Chemical and Pharmaceutical Bulletin
Online ISSN : 1347-5223
Print ISSN : 0009-2363
ISSN-L : 0009-2363
Featured articles
Displaying 161-160 of 255 articles
  • Volume 67 (2019) Issue 6 Pages 580-586
    T2 Relaxation Study to Evaluate the Crystalline State of Indomethacin Containing Solid Dispersions Using Time-Domain NMR Read more
    Editor's pick

    The aim of this study was to demonstrate the usefulness of T2 measurements conducted with a time-domain NMR (TD-NMR) for the characterization of active pharmaceutical ingredients (APIs) containing solid dosage forms. In the course of the experiments, the authors found that T2 measurements could detect the difference between the amorphous and crystalline API; furthermore, it was effective in monitoring the transformation from amorphous to crystalline during a thermal stress test. From these findings, the authors concluded that T2 measurement by TD-NMR is a promising analysis for the characterization of APIs in solid dosage forms, including SD-based pharmaceuticals.

  • Volume 67 (2019) Issue 6 Pages 587-593
    Direct Formylation of Fluorine-Containing Aromatics with Dichloromethyl Alkyl Ethers Read more
    Editor's pick

    Although fluorine-containing aryl formates have currently flourished as pharmaceutical and agrochemical intermediates, there is limited number of bearable methods in a large scale synthesis. In this article, the authors developed new operationally secure preparation method for dichloromethyl alkyl ethers having long carbon chains, and direct formylation of fluorine-containing aromatics with those reagents, which are applicable in a large scale synthesis. The authors also showed a number of examples for O-formylation of fluorine-containing and non-fluorine-containing aromatics with those reagents and the mechanistic aspect was discussed. The present method is simple and straightforward for laboratory and industrial use.

  • Volume 67 (2019) Issue 6 Pages 594-598
    Total Synthesis of 3-epi-Juruenolide C Read more
    Editor's pick

    This paper describes that the first total synthesis of 3-epi-Juruenolide C. The γ-lactone natural product, which was isolated from roots of Virola surinamensis, exhibits moderate antifungal activity against Cladosporium cladosporioides. The synthesis features a highly selective cross metathesis and the subsequent one-pot regioselective bromination, an intramolecular carbonylation using bis(triphenylphosphine)dicarbonylnickel, and a face-selective hydrogenation using a homogeneous Wilkinson’s catalyst. The sequential synthetic procedures could be useful to complete the synthetic and biological studies of other related γ-lactone natural products.

  • Volume 67 (2019) Issue 5 Pages 397-403
    Nickel-Catalyzed Hydrocyanation of Allenes and Its Application Read more
    Editor's pick

    Regioselective cyanation of simple and non-activated carbon–carbon bonds catalyzed by nickel complexes is described. This protocol enables to use of the substituted allenes for regio- and stereocontrolled transformations and their applications for cyclization, 3-component coupling reaction, heterocycle formation as well as natural product synthesis are demonstrated. The author reveals the origin of the above selectivity by axial chirality transfer process using optically active allenes as substrates. Steric bulk of substituents is found to be a key factor for discrimination of allenyl carbon–carbon double bonds in hydrometallation step.

  • Volume 67 (2019) Issue 5 Pages 439-444
    Measurement of Linezolid and Its Metabolites PNU-142300 and PNU-142586 in Human Plasma Using Ultra-Performance Liquid Chromatography Method Read more
    Editor's pick

    This paper describes the development and validation of a method for measuring linezolid and its metabolites PNU-142300 and PNU-142586 in human plasma, using ultra-performance liquid chromatography (UPLC) method. This method enables the simultaneous measurement of these three components within 3 min. Further, plasma concentrations of linezolid, PNU-142300 and PNU-142586 in patients treated with linezolid could be measured. The developed method is a useful tool for therapeutic drug monitoring and clinical pharmacokinetic/pharmacodynamic (PK/PD) profiling of linezolid, as well as for dose optimization during treatment.

