Advanced Materials Research Vol. 1023

Abstract: Treatment of 1,2-phenylenediamines and 3-(N-phenyl-N-methyl) aminoacrolein with ZrCl₄ as catalyst in refluxing 95% ethanol afforded unexpected 2H-benzimidazole derivatives as the major products. It was determined that the formation of 2H-benzimidazoles was not from the decomposition of the 2-aminovinyl benzimidazoles.

Abstract: The N-methylphenylamino moiety in Akt inhibitor-IV was efficiently substituted by a 1-phenylpiperazinyl group via an amine-exchange reaction to afford a novel Akt inhibitor-IV analogue.

Abstract: Two purine-nucleoside monophosphates have been prepared from the corresponding nucleoside 5′-H-phosphonate precursors via sequential silylation, oxidation, and hydrolysis reactions in a one-pot manner. Compared to the reaction performed in the presence of pyridine, the hydrolysis of iodophosphate in the absence of pyridine generated nucleoside 5′-monophosphates as the major product. The experimental results indicated that the reaction between the formed nucleoside 5′-monophosphate with the residual iodophosphate intermediate was relatively slow, making the self-condensed dinucleoside diphosphate a minor product in this reaction.

Abstract: A general and efficient method for the preparation of symmetrical dinucleoside diphosphates with purine bases has been developed. Ap₂A and Gp₂G were synthesized from the in situ hydrolysis of corresponding nucleoside 5′-phosphoropiperidates with 4,5-dicyanoimidazole as the activator. This method features easily accessible starting materials, simple procedures, and good yield.

Abstract: A series of novel 1,6-diaminohexanes functionalized with phosphonates have been synthesized under solvent-free conditions and characterized by NMR and MS. The experimental results indicated that excess aldehyde and phosphite and elevated temperature were required for effective formation of the bis-funcationalized alkyl diamines.

Abstract: Dinucleoside polyphosphates have potential medicinal value and are of substantial interest to both synthetic and medicinal chemists. A practical method for the synthesis of guanosine-containing asymmetrical dinucleoside triphosphates (Gp₃C and Gp₃U) with 4,5-dicyanoimidazole as activator has been developed.

Abstract: This study attempted to develop sustained release tablets based on exfoliated graphite. The in vitro evaluation of the prepared tablets was carried out to study its sustained release properties by means of UV/VIS spectroscopy. The results show that the release rate of aminophylline decreases with the increase of the content of graphite for the aminophylline sustained release tablets based on exfoliated graphite. The graphite in the aminophylline sustained release tablets will delay the release of aminophylline when the exfoliated graphite content in the sustained release tablets is less than 25%, the graphite will prevent the release of a part of the aminophylline when the exfoliated graphite content exceeds 40%. The reproducibility of the prepared aminophylline sustained release tablets is acceptable.

Abstract: Elodea nuttallii is well-known for its successful invasion to Europe and Asia. In addition to its high growth rate and nutrient storage capacity, chemical defense was recently found to play an important role in excluding other aquatic organisms. To reveal the chemical nature of its allelopathic effects on cyanobacterial development, extraction of plant exudates with different solvents and eluted procedures followed by 72h bioassays with Microcystis aeruginosa was conducted. The results showed that the fraction eluted with methanol exhibited the strongest inhibitory effects, which indicated that the anti-cyanobacterial active allelochemicals released by E.nuttallii was hydrophilic. Then ten phenolic acids were identified in the purified methanol fraction of Elodea exudates by GC-MS analysis. Quantification of the four phenolic acids therein showed the release contents were lower than 10μg/L when E.nuttallii was cultivated at 10g FW/L, which increased with the increasing culture density. When the culture density was 100g FW/L, the detected contents of vanillic acid, protocatechuic acid, ferulic acid and caffeic acid in E.nuttallii culture water were 23.41μg/L, 17.56 μg/L, 12.31 μg/L and 18.93μg/L, respectively. These results were helpful to understand the allelopathy mechanisms of E.nuttallii in aquatic ecosystems and useful in control of harmful cyanobacterial blooms.

Abstract: A practical method for the preparation of P¹,P³-distavudine triphosphate has been developed. Stavudine diphosphate was first synthesized from stavudine phosphoropiperidate. The coupling of stavudine diphosphate with excess stavudine phosphoropiperidate in the presence of 4,5-dicyanoimidazole afforded symmetrical distavudine triphosphate in good yield.

Abstract: A practical method for the synthesis of 5-hydroxymethyl-2′-deoxycytidine via dithio-deoxyuridine intermediate has been developed.