All issues
Predecessor
Volume 132, Issue 1
Displaying 1-20 of 20 articles from this issue
- |<
- <
- 1
- >
- >|
Symposium Reviews
-
Hajime MizukamiArticle type: Foreword
2012 Volume 132 Issue 1 Pages 1
Published: January 01, 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSDownload PDF (150K) -
Seigo IwakawaArticle type: Review
2012 Volume 132 Issue 1 Pages 3-5
Published: January 01, 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSCooperation in education and research in medical and pharmaceutical sciences between Kobe Pharmaceutical University and Kobe University was started in 2008 for training professionals in drug development and rational pharmacotherapy. Initially, we started a two-year pharmacy residency program. Our pharmacy residents can attend lectures at our universities, and they also help pharmacist preceptors educate undergraduate pharmacy students in practical training. As curricula for cooperative education of pharmacy, nursing and medical students, we developed two new elective subjects (early exposure to clinical training for first year students and IPW (inter-professional work) seminar for fifth year pharmacy students) to learn about the roles of health care professionals in a medical team. Cooperative research between faculty members and graduate students is also in progress. For faculty and staff developments, invited lectures by clinical pharmacy and medical professors from the United States on the clinical education system in pharmacy and medicine in the United States have been held. This systematic cooperation will contribute to the promotion of a new curriculum for inter-professional education in the health-science fields.
View full abstractDownload PDF (285K) -
Sachiko NagamineArticle type: Review
2012 Volume 132 Issue 1 Pages 7-9
Published: January 01, 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSIn Kobe Pharmaceutical University, postgraduate continuing professional development (CPD) has been held every year since 1975. Kobe Pharmaceutical University Extension Center was established in June 2007. Kobe Pharmaceutical Extension Center is accredited as a credentialing body (G07) by the Council on Pharmacist Credentials. The extension project of Kobe Pharmaceutical University works together with the alumni association to provide ongoing opportunities for increasing pharmacist competence and professionalism. The extension program is continuing to develop expanded links with pharmacy education.
View full abstractDownload PDF (334K) -
Mugen Teshima, Mikiro Nakashima, Susumi HatakeyamaArticle type: Review
2012 Volume 132 Issue 1 Pages 11-15
Published: January 01, 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSThe Nagasaki University School of Pharmaceutical Sciences has conducted a project concerning “development of an advanced education program for community medicine” for its students in collaboration with the University's School of Nursing Sciences, the University of Nagasaki School of Nursing Sciences, and the Nagasaki International University School of Pharmaceutical Sciences. The project was named “formation of a strategic base for the integrated education of pharmacy and nursing science specially focused on home-healthcare and welfare”, that has been adopted at “Strategic University Cooperative Support Program for Improving Graduate” by the Ministry of Education, Culture, Sports, Science and Technology, Japan from the 2009 academic year to the 2011 academic year. Our project is a novel education program about team medical care in collaboration with pharmacist and nurse. In order to perform this program smoothly, we established “Nagasaki pharmacy and nursing science union consortium (Nagasaki University, The University of Nagasaki, Nagasaki International University, Nagasaki Pharmaceutical Association, Nagasaki Society of Hospital Pharmacists, Nagasaki Nursing Association, Nagasaki Medical Association, Nagasaki Prefectural Government)”. In this symposium, we introduce contents about university education program and life learning program of the project.
View full abstractDownload PDF (581K) -
Kenji HazamaArticle type: Review
2012 Volume 132 Issue 1 Pages 17-20
Published: January 01, 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSIn Japan, the proportion of elderly people had reached up to 23% in 2009. The number of elderly people in long-term nursing homes or nursing facilities will increase in the next decade. By 2025, the majority of the elderly people would have developed cancer, stroke, cardio-vascular diseases, and dementia. Almost all of them would be treated with prescribed drugs. They would also have dysphagia and have difficulties in remembering their medications in the long term. Therefore, for the benefit of such a community, the work force, especially in the field of drug distribution, will need to be increased to prevent the incidence of patients who forget to take their medications. Further, the educational curriculum for pharmaceutical students has been changed to a new version, and some Japanese pharmacy shops have been switching over to “Pharmacy 3.0,” which is the next generation model. In this pharmacy, the pharmacists will play an additional new role; they will not only dispense drugs but also support home recuperation leveraging some vital signs and physical assessments. In my opinion, this novel scheme of medical service developed with pharmacists playing this new role may be a boon to the patient/elderly community in Japan who are facing the collapse of healthcare systems. In conclusion, Collaborative Drug Therapy Management (CDTM) in the practice of the pharmacists is essential for increasing the efficiency of the Japanese healthcare systems.
