, uteralgia and cough. Taking into account exploratory study, the present review aims to provide up-to date data about the routine uses, phytochemistry, and pharmacological actions of T. portulacastrum to explore their therapeutic value for future clinical settings. All data of T. portulacastrum were collected from library database and electronic search (ScienceDirect, Pubmed, and GoogleScholar). The different pharmacological information was gathered and orchestrated in a suitable spot on the paper. The genus Trianthema comprises of 64 species. Among them, the species of T. portulacastrum has been easily known for their customary uses. Phytochemical studies showed that T. portulacastrum included trianthamine, ecdysterone, flavonoid (5,2 dihydroxy-7methoxy-6,8 dimethyl flavone), leptorumol (5,7 dihydroxy-6,8 dimethyl chromone), and other intermediary bioactive compounds such as β-sitosterol, stigmasterol, and their β-glucopyranosides, β-cyanin, 3,4-dimethoxy cinnamic acid, 5-hydroxy-2-methoxy benzaldehyde, 3-acetyl aleuritolic acid, pmethoxy benzoic acid, and p-propoxy benzoic acid. The plant extracts showed significant antioxidant, anti-inflammatory, hepatoprotective, antihyperglycemic, antimicrobial, and anticancer activities. The toxicity study conducted in animals and no noteworthy mortality found till 4 g/kg b.w. Taking into account on animal studies, T. portulacastrum have different bioactivities including antihyperglycemic, hepatoprotective, anticancer, antimicrobial and modulate different cellular signals related to control of oxidative stress and inflammation. The phytoconstituents of T. portulacastrum have a various potential to exact pharmacological benefits and possible chemotherapeutic mediator. Nevertheless, more support for such properties/dynamic constituents have been obtained from cellular and molecular studies, while clinical studies are as yet deficient. Since animal research do not constantly interpret to human conditions, additional clinical studies are also warranted to infer the full interpretation impact of T. portulacastrum for prevention of human diseases. Hence, future comprehensive clinical studies are required to warrant the therapeutic usefulness of the T. portulacastrum.

Benzenoid biosynthesis in the flowers of Eriobotrya japonica: molecular cloning and functional characterization of p-methoxybenzoic acid carboxyl methyltransferase.

p -Methoxybenzoic acid carboxyl methyltransferase (MBMT) was isolated from loquat flowers. MBMT displayed high similarity to jasmonic acid carboxyl methyltransferases, but exhibited high catalytic activity to form methyl p -methoxybenzoate from p -methoxybenzoic acid. Volatile benzenoids impart the characteristic fragrance of loquat (Eriobotrya japonica) flowers. Here, we report that loquat produces methyl p-methoxybenzoate, along with other benzenoids, as the flowers bloom. Although the adaxial side of flower petals is covered with hairy trichomes, the trichomes are not the site of volatile benzenoid formation. Here we identified four carboxyl methyltransferase (EjMT1 to EjMT4) genes from loquat and functionally characterized EjMT1 which we found to encode a p-methoxybenzoic acid carboxyl methyltransferase (MBMT); an enzyme capable of converting p-methoxybenzoic acid to methyl p-methoxybenzoate via methylation of the carboxyl group. We found that transcript levels of MBMT continually increased throughout the flower development with peak expression occurring in fully opened flowers. Recombinant MBMT protein expressed in Escherichia coli showed the highest substrate preference toward p-methoxybenzoic acid with an apparent K m value of 137.3µM. In contrast to benzoic acid carboxyl methyltransferase (BAMT) and benzoic acid/salicylic acid carboxyl methyltransferase, MBMT also displayed activity towards both benzoic acid and jasmonic acid. Phylogenetic analysis revealed that loquat MBMT forms a monophyletic group with jasmonic acid carboxyl methyltransferases (JMTs) from other plant species. Our results suggest that plant enzymes with same BAMT activity have evolved independently.

Preparation of a graphene oxide/silica composite modified with nitro-substituted tris(indolyl)methane as a solid-phase extraction sorbent for the extraction of organic acids.

This paper describes the use of graphene oxide/silica modified with nitro-substituted tris(indolyl)methane as a solid-phase extraction sorbent for the determination of organic acids. The resultant graphene oxide/silica modified with nitro-substituted tris(indolyl)methane was characterized by FTIR spectroscopy and adsorption experiments. Solid-phase extraction parameters such as sorbent type, sample solution pH, sample loading rate, eluent salt concentration, eluent methanol concentration, elution rate, sample loading, and elution volume were optimized. The method showed good precision, accuracy, sensitivity, and linear response for organic acids analysis over a concentration range of 1-100 μg/L for benzoic acid, p-methoxybenzoic acid, and salicylic acid and 5-100 μg/L for the remaining organic acids (cinnamic acid, p-chlorobenzoic acid, and p-bromobenzoic acid) with coefficients of determination (r(2) ) of higher than 0.9957. Limits of detection from 0.50 to 1.0 μg/L for six organic acids were achieved. The developed method was successfully applied to determine organic acids in real samples.

