Chemical synthesis of phosphorylated tetraacyl disaccharide corresponding to a biosynthetic precursor of lipid A

A total synthesis of 2,2′-N; 3,3′-O-tetraquis[(R)-3-hydroxytetradecanoyl]-β(1–6)-D-glucosamine disaccharide 1,4′-diphosphate is described. This is the first confirmation of the fundamental structure of lipid A since the synthetic compound exhibited most of the characteristic biological activities of natural endotoxin.     

Chromoionophores Based on Crown Ethers and Related Structures for Alkali Metal Ion Sensing in Aqueous Media

Recent progress in chromoionophores based on (1) spherand and hemispherand, (2) cryptand, and (3) dibenzo-16-crown-5 and calix[4]crown which selectively respond to alkali metal ions in aqueous media is reviewed in relation to their molecular structure and photometric function. The design concept of the chromoionophores for colorimetry in aqueous media is discussed in the light of their acid dissociation and metal complex formation equilibria.     

Phenolic constituents in Erythrina x bidwilli and their activity against oral microbial organisms.

Five flavonoid compounds, including two new isoflavanones, were isolated from the root bark of Erythrina x bidwilli. Their structures were determined to be 2,10-di(gamma,gamma-dimethylallyl)-3,9-dihydroxypterocarpan (erythrabyssin II), 6,8-di(gamma,gamma-dimethylallyl)-7,2',4'-trihydroxyisoflavanone (bidwillon A), 8-gamma,gamma-dimethylallyl-2',4'-dihydroxy-[6",6"-di-methylpyrano - (2",3":7,6)]isoflavanone (bidwillon B), 8-gamma,gamma-dimethylallyl-7,4'-dihydroxyisoflavone (8-gamma,gamma-dimethyl-allyldaidzein), and 8-gamma,gamma-dimethylallyl-5,2',4'-trihydroxy-[6",6"-dimethylpyrano+ ++- (2",3":7,6)]isoflavone (auriculatin), by means of spectroscopic analysis. Some potent activities against oral microbial organisms (Fusobacterium nucleatum and Prevotella intermedia) were shown in these flavonoid compounds.     

Inclusion Compound Formation of Amylose by Sealed-Heating with Salicylic Acid Analogues

The inclusion compounds of linear amylose and salicylic acid analogues preparedby sealed-heating were evaluated by using powder X-ray diffraction and infraredspectroscopy. Sealed-heating of amylose and either salicylamide or benzoic acidinduced the amylose structural change from the 6₁- to the 7₁-helix structure, while sealed-heating with o-toluic acid, o-chlorobenzoic acid and o-nitrobenzoic acid induced the change from the 6₁- to the 8₁-helix structure. In contrast to theresults in the salicylic acid system, the amylose helix type of sealed-heated samplewas not varied by the load of the guest compound, but was fixed only by the guestspecies. No change of the helical structure of amylose depending on the amylose molecular weight was observed. From the comparison of inclusion compound formation among different guest systems, it was found that the higher vapor pressure at 100 °C of the guest resulted in faster inclusion compound formation. The vapor pressure of the guest compound would be an important factor affecting the progress of inclusion compound formation.     

The first electroresponsive phenylazomethine macrocycles: highly preferential formation and regular molecular packing

[structure: see text] Highly preferential formation of novel polyphenylazomethine macrocycles was achieved by further addition of TiCl(4) and/or the monomer during the course of the polycondensation. These macrocycles have unique structures based on the (E)/(Z)-conformation of the azomethine bonds, the extremely regular molecular-packing state, and the reversible redox properties by protic acid doping.     

Synthesis of azoxybenzene-SbCl5 complexes and their selective ortho-wallach rearrangement

When an equimolar solution of various azoxybenzenes and SbCl₅ in carbon tetrachloride were mixed, a 1:1 complex immediately deposited as orange crystals in high yield. The thermal reaction of these complexes in inert solvents gives o-hydroxy-azobenzene selectively. On the contrary, other Lewis acids such as TiCl₄, AlCl₃, FeCl₃ and ZnBr₂ failed to give an isolatable complex with azoxybenzene, and their direct thermal reaction with azoxybenzene resulted in deoxygenation to yield azobenzene as a main product.     

Significance of renal high uptake in bone marrow scintigraphy with 111In-chloride

The significance of high renal uptake found in patients with hematological disease who underwent bone marrow scintigraphy with 111In-chloride was investigated. In patients with a high renal uptake, the uptake in bone marrow was low, suggesting a reflection of erythropoietic activity. The reversal relationship, however, was not necessarily present. With regard to correlation with iron metabolism, significantly higher uptake of serum Fe and lower UIBC were found among those with high renal uptake, suggesting that the level of free trans ferrin in the serum is largely involved in the high uptake in the kidney.