View full abstractDownload PDF (263K) -
Hideki Ono, Yukihisa KuronoArticle type: Review
2012 Volume 132 Issue 1 Pages 21-29
Published: January 01, 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSEleven universities which have pharmacy, medical or nursing school, have cooperated in an attempt to build the human and material systems for 6-year pharmacy education and to apply them to practical pharmacy educations. Members are Nagoya City University, Gifu Pharmaceutical University, University of Shizuoka, Aichi Gakuin University, Kinjo Gakuin University, Meijo University, Suzuka University of Medical Science, Hamamatsu University School of Medicine, Mie University, Aichi Medical University and Fujita Health University. Tokai Cooperation Center for Clinical Pharmacy Education, the steering committee and 5 subcommittees established following projects; 1) WEB-based system for supplementary lesson of natural science (for freshmen), 2) FD (Faculty Development) activity (for teachers), 3) WEB-based data-base system of disease case for PBL (Problem-based Learning) and methods for practice of physical assessment (for 4th grade students), 4) WEB-based system for practical pharmacy training (for 5th grade students), 5) Matching and WEB system for graduation practice at university hospital (for 6th grade students).
View full abstractDownload PDF (725K) -
Kunihiko ItohArticle type: Review
2012 Volume 132 Issue 1 Pages 31-34
Published: January 01, 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSClinical case discussions based on the problem-based learning are one of the indispensable practices in the course of 6-year pharmacy education program. To perform the effective learning in clinical case discussions, it is important to prepare the cases in which quality and quantity are sufficient for practical use. Under the support of University Cooperation Program from Ministry of Education, Culture, Sports, Science and Technology, we tried to prepare educational cases from the cases of real patients, and to construct the database system for inter-university utilization of educational cases. In this review, I describe the achievements in our three-year activities.
View full abstractDownload PDF (472K) -
Recent Advance in Research of New Anti-Infectious Agents—Discovery Chemical Biology and Development—Hiroshi Tomoda, Kazuhisa SekimizuArticle type: Foreword
2012 Volume 132 Issue 1 Pages 35-36
Published: 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSDownload PDF (246K) -
Hiroshi TomodaArticle type: Review
2012 Volume 132 Issue 1 Pages 37-44
Published: 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSMethicillin-resistant Staphylococcus aureus (MRSA) is known as a major nosocomial pathogen that has also developed resistance to many antibiotics. Moreover, MRSA resistance to a last-resort antibiotic, vancomycin, has been reported. Therefore, new anti-infectious agents to prevent and treat MRSA infection are needed. Based on this background, our group has focused on the discovery of new microbial agents active against MRSA infection. Viridicatumtoxin and spirohexaline, produced by Penicillium sp. FKI-3368, were isolated as inhibitors of undecaprenyl pyrophosphate (UPP) synthase of Staphylococcus aureus, which was involved in cell wall synthesis. Viridicatumtoxin and spirohexaline with a pentacyclic spiro skeleton inhibited UPP synthase activity with an IC50 value of 4.0 and 9.0 μM, respectively. Actually, the growth of gram-positive bacteria including MRSA was strongly inhibited by the compounds. Our computational modeling experiments indicated that spirohexaline A was inserted into the substrate pocket of UPP synthase and interacted with Glu88 via a carbamoyl group of the compound, with Ala76, Met54 and Asn35 via three hydroxyl groups, and with certain hydrophobic amino acids via a spiro ring. Cyslabdan, produced by Streptomyces sp. K04-0144, was isolated as a potentiator of β-lactam imipenem activity against MRSA. The compound consisted of a labdan skeleton and an N-acetylcysteine. Cyslabdan potentiated imipenem activity by over 1000 fold, drastically reducing the MIC value of imipenem against MRSA from 16 to 0.03 μg/mL. The binding proteins of cyslabdan were investigated in the lysate of MRSA to identify FemA, which was involved in the formation of the pentaglycine interpeptide bridge in MRSA peptidoglycan.
