In the article, a
mild deacylation method for 3,5-dinitrobenzoates, which are often used to
improve their diastereomeric or enantiomeric purities by recrystallization
and also widely used as a pro-nucleophile in the Mitsunobu reaction, has been
developed by using methanolic solutions of amines, such as dialkylamines.
Removal of dinitrobenzoyl groups undergoes without affecting existing acetyl
groups and also without affecting stereochemistry in α-hydroxy ketone.
Encouraged by the promising versatility, the authors successfully applied
this method to the efficient asymmetric synthesis of Colorado potato beetle
antileukemic ansa macrolide, maytansine was first isolated from Maytenus ovata, plants belong to
Celastraceae draw the attention of natural product chemists. The authors
focused on the plants collected in Okinawa Islands, and Celastraceae plant, Microtropis japonica was chosen for
the target material. ent-Labdane
glycoside and 6'-O-(2"S,3R")-2"-ethyl-2",3"-dihydroxybutyrates of aliphatic
branches have been isolated from leaves and branches respectively. Current
investigation of leaves afforded further ent-labdane glucosides, 6'-O-2"-ethyl-2",3"-dihydroxybutyrates
of aliphatic alcohol β-D-glucosides,
ursane-type triterpene diglucoside, and flavonol glycoside.
Density functional theory calculations were
performed to explore the mechanism of Ni-catalyzed cross-coupling reactions
involving organo-lithium and -zinc reagents though ethereal C–O bond cleavage.
In comparison with our previous mechanistic study on etheric Kumada–Tamao
reaction, it shows that the the Ni(0)-ate complex-mediated reaction pathway is
a new and general mechanism for ethereal cross-coupling reactions, which can
well explain the experimental findings for several ethereal C–O bond cleavage
couplings. The present work also
suggests that the anionic character of organometallic nucleophiles can change
oxidative addition mechanisms/pathways, which may provide new reactivity and
We evaluated the adhesion force of the film
coating layer to the surface of tablets prepared using an external lubrication
method. Increasing lubrication decreased wettability of the tablet surface.
However, no change was observed in the adhesion force of the film coating
layer. The magnesium stearate distribution state on the tablet surface was
assessed and the lubricant was uniformly dispersed in the external lubrication
samples. The distribution state of the lubricant affects the adhesion force of
the film coating layer, and external lubrication maintained sufficient
lubricity and adhesion force of the film coating layer with a small amount of lubricant.
Four new lignans, a furofuran lignan medioresinol B (10) and three tetrahydrofuran lignans
kobusinol C (16), 7'-methoxy magnostellin
A (21), and mangnostellin D (23), along with 19 known lignans, were
isolated from the flower buds of Magnolia
biondii Pamp. The structures of the isolates were elucidated using
spectroscopic analysis, mainly one- and two-dimensional NMR, high resolution
mass spectrometry, and circular dichroism techniques as well as Mosher’s
esterification method. The anti-allergic effects of the isolated compounds were
evaluated by analyzing the inhibition of interleukin-2 (IL-2) expression in
Jurkat T-cells. Compounds 11−14 reduced IL-2 expression in a
Fluorophores undergoing excited-state intramolecular proton transfer (ESIPT) exhibit several unique characteristics. In the paper, a range of 7-hydroxy-3-methyleneisoindolin-1-ones is investigated as new ESIPT fluorophores. In fact, dual emission is observed in alcohols and DMSO; ~380 and ~530 nm (exc. = ~336 nm), and a single emission is observed (~500 nm) in EtOH-H2O binary mixtures. Furthermore, the wavelength of fluorescence maxima is dependent on the dielectric constant of the solvent, suggesting their potential utility for monitoring aqueous environments.
The hedgehog (Hh) signaling pathway performs important roles in cellular process, however, in many cancer cells Hh signaling is aberrantly activated, which has provided a strong impetus for the development of Hh pathway inhibitors. In the paper, a series of heterocyclic flavonoids are prepared and evaluate their Hh signaling inhibitory activity. As a result, some of the synthetic flavonoids show good Hh inhibitory activity as well as cytotoxicity toward human cancer cells. Western blotting analyses also reveal that PTCH and GLI1 expression is reduced.
This paper focuses on melt adsorption as manufacture method of wax matrices to control particles size of granules more easily than melt granulation, and demonstrated for the first time that melt adsorption using a hydrophobic material has the potential capability to control the particle size of granules and offers the possibility of application as a novel controlled release technique.
Cellular functions are mediated by a great variety of enzymes, and altered enzymatic functions are often observed during disease onset and progression. Therefore, discovering the novel connection between the functions of enzymes and specified diseases is the key to developing novel diagnostic methods, as well as therapeutic drugs. In this review, we describe the recently advancing field of chemical biology that aims to discover and characterize disease-related alternation of enzymatic functions, which can be termed as “enzym-omics (omics of enzymes)”. The review covers several key technologies that can be considered as the representative experimental systems used for this purpose.