Syntheses, structures and magnetic properties of a series of lanthanide complexes based on p-methoxybenzoic acid

A new series of lanthanide metal complexes [Ln(L)3]n (L=p-methoxybenzoic acid, Ln=Pr 1, Eu 2, Tb 3, Dy 4, Ho 5, Er 6, Yb 7) have been synthesized under hydrothermal conditions. Single-crystal X-ray diffraction measurements reveal that these compounds are isostructural, crystallizing in the monoclinic space group P21/c and giving 1D chain structures. Magnetic studies reveal antiferromagnetic behavior for complexes 1, 3, 5 and 6, ferromagnetic behavior for complex 4 and spin-canting behavior for 7.

A New Octadecenoic Acid Derivative from Caesalpinia gilliesii Flowers with Potent Hepatoprotective Activity.

Background:Caesalpinia gilliesii Hook is an ornamental shrub with showy yellow flowers. It was used in folk medicine due to its contents of different classes of secondary metabolites. In our previous study, dichloromethane extract of C. gilliesii flowers showed a good antioxidant activity.Aim of the Study:Isolation and identification of bioactive hepatoprotective compounds from C. gilliesii flowers dichloromethane fraction.Materials and Methods:The hepatoprotective activity of dichloromethane fraction and isolated compounds were studied in CCl4-intoxicated rat liver slices by measuring liver injury markers (alanine aminotransferase, aspartate aminotransferase and glutathione [GSH]). All compounds were structurally elucidated on the basis of electron ionization-mass spectrometry, one- and two-dimensional nuclear magnetic resonance.Results:A new 12,13,16-trihydroxy-14(Z)-octadecenoic acid was identified in addition to the known β-sitosterol-3-O-butyl, daucosterol, isorhamnetin, isorhamnetin-3-O-rhamnoside, luteolin-7,4’-dimethyl ether, genistein-5-methyl ether, luteolin-7-O-rhamnoside, isovanillic acid, and p-methoxybenzoic acid. Dichloromethane fraction and isorhamnetin were able to significantly protect the liver against intoxication. Moreover, the dichloromethane fraction and the isolated phytosterols induced GSH above the normal level.Conclusion:The hepatoprotective activity of C. gilliesii may be attributed to its high content of phytosterols and phenolic compounds.SUMMARY Bioactive Hepatoprotective phytosterols and phenolics from chloroform extract of Caesalpinia gilliesii Abbreviations used: ALT: Alanine Aminotransferase; AST: Aspartate aminotransferase; GSH: Glutathione; SC50: Scavenging Capacity 50 (SC 50); COSY: Correlation spectroscopy; NMR: Nuclear Magnetic Resonance; CC: Column chromatography; EI-MS: Electron-impact mass spectrometry; HSQC: Heteronuclear single-quantum correlation.

Determination of Antioxidant Composition in Berry Juices Using Solid Phase Extraction with Copper Phthalocyanine

The paper studies selective extraction of organic fractions with antioxidant activity from plant raw materials on the new sorbent with surface layer of phthalocyanine metal complexes and further HPLC determination. The possibility of sorption concentration of the antioxidant substances amount, which include mostly vitamin B groups, on the layer of copper phthalocyanine on polymer sorbent Polysorb-2. We determined antioxidant composition of honeysuckle, huckleberry and cowberry juice, namely, gallus, gentisinic, chlorogenic, caffeic, cumaric and p-methoxybenzoic acids; epicatechin and quercetine. Detection limit of this technique is 5 mg/l using copper phthalocyanine in the concentrator.

Thermodynamic properties of the methyl esters of p-hydroxy and p-methoxy benzoic acids

The vapor pressures of crystalline and liquid phases of methyl p-hydroxybenzoate and of methyl p-methoxybenzoate were measured over the temperature ranges (338.9 to 423.7)K and (292.0 to 355.7)K respectively, using a static method based on diaphragm capacitance gauges. The vapor pressures of the crystalline phase of the former compound were also measured in the temperature range (323.1 to 345.2)K using a Knudsen mass-loss effusion technique. The results enabled the determination of the standard molar enthalpies, entropies and Gibbs free energies of sublimation and of vaporization, at T=298.15K, as well as phase diagram representations of the (p,T) experimental data, including the triple point. The temperatures and molar enthalpies of fusion of both compounds were determined using differential scanning calorimetry and were compared with the results indirectly derived from the vapor pressure measurements. The standard (p°=105Pa) molar enthalpies of formation, in the crystalline phase, at T=298.15K, of the compounds studied were derived from their standard massic energies of combustion measured by static-bomb combustion calorimetry. From the experimental results, the standard molar enthalpies of formation, in the gaseous phase at T=298.15K, were calculated and compared with the values estimated by employing quantum chemical computational calculations. A good agreement between experimental and theoretical results is observed. To analyze the thermodynamic stability of the two compounds studied, the standard Gibbs free energies of formation in crystalline and gaseous phases were undertaken. The standard molar enthalpies of formation of the title compounds were also estimated from two different computational approaches using density functional theory-based B3LYP and the multilevel G3 methodologies.

