In this study, the total synthesis of 3-epi-juruenolide C is achieved in 10 steps (longest linear sequence) starting from ethyl (2E,4S,5S)-4,5-dihydroxy-2-hexenoate. The synthetic highlights of our approach include one-pot regioselective bromination, intramolecular carbonylation using bis(triphenylphosphine)dicarbonylnickel, and face-selective hydrogenation using a homogeneous Wilkinson’s catalyst.

Cyano (CN) groups are equivalent to carbonyl as well as amino- and hydroxymethyl groups. Therefore, their catalytic introduction under metal catalysis is an important issue in synthetic organic chemistry. Ni-catalyzed hydrocyanation is one of the most well-investigated, powerful tools for installing a CN group. However, it is still difficult to control chemo- and regioselectivity. In this review, the author uses allenes to enable regio-, stereo-, and face-selective transformations to natural product synthesis and axial chirality transfer.

An ultra-performance liquid chromatography (UPLC) method was developed and validated for the quantification of linezolid, PNU-142300, and PNU-142586 in human plasma. After protein precipitation using acetonitrile, the protein-free supernatant was separated using reverse-phase chromatography using an ACQUITY UPLC HSS T3 column and monitored at 254 nm. p-Toluic acid was used as the internal standard. No interference peak was observed at the retention times of linezolid, PNU-142300, PNU-142586, and p-toluic acid from blank plasma. The calibration curve of linezolid was linear from 0.2 to 50.0 µg/mL (coefficient of determination (r²) > 0.9999) and those of PNU-142300 and PNU-142586 were linear from 0.2 to 20.0 µg/mL (r² > 0.9996 and > 0.9998, respectively). The intra- and inter-assay accuracy (%) and precision (relative standard deviation (RSD) %) of the three components were confirmed to meet the criteria of the U.S. Food and Drug Administration guidelines. Tests confirmed the stability of linezolid, PNU-142300, and PNU-142586 in plasma during three freeze-thaw cycles and long-term storage of frozen plasma for up to 30 d; in extracts they were stable in the UPLC autosampler for over 48 h at 4°C. Furthermore, plasma concentrations of linezolid, PNU-142300 and PNU-142586 in patients treated with linezolid could be measured using the UPLC method developed in this study. This assay would be a powerful tool for therapeutic drug monitoring and clinical pharmacokinetic/pharmacodynamic (PK/PD) analyses in the optimization of linezolid treatment.

Crystallization by pH adjustment, as a type of reaction crystallization, is a solid–liquid separation method widely used in the area of pharmaceutical and pharmaceutical intermediate manufacturing. On the other hand, 3-alkenyl cephem compound is a typical zwitterionic pharmaceutical intermediate that possesses both an amino group and a carboxylic acid group. Such structure affords three main pH regions in solution and results in difficulties using crystallization by pH adjustment for isolation. As a consequence, 3-alkenyl cephem compound is usually crystallized at the point away from the solubility curve, causing unrestricted nucleation and flocculation behavior for the deposited particles which is difficult to filtrate. In this study, the pK_a of 3-alkenyl cephem compound was intensively investigated to inhibit the nucleation. An optimal pH level point was also sought to make monodisperse particles. In particular, during crystallization by pH-modulation operation, the key point was identified to be the number of primary particles aggregated in the secondary particles. It was revealed that the increment number of primary particles led to the generation of larger monodisperse particles. This investigation, combined with solid–liquid equilibrium, enabled the acquisition of target species with good operability for filtration process. This present investigation becomes the prosperity in the zwitterion compound production that it has hardships to crystallize and filtrate.

Surugamides are a group of non-ribosomal peptides isolated from marine-derived Streptomyces. Surugamide A (1) and its closely related derivatives, surugamides B–E (2–5), are D-amino acid containing cyclic octapeptides with cathepsin B inhibitory activity. The D-isoleucine (Ile), the nonproteinogenic amino acid residue embedded in 1, is less common in natural peptides because a rare C_β-epimerization is required for its biosynthesis. Taking advantage of the synthetic route of 2 previously established by our group, we synthesized the cyclic octapeptide 1 containing D-Ile by solid phase peptide synthesis. The structure of 1 actually contains D-allo-Ile in place of D-Ile, which was corroborated by chemical syntheses and chromatographic comparisons.

