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1.
Arq. bras. med. vet. zootec. (Online) ; 73(5): 1001-1013, Sept.-Oct. 2021. tab, ilus
Article in English | LILACS, VETINDEX, HomeoIndex Homeopathy | ID: biblio-1345278

ABSTRACT

The goal of this research was to compare the effect of the following products on dairy cattle, parasitized by Rhipicephalus microplus: organosynthetics - Clorfenvinfós and Ivermectina (OG); phytotherapics - Eucalyptus oil (EG) and Neem cake (NG); Homeopathy (HG); The control group (CG) received no treatment. Infestation was by R. microplus (MIC) and weight gain (GP) were evaluated. The study included 60 animals (5 groups) from ­ Dutch / Zebu, aged between 25-44 months and initial weight between 211-477kg. EG and NG showed MIC 84.9% and 14.0% greater than CG, respectively (P <0.05; P = 0). HG and OG had MIC less than CG 24.4% and 16.9%, respectively (P<0.05; P <0.05). EG, NG and OG obtained GP lower than CG in 7.9%, 8.9% and 8.06% (P <0.05) respectively. The HG GP was 4.9% higher (P <0.05) than CG. This was the first research to prove parasitism control by R. microplus in a field test, using homeopathy. The methodology for choosing Homeopathy for the control of enzooties, developed and tested for the first time in this study, proved to be adequate and efficient, opening the possibility for establishing a new methodology for strategic control of parasitism by R. microplus.(AU)


O objetivo desta pesquisa foi comparar o efeito dos seguintes produtos sobre bovinos leiteiros, parasitados por Rhipicephalus microplus: organossintéticos - clorfenvinfós e ivermectina (OG); fitoterápicos - óleo de eucalipto (EG) e torta de Neem (NG) e homeopatia (HG). O grupo controle (CG) não recebeu tratamento. Foram avaliados infestação por R. microplus (MIC) e ganho de peso/grupo (GP) em 60 animais (5 grupos), a partir de ­ holandês/zebu, com idade entre 25 e 44 meses e peso inicial entre 211 e 477kg. EG e NG apresentaram MIC 84,9% e 14,0% maior que CG, respectivamente (P<0,05; P=0). HG e OG apresentaram MIC menor que CG 24,4% e 16,9%, respectivamente (P<0,05; P<0,05). EG, NG e OG obtiveram GP menor que CG em 7,9%, 8,9% e 8,06% (P<0,05), respectivamente. O GP do HG foi 4,9% maior (P<0,05) que o CG. Esta foi a primeira pesquisa a comprovar controle do parasitismo por R. microplus em teste a campo, usando homeopatia. A metodologia para escolha de medicamentos homeopáticos para controle de enzootias, desenvolvida e testada pela primeira vez neste estudo, mostrou-se adequada e eficiente, abrindo a possibilidade para estabelecimento de nova metodologia para controle estratégico do parasitismo por R. microplus.(AU)


Subject(s)
Animals , Female , Cattle , Ticks , Homeopathic Remedy , Tick Control/methods , Acaricides
2.
J Phys Chem A ; 124(31): 6303-6318, 2020 Aug 06.
Article in English | MEDLINE | ID: mdl-32513000

ABSTRACT

The conformational space of 5-acetic acid hydantoin {5AAH; [2-(2,5-dioxoimidazolidin-4-yl)acetic acid]} was investigated by quantum chemical calculations performed at the DFT(B3LYP)/6-311++G(d,p) level of theory. A total of 13 conformers were located in the potential energy surface of the molecule, six of them bearing the carboxylic group in the cis arrangement (O═C-O-H dihedral equal to ∼0°) and the other seven possessing this group in the trans configuration (O═C-O-H dihedral equal to ∼180°). The most stable conformer (cis-I) was trapped from the gas phase into a low temperature argon matrix (10 K), and its infrared spectrum was fully assigned, also with help of results of normal coordinates' analysis based on the DFT computed vibrational data. The electronic structure of this conformer was analyzed by using the natural bond orbital (NBO) method. The investigation of the thermal properties of 5AAH was undertaken by differential scanning calorimetry (DSC), polarized light thermal microscopy (PLTM) and Raman spectroscopy, allowing identification of five different polymorphs. Very interestingly, in the room temperature stable polymorph the molecular units of 5AAH assume the geometry of the highest-energy conformer predicted by the calculations for the isolated molecule.

