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.     

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.     

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).     

Briaviodiol A, a new Cembranoid from a soft coral Briareum violacea

A new cembrane diterpenoid, briaviodiol A (1), has been isolated from a soft coral Briareum violacea. The structure of 1 was determined by spectroscopic methods and further confirmed by a single-crystal X-ray diffraction analysis.     

Total synthesis of leucascandrolide a: a new application of the Mukaiyama aldol-Prins reaction

A total synthesis of the marine natural product leucascandrolide A has been completed. The titanium tetrabromide-mediated Mukaiyama aldol-Prins (MAP) reaction with aldehydes developed in our group provided a highly convergent and stereoselective method for assembling the core of the molecule. A new class of MAP reactions with acetals is introduced, and mechanistic considerations for both MAP methods are described. The total synthesis was completed by coupling of the side chain through two avenues: a known Still-Gennari olefination and a new Z-selective aldol/dehydroselenation reaction. Both procedures were highly selective and provided the natural product.     

Determination of the Crystal Structure of a New Polymorph of Theophylline

A new approach to crystal structure determination, combining crystal structure prediction and transmission electron microscopy, was used to identify a potential new crystal phase of the pharmaceutical compound theophylline. The crystal structure was determined despite the new polymorph occurring as a minor component in a mixture with Form II of theophylline, at a concentration below the limits of detection of analytical methods routinely used for pharmaceutical characterisation. Detection and characterisation of crystallites of this new form were achieved with transmission electron microscopy, exploiting the combination of high magnification imaging and electron diffraction measurements. A plausible crystal structure was identified by indexing experimental electron‐diffraction patterns from a single crystallite of the new polymorph against a reference set of putative crystal structures of theophylline generated by global lattice energy minimisation calculations.     

Base-initiated reactions of N-fluoropyridinium salts; a novel cyclic carbene proposed as a reactive species

A new type of base-initiated reactions of pyridinium salts was found and a novel cyclic carbene was proposed as the reactive species.     

Enantioselective total synthesis of (+)-testudinariol a using a new nickel-catalyzed allenyl aldehyde cyclization

An enantioselective total synthesis of (+)-testudinariol A was completed. A new nickel-catalyzed allenyl aldehyde cyclization was developed in the approach. In addition, an asymmetric anti aldol reaction and a two-directional oxocarbenium ion/vinyl silane condensation were employed as key steps.     

Influence of a δ-lactam-type cyclic protecting group on the reactivity of a 4-hydroxy glycosyl acceptor derivative of d-glucosamine

Russian Chemical Bulletin - A new 4-hydroxy glycosyl acceptor derivative of d-glucosamine containing a lactam-type N-protecting group was synthesized. The new glycosyl acceptor containing a hydroxy...     

Pongaflavanol: a prenylated flavonoid from Pongamia pinnata with a modified ring A

A new prenylated flavon-4-ol with a modified ring A, which we have named pongaflavanol (1), was isolated from the stem bark of Pongamia pinnata along with the known compound tunicatachalcone (2). The structure of compound 1 was elucidated on the basis of spectroscopic data.     

Ion chromatographic system with a novel switching suppression device

Ion chromatography (IC) has been a powerful tool for measuring ionic species in environmental samples such as tap, river and drain waters. Suppressor modules (membrane and disposable column types) have been used for reducing the background of a baseline. A new type of suppressor device, which has a suppressor resin and switching valve was developed. Fresh ionic resin is introduced into a groove for each analysis to perform the suppression of the working eluent. The eluent composition for obtaining higher sensitivity and better resolutions among ionic species and carbonate ion was also investigated. Although carbonate buffers are used for ion separation in general, the separation of carbonate ion from other ions was not achieved. A borate eluent resulted in good resolutions and higher sensitivity. A new column was also developed for obtaining higher column efficiency and resolution. The optimization of anion separation using a new IC system (IC-2001) that consists of a new suppressor device, an anion-exchange column (TSKgel SuperIC-Anion, 150x4.6 mm), an autosampler, a conductivity cell and a pump in a compact module is described.     

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.     

A new saccharide sensor based on a tetrathiafulvalene-anthracene dyad with a boronic acid group

[reaction: see text] A new saccharide sensor based on a tetrathiafulvalene-anthracene dyad with a boronic acid group was designed and synthesized. Our study employed the tetrathiafulvalene (TTF) unit as the electron-rich group in the saccharide sensor instead of an amine group, and this new sensor detects fructose with good selectivity.     

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.     

Monodictyquinone A: a new antimicrobial anthraquinone from a sea urchin-derived fungus Monodictys sp

A new antimicrobial anthraquinone, 1,8-dihydroxy-2-methoxy-6-methylanthraquinone, monodictyquinone A (1), was isolated from a culture of a marine-derived fungus of the genus Monodictys which was isolated from the sea urchin, Anthocidaris crassispina, along with three known compounds, pachybasin (2), chrysophanol (3), and emodin (4).     

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.     

An unprecedented intramolecular coupling of o-carboranyl and cyclopentadienyl. Synthesis and structural characterization of a ruthenium complex containing a novel doubly-bridged cyclopentadienyl-carboranyl ligand

A novel ruthenium-mediated coupling reaction of a carboranyl with a cyclopentadienyl was discovered for the first time, leading to a brand new doubly-bridged cyclopentadienyl-carboranyl ligand bearing two five-membered rings and to a new type of chiral ruthenium complex.     

一种蓝色荧光材料的合成

本文设计和合成了一种带有吡唑啉侧链基因的低聚酰胺,可用作蓝色荧光材料。分子中特殊的氢键序列(AADADD)及芳酰胺链可与制着器件所用的高分子基材分子之间的形成较强的作用力,从而将发光基团“铆定”在功能膜中。     

Total synthesis of bryostatin 16 using a Pd-catalyzed diyne coupling as macrocyclization method and synthesis of C20-epi-bryostatin 7 as a potent anticancer agent

Asymmetric total synthesis of bryostatin 16 was achieved in 26 steps in the longest linear sequence and in 39 total steps from aldehyde 10. A Pd-catalyzed alkyne-alkyne coupling was employed for the first time as a macrocyclization method in a natural product synthesis. A route to convert bryostatin 16 to a new family of bryostatin analogues was developed. Toward this end, 20-epi-bryostatin 7 was synthesized from a bryostatin 16-like intermediate; the key step involves a Re-catalyzed epoxidation/ring-opening reaction. Preliminary biological studies indicated that this new analogue exhibits nanomolar anti-cancer activity against several cancer cell lines.     

Polyporolide, a new acetogenin from the mycelial culture of a Polyporus fungus

A new acetogenin, polyporolide (1), was isolated from the mycelial solid cultures of a Polyporus basidiomycete. Its structure was elucidated as 4-hydroxy-5-(1-hydroxyhexyl)-dihydrofuran-2-one by spectroscopic methods. Its toxicity to brine shrimps was assessed.