Formulation of a drug as liposomes facilitates its delivery to the disease target. Rightly, liposomes are gaining popularity in the medical field. In order for the drug to show efficacy, release of the encapsulated drug from the liposome at the target site is required. However, the release is affected by the permeability of the lipid bilayer of the liposome, and it is important to examine the effect of the surrounding environment on the permeability. In this study, we showed the usefulness of fluorescence analysis, especially fluorescence fingerprint, for a rapid and simple monitoring of release of an encapsulated anticancer drug (doxorubicin) from its liposomal formulation (DOXIL). Our result indicated that the release is accelerated by the existence of membrane permeable ions, such as tris(hydroxymethyl)aminomethane, and blood proteins like albumin. Hence, monitoring of doxorubicin release by fluorescence analysis is useful for the efficacy evaluation of DOXIL in a biomimetic environment.

Recently, active pharmaceutical ingredients (APIs) have been dramatically expanding from low-molecular weight drugs to peptides, proteins, antibodies, genes, oligonucleotides, cells, and machines. Therefore to develop pharmaceutical technologies and drug delivery systems (DDS) for these APIs, advanced molecules and novel concepts are needed. In this review, we introduce cyclodextrin-based supramolecular accessories such as molecular necklace, molecular earring, and intelligent molecular necklace, and describe their application for pharmaceutical technology and DDS. In addition, we also introduce utility of supramolecular accessories as antitumor drugs. Finally, we propose a new concept in pharmaceutical sciences termed as “supramolecular pharmaceutical sciences,” which combines pharmaceutical sciences and supramolecular chemistry. This concept could be useful for developing new ideas, methods, hypotheses, strategies, materials, and mechanisms in pharmaceutical sciences.

The different states of water incorporated in wet granules were studied by a low-field benchtop ¹H-NMR time-domain NMR (TD-NMR) instrument. Wet granules consisting different fillers [cornstarch (CS), microcrystalline cellulose (MCC), and D-mannitol (MAN)] with different water contents were prepared using a high-speed granulator, and then their spin–spin relaxation time (T₂) was measured using the NMR relaxation technique. The experimental T₂ relaxation curves were analyzed by the two-component curve fitting, and then the individual T₂ relaxation behaviors of solid and water in wet granules were identified. According to the observed T₂ values, it was confirmed that the molecular mobility of water in CS and MCC granules was more restricted than that in the MAN granule. The state of water appeared to be associated with the drying efficiency and moisture absorption capacity of wet granules. Thus, it was confirmed that the state of water significantly affected the wet granulation process and the characteristics of the resultant granules. In the final phase of this study, the effects of binders on the molecular mobility of water in granulation fluids and wet granules were examined. The state of water in granulation fluids was substantially changed by changing the binders. The difference was still detected in wet granules prepared by addition of these fluids to the fillers. In conclusion, TD-NMR can offer valuable knowledge on wet granulation from the viewpoint of molecular mobility of water.

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. To address this concern, we performed a retrospective analysis to assess the impact of tigecycline treatment on coagulation parameters in 50 patients with bacterial infections in our hospital (Shandong Provincial Hospital, China). These patients were treated with tigecycline at Shandong Provincial Hospital in 2015–2016 at either a recommended (50 mg q12h) or a higher dose (100 mg q12h). Coagulation parameters, including Fibrinogen (FIB) levels, prothrombin time (PT), activated partial thromboplastin time (aPTT), platelet count (PLT) and D-dimer, were evaluated in order to assess the impact of tigecycline treatment in these severely infected patients. What we found was that the plasma fibrinogen (FIB) level was 4.63 ± 1.56 g/L before tigecycline treatment, and decreased to 2.92 ± 1.23 g/L during treatment, which was statistically significant (p < 0.001). The mean values of aPTT and PT were significantly increased from 39.58 ± 8.72 to 44.05 ± 10.45 s (p = 0.002), and from 15.37 ± 1.53 to 16.37 ± 2.64 s (p = 0.004), respectively. This study demonstrates that treatment of tigecycline could reduce FIB, prolong aPTT and PT. In conclusion, we advise that it is necessary for practitioners routinely monitor coagulation level in at-rick patient populations treated with tigecycline.

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 resulted in four major product peaks in HPLC. All the products were identified as isomers of cyclobutane thymidine dimers by MS and NMR. The cyclobutane thymidine dimers were generated from thymidine 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.

