Search

Boerhavia diffusa is a medicinal plant used for various therapeutic benefits ant the plant can be found in tropics and subtropics regions. It has the pharmacological activities which include antifibrinolytic, immunosuppressive, diuretic, hepatoprotective, antidiabetic, anti-inflammatory, anticancer, immunomodulatory, antilympho proliferative, analgesic properties and also for the treatment of pulmonary tuberculosis. This study deals with the determination of possible phytocompounds present in the hydroethanolic extract of the plant Boerhavia diffusa using Gas chromatography- Mass Spectroscopy technique. Using GC-MS technique the phytocompounds present in the hydroethanolic extract of the plant Boerhavia diffusa was investigated and the mass spectra of the compounds found in the extract were matched with National Institute of Standards and Technology library. GC-MS Analysis of Boerhavia diffusa extract reveals that the existence of phytocompounds which includes 1, 2-Benzenedicarboxylic acid, diethyl ester, Hexadecanoic Acid, 1,2- Benzenedicarboxylic acid, dibutyl ester and 1,2-Benzenedicarboxylic Acid, Dioctyl Ester. This research paper helps to identify the phytocompounds which are present in the extract of Boerhavia diffusa and also prove the biological activities of the phytocompounds present. Furthermore, studies were made in-depth to find the mode of action of the phytocompounds.

99mTc-ethylene dicysteine diethyl ester (99mTc-ECD) is an established radiopharmaceutical used for brain perfusion imaging; however it does not have any recognized biological quality control to ascertain its in vivo efficacy. The present paper describes an in vitro enzymatic method that can be adapted as a regular biological quality control for ECD kit evaluation before its release for patient end use. The method involves reaction of 99mTc-ECD (

A new method for simultaneous quantitative determination of chlormadinone acetate and ethinyl estradiol in human blood plasma by means of HPLC with mass-spectrometric (MS) detection was developed. Sample preparation was performed by means of liquid-liquid extraction into hexane/diethyl ester mixture. The method was validated with respect to the following characteristics: selectivity, linearity, accuracy, precision, cross-transfer, and stability. The proposed HPLC/MS method allows carrying out simultaneous determination of chlormadinone acetate and ethinyl estradiol concentration in blood plasma of volunteers during drug development and can be applied for studying drug pharmacokinetics.

This paper reports that the bulk polymerization of L-aspartic acid diethyl ester catalyzed by immobilized CAL-B at 80 °C for 24 h gives primarily (∼95%) α-linked poly(L-aspartate) in 70% yield with DPavg = 50 and regioselectivity (α/β) = 94 : 6. Plots of log{[M]0/[M]t} vs. time and DPavgvs. conversion indicate that this polymerization proceeds in a controlled manner by a chain-growth mechanism up to 90% conversion. Thereafter, competition occurs between chain growth and step mechanisms.

A new method for the synthesis of the influenza antiviral drugs oseltamivir and tamiphosphor starting from 4-hydroxycyclohexenone has been developed. Stereoselective aziridination of a protected 4-hydroxycyclohexenone was used as a key step and the aziridine formed was resolved enzymatically with a very high yield and enantiomeric excess. The subsequent conversion to oseltamivir and tamiphosphor diethyl ester in 10 or 12 additional steps and 22% or 19% yield from intermediate 7, respectively, is described.

Hetero Diels-Alder (HDA) reactions between 2,3-dimethyl-1,3-butadiene and diethyl ester of aroyl phosphonates catalyzed by AlCl3 to afford (3,6-dihydro-2H-pyran-2-yl) phosphonate derivatives were investigated. Aroyl phosphonates with electron-withdrawing groups generally resulted in better isolated chemical yields. A stoichiometric amount of AlCl3 rather than a catalytic amount was necessary to activate the cycloaddition reaction. The amount of AlCl3 catalyst and its effect on LUMO of ethyl ester benzoyl phosphonate were also investigated by performing density functional theory (DFT) (B97D/6-31+G(d,p)) computations in dichloromethane. An increased loading of AlCl3 induced a considerable decrease in the LUMO energy of ethyl ester of benzoyl phosphonate. The computed Gibbs free activation energy is 17.03 kcal/mol in DCM at 0°C using the same computational level.