3.
J Phys Chem A ; 121(28): 5267-5279, 2017 Jul 20.
Article in English | MEDLINE | ID: mdl-28640617

ABSTRACT

The molecular structure, vibrational spectra and photochemistry of 5-methylhydantoin (C4H6N2O2; 5-MH) were studied by matrix isolation infrared spectroscopy and theoretical calculations at the DFT(B3LYP)/6-311++G(d,p) theory level. The natural bond orbital (NBO) analysis approach was used to study in detail the electronic structure of the minimum energy structure of 5-MH, namely the specific characteristics of the σ and π electronic systems of the molecule and the stabilizing orbital interactions. UV irradiation of 5-MH isolated in argon matrix resulted in its photofragmentation through a single photochemical pathway, yielding isocyanic acid, ethanimine, and carbon monoxide, thus following a pattern already observed before for the parent hydantoin and 1-methylhydantoin molecules. The investigation of the thermal properties of 5-MH was undertaken by differential scanning calorimetry (DSC), polarized light thermal microscopy (PLTM) and Raman spectroscopy. Four different polymorphs of 5-MH were identified. The crystal structure of one of the polymorphs, for which it was possible to grow up suitable crystals, was determined by X-ray diffraction (XRD). Two of the additional polymorphs were characterized by powder XRD, which confirmed the molecules pack in different crystallographic arrangements.

4.
Spectrochim Acta A Mol Biomol Spectrosc ; 172: 189-198, 2017 Feb 05.
Article in English | MEDLINE | ID: mdl-26944509

ABSTRACT

The synthesis of a new hydrazone, 2-oxoacenaphthylen-1(2H)-ylidene nicotinohydrazide, and its structural and spectroscopic characterization is reported. The obtained powder was recrystallized from DMSO and ethanol that afforded small crystals used for single-crystal X-ray diffraction studies. The compound was found to crystallize in two polymorphs, depending on the crystallization conditions. One of the polymorphs (form I) crystallizes in the centrosymmetric P21/c monoclinic space group, the other (form II) crystallizes in the non-centrosymmetric, but achiral, orthorhombic space group P212121. Conformation of the molecules is similar in both polymorphs, but the network of weak intermolecular interactions determining the crystal packing is different. In form II an additional C-H⋯O bond connects molecules related by the screw-axis running parallel to the a-axis. Crystals of both polymorphs were also screened by FT-IR and Raman microscopy; a detailed analysis of the spectra and comparison with those of the isolated molecule calculated by ab-initio HF/MP2 and DFT/B3LYP methods using a correlation consistent cc-pVDZ basis set is presented. In addition, UV-vis and NMR studies were performed in solution.

5.
J Phys Condens Matter ; 28(16): 166004, 2016 Apr 27.
Article in English | MEDLINE | ID: mdl-27009357

ABSTRACT

The investigation focuses on the crystal structure, microstructure, local ferroelectric and magnetic properties of the Bi0.9Sr0.1Fe1-x Ti(x)O(3-δ) (x = 0.05, 0.1, 0.15; δ = (0.1 - x)/2) multiferroics prepared by a solid-state reaction method. All the samples have been found to be isostructural with the pure BiFeO3 (the material crystallizes in a polar rhombohedral structure belonging to the space group R3c). It has been shown that the pattern of changes in the lattice parameters of the Bi0.9Sr0.1Fe(1-x)Ti(x)O(3-δ) samples can be interpreted as consistent with the doping-driven elimination of anion vacancies at x ⩽ 0.1 and the formation of cation vacancies at x > 0.1. The readjustment of the defect structure associated with the mechanism of charge compensation in the aliovalent-substituted BiFeO3 is accompanied by correlated changes in the morphology, ferroelectric/ferroelastic domain structure and magnetic properties of the materials. In particular, it has been found that the deviation from the ideal (δ = 0) cation-anion stoichiometry in the Bi0.9Sr0.1Fe(1-x)Ti (x)O(3-δ) system leads to a significant decrease in the average size of crystal grain and ferroelectric domains and gives rise to an antiferromagnetic-weak ferromagnetic transformation. Results of this study have been compared with those obtained for equally substituted samples of the Bi0.9Ca0.1Fe(1-x)Ti(x)O(3-δ) series (Khomchenko and Paixão 2015 J. Phys.: Condens. Matter 27 436002) to demonstrate how the variation in the chemical pressure introduced by the partial replacement of Bi(3+) with bigger (Sr(2+)) and smaller (Ca(2+)) ions can affect the multiferroic behavior of Ti-doped bismuth ferrites.