View full abstractDownload PDF (730K) -
Kunihiko NishinoArticle type: Review
2012 Volume 132 Issue 1 Pages 45-50
Published: January 01, 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSSince the discovery of antibiotics, the battle between humans and drug resistant bacteria has never stopped. Bacteria have developed various ways to resist the toxic effects of antibiotics and other drugs. Multidrug efflux pumps are integral membrane proteins that utilize cellular energy to extrude antibiotics or biocides actively out of the cell. In this symposium, I first introduce the post-genomic approach to analyze all putative drug efflux genes. Next, I discuss the regulation of drug efflux pumps responding to environmental signals. I also introduce the physiological roles of drug efflux pumps in virulence, which is an ongoing research area. Multidrug efflux pumps have greater clinical relevance than has previously been thought, because there is now accumulating evidence that certain classes of efflux pumps not only confer resistance to drugs used in therapy but also have a role in bacterial pathogenicity.
View full abstractDownload PDF (797K) -
Ryutaro Utsumi, Masayuki IgarashiArticle type: Review
2012 Volume 132 Issue 1 Pages 51-58
Published: January 01, 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSGene clusters contributing to processes such as cell growth and pathogenicity are often controlled by two-component signal transduction systems (TCSs). TCS consists of a histidine kinase (HK) and a response regulator (RR). TCSs are attractive as drug targets for antimicrobials because many HK and RR genes are coded on the bacterial genome though few are found in lower eukaryotes. The HK/RR signal transduction system is distinct from serine/threonine and tyrosine phosphorylation in higher eukaryotes. Specific inhibitors against TCS systems work differently from conventional antibiotics, and developing them into new drugs that are effective against various drug-resistant bacteria may be possible. Furthermore, inhibitors of TCSs that control virulence factors may reduce virulence without killing the pathogenic bacteria. Previous TCS inhibitors targeting the kinase domain of the histidine kinase sensor suffered from poor selectivity. Recent TCS inhibitors, however, target the sensory domains of the sensors blocking the quorum sensing system, or target the essential response regulator. These new targets are introduced, together with several specific TCSs that have the potential to serve as effective drug targets.
View full abstractDownload PDF (634K) -
Hideki HashizumeArticle type: Review
2012 Volume 132 Issue 1 Pages 59-67
Published: 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSThe widespread emergence of multidrug-resistant Gram-positive pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) is a high threat for human health. In the course of screening for active compounds against the above drug-resistant bacteria from microbial metabolites, we discovered three kinds of novel compounds designated tripropeptins, pargamicin, and amycolamicin. Tripropeptin C (TPPC), major component of tripropeptins, is the most promising compound because it is efficacious against MRSA and VRE both in vitro and in a mouse septicemia model, and shows no cross-resistance to available drugs including vancomycin. Studies of incorporation of radioactive macromolecular precursors and accumulation of UDP-MurNAc-pentapeptide in the cytoplasm in S. aureus Smith revealed that TPPC is a cell wall synthesis inhibitor. Antimicrobial activity of TPPC was weakened by addition of prenylpyrophosphates but not with prenylphosphates, UDP-linked sugars, or the pentapeptide of peptidoglycan. Direct interaction between TPPC and undecaprenyl pyrophosphate (C55-PP) was observed by mass spectrometry and thin layer chromatography, and TPPC inhibits C55-PP phosphatase, which plays a crucial role in peptidoglycan synthesis at an IC50 of 0.03-0.1 μM in vitro. From the analysis of accumulation of lipid carrier-related compounds, TPPC caused accumulation of C55-PP in situ, leading to the accumulation of a glycine-added lipid intermediate, suggesting a distinct mode of action from that of clinically important drugs such as vancomycin, daptomycin, and bacitracin. TPPC might represent a promising novel class of antibiotic against MRSA and VRE infections.