An improved synthesis of the bis-methylamido Hantzsch dihydropyridine is described. The Hantzsch amide is demonstrated to be an effective transfer hydrogenation reagent using α,β-unsaturated ketones as the test case. Unreacted Hantzsch amide and the bis-methylamidopyridine byproduct are effectively removed by extraction in contrast to the commonly used Hantzsch diethyl ester. Several examples are given with the reaction being more effective for conjugated aromatic substrates than for aliphatics.

Dalbergia cochinchinensis Pierre hardwood is widely accepted by consumers as one of the most desirable materials in making furniture and handicrafts for its properties of enriched aroma and sense of touch. The unique characteristics of this wood are attributed to its organic compounds in gum canal and parenchyma cells. However, many valuable organic compounds are not properly protected and retained during the conventional kiln drying. In order to investigate the organic compounds in D. cochinchinensis Pierre and find the favorable drying method which reserves organic compounds, the wood extract was analyzed by gas chromatography-mass spectrometer (GC–MS) at first. Then the samples were dried to absolute dry state by conventional drying (CD), vacuum drying (VD) and vacuum freeze drying (VFD) respectively, to obtain extract and calculate the yield. Lastly, these extracts from absolute dried wood were also analyzed and compared with each other. Results illustrated that there were some components with obvious medical efficacy existing in D. cochinchinensis Pierre, and VFD outperformed the other two methods in maintaining organic compounds in D. cochinchinensis Pierre.

A variety of commercial tire treatments are available that purport to help automobile tires better cling to the surface of a road or racetrack, raising concerns in the professional racing community that such products might be used to illicitly boost performance in competitive events. These tire treatments are reputed to cut lap times and improve handling and maneuverability. In some cases, the manufacturers even boast that their products are “undetectable” (i.e., impervious to the scrutiny of laboratory testing). In this study, a number of banned tire treatment products were evaluated principally by gas chromatography-mass spectrometry (GC-MS) using solid phase microextraction (SPME) as a pre-concentration technique. The chemicals off-gassed by each product were determined and grouped into two broad categories: ‘plasticizer-based’ tire treatment products and ‘hydrocarbon-based’ tire treatment products. This information was then applied to the analysis of genuine tire samples provided by the United States Auto Club (USAC), a professional racing association. Over the course of one year, 10 out of the 71 questioned samples tested positive for a prohibited treatment product. The manufacturers' claims regarding their products' invisibility to lab tests were largely proven to be unfounded: both the products themselves and the tires treated with them can be identified by a number of characteristic volatile compounds. These included known plasticizers such as pentanedioic acid diethyl ester, plasticizer-related compounds such as 2-ethyl-1-hexanol, and dearomatized distillates.

Certain factors may influence the special metabolite production in plants. Leaves of Byrsonima verbascifolia (MALPIGHIACEAE) were collected during different seasons and times of day, to determine the concentration and chemical composition of volatile oils. Chemical analysis indicated that oxygenated sesquiterpenes were the most concentrated, and oxygenated monoterpenes were the least concentrated. The primary components of the essential oil were pentacosane (2.747 to 9.613%), spathulenol (3.398 to 10.552%), and benzene-1,2-dicarboxylic acid diethyl ester (3.861 to 15.307%). Seasonal and circadian variations did not influence the essential oil content. However, the essential oil’s chemical composition was influenced by seasonal variation, among them the spathulenol. Key words: Murici, seasonality, circadian variation, terpens, leafs.