6.
J Food Sci ; 80(12): S2944-9, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26523944

ABSTRACT

The ideal sucrose concentration and equivalent concentrations of the stevia, sucralose, aspartame, and neotame in chocolate milk with chia oil as well as the dynamic behavior of certain sensory attributes were investigated using a time-intensity methodology. The use of just-about-right (JAR) identified an ideal sucrose concentration of 9% (w/w). In addition, the magnitude estimation method showed that stevia had the lowest sweetness power whereas neotame presented the highest. Furthermore, the time-intensity analysis indicated that there was no significant change between the maximum intensities of the sweetness for any evaluated sweeteners. In general, the desired sensory profile and some economic considerations are decisive on the choice of which sweetener is better to be used in chocolate milk formulation added with chia oil.


Subject(s)
Cacao , Food Handling/methods , Milk/chemistry , Plant Oils , Salvia , Sweetening Agents/analysis , Taste , Animals , Aspartame/analysis , Dietary Sucrose/analysis , Dipeptides/analysis , Diterpenes, Kaurane/analysis , Flavoring Agents , Glucosides/analysis , Humans , Stevia , Sucrose/analogs & derivatives , Sucrose/analysis
7.
J Phys Condens Matter ; 27(43): 436002, 2015 Nov 04.
Article in English | MEDLINE | ID: mdl-26447603

ABSTRACT

Recognition of the factors that may significantly affect the multiferroic properties of BiFeO3-based perovskites remains one of the most challenging tasks in condensed matter physics. To reveal the reasons behind the doping-driven instability of the cycloidal antiferromagnetic order in the polar phase of Bi(1-x)Ca(x)FeO(3-x/2), synthesis and investigation of the crystal structure, microstructure, local ferroelectric and magnetic properties of the ceramic samples of Bi0.9Ca0.1Fe(1-x)Ti(x)O(3-δ) (x = 0.05, 0.1, 0.15) have been carried out. The compounds possess a rhombohedral structure (space group R3c). The compositional dependence of unit cell volume in this series can be interpreted as suggesting the doping-induced elimination of anion vacancies at x ⩽ 0.1 and the formation of cation vacancies at x > 0.1. The filling of oxygen vacancies suppresses a weak ferromagnetic contribution characteristic of the parent Bi0.9Ca0.1FeO2.95. The appearance of cation vacancies restores the weak ferromagnetic phase. The key role of lattice defects in the magnetic behavior of Ca-doped BiFeO3 has been confirmed by the observation of a correlation between the magnetic properties and the morphology/ferroelectric domain structure of the Bi0.9Ca0.1Fe(1-x)Ti(x)O(3-δ) ceramics.

8.
J Dairy Sci ; 98(11): 7544-51, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26387013

ABSTRACT

For years, just-about-right (JAR) scales have been among the most used techniques to obtain sensory information about consumer perception, but recently, some researchers have harshly criticized the technique. The present study aimed to apply survival analysis to estimate the optimum sucrose concentration in probiotic petit suisse cheese and compare the survival analysis to JAR scales to verify which technique more accurately predicted the optimum sucrose concentration according to consumer acceptability. Two panels of consumers (total=170) performed affective tests to determine the optimal concentration of sucrose in probiotic petit suisse using 2 different methods of analysis: JAR scales (n=85) and survival analysis (n=85). Then an acceptance test was conducted using naïve consumers (n=100) between 18 and 60 yr old, with 2 samples of petit suisse, one with the ideal sucrose determined by JAR scales and the other with the ideal sucrose content determined by survival analysis, to determine which formulation was in accordance with consumer acceptability. The results indicate that the 2 sensory methods were equally effective in predicting the optimum sucrose level in probiotic petit suisse cheese, and no significant differences were detected in any of the characteristics related to liking evaluated. However, survival analysis has important advantages over the JAR scales. Survival analysis has shown the potential to be an advantageous tool for dairy companies because it was able to accurately predict the optimum sucrose content in a consumer-friendly way and was also practical for researchers because experimental sensory work is simpler and has been shown to be more cost effective than JAR scales without losses of consumer acceptability.