  • Volume 67 (2019) Issue 5 Pages 461-466
    Study on Control of pH-Modulation Crystallization Utilizing Concept of Dissociation Equilibrium Read more
    Editor's pick

    3-Alkenyl cephem compound is a pharmaceutical intermediate. It is typically crystalized by pH adjustment method. However, since the filtration time in the solid-liquid separator is a bottleneck in the production, there is a need to control crystal morphology while changing the pH. This study could be shorten filtration time by pH-modulation operation that repeating the crystallization operation in the vicinity of solubility. The obtained monodisperse particles were like a pseudo-growth body in which a large number of primary particles were aggregated and increased, rather than being a crystallite growth.

  • Volume 67 (2019) Issue 5 Pages 476-480
    The Revised Structure of the Cyclic Octapeptide Surugamide A Read more
    Editor's pick

    Surugamide A, a non-ribosomal peptide with cathepsin B inhibitory activity, and its closely related derivatives, surugamides B-E are cyclic octapeptides produced by several Streptomyces species. All these peptides except for surugamide B contain a D-Ile residue that involve Cβ-epimerization step during its biosynthesis. However, the genes responsible for this conversion is absent in the biosynthetic gene cluster of surugamides. To clarify this issue, surugamide A containing D-Ile as well as its epimer having D-allo-Ile were synthesized. HPLC and Marfey’s analyses showed that surugamide A actually possesses D-allo-Ile instead of D-Ile, requiring structural collection of this group of peptides.

  • Volume 67 (2019) Issue 4 Pages 367-371
    A Simple and Easy Method of Monitoring Doxorubicin Release from a Liposomal Drug Formulation in the Serum Using Fluorescence Spectroscopy Read more
    Editor's pick

    In order to maximize the effect of drugs, nanomedicines, drug-containing nanoparticles, have become popular in the field of medicine as they allow selective delivery of drugs to the disease target. It is important to understand the drug release form nanomedicine at the disease target. In this study, the authors developed a simple and easy method of monitoring drug release from nanomedicine using a fluorescence analysis, especially fluorescence fingerprint. The authors used DOXIL as a typical nanomedicine and found out that the release of the encapsulated drug, doxorubicin, is accelerated by albumin which is the most abundant protein in the blood.

  • Volume 67 (2019) Issue 4 Pages 289-298
    Cyclodextrin-Based Molecular Accessories for Drug Discovery and Drug Delivery Read more
    Editor's pick

    A person may choose to wear an accessory so as to enhance their appearance and give them confidence and thus a change of character. So what happens when accessories are decorated with drugs? The author has developed molecular accessories for drugs through supramolecular chemistry to create new medicines and pharmaceutical technologies. In this article, the author introduces cyclodextrin-based supramolecular accessories such as molecular necklace, molecular earring, and intelligent molecular necklace, and describes their application in pharmaceutical sciences. Moreover, the author proposes a new concept in pharmaceutical sciences termed as “supramolecular pharmaceutical sciences,” which combines pharmaceutical sciences and supramolecular chemistry.

  • Volume 67 (2019) Issue 3 Pages 271-276
    A Time-Domain NMR Study of the State of Water in Wet Granules with Different Fillers and Its Contribution to the Wet Granulation Process and to the Characteristics of Granules Read more
    Editor's pick

    Wet granulation is one of the fundamental unit operations for manufacturing pharmaceutical solid dosage forms including tablets. This study investigated in detail the states of water incorporated in wet granules composed of different fillers. The key instrument to evaluate the state of water was a low-field benchtop 1H-NMR time-domain NMR (TD-NMR). This study successfully concluded that the state of water significantly affected the wet granulation process and the characteristics of the resultant granules. The findings can offer valuable knowledge on wet granulation process from the viewpoint of molecular mobility of water.

