713A, a new metabolite isolated from a fungal strain 713

A new compound named 713A was isolated from the fermentation broth of a fungal strain 713. The structure of 713A was elucidated by spectroscopic methods. In the screening for interleukin-6 (IL-6) receptor antagonist, 713A exhibited inhibitory activity to the binding of IL-6 and IL-6 receptor with an IC50 value of 8.6 microM.     

Seragakinone A, a new pentacyclic metabolite from a marine-derived fungus

A new anthracycline-derived pentacyclic metabolite, seragakinone A (1), was isolated from the mycelium of an unidentified fungus, which was separated from the Okinawan marine rhodophyta Ceralodictyon spongiosum, and the structure was elucidated by spectroscopic data.     

Flow Injection Fluoroimmunoassay for Human Transferrin Using a Protein a Immunoreactor

Abstract

A protein A immunoreactor (immobilized protein A) incorporating flow injection technique was used for on-line fluoroimmunoassay of human transferrin. Antibody immobilized on protein A and antibody-antigen complex formation took place in phosphate buffered saline (PBS, PH 7.4). After washing off excess lucifer yellow VS labelled human transferrin, the antibody-antigen complex was eluted with acid buffer and detected. Experimental variables have been studied and the method has been used to determine the transferrin contents in human serum.     

Sensing capabilities of colloidal gold modified with a self-assembled monolayer of a glucose-carrying polymer chain on a glass substrate

A disulfide-carrying polymer with pendent glucose residues (poly(2-methacryloyloxyethyl D-glucopyranoside)) was obtained by using a benzyl N,N-diethyldithiocarbamoyl derivative which shows the abilities of initiation, chain transfer, and termination (iniferter). The disulfide-carrying polymer was accumulated on a colloidal Au-immobilized glass substrate, and the usefulness of the polymer as a sensing element of concanavalin A (Con A) was examined by using a UV-visible spectrophotometer with the help of surface plasmon resonance. The sensor showed a concentration-dependent specific binding of Con A with a detection limit of 1.9 nM, and furthermore, it had a very high stability at high ionic strength. The polymer-coated device examined here was not only useful as a simple biosensor chip but is also expected to expand our knowledge of interfacial phenomena by introducing various functional polymers on colloidal Au.     

Colubricidin A, a novel macrolide antibiotic from a Streptomyces sp.

A new 34-membered macrolide antibiotic, colubricidin A (1), was isolated from the fermentation broth of a new streptomyces species. Its structure was elucidated on the basis of analysis of the spectroscopic data and chemical degradation. It was identified as a glycomacrolide with an unprecedented aromatic chromophore. Colubricidin A showed excellent activity against Gram-positive bacteria.     

Formation of a tris-capsule and a tris-carceplex from a cyclic six-bowl assembly

A macrocycle composed of six cavitands was assembled into a tris-capsule and a tris-carceplex, each of which encapsulates three guest molecules.     

Total synthesis of (+)-phomactin a using a B-alkyl Suzuki macrocyclization

A total synthesis of (+)-phomactin A is described using a B-alkyl Suzuki macrocyclization to incorporate the isolated trisubstituted olefin. This macrocyclization was accomplished with the sensitive hydrated furan ring in place. (R)-(+)-pulegone was used to establish the highly substituted cyclohexene core of the molecule.     

Synthesis of dehydroxymethylbulgecin a

The dehydroxymethyl analog of bulgecin A was synthesized in order to establish a synthetic route of bulgecin A.     

Analysis of a biopolymer by capillary electrophoresis with a chemiluminescence detector using a polymer solution as the separation medium.

We developed capillary electrophoresis with a chemiluminescence detector using a polymer solution as the separation medium for the analysis of biopolymers, such as DNA and protein. A peroxyoxalate chemiluminescence reagent of bis(2,4,6-trichlorophenyl)oxalate was used together with fluorescein-labeling reagent. When a migration buffer solution containing carboxylmethylcellulose was used, the flow-type chemiluminescence detection cell was found to give a better resolution than the batch-type one. Fluorescein-labeled adenosine triphosphate of 1.0 x 10(-4) M was examined by means of capillary electrophoresis with absorption (260 nm), fluorescence (ex. 496 nm and em. 517 nm), and chemiluminescence detectors. The chemiluminescence detection showed the highest sensitivity among them; the S/N ratios obtained by absorption, fluorescence, and chemiluminescence detections were 4, 38, and 130, respectively. Fluorescein-labeled DNA was prepared through a polymerase chain reaction using fluorescein-labeled deoxyadenosine triphosphate. A mixture of the labeled DNA fragments (500, 600, 700, 800, 900, and 993 bp) was successfully separated and detected by the present system. A mixture of proteins (lysozyme, cytochrome C, and ribonuclease A) which were labeled with fluorescein isothiocyanate was also separated and detected.     

Efficient C-C double-bond formation reaction via a new synthetic strategy: a self-sorting tandem reaction

[reaction: see text] A novel and efficient carbon-carbon double-bond formation reaction via coupling of aryl or heteroaryl methyl ketones has been developed. A dimethyl sulfoxide-iodine-CuO system was proven to be efficient for this reaction and afforded the expected products in good yields. A new synthetic strategy, a self-sorting tandem reaction, was involved in this type of reaction and was presented for the first time.     