Subject(s)
Cheese/analysis , Consumer Behavior , Probiotics/administration & dosage , Sucrose/analysis , Adolescent , Adult , Animals , Color , Female , Food Handling , Food Microbiology , Humans , Linear Models , Male , Middle Aged , Taste , Young Adult
9.
J Org Chem ; 80(1): 392-400, 2015 Jan 02.
Article in English | MEDLINE | ID: mdl-25438067

ABSTRACT

The molecular structure and photochemistry of 5-thiosaccharyl-1-methyltetrazole (TSMT) were studied by means of matrix-isolation FTIR spectroscopy, X-ray crystallography, and theoretical calculations. The calculations predicted two conformers of TSMT that differ in energy by more than 15 kJ mol(-1). The infrared spectrum of TSMT isolated in solid argon was fully assigned on the basis of the spectrum calculated (O3LYP/6-311++G(3df,3pd)) for the most stable conformer. In the crystal, TSMT molecules were found to assume the same conformation as for the isolated molecule, with each molecule forming four hydrogen bonds with three neighboring molecules, leading to a network of TSMT oligomers. Upon UV (λ = 265 nm) irradiation of the matrix-isolated TSMT, two photodegradation pathways were observed, both arising from cleavage of the tetrazolyl ring. Pathway a involves cleavage of the N1-N2 and N3-N4 bonds with extrusion of N2, leading to photostable diazirine and thiocarbodiimide derivatives. The photostability of the photoproduced diazirine under the conditions used precluded its rearrangement to the nitrile imine, as reported for 5-phenyltetrazole by Bégué et al. ( J. Am. Chem. Soc. 2012 , 134 , 5339 ). Pathway b involves cleavage of the C5-N1 and N4-N3 bonds, leading to a thiocyanate and methyl azide, the latter undergoing subsequent fragmentation to give CNH.

10.
J Dairy Sci ; 97(12): 7344-53, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25606602

ABSTRACT

The introduction of new products catering to specific dietary needs and the corresponding changes in the consumer profile reflect a growing demand for diet and "light" products. However, little information is available regarding the sensory effects of different sweeteners in products consumed at different temperatures and with varying fat contents. In this regard, this study aimed to determine the influence of temperature and fat content on the ideal sucrose concentration and the sweetness equivalence and sweetening power of different sweeteners: Neotame (NutraSweet Corp., Chicago, IL), aspartame, neosucralose, sucralose, and stevia (95% rebaudioside A), with sucrose as reference, in a chocolate milk beverage using a just-about-right (JAR) scale and magnitude estimation. Increasing temperature of consumption had an inverse effect on the ideal sucrose concentration in whole milk beverages, whereas no difference was noted in beverages made skim milk. In addition, a decrease in sweetening power was observed for all of the sweeteners analyzed considering the same conditions. The findings suggest that different optimal conditions exist for consumption of chocolate milk beverage related to sweetness perception, which depends on the fat level of milk used in the formulation. This information can be used by researchers and dairy processors when developing chocolate milk beverage formulations.


Subject(s)
Cacao , Fats/chemistry , Food Additives , Milk/chemistry , Sweetening Agents/chemistry , Taste , Animals , Beverages/analysis , Cattle , Dairy Products , Humans , Sucrose/chemistry , Temperature
11.
J Phys Condens Matter ; 25(13): 135902, 2013 Apr 03.
Article in English | MEDLINE | ID: mdl-23470681

ABSTRACT

Neutron powder diffraction and magnetization measurements of the Bi(1-x)Ca(x)FeO3 (0.05 ≤ x ≤ 0.14) compounds were carried out to follow the effect of the heterovalent A-site doping on the long-range structure and magnetic properties of the BiFeO3 multiferroic. Ca substitution induces the appearance of weak ferromagnetism in the initial ferroelectric R3c phase, but modifies the picture of polar displacements, so the average PbZrO3-like antiferroelectric structure is stabilized at x = 0.11. Further increase of the Ca content leads to transformation of the antipolar ionic shifts to give rise to the Pbam → Imma transition near x = 0.14. A structural study performed for the x = 0.05 compound at high temperature revealed the R3c → Pnma phase transition at 950 K. For x = 0.1 samples, an intermediate heating-induced structure separating the R3c and Pnma phases was found.