A calix[4]pyrrole strapped by a bulky calix[4]arene diester locked in its cone conformation has been prepared. On the basis of (1)H NMR spectroscopic analyses carried out in CDCl3, it is concluded that this hybrid system, receptor 2, binds only the fluoride anion and does so with remarkably high affinity even in the presence of an excess of various potentially competing environmentally and biologically ubiquitous anions (studied as the tetrabutylammonium, cesium, or lithium salts). Solid state structural analyses provide support for the notion that receptor 2 interacts well with the fluoride anion in the solid state.

Closed-cell polyimide rigid foams with different Calculated Molecular Weight (Calc'd Mn) and foam density (ρ) have been prepared by thermal foaming of nadimide-endcapped imideoligomers (NAIO) powder. The NAIO powder was obtained by thermally treating of a PMR poly(amide ester) solution derived from the reaction of diethyl ester of 2,3,3′,4′-biphenyltetracarboxylic dianhydride (α-BPDE) and p-phenylenediamine (p-PDA) using monoethyl ester of cis-5-norbornene- endo-2,3-dicarboxylic acid (NE) as reactive endcapping agent in ethyl alcohol. Effect of Calc'd Mn and foam density (ρ) on mechanical and thermal properties of the polyimide rigid foams have been systematically investigated. It was found that the thermal foaming properties of NAIO powders were affected by the Calc'd Mn. The appreciate Calc'd Mn could yield polyimide foams with both high closed-cell content (Cc) (>80%) and outstanding mechanical properties. Moreover, the thermal properties were reduced by increasing of Calc'd Mn and the mechanical properties improved gradually by increasing foam densities. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3282–3291, 2013

The synthesis of nitrogen containing heterocyclic compounds from diethyl ester, formaldehyde, and various aromatic/aliphatic amines via a simple and efficient one-pot multicomponent reaction in ionic liquid is described. The catalyst can be recycled at least three times without obvious loss in catalytic activity.

An efficient approach for the formation of 5-amino- and 7-amino-6-azaoxindole derivatives was developed. 2-Amino-4-chloro-3-nitropyridine (8), and its 5-nitro-substituted regioisomer (9), respectively, were obtained by reaction with ethyl malonate. The resulting 2-amino-3/5-nitropyridine derivatives substituted in the 4-position with malonic acid diethyl ester (10, 11) were subjected to reductive cyclization yielding 3-ethoxycarbonyl-6-azaoxindole derivatives 4a and 5a. Protection of the amino function was not required. Intermediates 10 and 11 could also be converted to the corresponding 4-acetic acid ethyl esters 12 and 13 by dealkoxycarbonylation with LiCl, and subsequently cyclized under reductive conditions yielding 3-unsubstituted 5-/7-aminooxazindoles.

A series of novel [1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles bearing pyridine ring derivatives was synthesized from 2,6-dimethylpyridin-3,5-dicarboxylic acid diethyl ester. The structures of the compounds were characterized by use of IR, NMR, EI-MS, and elemental analysis. The structure of one compound was further confirmed by X-ray diffraction analysis. Biological assays showed that these compounds had potential insecticidal activity with especially strong regulation of the growth of 2nd instar Mythimna separata larvae. The effects on bioactivity of substituent groups on phenyl ring were also screened. .

Protection of the thiolate function of dimercaptosuccinic acid (DMSA) and ethylenedi-l-cysteine diethyl ester (ECD) by S-thiomethylation allowed automatic deprotection during technetium-99m (99mTc) radiolabelling by direct reduction with stannous chloride dihydrate. Protection of the free thiolate group increased the stability of the ligands as well as deprotection during complexation, which resulted in the desired radiopharmaceuticals. The complexes obtained from the protected ligands were chromatographically (HPLC) and biologically compared with the corresponding 99mTc complexes of the unprotected ligands. The results suggest that the aforementioned method of protection by S-thiomethylation could be utilized for the development of single-vial DMSA and ECD kit. Copyright © 2012 John Wiley & Sons, Ltd.