  • Volume 67 (2019) Issue 3 Pages 258-264
    A Retrospective Analysis of the Effect of Tigecycline on Coagulation Function Read more
    Editor's pick

    A number of clinical trials demonstrated that tigecycline was effective and well tolerated in the treatment of patients with various bacterial infections, but few literatures had shown the coagulopathy induced by tigecycline. The retrospective analysis in this paper to assess the impact of tigecycline on coagulation parameters in 50 patients showed that the plasma fibrinogen (FIB) level decreased during treatment, which was statistically significant (P < 0.001). The mean values of activated partial thromboplastin time (aPTT) and prothrombin time (PT) were significantly increased, respectively. It is necessary for practitioners routinely monitor coagulation level in at-rick patient populations treated with tigecycline.

  • Volume 67 (2019) Issue 2 Pages 130-134
    Salicylic Acid as a Photosensitizer for Thymidine Dimerization Induced by UV Read more
    Editor's pick

     When a neutral solution of a nucleoside mixture was irradiated with UV light having wavelength longer than 300 nm, addition of salicylic acid to the solution greatly accelerated the reaction of thymidine. The UV light irradiation of thymidine solution in the presence of salicylic acid generated isomers of cyclobutane thymidine dimers almost exclusively. UV irradiation with the longer wavelength of 350 nm induced almost no reaction. The results indicate that salicylic acid is a photosensitizer for thymidine dimerization excited by UV light of wavelength 300 to 350 nm.

  • Volume 67 (2019) Issue 2 Pages 112-119
    Preparation of Cocoa Powder-Containing Orally Disintegrating Tablets of Rebamipide (Rebamipide Chocolet) and Evaluation of Their Clinical Palatability Read more
    Editor's pick

     “Chocolet” is an orally disintegrating tablet formulated with cocoa powder to mask the bitterness of drugs. The name “Chocolet” indicates that the formulation combines the good taste of chocolate with the ease of taking of an orally disintegrating tablet. Rebamipide chocolet has been prepared with excellent palatability properties, which could not be achieved using a sweetener alone, by using the combination of a sweetener and cocoa powder as an agent for masking bitterness. “Chocolet” can be used to provide patient-friendly tablets, thus helping to improve medication adherence.

  • Volume 67 (2019) Issue 1 Pages 64-70
    Synthetic Studies of Isoschizogamine: Alternative Preparation of the Key Intermediate Read more
    Editor's pick

    Isoschizogamine is a member of the schizozygane family of indole alkaloids. Its highly fused hexacyclic structure containing an aminal adjacent to a quaternary stereocenter makes it a challenging synthetic target. While the authors reported the total synthesis of (–)-isoschizogamine in 2012, this paper describes an alternative preparation of their pivotal synthetic intermediate. The synthesis features a stereoselective construction of a quaternary carbon by the Claisen-Johnson rearrangement and a stereoselective rhodium-mediated 1,4-addition of arylboronic acid. The reliability of this synthetic route enables a sufficient supply of the intermediate for the total synthesis of isoschizogamine.

  • Volume 67 (2019) Issue 1 Pages 59-63
    Assessment of Repeatability in Supercritical Fluid Chromatography with Electrochemical Detection Based on the ISO 11843 Part 7 Read more
    Editor's pick

    Assessment of repeatability in supercritical fluid chromatography with electrochemical detection (SFC-ECD) system is necessary to construct an SFC-ECD as a quantitative method with satisfactory precision.   This article is the first report that a method for the assessment of repeatability in SFC-ECD has been proposed by means of the ISO 11843 part 7 which can theoretically provide detection limits and standard deviation (SD) through the stochastic properties of baseline noise without repetitive measurements of real samples.   The present method is practically useful, and both experimental time and chemicals can be saved to estimate the repeatability in SFC-ECD.   

