Sonogashira reaction of 2-isopropyl-3-(trifluoromethanesulfonyloxy)psoralen with terminal arylacetylenes gave 2-isopropyl-3-(arylethynyl)psoralens which were converted into the corresponding Z-alkenes by reduction with hydrogen in the presence of Lindlar catalyst or by thermal decomposition of preliminarily prepared Ti(II)–alkyne complexes. The reaction of 2-isopropyl-3-(trifluoromethanesulfony...

Base-catalyzed reversal of a psoralen-DNA cross-link has been observed under denaturing alkaline conditions at elevated temperatures. The cross-link was formed between 4'-(hydroxymethyl)-4,5',8-trimethylpsoralen and the two thymidine residues (T) on opposite strands of the double-stranded DNA formed from the self-complementary oligonucleotide 5'-GGGTACCC-3'. In contrast to the photoreversal of ...

Synthetic DNA substrates containing a site-specifically engineered psoralen monoadduct or diadduct were used to characterize the response of the E. coli RNA polymerase elongation complex to these lesions. The psoralen derivative HMT (4'-hydroxymethyl-4,5', 8-trimethylpsoralen) was site specifically placed into two synthetic double-stranded DNA fragments each of which contained an E. coli RNA po...