Structure of concanamycin a

The structure of concanamycin A was proposed on the basis of PMR analyses of concanamycin A and its ozonolysis products.     

Synthesis and properties of a novel phenylazomethine dendrimer with a tetraphenylmethane core

[structure: see text] A new type of phenylazomethine dendrimer with a tetraphenylmethane core was synthesized by a convergent method. The properties of the dendrimer were confirmed by thermal, rheological, TEM, and AFM measurements. A stepwise radial complexation was clearly observed with SnCl(2).     

Structure of salvioccidentalin, a diterpenoid with a rearranged neo-clerodane skeleton from Salvia occidentalis

From the aerial parts of Salvia occidentalis (Labiatae) a new diterpenoid with a rearranged neo-clerodane skeleton was isolated. This new compound was named salvioccidentalin and its structure was established by spectroscopic means. A probable biogenetic relationship with salvigenolide from S. fulgens and salvileucalin A and spiroleucantholide from Salvia leucantha is proposed.     

Hainanmycin A,a cyclo-heptadeca macrolide bearing a cyclopentenone moiety from the mangrove-derived Streptomyces sp. 219807

A macrocyclic polyketide with novel carbon skeleton, namely hainanmycin A, was isolated from the mangrove-derived Streptomyces sp. 219807. This polycyclic compound featured a cyclo-heptadeca framework possessing a 5,6-disubstituted-4-hydroxy-2-pyrone moiety in conjunction with a 2-cyclopentenone residue. The structure was established by spectroscopic analyses, and the stereochemistry was determined by NMR chemical shifts calculations and time-dependent density functional theory (TDDFT) calculation of electronic circulardichroism (ECD). A possible biogenetic pathway for hainanmycin A was proposed.     

Crack-craze opening profiles near a crack tip in a polytetrafluoroethylene

The crack opening and craze profiles near a crack tip in a polytetrafluoroethylene have been experimentally investigated. A double-edge-crack plate specimen under uniaxial tensile load was used in the experiment and the experimental procedure was performed using the Digital Image Correlation method, which is a well-established optical-numerical method for estimating full-field displacement. A theoretical model of the stress intensity factor based on linear elastic fracture mechanics combined with a classical saturated expression was proposed. The proposed model is in good agreement with experimental data and predictions of the model may be used to verify the non-linear behavior from crack and craze (cohesive) zones.     

Callynormine A, a new marine cyclic peptide of a novel class

[structure: see text] A novel cyclic peptide, callynormine A, was isolated from the Kenyan marine sponge Callyspongia abnormis and its structure elucidated by interpretation of its NMR data and X-ray diffraction analysis. Callynormine A represents a new class of heterodetic cyclic peptides (designated endiamino peptides) possessing an alpha-amido-beta-aminoacrylamide cyclization functionality.     

Crystal Structure of Carboxypeptidase a Complexed with an Inactivator in a New Crystalline Form

1INTR0DUCTIONInrecentyears,zinc-containingmeta1loenzymeshavereceivedspecialattentionbecauseoftheroletheyplayintheetiologyofmanyseriousdiseases.Theyserveastargetsinthedesignoftherapeuticallyusefulinhibitorsoftheseenzymes.Inthisre-spect,carboxypeptidaseA(CPA),awell-studiedzinc-containingmetalloex-opeptidase,bearsanunusualimportancebecauseitservesasamodelformanymetal-loenzymes.Thetertiarystructure0fCPAinc1udingthatoftheactivesitehasbeenwellcharacterizedalth0ughthecataIyticmechanismatthemo…     

Webcam camera as a detector for a simple lab-on-chip time based approach

A modification of a webcam camera for use as a small and low cost detector was demonstrated with a simple lab-on-chip reactor. Real time continuous monitoring of the reaction zone could be done. Acid-base neutralization with phenolphthalein indicator was used as a model reaction. The fading of pink color of the indicator when the acidic solution diffused into the basic solution zone was recorded as the change of red, blue and green colors (%RBG.) The change was related to acid concentration. A low cost portable semi-automation analysis system was achieved.     

Self-assembly of a bis-urea macrocycle into a columnar nanotube

A bis-urea macrocycle 1 was synthesized and shown to form extended nanotubular columns by X-ray crystallography.     

Study of a nanocomposite based on a conducting polymer: polyaniline

A simple way to obtain a conducting nanocomposite is described, and the conducting particles are characterized. Core-shell particles [polystyrene-polyaniline (PANI)] have been obtained by the dispersion process from three types of polystyrene latexes: a no-cross-linked core stabilized by a nonylphenolethoxylate (NP40) and two cross-linked cores stabilized by NP40 and a mixture NP40/Surfamid (a surfactant bearing an amide group). The surface of these particles has been extensively characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy, and scanning electron microscopy. A maximum coverage of 94% was obtained for the high PANI content as revealed by XPS analysis. A better coverage was obtained for the cross-linked polystyrene latex stabilized by the Surfamid. The amide group of this surfactant allows the H-bonding formation with the PANI backbone and, thus, improves the conductivity. It was shown that a uniform coverage of the core particles was not required to ensure a good conductivity.