From the Michael addition reaction of CH3NO2 to the diethyl ester of coumarin-3-phosphonic acid 1 in the presence of a base—KF or a nucleophilic agent (HNu = EtOH, piperidine, PrNH2)—the esters and amides 2, 4, and 5 were isolated. In order to avoid ring opening and to isolate only the product of the Michael addition reaction 3, the reaction was performed in the absence of a nucleophilic agent. In this case only, the product 3—a 2-oxochromane—was isolated. When the reaction was carried out in the presence of amines (Et3N, piperidine), a new product—1-hydroxy-4-(2′-hydroxyphenyl)-2,5-dioxopyrrolidin-3-yl-phosphonate 6—was formed by a new rearrangement reaction. [Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: .cif files.]

Diethyl phthalate (1,2-benzenedicarboxylic acid diethyl ester, DEP) is one of a group of widely used plasticizers, which can lead to serious environmental problems. Because of manufacturing and application, DEP can be released into the atmosphere where it can undergo transport and chemical transformation. To assess the atmospheric behavior of pollutants, it is critical to know their atmospheric reactions. In this paper, the reaction mechanism and possible oxidation products for the OH-initiated atmospheric reaction of DEP were theoretically investigated by using the density functional theory (DFT) method. The geometries and frequencies of the reactants, intermediates, transition states, and products were calculated at the MPWB1K/6–31+G(d,p) level, and the energetic parameters were further refined by the MPWB1K/6–311+G(3df,2p) method. The present study shows that H abstractions from the CH3 and CH2 groups, as well as OH addition to the benzene ring, are energetically favorable reaction pathways for the reaction of DEP with OH radicals. Detailed degradation products are provided.

(2-Amino-3-cyano-4H-chromen-4-yl) phosphonic acid diethyl esters are prepared via a single-step multi-component reaction of structurally diverse salicylaldehydes with malononitrile and triethyl phosphite using a catalytic amount of potassium phosphate in ethanol at ambient temperature. Use of potassium phosphate as an inexpensive catalyst makes the protocol more economical. Mild reaction conditions, simple work-up procedure are the added advantages of the present method.

Aragwadharishtam is an Ayurvedic preparation used mainly to detoxify the body. Its main use is in the cure of skin diseases, ulcers and piles. The present study deals with the GC MS analysis of Aragwadharishtam to know the presence of phytochemicals present in this medicine. The GC MS profile indicated the presence of some very important molecules such as Phnylethyl alcohol, Ethyl hydrogen succinate, Butanedioic acid diethyl ester, 4Ethyl-2-hydroxycyclopent-2-en-1-one, Eugenol, Ethyl gallate, 1, 2, 3-Benzenetriol, Benzeethanol, 4-hydroxy-, Hexadecanoic acid, 2-hydroxy-1-(hydroxymethyl) ethyl ester and Octadecanoic acid, 2, 3-hydroxypropyl ester etc. These molecules have a number of important medicinal roles which could substantiate their participation towards the medicinal activity of Aragwadharishtam as a detoxifying formula as claimed by Ayurveda. However, further work in this direction is warranted to prove the medicinal efficacy of the medicine.

Phosphonic analogue 1 of benzo[c]pyroglutamic acid was synthesized by three-step synthesis starting from N-tert-butylphtalimide and triethylphosphite. The acid-catalyzed, oxidative cascade conversion of phosphonate 11 to phthalimide and phosphoric acid diethyl ester was observed. A mechanism for this transformation was proposed.

By the interaction of the diethyl ester of 2,6-bis(bromomethyl)-4-phenyl-1,4-dihydropyridine-3,5-dicarboxylic acid with two moles of the alkaloid cytosine, the corresponding 2,6-bis(cytisinomethyl) derivative was obtained. The spatial structure of the product was demonstrated by 1H NMR spectroscopy and X-ray structural analysis.

