Investigation of Permeation of Theophylline through Skin Using Selected Piperazine-2,5-Diones
摘要:
药物经皮给药,直接穿透进入血液循环,在许多药物中具有许多优点,并且由于其易于应用和患者良好的依从性,对许多药物来说是很有前景的。 (S)-8-甲基-6,9-二氮杂螺[4.5]癸烷-7,10-二酮(alaptide)已被研究作为潜在的化学渗透增强剂。基于其结构,通过多步合成途径合成了四种选择的哌嗪-2,5-二酮。所有化合物均在亲水性介质丙二醇:水(1:1)中增强模型药物茶碱的渗透能力。在恒定温度34±0.5°C下,使用垂直Franz扩散池进行体外实验,并使用全厚度猪(Sus scrofa f. domestica)耳皮肤。通过RP-HPLC分析提取的样品,以确定茶碱的渗透量。所有化合物均按照与茶碱量的比例1:10(w/w)应用。在应用后一小时,含有alaptide和(3S,6S)-3,6-二甲基哌嗪-2,5-二酮的配方中,茶碱的渗透量分别比不含被测试化合物的配方高约15倍和12倍。尽管两种增强剂在稳态下的增强比约为2.3,但在1至3小时的时间范围内的伪增强比为4.4。这些增强比表明这些化合物能够增强药物通过皮肤的渗透;然而,两种化合物配方的短期应用似乎更有优势。此外,使用三种细胞系对所有制备的化合物的细胞毒性进行了筛查,这些化合物没有显示出任何显著的毒性作用。
A step-economic and one-pot access to chiral C<sup>α</sup>-tetrasubstituted α-amino acid derivatives <i>via</i> a bicyclic imidazole-catalyzed direct enantioselective <i>C</i>-acylation
Cα-Tetrasubstituted α-amino acids are ubiquitous and unique structural units in bioactive natural products and pharmaceutical compounds. The asymmetric synthesis of these molecules has attracted a lot of attention, but a more efficient method is still greatly desired. Here we describe the first sequential four-step acylation reaction for the efficientsynthesis of chiral Cα-tetrasubstituted α-amino acid derivatives
Novel C4- and C7-modified FK228 analogues were efficiently synthesized in a highly convergent and unified manner. This synthesis features the amide condensation of glycine-d-cysteine-containing segments with d-valine-containing segments for the direct assembly of the corresponding seco-acids, which are key precursors of macrolactones. The HDAC inhibition assay and cell-growth inhibition analysis of
COX-2 metabolized the pentapeptide into small fragments consisting mainly of di- and tripeptides that ensured the safe breakdown of the peptide under in vivo conditions. The kinetic parameter Kcat/Km for COX-2-mediated metabolism of the peptide (6.3 × 105 M-1 s-1) was quite similar to 9.5 × 105 M-1 s-1 for arachidonic acid. Evidenced by the molecular dynamic studies and the use of Y385F COX-2, it was
Tripeptide-induced modulation of mesenchymal stem cell biomechanics stimulates proliferation and wound healing
作者:Swati Sharma、Chirag Kulkarni、Manish M. Kulkarni、Rafat Ali、Konica Porwal、Naibedya Chattopadhyay、Deepshikha Tewari、Sandeep Verma
DOI:10.1039/c9cc10043a
日期:——
We demonstrate the ability of two tripeptides to promote proliferation and modulate the mechanical properties of human mesenchymal stem cells (hMSCs).
我们展示了两种三肽促进人类间充质干细胞(hMSCs)增殖并调节机械性能的能力。
Linear polypeptides of a known repeating sequence of amino-acids. Synthesis of poly-(L-tyrosyl-L-glutamyl-L-alanylglycyl)[1-14C]glycine ethyl ester
作者:Brian J. Johnson、Elwood G. Trask
DOI:10.1039/j39690002644
日期:——
observe the variations in polymer size and incorporation of radioactivity with concentration. The initial polymerisation gave poly-(O-t-butyl-L-tyrosyl-γ-t-butyl-L-glutamyl-L-alanylglycyl)[1-14C]glycine ethyl ester The t-butyl groups were removed to give the title compound. Polypeptides with molecular weights of ca. 1 × 105 could be prepared at all concentrations, and the radioactive monomer was usually incorporated