In this review, new and reliable procedures for the construction of diverse ring systems based on the chemistry of sp-hybridized species are described. The synthetic application includes (i) multi-cyclic skeletons by the Rh-catalyzed reaction of allenes with other π-components such as alkyne, alkene, and allene, (ii) hetero- and carbocycles from appropriate allenes and nucleophiles, and (iii) natural products and related compounds.
This review summarizes author’s recent reports on Pd(0)-catalyzed benzylic C(sp3)-H functionalization for the synthesis of various heterocycles including oxindoles, spirooxindoles, 2-arylindoles, benzocarbazoles, indolocarbazoles, and indoloquinazolinones. The key feature would be a chemoselective C(sp3)-H activation in the oxindole synthesis. The developed method was successfully applied to the total synthesis of several pyrrolophenanthridine alkaloids as well as a synthesis of the right-hand fragment of benzohopane.
In this communication, development of a new
type of red-shifted channelrhodopsins (ChRs) is described. Optogenetics is a powerful new
technique which allows control of neuronal activity by light, and ChRs are now
widely used in optogenetics due to their function of a light-gated cation
channel. In neuroscience, ChRs responding to a long-wavelength light are eagerly
required, because ChRs now used are maximally sensitive to green and blue light, and does not penetrate tissues. Here developed new type of ChRs model consisted of
red-shifted chromophores (retinal-based enamine-type Schiff bases) and mutated
channelopsin (C1C2-K296G), in which chromophores were incorporated noncovalently. Thus prepared new ChRs
exhibited absorption maxima that were 10-30 nm red-shifted compared with the
In this paper, the
adsorption capacity of methylene blue (MB) and crystal violet (CV) to
poly-γ-glutamic acid (PGA) is described. PGA contained in natto (Japanese
traditional fermented food) is a homopolyamide having
bonds between α-amino and
γ-carboxy groups of D- and L-glutamic acid monomers. The removal rate of MB or CV by PGA was 94.6 to 100% after 120 min. In addition, PGA has a dye
adsorption capacity in a binary solution system. The results of this study
indicate that PGA is useful for removing dyes from aqueous solutions.
In this article, injectable products composed of biocompatible and biodegradable poly-lactic glycolic acid copolymer (PLGA) microparticles are described. In order to improve the dispersibility of MRPs in injection solutions, MRPs were subjected to a secondary processing, i.e., the drop freeze-drying technique. The suspension with MRPs and water-soluble additives were rapidly dripped into liquid nitrogen in the form of droplets. The resultant frozen particles were freeze-dried to prepare spherical granules containing multiple MRPs (Granulated-MRPs). When the G-MRPs were placed in water for injection, the porous matrix base was immediately dissolved, and each embedded MRPs were individually released, thus inducing monodispersion and significantly improved dispersibility. The granular products could be automatically filled into the pre-filled syringes and may give rise to the excellent passage of PLGA MRPs through needles for use in depot injected formulation as a ready-to-use.
this paper, the authors used the charge-transfer complexes between iodine and
tertiary amines for the initiation of atom-transfer radical reactions. The visible
light irradiation of charge-transfer complex in the ground state gives the excited
state complex, in which the single electron transfer from the donor amine to
the acceptor iodine proceeds effectively to give an iodine radical.
In this study, the authors focused on two permeation enhancers:
nerolidol and levulinic acid to clarify the mechanism of action of permeation
enhancers on lipids structures. Synchrotron X-ray diffraction revealed that nerolidol
strongly affected the orthorhombic and hexagonal structures, whereas levulinic
acid had little effect on the lateral packing structures.
In this paper, the authors used a panel of
fluorogenic substrates to search for altered enzyme activities in
bronchoalveolar lavage fluid (BALF) from a mouse model of lung inflammation and
found that acylamino acid releasing enzyme (APEH) activity was highly elevated,
apparently reflecting the increased population of immune cells in the inflamed
In the review, the authors summarize recent reports on direct translocation of arginine-rich cell-penetrating peptides (CPPs) through cell membranes, including counteranion-assisted delivery method, and discuss its mechanism, which would provide insight into highly efficient intracellular delivery.
This review summarizes the authors’ recent work on photocontrolable releases, or caged compounds, which can release specific biological mediators such as NO, HNO, and H2S, upon photoirradiation, and a wide range of colors (wavelengths), from ultraviolet to near infrared, are available depending on the properties of the compounds. These photocontrollable compounds realized the spatiotemporal control of the release, and the manipulation of biological responses specific for the mediators. One of our photocontrollable NO releasers with the near infrared two photon excitation succeeded to control vasodilation in the anesthetized mouse brain with spatiotemporal resolution, and the ex vivo rat aorta relaxation was also achieved with another controllable NO releaser by the visible light irradiation.