A one-pot procedure with cobalt-mediated oxidation of 2,2'-dilithio-1,1'-binaphthyl by ferrocenium salts afforded the chiral cyclic hexamer of naphthylene, [6]cyclo-1,2-naphthylene (1). The molecular structure of 1 was determined by single crystal X-ray crystallography and NMR analyses, revealing its cyclic structure with an approximate D symmetry. Compound 1 exhibits blue emission at 383 nm with high photoluminescence quantum yield of 97 %, which can be attributed to its rigid twelve-membered ring structure.
View Article and Find Full Text PDFBackground: Vancomycin regimens are designed to achieve an area under the concentration-time curve/minimum inhibitory concentration (AUC/MIC) ratio ranging between 400 and 600 µg·h/mL in the steady state. However, in cases of critical infections such as bacteremia requiring an early treatment approach, the clinical course may be affected by the AUC/MIC before reaching the steady state, that is, the AUC/MIC values 24 h after the first dose (first 24-h AUC/MIC). This study evaluated the relationship between the first 24-h AUC/MIC and the clinical course of methicillin-resistant (MRSA) infection.
View Article and Find Full Text PDFBackground: Fentanyl is widely used as an analgesic and sedative for patients with severe burn injuries in intensive care units. However, pharmacokinetic (PK) data for fentanyl, particularly for continuous intravenous infusion during the acute phase of burn injuries, are limited. Here, we report the clinical course and changes in blood fentanyl concentrations during the acute phase in a patient with severe burns treated with continuous intravenous infusion of fentanyl.
View Article and Find Full Text PDFHypersensitivity reactions are an adverse effect of anticancer drug therapy. Prophylactic administration of antiallergic drugs and steroids is recommended when administering drugs associated with a high hypersensitivity reaction incidence. First-generation antihistamines are generally used in this setting.
View Article and Find Full Text PDFCancer-associated cachexia, a multifactorial syndrome involving loss of muscle mass and anorexia, affects the survival of cancer patients. Anamorelin was the first drug approved in Japan for the treatment of cachexia. However, cases in which anamorelin is discontinued within 3 weeks are often observed in clinical practice.
View Article and Find Full Text PDFIntroduction: The Cancer and Aging Research Group (CARG) prediction tool was designed in the United States to predict grade ≥ 3 chemotherapy-related adverse events (CRAE) in older patients. However, its usefulness among Japanese people, who have different sensitivities to anticancer drugs and life expectancy, remains unknown. We aimed to prospectively evaluate the utility of the CARG tool for predicting severe CRAE in older Japanese patients with cancer.
View Article and Find Full Text PDFPhotolysis is an attractive method in organic synthesis to produce free radicals through direct bond cleavage. However, in this method, specific irradiation wavelengths of light have been considered indispensable for excitation through S-S or S-T transitions. Here we report the photoinduced homolysis of electronegative interelement bonds using light at wavelengths much longer than theoretically and spectroscopically predicted for the S-S or S-T transitions.
View Article and Find Full Text PDFDearomative construction of multiply-fused 2D/3D frameworks, composed of aromatic two-dimensional (2D) rings and saturated three-dimensional (3D) rings, from readily available quinolines has greatly contributed to drug discovery. However, dearomative cycloadditions of quinolines in the presence of photocatalysts usually afford 5,6,7,8-tetrahydroquinoline (THQ)-based polycycles, and dearomative access to 1,2,3,4-THQ-based structures remains limited. Herein, we present a chemo-, regio-, diastereo-, and enantioselective dearomative transformation of quinolines into 1,2,3,4-THQ-based 6-6-4-membered rings without any catalyst, through a combination of nucleophilic addition and borate-mediated [2+2] photocycloaddition.
View Article and Find Full Text PDFWe have established a facile and efficient protocol for the generation of germyl radicals by employing photo-excited electron transfer (ET) in an electron donor-acceptor (EDA) complex to drive hydrogen-atom transfer (HAT) from germyl hydride (RGeH). Using a catalytic amount of EDA complex of commercially available thiol and benzophenone derivatives, the ET-HAT cycle smoothly proceeds simply upon blue-light irradiation without any transition metal or photocatalyst. This protocol also affords silyl radical from silyl hydride.
View Article and Find Full Text PDFWe present herein the synthesis of novel pseudo-metalla-carbaporphyrinoid species (1M: M=Pd and Pt) achieved through the inner coordination of palladium(II) and platinum(II) with an acyclic N-confused tetrapyrrin analogue. Despite their tetrapyrrole frameworks being small, akin to well-known porphyrins, these species exhibit an unusually narrow HOMO-LUMO gap, resulting in an unprecedentedly low-energy absorption in the second near-infrared (NIR-II) region. Density functional theory (DFT) calculations revealed unique d-p-conjugated electronic structures involving the metal d-ligand p hybridized molecular orbitals of 1M.
View Article and Find Full Text PDFAlthough second near-infrared (NIR-II, 1000-1500 nm) light has attracted considerable attention, especially for life sciences applications, the development of organic dyes with NIR-II absorption remains a formidable challenge. Herein we report the design, synthesis, and electronic properties of 20π-electron antiaromatic benziphthalocyanines (BPcs) that exhibit intense absorption bands in the NIR region. The strong, low-energy absorption of the antiaromatic BPcs is attributed to electric-dipole-allowed HOMO-LUMO transitions with narrow band gaps, enabled by the reduced structural symmetry of BPc compared with regular porphyrins and phthalocyanines.