  • Volume 67 (2019) Issue 1 Pages 47-58
    Discovery of Novel 7-[(1R,5S)-1-Amino-5-fluoro-3-azabicyclo[3.3.0]octan-3-yl]-6-fluoro-1-[(1R,2S)-2-fluorocyclopropane]-8-(methoxy or methyl)quinolones Read more
    Editor's pick

    A series of 8-methoxy or 8-methylquinolones bearing novel 3-aminooctahydrocyclopenta[c]pyrrole derivatives at the C-7 position was synthesized, and the pharmacological, physicochemical, and toxicological properties of the individual compounds were evaluated. Novel 7-[(1R,5S)-1-amino-5-fluoro-3-azabicyclo[3.3.0]octan-3-yl]-6-fluoro-8-methylquinolone 7 exhibited potent and better activity than LVFX and MFLX against streptococci, staphylococci, enterococci, E. coli, A. baumannii, and anaerobes. Compound 7 also demonstrated favorable pharmacokinetic and pharmacodynamic properties and an acceptably safe toxicological profile. Consequently, compound 7 was selected as a clinical candidate for further evaluation as a new-generation, broad-spectrum quinolone antibiotic. Compound 7 is expected to become an option for antibacterial therapy against multidrug-resistant A. baumannii.

  • Volume 67 (2019) Issue 1 Pages 32-40
    Repurposing of Approved Cardiovascular Drugs against Ischemic Cerebrovascular Disease by Disease–Disease Associated Network-Assisted Prediction Read more
    Editor's pick

    Polygenetic and complex diseases are great burden and challenge of human, such as ischemic cerebrovascular disease (ICD) and cardiovascular diseases (CVD). Drug repositioning, is one important approach to reexamine the new indications of marketed drugs, especially drugs with multi-targets. Based on the interplay among diseases, genes (targets) and drugs, new method can be applied to dissect the association information. A multi-database, in silico target identification, gene function enrichment, and network pharmacology analysis integrated methods were proposed to investigate the approved CVD drugs repurposing for ICD. It provides promising alternative to inferring novel disease indications for existing safe and effective drugs.

  • Volume 67 (2019) Issue 1 Pages 1-17
    Development of New Synthetic Methods Using Oxiranyl Anions and Application in the Syntheses of Polycyclic Ether Marine Natural Products Read more
    Editor's pick

    Oxiranyl anions are very unstable and uncommon nucleophiles while epoxies are widely used as electrophiles in organic chemistry. A sulfonyl-stabilized oxiranyl anion reacts efficiently with a triflate to afford an alkylated product in high yield. The high synthetic potential of the oxiranyl anion chemistry was demonstrated by the total synthesis of gymnocin-A, a cytotoxic polycyclic ether marine natural product produced by the red tide organism Karenia mikimotoi.

  • Volume 66 (2018) Issue 12 Pages 1196-1198
    Facile Total Synthesis of (+)-Spinoxazine B Read more
    Editor's pick

    This paper describes a short total synthesis of (+)-spinoxazine B, which inhibits NO production in BV-2 microgrial cells. The synthesis features a double cyclization to rapidly construct the bicyclic skeleton of spinoxazine B. Spinoxazine B is the first example of a natural alkaloid containing an oxazinone-pyrrolidone nucleus. Because new ring system is considered to be a new resource for drug discovery, spinoxazine B is expected to serve as a novel drug lead compound as well as a drug discovery scaffold.

  • Volume 66 (2018) Issue 12 Pages 1174-1180
    Characterization of UV-Sensitive Marker Constituents of Polygala Root for TLC: Applications in Quality Control of Single Crude Drug Extract Preparations Read more
    Editor's pick

    A TLC-based simple and convenient method using UV-sensitive constituents as markers to identify the crude drug Polygala Root (the root of Polygala tenuifolia Willdenow; Japanese name “Onji”) was investigated. Twenty-three aromatic compounds including two new compounds, polygalaonjisides A and B, were characterized. Based on the phytochemical results obtained, a TLC method focusing on three marker spots with Rf values of approximately 0.4-0.5 due to tenuifolisides A and B and 3,6-di-O-sinapoylsucrose was proposed as a simple and convenient test to identify Polygala Root and its single-extract products on the market. The data presented in this paper could be useful in stipulating a confirmation test to identify Polygala Root.