View full abstractDownload PDF (799K) -
Hirokazu TamamuraArticle type: Review
2012 Volume 132 Issue 1 Pages 69-78
Published: January 01, 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSRecently, highly active anti-retroviral therapy (HAART), which involves a combinational use of reverse transcriptase inhibitors and HIV protease inhibitors, has brought us a great success in the clinical treatment of AIDS patients. However, HAART has several serious clinical problems. These drawbacks encouraged us to find novel drugs and increase repertoires of anti-HIV agents with various action mechanisms. The recent disclosing of the dynamic supramolecular mechanism in HIV-entry has provided potentials to find a new type of drugs. To date, we have synthesized HIV-entry inhibitors, especially coreceptor CXCR4 antagonists. In addition, CD4 mimics in consideration of synergic effects with other entry inhibitors or neutralizing antibodies have been developed. The development of the above anti-HIV agents is based on the concept of reverse chemical genomics, in which target molecules are fixed. On the other hand, based on the concept of forward chemical genomics, in which active compounds are searched according to the screening of random libraries, effective peptide leads such as integrase inhibitors derived from fragment peptides of HIV-1 Vpr have been discovered. As such, from a point of view on chemical biology, anti-HIV leads have been found utilizing reverse and forward chemical genomics. Furthermore, antibody-based therapy or AIDS vaccine is still thought to be a promising treatment. Thus, peptidic antigen molecules based on artificial remodeling of the dynamic structures of a surface protein gp41 in HIV fusion have been developed. The present chemical biology approaches would be essential for discovery of anti-HIV agents in consideration of cocktail therapy of AIDS.
View full abstractDownload PDF (843K) -
Hiroshi Hamamoto, Makoto Urai, Atmika Paudel, Ryo Horie, Kazuhisa Mura ...Article type: Review
2012 Volume 132 Issue 1 Pages 79-84
Published: January 01, 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSMost antibiotics obtained by in vitro screening with antibacterial activity have inappropriate properties as medicines due to their toxicity and pharmacodynamics in animal bodies. Thus, evaluation of the therapeutic effects of these samples using animal models is essential in the crude stage. Mammals are not suitable for therapeutic evaluation of a large number of samples due to high costs and ethical issues. We propose the use of silkworms (Bombyx mori) as model animals for screening therapeutically effective antibiotics. Silkworms are infected by various pathogenic bacteria and are effectively treated with similar ED50 values of clinically used antibiotics. Furthermore, the drug metabolism pathways, such as cytochrome P450 and conjugation systems, are similar between silkworms and mammals. Silkworms have many advantages compared with other infection models, such as their 1) low cost, 2) few associated ethical problems, 3) adequate body size for easily handling, and 4) easier separation of organs and hemolymph. These features of the silkworm allow for efficient screening of therapeutically effective antibiotics. In this review, we discuss the advantages of the silkworm model in the early stages of drug development and the screening results of some antibiotics using the silkworm infection model.
View full abstractDownload PDF (555K)
Reviews
-
Kaneto UekamaArticle type: Review
2012 Volume 132 Issue 1 Pages 85-105
Published: January 01, 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSThe α-, β-, and γ-CyDs are the most common natural CyDs, consisting of six, seven, and eight glucose units, respectively. Among the natural CyDs, bioadaptable γ-cyclodextrin (γ-CyD) is useful to improve the undesired properties of drug molecules through the formation of inclusion complex. Recently, various kinds of CyD derivatives such as hydrophilic, hydrophobic, amphiphatic and anionic CyDs have been developed, anticipating the design of CyD-based drug delivery system. The objective of this contribution is to outline our recent findings on the combinational use of γ-CyD and functional ingredients, focusing on the ability to increase the drug absorption, the ability to control the rate and time profiles of drug release, and the ability to deliver a drug to a targeted site. In addition, the multi-functional characteristic of hydroxyalkylated CyDs, in particular, 2-hydroxypropyl-β-CyD (HP-β-CyD) is applicable to design the novel pharmaceutical formulation, focusing on the ability to form hydrophilic nano-particles. Moreover, some amphiphatic CyDs such as 2,6-di-O-methyl-β-CyD (DM-β-CyD) and 2-hydroxybutyl-β-CyD (HB-β-CyD) are useful to control the crystallization and polymorphic transition of solid drugs and will provide an opportunity to isolate labile intermediate metastable polymorphs. On the basis of above-mentioned knowledge, this review explores the use of CyDs to better understand their pharmaceutical applications as well as their limitations in the approach of CyD-based drug delivery system.