Orally disintegrating tablets (ODTs), which are administered without water, are beneficial for elderly patients and patients with dysphagia. Masking the unpleasant taste of a drug is an important factor associated with adherence of patients consuming ODTs. We prepared cocoa powder-containing ODTs of bitter-tasting rebamipide (rebamipide chocolet) and evaluated their clinical palatability. We prepared rebamipide ODTs by adding a sweetener and 0, 2.5, 5, and 10% cocoa powder (Ch0-ODTs, Ch2.5-ODTs, Ch5-ODTs, and Ch10-ODTs, respectively). Rebamipide ODTs without cocoa powder and sweetener were used as controls (Cont-ODTs). We performed a gustatory sensation test in 30 healthy adult volunteers. We used the 100-mm visual analog scale (VAS) to evaluate bitterness, sweetness, scent, and overall palatability of the ODTs. The acceptability of each ODT was evaluated on a 5-point scale. Compared to Cont-ODTs, Ch0-ODTs showed no significant improvement in the VAS score for bitterness, scent, and overall palatability during disintegration. However, compared to Cont-ODTs, Ch2.5-ODTs, Ch5-ODTs, and Ch10-ODTs showed an improvement in all items evaluated using the VAS. In particular, Ch2.5-ODTs showed a significant improvement compared to the Cont-ODTs in the VAS score of all items. Evaluation on a 5-point scale indicated that Ch2.5-ODTs and Ch10-ODTs had the highest acceptability. We prepared rebamipide chocolet with excellent palatability properties, which could not be achieved using a sweetener alone, by using the combination of a sweetener and cocoa powder as a new agent for masking bitterness. Our results indicate that cocoa powder may be used as a taste-masking agent in ODTs.

An alternative synthetic route toward a key intermediate in the total synthesis of isoschizogamine is described. The Claisen–Johnson rearrangement stereoselectively constructed a quaternary carbon. Trifluoroperacetic acid mediated the Baeyer–Villiger oxidation to form a bicyclic lactone. The Mukaiyama–Matsuo protocol converted the lactone into an α,β-unsaturated lactone, that was used as the substrate for the rhodium-mediated 1,4-addition of an arylboronic acid.

The present study proposes a method for the assessment of repeatability in supercritical fluid chromatography with electrochemical detection (SFC-ECD), based on the ISO 11843 part 7 (ISO 11843-7:2018) which can theoretically provide detection limits and standard deviation (S.D.) through the stochastic properties of baseline noise without repetitive measurements of real samples. On the baseline noise of SFC-ECD, large-amplitude and periodic noises with less than 0.05 Hz were observed, and the power spectrum of the baseline noise showed 1/f fluctuation (f = frequency). It was found that the present power spectrum analysis, according to the law of error propagation, can provide suitable noise parameters to calculate S.D. of baseline noise and a relative S.D. (RSD) of peak area by ISO 11843-7. The chromatographic determinations of α-, β-, γ- and δ-tocopherol have been taken as examples. In the present SFC-ECD, the RSDs of peak areas for α-, β-, γ- and δ-tocopherol obtained by ISO 11843-7 were within 95% confidence intervals of the RSD of them obtained by repetitive measurements (n = 6). Thus, we found that ISO 11843-7 is applicable to the assessment of repeatability in SFC-ECD for determining tocopherols without repetitive measurements.

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 8-methylquinolone 7, which includes a 3-amino-7-fluorooctahydrocyclopenta[c]pyrrole moiety at the C-7 position, showed potent antibacterial activity against both Gram-positive and negative pathogens. Compound 7 also demonstrated favorable pharmacokinetic and pharmacodynamic properties and an acceptably safe toxicological profile. Consequently, compound 7 was selected as a clinical candidate.

