| 摘要 |
<p>Novel pyroglutamic acid derivatives (I), wherein R<sub>1</sub> is -OH, -ORa, wherein Ra is alkyl, cycloalkyl, alkenyl, cycloalkenyl, aryl, aralkyl or heterocyclyl; R<sub>2</sub>, R<sub>3</sub> and R<sub>4</sub> are independently H, a nitrogen protecting group which hydrolyzes under acidic conditions or phtalamide; X is a pharmaceutically acceptable anion; and Y is a N-containing group; either in the form of their isolated optically active stereoisomers or in the form of mixtures thereof, are useful compounds for enhancing an immuneresponse in a subject and/or for treating tumours, bacterial, fungal or viral infections, or autoimmune diseases.</p> |