A rapid, low temperature hydrolysis of tenofovir diethyl ester mediated by TMSCl and NaBr was identified and demonstrated to be superior to the current production method, TMSBr-mediated hydrolysis. This mild phosphonate ester hydrolysis was then coupled to alkylation of the phosphonic acid, providing a one-pot procedure for formation of tenofovir disoproxil from tenofovir diethyl ester. The hydrolytic conditions developed here dramatically improve the synthesis of tenofovir disoproxyl and will lead to lower cost HIV/AIDS treatment in the developing world.

A new para-hydroxy[bis(ortho-morpholinylmethyl)]phenyl-1,4-DHP substituted compound, (4-(4-hydroxy-3,5-bis(morpholin-4-ylmethyl)phenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylic acid diethyl ester, LQM300), with antihypertensive and antiarrhythmic properties, has been synthesized. Four pKa values of this compound have been determined with the aid of the program SQUAD, at pseudo-physiological conditions (T = 37 degrees C and I = 0.15 M) by UV spectrophotometry and at T = 25 degrees C and I = 0.05 M by Capillary Zone Electrophoresis (CZE). The logP = 2.7 +/- 0.2 between n-octanol and water, has been estimated by UV spectrophotometry. The antihypertensive and antiarrhythmic efficacies as well as the logP values have been compared with other compounds of the same kind and related with their structure.

Two ester-phosphonate analogs of cephalin of the type Structure (I). have been synthesized in the L-dipalmitoyl (R C15H31) and DL-distearoyl (R C17H35) forms. 2-Phthalimidoethylphosphonic acid was prepared by hydrogen bromide cleavage of its crude diethyl ester. Reaction of D-αβ-dipalmitin or DL-αβ-distearin with 2-phthalimidoethylphosphonyl dichloride gave, after hydrazinolysis and purification of the product on a silicic acid column, the corresponding phosphono-cephalins (I). A diether-phosphonate analog of cephalin, was prepared in high yield by condensation of with 2-hydroxyethylphthalimide and trichloroacetonitrile, followed by hydrazinolysis of the phthalyl diether phosphonocephalin.

Benzoguanamine (2,4-diamino-6-phenyl-s-triazine) and acetoguanamine (2,4-diamino-6-methyl-s-triazine) both react with an excess of ethyl chlorocarbonate; in this reaction two hydrogen atoms from the guanamines are replaced by two carbethoxy groups. The I.R. spectrum reveals that this double substitution takes place on one amino group; in consequence, the resulting compounds are derivatives of iminodicarboxylic acid diethyl ester. Upon heating above the melting point, the compounds decompose, during which process a very short occurrence of isocyanate absorption can be observed in the I.R. spectrum.

The regioselective synthesis of 3-diethoxyphosphonopyrazoles has been accomplished through the addition of aryl or alkyl hydrazines to (3-ethoxyacryloyl)phosphonic acid diethyl ester. An example of hydrolysis of the pyrazolephosphonic ester to the corresponding acid is described.

The reaction of N-sulfinyltrifluoromethanesulfonamide CF3SO2NSO with triethylphosphate and triethylphosphite results in N-(trifluoromethanesulfonyl)triethoxyphosphazene CF3SO2N=P(OEt)3, which upon heating is converted into the diethyl ester of N-trifluoromethylsulfonylamidophosphoric acid CF3SO2NHP(O)·(OEt)2. The latter was also prepared by alcoholysis of N-(trifluoromethanesulfonyl)trichlorophosphazene or of potassium salt of dichloroanhydride of N-trifluoromethylsulfonylamidophosphoric acid, or by the reaction of the salt CF3SO2NHNa with diethylchlorophosphate. Compound CF3SO2N=P(OEt)3 does not rearrange into the isomeric diethyl ester of N-ethyl-N-(trifluoromethylsulfonyl)amidophosphoric acid CF3SO2N(Et)P(O)(OEt)2, contrary to the statement in the literature on the easy rearrangement of phosphazenes RFSO2N=P(OEt)3 into amidates RFSO2N(Et)P(O)(OEt)2.