View full abstractDownload PDF (1483K) -
Miki NakajimaArticle type: Review
2012 Volume 132 Issue 1 Pages 107-116
Published: January 01, 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSMicroRNAs (miRNAs) are endogenous ∼22-nucleotide non-coding RNAs that regulate gene expression through the translational repression or degradation of target mRNAs. The human genome contains over 1400 miRNAs and over 60% of human mRNAs are predicted to be targets of miRNAs. The miRNAs have roles in fine-tuning the expression of their target genes forming intricate networks. Research on miRNA is growing exponentially, and it is now clear that miRNAs can potentially regulate every aspect of cellular processes such as differentiation, proliferation and apoptosis as well as a large range of physiological processes such as development, immune response, metabolism, tumor formation, and disease development. The roles of miRNAs in the metabolism of xenobiotics and endobiotics have only recently been revealed. This review describes the current knowledge on the regulation of cytochrome P450s and transcriptional factors by miRNAs, and its physiological and clinical significance, which were disclosed in our studies. The miRNA expression is readily altered by chemicals, carcinogens, drugs, hormones, stress, or diseases, and the dysregulation of specific miRNAs might lead to changes in the drug metabolism potency or pharmacokinetics as well as pathophysiological changes. Utilizing miRNAs opens a new era in the fields of drug metabolism and pharmacokinetics as well as toxicology.
View full abstractDownload PDF (1230K) -
Go HiraiArticle type: Review
2012 Volume 132 Issue 1 Pages 117-124
Published: January 01, 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSEnzyme inhibitors have been utilized as useful tools for elucidating the function and structure of specific enzymes and for cell biology studies. Recently, chemical screening from natural sources and compound libraries has led to the rapid discovery of enzyme inhibitors. To create more useful inhibitors with high enzyme selectivity, and molecular probes for analyzing the precise mode of actions for enzymes, synthetic approaches based on natural products and bio-molecules are considered to have an important role in medicinal chemistry and chemical biology. In this review, the “focused library approach” for the development of inhibitors and modulators for enzymes related to protein phosphorylations and de-phosphorylations was introduced. As protein kinase C modulators, we constructed a focused library with the conformationally-constrained 1,2-diacylglycerol (DAG) motif as the core structure. Among the synthesized compounds, we found some characteristic molecules with different binding affinity to the C1 domain and activation ability for PKCα. As inhibitors for the dual-specificity protein phosphatase VHR, the neutral phosphate-mimicking core structure was designed based on natural product RK-682. Among the derivatives of the constructed focused library, including the neutral core structure stated above, we found the selective inhibitor for VHR, which showed cell cycle arresting activity for NIH3T3 cells and inhibitory activity for the de-phosphorylation of ERK and JNK.
View full abstractDownload PDF (842K)
Regular Articles
-
Naoki Kuroda, Satoshi Ueshima, Tomoaki Sato, Eriko Kobiki, Yoichi Kawa ...Article type: Regular Article
2012 Volume 132 Issue 1 Pages 125-133
Published: January 01, 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSTo clarify whether the new Japanese glomerular filtration rate (eGFR) equation was able to accurately determine the initial and individualized dosage adjustment concentrations of vancomycin (VCM), the predictive performance for VCM concentrations using the eGFR and Cockcroft-Gault (CG) equations was compared. Data were retrospectively collected from clinical records of 90 patients with MRSA infection whose trough and peak VCM concentrations had been determined. The predicted VCM initial and individualized dosage adjustment concentrations were performed with the 2-compartment linear model using pharmacokinetic parameter means and their individual values via Bayesian estimation, respectively. The prediction error (PE) and its absolute value (APE) between the observed and predicted VCM concentrations were calculated as indices of bias and accuracy in predictive performance, respectively. In the initial dosage adjustment of VCM, the PE value, calculated with the eGFR equation in trough and peak VCM concentrations of patients whose BMI were 18.5 kg/m2 and higher, was significantly smaller than that calculated with the CG equation. In particular, both PE and APE values obtained from the eGFR calculated concentrations from nonelderly patients (younger than 65 years old) were significantly improved compared with those from the CG equation. In the individualized dosage adjustment of VCM, the eGFR equation gave a significantly smaller PE value in nonelderly patients' trough concentrations than the CG equation. These findings provide useful information for adjusting the VCM dosage to achieve optimal therapeutic efficacy in patients with MRSA infection.