Stroke is one of the leading causes of death and disability globally, while intravenous thrombolysis with recombinant tissue plasminogen activator remains the only Food and Drug Administration (FDA)-approved therapy for ischemic stroke. The attempts to develop new treatments for acute ischemic stroke meet costly and spectacularly disappointing results, which requires both long time and high costs, whereas repurposing of safe existing drugs to new indications provides a cost-effective and not time-consuming alternative. Vascular protection is a promising strategy for improving stroke outcome, as vascular function is critical to both cardiovascular diseases (CVD) and ischemic cerebrovascular disease (ICD). Vascular function related biological processes and pathways maybe the critical associations between CVD and ICD. In this study, a multi-database, in silico target identification, gene function enrichment, and network pharmacology analysis integration approach was proposed and applied to investigate the FDA-approved CVD drugs repurposing for ICD. A list of 119 candidate drugs can be obtained for further investigation of their potential in ICD treatment. As a pleiotropic drug with multi-target, carvedilol was set an example to investigate its promising potential for ICD therapy. Our results indicated that the mode of action of carvedilol for ICD treatment may tightly associated with vascular function regulation and the mechanism is multi-target and multi-signaling pathway related. The disease–disease association network-assisted prediction needs further investigations. In summary, the proposed methods herein may provide a promising alternative to inferring novel disease indications for known drugs.

This review reports on the development of new synthetic methods using oxiranyl anions and their application to the synthesis of polycyclic ether marine natural products. Novel iterative and convergent methods for large, complex polycyclic ether structures have been devised. In these, the reactions of sulfonyl-stabilized oxiranyl anions were employed to construct trans-fused polyether ring systems, along with 6-endo cyclization and ring expansion reactions. Total syntheses of polycyclic ether marine toxins, viz. hemibrevetoxin B, gambierol, and gymnocin-A, were achieved based on the oxiranyl anion strategy developed.

Herein we describe a short total synthesis of (+)-spinoxazine B, which inhibits nitric oxide (NO) production in BV-2 microgrial cells. Spinoxazine B is the first example of a natural alkaloid containing an oxazinone-pyrrolidone nucleus, and it is expected to serve as a novel drug lead compound as well as a drug discovery scaffold.

Polygala Root (the root of Polygala tenuifolia WILLDENOW; Japanese name “Onji”), a well-known crude drug, traditionally used as an expectorant and sedative, has been attracting increased interest in recent years owing to its newly found pharmacological effect related to neuroprotection. However, there is no specific method for identifying and estimating the quality of this crude drug in the Japanese Pharmacopoeia, 17th edition. Therefore, in order to develop a TLC-based simple and convenient identification method using characteristic chemical marker(s) for the drug and its extract products, UV-sensitive constituents of Polygala Root were first investigated. A total of 23 aromatic compounds were isolated and characterized. Two new compounds, namely, polygalaonjisides A (1) and B (2), were characterized as syringic acid 4-O-(2′-O-β-D-apiosyl)-β-D-glucoside and 2-O-(β-D-glucosyl)-3′-O-benzoylsucrose, respectively. Based on these phytochemical results, a TLC method focusing on three marker spots with Rf value 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 or 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.

Fluorinated aromatic compounds are found in a variety of biologically active compounds, including clinical drugs and agrochemicals. Therefore, the synthesis of aryl fluorides is particularly important in the medicinal and process chemistry fields. In this paper, we report a method for the synthesis of aryl fluorides by benzyne fluorination under microflow conditions using the efficient Comet X-01 micromixer. In comparison to our previously reported method under ordinary batch conditions, this approach facilitates a significant reduction in reaction times, to ca. 10 s, as well as increases in the yields of fluoroarenes (by up to 51%).

A series of organotin(IV) complexes was herein prepared and characterized. A one-pot synthetic strategy afforded reasonable to high yields, depending on the nature of the ligand. All new complexes were fully characterized by spectroscopic techniques, consisting of IR, MS and NMR (¹H, ¹³C and ¹¹⁹Sn). The in vitro cytotoxicity tests demonstrated that the organotin complexes produced a greater inhibition, versus cisplatin (the positive control), of the growth of six human cancer cell lines: U-251 (glioblastoma), K-562 (chronic myelogenous leukemia), HCT-15 (colorectal), MCF-7 (breast), MDA-MB-231 (breast) and SKLU-1 (non-small cell lung). The potency of this cytotoxic activity depended on the nature of the substituent bonded to the aromatic ring. All complexes exhibited excellent IC₅₀ values. The test compounds were also screened in vitro for their antifungal effect against Candida glabrata and Candida albicans, showing minimum inhibitory concentration (MIC) values lower than those obtained for fluconazole. A brine shrimp bioassay was performed to examine the toxic properties. Molecular docking studies demonstrated that the organotin(IV) complexes bind at the active site of topoisomerase I in a similar manner to topotecan, sharing affinity for certain amino acid side chains (Ile535, Arg364 and Asp533), as well as for similar DNA regions (DA113, DC112 and DT10).