View Article and Find Full Text PDFWe have developed visible-light-induced -hydroboration of diaryl alkynes via direct photoexcitation of in-situ-generated diboron complexes, affording previously elusive ()-1,2-diaryl-vinylboronates with high stereoselectivity. Experimental, spectroscopic, and theoretical mechanistic studies revealed that the triplet-state borate complex facilitates B-B bond cleavage and the desired C-B bond formation. This methodology does not require any catalyst and is operationally simple.
View Article and Find Full Text PDFActivation of bis(pinacolato)diboron with aromatic lithium amide promotes diboration of the proximal C-C triple bond, leading to BN-embedded aromatic compounds. In situ treatment of the initially generated spirocyclic borate intermediate with aqueous acid or organometallic reagents enables ligand installation on the endocyclic boron atom.
View Article and Find Full Text PDFBelL and HrmJ are α-ketoglutarate-dependent nonheme iron enzymes that catalyze the oxidative cyclization of 6-nitronorleucine, resulting in the formation of two diastereomeric 3-(2-nitrocyclopropyl)alanine (Ncpa) products containing -cyclopropane rings with (1'2') and (1'2') configurations, respectively. Herein, we investigate the catalytic mechanism and stereodivergency of the cyclopropanases. The results suggest that the nitroalkane moiety of the substrate is first deprotonated to produce the nitronate form.
View Article and Find Full Text PDFEpipolythiodioxopiperazines (ETPs) make up a class of biologically active fungal metabolites with a transannular disulfide bridge. In this work, we used DFT calculations to examine in detail the degradation (desulfurization) pathways of α-β/α-α bridged ETPs. The chemical stability of ETPs is influenced by the type of sulfur bridge, the structural features, and the storage conditions.
View Article and Find Full Text PDFWe describe a π-topological transformation-based synthetic method for the preparation of a new type of near-infrared (NIR)-emissive rhodamine dye called Polymethine-embedded Rhodamine Fluorophore (PeR Fluor). In contrast to conventional NIR-emissive dyes that require tedious synthetic steps and/or a high cost, linear fully π-conjugated PeR Fluor can be regioselectively prepared in one step by mixing different nucleophiles with ABPXs, a family of rhodamines with a cross-conjugated structure. PeR Fluor exhibits bright NIR fluorescence emission and high photostability owing to the cooperative π-electron system of rhodamines and polymethine scaffolds.
View Article and Find Full Text PDFPeniroquesine, a sesterterpenoid featuring a unique 5/6/5/6/5 fused pentacyclic ring system, has been known for a long time, but its biosynthetic pathway/mechanism remains elusive. Based on isotopic labeling experiments, a plausible biosynthetic pathway to peniroquesines A-C and their derivatives was recently proposed, in which the characteristic peniroquesine-type 5/6/5/6/5 pentacyclic skeleton is synthesized from geranyl-farnesyl pyrophosphate (GFPP) via a complex concerted A/B/C-ring formation, repeated reverse-Wagner-Meerwein alkyl shifts, three successive secondary (2°) carbocation intermediates, and a highly distorted -fused bicyclo[4.2.
View Article and Find Full Text PDFA catalytic amount of CsI enables dual concurrent activation of poorly reactive perfluoroalkoxide and alkyl halides, especially alkyl chlorides, leading to the formation of diverse perfluoroalkoxylated organic compounds. Installation of perfluoroalkoxy groups by this methodology is cost-effective, circumventing the need for over-stoichiometric cesium or silver salts. This methodology also provides high functional group compatibility and tolerance of sterically hindered substrates.
View Article and Find Full Text PDFIntroduction: Dexamethasone (DEX)-sparing strategy with 5-hydroxytryptamine-3 receptor antagonist (5HT3RA) and aprepitant (APR), as triplet antiemetic prophylaxis, is associated with poor control of delayed chemotherapy-induced nausea and vomiting (CINV) in patients receiving carboplatin (CBDCA)-based chemotherapy. This study aimed to evaluate whether using palonosetron (PALO) as a 5HT3RA provides superior control with CINV than first-generation (1st) 5HT3RA in triplet antiemetic prophylaxis with a DEX-sparing strategy.
Methods: Pooled patient-level data from a nationwide, multicenter, and prospective observational study were analyzed to compare the incidence of CINV between patients administered PALO and 1st 5HT3RA in combination with 1-day DEX and APR.
Near-IR (NIR) organic dyes have been widely utilized in life sciences and materials science. Herein we report an unusually large NIR solvatochromism of monohydroxybenziphthalocyanine, an analogue of 18π-electron aromatic phthalocyanine in which a single isoindoline unit is replaced with a phenol ring. The solvatochromism is attributed to deprotonation of the phenol moiety in highly polar solvents, leading to the generation of a strongly NIR-absorptive 18π-electron aromatic quinoidal monoanion.
View Article and Find Full Text PDFChem Pharm Bull (Tokyo)
June 2023
Organic compounds with near-IR (NIR) fluorescence have many potential applications in materials and life sciences, but the much weaker intensity of fluorescence in the NIR region than in the UV-visible region is a major obstacle. Herein we show that deuteration of phthalocyanines, a representative class of organic NIR dyes, increases both the fluorescence quantum yield and the fluorescence lifetime compared with non-deuterated phthalocyanines.
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