View full abstractDownload PDF (490K) -
Keisuke Awa, Hiroki Satoh, Satoko Hori, Yasufumi SawadaArticle type: Regular Article
2012 Volume 132 Issue 1 Pages 135-144
Published: January 01, 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSTopical dermatological formulations of non-steroidal anti-inflammatory drugs (NSAIDs) are reported to show their pharmacological effect partially through the systemic circulation, and to induce systemic side effects. However, pharmaceutical equivalence and pharmacokinetic bioequivalence between brand-name and generic products are not required. Therefore, we aimed to predict systemic drug exposure from brand-name and nine generic ketoprofen tapes. In vitro release profiles were examined using the paddle-over-disk method, then analyzed by the W. I. Higuchi equation incorporating an initial burst effect. Pharmacokinetic parameters were estimated from observed release profiles and the reported time-plasma concentration profile of the brand-name product. Plasma concentration profiles of generic products were predicted from the observed release profiles and the pharmacokinetic parameters of the brand-name product. In vitro release profiles differed markedly, and estimated release rates for initial burst effect and at 24 hours ranged from 4.20 to 88.75% and from 45.27 to 95.83%, respectively. The predicted plasma concentration profile of each product reflected its release profile, and estimated Cmax ranged from 61.70 to 290.30 ng/mL (0.46- to 2.15-fold vs. brand-name product). Generic products were classified into three types, i.e., systemic exposure comparable with, higher than and lower than that of brand-name product. Cmax was predicted to increase with enhanced skin permeability for all products, but the increase rates differed among products. These results suggest that safety and efficacy differ between brand-name and generic ketoprofen tapes. Healthcare professionals should carefully monitor systemic side effects, especially when switching from brand-name to generic products for which higher systemic exposure is predicted.
View full abstractDownload PDF (950K)
Note
-
Hirohito Ikeda, Hanae Moriwaki, Tomonori Matsubara, Miho Yukawa, Yukik ...Article type: Note
2012 Volume 132 Issue 1 Pages 145-153
Published: January 01, 2012
Released on J-STAGE: January 01, 2012
JOURNAL FREE ACCESSThe influence of the presence of a galloyl group in catechin on complexation with risperidone (RISP) was examined using (−)-epigallocatechin gallate (EGCg) and (−)-epigallocatechin (EGC), which are present in green tea as tea catechins. By quantitative analysis using HPLC, it was found that EGCg formed an insoluble complex with RISP for concentration dependence, whereas EGC did not. The large contribution of the galloyl group of catechin to form an insoluble complex with RISP was recognized in this study. In a molecular modeling study, it was found that the EGCg-R complex (EGCg with RISP) formed three hydrogen bonds between the hydroxyl groups of EGCg and the two N atoms and an O atom of RISP. The hydrogen bond between the hydroxyl group of the galloyl ring in EGCg and the N atom of the piperidine ring in RISP stabilized EGCg-R more energetically. The EGC-R complex (EGC with RISP) also formed three hydrogen bonds, but the N atom of the piperidine ring in RISP did not participate in hydrogen bond formation. According to the calculation using the COSMO-RS method, the water solubility of the EGCg-R complex was 1/26 that of the EGC-R complex. Therefore, the EGCg-R complex was difficult to dissolve in water. In the 1H-NMR spectra of RISP in DMSO-d6, although chemical shifts of protons near the N atom on the piperidine ring moved downfield on the addition of EGCg, no change in chemical shifts of these protons was observed on the addition of EGC. Therefore, based on these results, the galloyl group of EGCg contributes to the formation of an insoluble complex between tea catechin and RISP, and this insoluble complex is stabilized by the hydrogen bond between the hydroxyl group of the galloyl ring in EGCg and the N atom of the piperidine ring in RISP.
View full abstractDownload PDF (761K)
- |<
- <
- 1
- >
- >|