12.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 6): o1603-4, 2012 Jun 01.
Article in English | MEDLINE | ID: mdl-22719410

ABSTRACT

In the title compound, C(17)H(27)NO(4), which is an hydro-sinapic acid derivative with increased lipophilicity conferred by an additional alkyl chain, the central and the hexyl linear chains contain slightly shorter bond lengths [C-N = 1.316 (2) Å; average linear chain C-C = 1.487 (6) Å] than reported average values [Csp(2)-N = 1.334, C-C for CH(2)-CH(2) = 1.524 and 1.513 Šfor CH(2)-CH(3)]. The 4-hy-droxy-3,5-dimeth-oxy-phenyl plane [r.m.s. deviation 0.055 (12) Å] makes an angle of 59.89 (5)° with the central plane of the mol-ecule (composed of the N atom, the carbonyl group and the two methyl-ene C atoms linking the carbonyl group and the ring, [r.m.s. deviation 0.0026 (10) Å], which, in turn, makes an angle of 64.24 (13)° with the essentially planar hexyl chain [r.m.s. deviation 0.035 (18) Å]. The N-H group of the amide group is involved in a bifurcated hydrogen bond towards the hy-droxy and one of the meth-oxy O atoms of the 4-hy-droxy-3,5-dimeth-oxy-phenyl substituent of a neighbouring mol-ecule, forming a two-dimensional network in the (100) plane. In addition, the same hy-droxy group acts as a donor towards the carbonyl O atom of another neighbouring mol-ecule, forming chains running along the b axis.

13.
Article in English | MEDLINE | ID: mdl-22259518

ABSTRACT

The title cholestan, C(28)H(46)O(3), was prepared by epoxidation of 7-norcholest-5-en-3ß-yl acetate and crystallized by slow evaporation from an ethano-lic solution. All rings are trans fused. The 3ß-acetate and the 17ß-cholestane side chain are in equatorial positions. The mol-ecule is highly twisted due to its B-nor characteristic. A quantum chemical ab-initio Roothaan Hartree-Fock calculation of the equilibrium geometry of the isolated mol-ecule gives values for bond lengths and valency angles in close agreement with the experimental ones.

14.
Lett Appl Microbiol ; 53(5): 518-24, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21883318

ABSTRACT

AIMS: To detect Pseudomonas aeruginosa in water and treatment equipment biofilms of a thermae hydropathic facility and to study antibiotic susceptibility and genetic diversity. METHODS AND RESULTS: One hundred and fifty-four planktonic isolates were obtained from 2220 water samples during 4 years. Seventy-two biofilm isolates were obtained from 23 samples of inner parts of three inhalation equipments. Antibiotic susceptibility was determined by disc diffusion. All isolates were susceptible to tested antimicrobials, except two biofilm isolates and one planktonic isolate. Twenty-one resistant mutants were observed (nine from biofilms), mostly with imipenem (IP) resistance (81%), by diminished expression of OprD porin, as it was observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Random amplification polymorphic DNA showed a genetically heterogeneous population that is spread through the entire system and persistent in time. IP resistance mutation ability was spread through the population. CONCLUSIONS: The permanent assessment of Ps. aeruginosa is necessary not only in water, as expressed in official programmes, but also in equipments where biofilms are evident. Ps. aeruginosa was more prevalent in biofilm populations and presented higher ability to adapt to antibiotic pressure. SIGNIFICANCE AND IMPACT OF THE STUDY: Twenty-one million people use thermae in Europe. Official microbiological quality control programmes only consider water surveillance. Present study proves the need of a review on current official programmes.


Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial/genetics , Imipenem/pharmacology , Pseudomonas aeruginosa/physiology , Water Microbiology , Biofilms/drug effects , Biofilms/growth & development , DNA/genetics , Electrophoresis, Polyacrylamide Gel , Europe , Genetic Variation , Humans , Microbial Sensitivity Tests , Mutation , Porins/genetics , Porins/metabolism , Pseudomonas aeruginosa/classification , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/isolation & purification , Water Purification/methods
15.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 7): o1643-4, 2011 Jul 01.
Article in English | MEDLINE | ID: mdl-21837048

ABSTRACT

The title hydrated tetrol, C(19)H(32)O(4)·3H(2)O, was synthesized by stereoselective reduction of the compound 3ß,5α,6ß-trihy-droxy-androstan-17-one. All rings are fused trans. The organic mol-ecules are connected head-to-tail along the c axis via O-H⋯O hydrogen bonds. Layers of water mol-ecules in the ab plane inter-connect these chains. A quantum chemical ab initio Roothan Hartree-Fock calculation of the isolated mol-ecule gives values for the mol-ecular geometry close to experimentally determined ones, apart from the C-O bond lengths, whose calculated values are significantly smaller than the measured ones, probably a consequence of the involvement of the C-OH groups in the hydrogen-bonding network.

