Slupska Marta, Pulka-Ziach Karolina, Deluga Edyta, Sosnowski Piotr, Wilenska Beata, Kozminski Wiktor, Misicka Aleksandra
Faculty of Chemistry, University of Warsaw, Warsaw, Poland.
J Pept Sci. 2015 Dec;21(12):893-904. doi: 10.1002/psc.2832.
The Pictet-Spengler (PS) cyclizations of β(3)-hTrp derivatives as arylethylamine substrates were performed with L-α-amino and D-α-amino aldehydes as carbonyl components. During the PS reaction, a new stereogenic center was created, and the mixture of cis/trans 1,3-disubstituted 1,2,3,4-tetrahydro-β-carbolines was obtained. The ratio of cis/trans diastereomers depends on the stereogenic centre of used amino aldehyde and the size of substituents. It was confirmed by 1H and 2D NMR (ROESY) spectra. The conformations of cyclic products were studied by 2D NMR ROESY spectra. Products of the PS condensation after removal of protecting group(s) can be incorporated into a peptide chain as tryptophan mimetics with the possibility of the β-turn induction.
以L-α-氨基醛和D-α-氨基醛作为羰基组分，对作为芳基乙胺底物的β(3)-hTrp衍生物进行了 Pictet-Spengler（PS）环化反应。在PS反应过程中，产生了一个新的手性中心，并得到了顺式/反式1,3-二取代的1,2,3,4-四氢-β-咔啉混合物。顺式/反式非对映异构体的比例取决于所用氨基醛的手性中心和取代基的大小。这通过1H和二维核磁共振（ROESY）光谱得到了证实。通过二维核磁共振ROESY光谱研究了环状产物的构象。去除保护基后的PS缩合产物可以作为色氨酸模拟物掺入肽链中，并有可能诱导β-转角。
