ABSTRACT
Inhibition of bitterness is a significant measure to improve the compliance and clinical efficacy of traditional Chinese medicine(TCM) decoction. According to the characteristics of TCM decoction, such as high dispersion of bitterness components, multi-component bitterness superposition and strong instantaneous stimulation, the research group put forward a new strategy to inhibit bitterness in the early stage based on the self-assembly characteristics of amphiphilic substances in aqueous solution, in order to reduce the distribution of bitterness components in real solution and achieve the purpose of bitter-masking. It was found that the bitter-masking effect of amphiphilic substances was different on the bitter compounds of various structures. Therefore, it was speculated that there might be a certain relationship between the bitter inhibition effect and the substrate structure. In this paper, the interaction between mPEG-PLLA and five bitter alkaloids(bamatine, jatrorrhizine, berberine, epiberberine and coptisine) in Coptidis Rhizoma was studied to explore the effect of substrate structure on the inhibition of bitterness. The sensory test of volunteers was used to determine the bitter-masking effect of mPEG-PLLA on the decoction of Coptidis Rhizoma and its main bitter alkaloids. The molecular docking and molecular force field were applied to locate the bitter groups and the bitter-masking parts. The relationship between the bitter strength and the structure was analyzed by the surface electrostatic potential of the bitter alkaloids, and the correlation between the bitter-masking effect and the structural parameters of the bitter components was explored by factor analysis, so as to clarify the structure-activity relationship of mPEG-PLLA in masking the bitterness of coptis alkaloids. It was found that mPEG-PLLA had significant taste masking effect on the decoction of Coptidis Rhizoma and five alkaloids. The masking effect was obviously related to the structure of different alkaloids: the effect increased with the increase of the number of hydrogen donors, rotatable bonds, molecular weight, and hydrophobicity, and decreased with the increase of surface electrostatic potential, electrophilicity and binding energy with bitter receptors. In this study, the influence of alkaloid structure of Coptidis Rhizoma on the butter-masking effect of mPEG-PLLA was preliminarily elucidated, providing a scientific basis for better exerting the bitter-masking effect of amphiphilic block copolymers.
Subject(s)
Humans , Alkaloids , Coptis , Drugs, Chinese Herbal , Molecular Docking Simulation , Structure-Activity Relationship , TasteABSTRACT
RESUMOA tomografia computadorizada quantitativa periférica de alta resolução (HR-pQCT) é uma nova tecnologia disponível comercialmente há menos de 10 anos que permite a feitura de exames in vivo para a avaliação de parâmetros ósseos. A HR-pQCT avalia a forma, o número, o volume, a densidade, a conectividade e a separação das trabéculas; a densidade e a espessura do osso cortical e o volume e a densidade total, em alta definição, o que permite a construção digital da microarquitetura óssea adicionalmente. A aplicação de cálculos matemáticos aos dados capturados, método denominado elemento finito (FE), permite a estimativa das propriedades físicas do tecido e simula cargas suportadas de forma não invasiva. Desse modo, a HR-pQCT adquire simultaneamente dados antes fornecidos separadamente pela densitometria óssea, pela ressonância magnética e pela histomorfometria e agrega estimativas biomecânicas antes só possíveis em tecidos extraídos. A reprodutibilidade do método é satisfatória, com coeficientes de variação que raramente ultrapassam os 3%. Quanto à acurácia, os parâmetros apresentam de regular a boa concordância (r2= 0,37-0,97).A principal aplicação clínica é na quantificação e no monitoramento das doenças osteometabólicas, porque avalia de modo mais completo a resistência óssea e o risco de fratura. Na artrite reumatoide permite-se a aferição do número e do tamanho das erosões e dos cistos, além do espaço articular. Na osteoartrite é possível caracterizar as áreas edema-símile que guardam correlação com a degradação da cartilagem.Restritas ainda a um instrumento de pesquisa, dado o seu elevado custo, a alta resolução e a eficiência mostram-se como vantagens em relação aos métodos atualmente usados para a avaliação óssea, com um potencial para tornar-se uma importante ferramenta na prática clínica.
ABSTRACTHigh resolution peripheral quantitative computed tomography (HR-pQCT) is a new technology commercially available for less than 10 years that allows performing in vivo assessment of bone parameters. HR-pQCT assesses the trabecular thickness, trabecular separation, trabecular number and connectivity density and, in addition, cortical bone density and thickness and total bone volume and density in high-definition mode, which additionally allows obtaining digital constructs of bone microarchitecture. The application of mathematics to captured data, a method called finite element analysis (FEA), allows the estimation of the physical properties of the tissue, simulating supported loads in a non-invasive way. Thus, HR-pQCT simultaneously acquires data previously provided separately by dual energy x-ray absorptiometry (DXA), magnetic resonance imaging and histomorphometry, aggregating biomechanical estimates previously only possible in extracted tissues. This method has a satisfactory reproducibility, with coefficients of variation rarely exceeding 3%. Regarding accuracy, the method shows a fair to good agreement (r2 = 0.37-0.97).The main clinical application of this method is in the quantification and monitoring of metabolic bone disorders, more fully evaluating bone strength and fracture risk. In rheumatoid arthritis patients, this allows gauging the number and size of erosions and cysts, in addition to joint space. In osteoarthritis, it is possible to characterize the bone marrow edema-like areas that show a correlation with cartilage breakdown.Given its high cost, HR-pQCT is still a research tool, but the high resolution and efficiency of this method reveal advantages over the methods currently used for bone assessment, with a potential to become an important tool in clinical practice.
Subject(s)
Humans , Bone and Bones/anatomy & histology , Bone and Bones/diagnostic imaging , Tomography, X-Ray Computed , Biomechanical Phenomena , Finite Element Analysis , Tomography, X-Ray Computed/methodsABSTRACT
Objective To explore the relationship between skin photo reactions and structural pa-rameters. Methods Benzophenone-1, Benzophenone-2 and Benzophenone-3 were assessed by phototoxici-ty test and photoallergic test on guinea pig. And the phototoxicity index and photoallergic index were cal-culated after clinical assessment. Structural parameters of the three sunscreens like total energy, binding energy, electronic energy, heat of formation, dipole and sum of the net charges were also calculated by the soft of HyperChem7.0, respectively. Results The phototoxicity index rised with total energy, elec-tronic energy and sum of net charges increasing. And the photoallergy index rised only with binding ener-gy increasing. So there was some correlation between phototoxicity index and total energy, electronic en-ergy and sum of net charges (P<0.01). Significant relationship was only between the photoallergy index and binding energy (P<0.01). Conclusions The phototoxicity is correlated with total energy and e-lectronic energy, while photoallergy is related to binding energy. It is possible to establish a model evalua-ting the safety and structural parameters of benzophenone ramifications.
ABSTRACT
In response to problems from the development of multi-drug-resistant pathogenic bacteria,it is urgent to find new antimicrobials.Antimicrobial peptides(AMPs) are a kind of ideal new antimicrobials with the advantages including their potential for broad-spectrum activity,rapid bactericidal activity and low propensity for resistance development,and have a bright future.Alpha-helical antimicrobial peptides are a main kind of AMPs.The following features was reviewed and elucidated including the structure and activity relationship(SAR) from different aspects including the degree of helicity,hydrophobic moment,hydrophobicity,net positive charges and so on,and the application of SAR on the molecular design and improvement of AMPs.