16.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 5): o1056-7, 2011 May 01.
Article in English | MEDLINE | ID: mdl-21754383

ABSTRACT

The title compound, C(19)H(30)O(4), is an androstan-17-one derivative synthesized from the dehydro-epiandrosterone through a sequential addition of an oxidant, followed by a trans-diaxial opening of the epoxide generated, with Bi(OTf)(3) (OTf is trifluoro-methane-sulfonate). The six-membered rings have a slightly flattened chair conformation, while the five-membered ring adopts a 14-α envelope conformation. All rings are trans fused. In the crystal, the mol-ecules are connected by O-H⋯O hydrogen bonds involving the hydroxyl and carbonyl groups, forming a three-dimensional network. A quantum mechanical ab initio Roothan Hartree-Fock calculation of the free mol-ecule gives bond lengths, valency angles and ring torsion angles of the free molecule at equilibrium geometry (energy minimum) close to the experimental values.

17.
J Phys Condens Matter ; 23(2): 026002, 2011 Jan 19.
Article in English | MEDLINE | ID: mdl-21406852

ABSTRACT

A resonant x-ray scattering investigation of the NpAs(1 - x)Se(x) system with single crystals of 5 and 10% Se content is reported. The main features of the magnetic phase diagram previously studied by neutron scattering were confirmed. The coexistence within a single domain of ferro- and antiferro-components in the low-T ferrimagnetic phase was established, as well as the single-k character of the incommensurate phase and of the antiferromagnetic component of the ferrimagnetic phase. A tetragonal lattice distortion was found in the ferro- and ferrimagnetic phases which is not compatible with the proposed model for the ferromagnetic phase. The study of ferromagnetism was carried out using polarization analysis of the diffracted beam to separate the scattering intensities originating from magnetism and charge, which are superimposed in reciprocal space. The magnetic character of the ferromagnetic signal calculated from the measured intensities in the polarization analysis σπ and σσ channels was confirmed by analysis of the corresponding temperature dependence.


Subject(s)
Ferric Compounds/chemistry , Magnetics , Neptunium/chemistry , Selenium Compounds/chemistry , X-Ray Diffraction
18.
Acta Crystallogr C ; 66(Pt 10): o499-502, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20921615

ABSTRACT

The title compounds, C(17)H(13)FN(2)O(3) and C(18)H(16)N(2)O(4), are new potent aromatase inhibitors combining the common features of second- and third-generation nonsteroid anti-aromatase compounds. The molecules have a propeller shape, with dihedral angles between adjacent planes in the range 49-86°. A quantum mechanical ab initio Roothaan-Hartree-Fock calculation for the isolated molecules shows values for these angles close to the ideal value of 90°. Docking studies of the molecules in the aromatase substrate show that their strong inhibitor potency can be attributed to molecular flexibility, hydrophobic interactions, heme Fe coordination and hydrogen bonding.


Subject(s)
Aromatase Inhibitors/chemistry , Aromatase Inhibitors/pharmacology , Benzodioxoles/chemistry , Imidazoles/chemistry , Crystallography, X-Ray , Hydrogen Bonding , Molecular Structure , Quantum Theory
19.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 3): o524, 2010 Feb 06.
Article in English | MEDLINE | ID: mdl-21580297

ABSTRACT

In the title compound, CH(6)N(3) (+)·C(7)H(6)NO(2) (-), the cation and anion lie on crystallographic mirror planes. The 4-amino-benzoate anion is almost in a planar conformation with a maximum deviation of 0.024 (2) Šfor the N atom. The bond length in the deprotonated carboxyl group is inter-mediate between those of normal single and double Csp(2)=O bonds, indicating delocalization of the charge over both O atoms of the COO(-) group. In the crystal, N-H⋯O hydrogen bonds assemble the ions in layers propagating in the bc plane. This structure is very similar to that of guanidinium benzoate.

20.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 7): o1878-9, 2010 Jun 30.
Article in English | MEDLINE | ID: mdl-21588073

ABSTRACT

The title triterpene, C(34)H(52)N(2)O(3), is a C-28 carbamate derivative of betulin prepared in a one-step reaction from the commercially available 1,1'-carbonyl-diimidazole (CDI). All rings are fused trans. The X-ray study shows the retention of the configuration of C-28 with respect to the known chiral centres of the molecule. In the crystal, the mol-ecules are O-H⋯O hydrogen bonded via the hy-droxy group and the carbonyl group of the carbamate function into chains running along the c axis. A quantum-mechanical ab initio Roothaan Hartree-Fock calculation of the equilibrium geometry of the isolated mol-ecule gives values for bond-lengths and valency angles close to the experimental values. The calculations also reproduce the mol-ecular conformation well, with calculated puckering parameters that agree well with the observed values.

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