Syntheses of Bile Pigments. Part 18. Synthesis and conformational studies of oxa- and thia-deaza-biliverdin analogues
作者:Petr Nesvadba、Do Ngoc-Phan、Fredy Nydegger、Arturo Espinosa Ferao、Albert Gossauer
DOI:10.1002/hlca.19940770715
日期:1994.11.2
for the synthesis of bile pigments, some oxa- and thia-deazabiliverdin analogues were synthetized for the first time. Both UV/VIS spectroscopic and 1H1H}-NOE difference studies reveal that the oxa-deaza-biliverdin analogue 8a occurs in apolar solvents in a partly ‘stretched’ conformation, whereas the corresponding thia derivative 8b behaves rather like a genuine bile pigment. Unexpectedly, the helical-shaped
遵循用于合成胆汁颜料的常规方法,首次合成了一些草酸和噻二氮杂脱氢胆红素类似物。UV / VIS光谱和1 H 1 H} -NOE差异研究均表明,氧杂-脱氮-胆色素类似物8a以部分“拉伸”构型出现在非极性溶剂中,而相应的硫杂衍生物8b的行为却像真正的胆汁颜料。出乎意料的是,螺旋形构象在三恶英-特里达扎-胆红素类似物中也占优势,只能以其质子化形式14表征。