Cytotoxic glucosydic iridoids from Veronica americana

Fractionation guided by the cytotoxic activity of the methanolic extract of Veronica americana led to the isolation of two new iridoids identified as 4β-hydroxy-6-O-(p-hydroxybenzoyl)-tetrahydrolinaride (1) and 10-O-protocatechuyl-catalpol (2), together with four known aromatic acids, veratric acid (3) p-methoxybenzoic acid (4), p-hydroxybenzoic acid (5) and protocatechuic acid (6). The structure of these compounds was determined by spectroscopic analysis. Iridoid glycosides 1 and 2 showed selective cytotoxic activity against the human cancer cell lines HF-6 (IC50=0.031 and 0.066μM, respectively) and PC-3 (IC50=0.721 and 0.801μM, respectively), with less sensitivity in normal MRC-5 cells (IC50=77.103 and 1451.562μM, respectively). Compound 1 was 9.9 times more potent than camptothecin against HF-6 cell line, while compound 2 was 4.7 times, more potent, against the same cell line, than camptothecin. The found biological efficacy of 1 and 2 allow us to propose these compounds as candidates for the development of effective anticancer therapeutic agents.

Supramolecular Assembly and Ab Initio Quantum Chemical Calculations of 2-Hydroxyethylammonium Salts of para-Substituted Benzoic Acids

Crystal structures of seven salts of 2-hydroxyethylamine with benzoic acid (1) and different substituted benzoic acids, such as p-methylbenzoic acid (2), p-methoxybenzoic acid (3), p-hydroxybenzoic acid (4), p-chlorobenzoic acid (5), p-bromobenzoic (6), and p-iodobenzoic (7) have been studied. The salts units of 1–7 serve as building blocks (BB) of the supramolecular architecture. In a crystal they are held together via proton-transferred N–H···O and normal O–H···O hydrogen bonds. The substituents on anions influence dipole–dipole interactions between anions and cations in molecular aggregates. As a result, they are organized in building blocks either via one charge-assisted (1, 2) hydrogen bond or via two (3–7) hydrogen bonds. The dispersion interaction significantly contributes to intermolecular force fields driving the organization of hydrogen bonds in BB. In all studied compounds, building blocks are consolidated into 2-D layers through the N–H···O and O–H···O hydrogen bonds. For the crystal structure...

Trianthema portulacastrum linn. (bishkhapra)

World Health Organization (WHO) has recommended that traditional health and folk medicine systems are proved to be more effective in health problems worldwide. Trianthema portulacastrum Linn. is a herb used in Ayurvedic medicine. The principal constituent of T. portulacastrum Linn. is ecdysterone and the other constituents are trianthenol, 3-acetylaleuritolic acid, 5,2’-dihydroxy-7-methoxy-6,8-dimethylflavone, leptorumol, 3,4-dimethoxy cinnamic acid, 5-hydroxy-2-methoxybenzaldehyde, p-methoxybenzoic acid, and beta cyanin. Different parts of Trianthema portulacastrum Linn. are traditionally used as analgesic, stomachic, laxative, treatment of blood disease, anemia, inflammation, and night blindness. Laboratory investigations on extracts of the plant have demonstrated significant pharmacological activities, such as antioxidant, diuretic, analgesic, hepatoprotective, and anticarcinogenic. This article compiles all updated information related to T. portulacastrum Linn. Scientifically proved activities are co-related with traditional concepts. Scientific evidence exists with respect to their major and minor constituents. The novelty and applicability of T. portulacastrum are hidden. Such things should be overcome through modern scientific concepts.

A MARKER-BASED STABILITY INDICATING HIGH PERFORMANCE THIN LAYER CHROMATOGRAPHIC METHOD FOR VITEX TRIFOLIA

Casticin, chrysoplenol-D, p-hydroxy benzoic acid, and p-methoxy benzoic acid are representative flavonoids and benzoic acid derivatives in Vitex trifolia, a well-known traditional Chinese, as well as ayurvedic medicine, with a wide range of biological activities. In the present paper, the aforementioned four markers were isolated and simultaneously quantified by TLC densitometric method. In the present study, a novel stability-indicating high-performance thin-layer chromatography (HPTLC) method for quantitative determination of the aforementioned four markers has been developed and validated on silica using solvent dichloromethane–methanol–formic acid (9.6:0.4:0.06 v/v/v) in the absorbance mode at 254 nm. The method showed a good linear relationship (r2 = 0.999) in the concentration range 100–2400 ng per band. It was found to be linear, accurate, precise, specific, robust, and stability-indicating and can be applied for quality control and standardization of other multi-component formulations based on Vitex trifolia.