Linked Life Data

8164263

Source:http://linkedlifedata.com/resource/pubmed/id/8164263

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1994-5-24
pubmed:abstractText
he synthesis, DNA binding and in vitro photoinduced cytotoxic properties of a number of minor groove and sequence-directed psoralen and coumarin conjugates of pyrrole- and imidazole-containing distamycin analogues 2-5 are described. Results from an ethidium displacement assay on calf thymus and T4 DNA suggest that like distamycin these agents bind strongly to the minor groove of DNA. The data show that these conjugates exhibit a lower AT preference than distamycin and the decrease is significantly greater for the imidazole-containing compounds. All of the compounds along with 8-methoxypsoralen, 1, were relatively noncytotoxic in the dark with only the imidazole-psoralen compound 3 giving an IC50 value below 100 microM. Following UV activation, all compounds showed an increased potency with photoinduced dose modifications in the human chronic myeloid leukemia K562 cells of > 333, 12, > 1.3, and > 2.5 for compounds 2-5, respectively, under the UV irradiation conditions employed. The psoralen-pyrrole analogue 2 was over 300 times more active following UV activation than agent 1, 250 times more potent than the corresponding coumarin conjugate 4, and 15-fold more potent than its imidazole analogue 3. Data from CD dilution (with DMF) studies show that upon irradiation with light at 366 nm, compounds 2-5 bind irreversibly to DNA. Furthermore, upon irradiation compound 2 produced interstrand cross-linked DNA in quantitative yield, with isolated DNA, at > 300- and > 3000-fold lower drug concentrations than the imidazole analogue 3 and 8-methoxypsoralen, respectively. As expected coumarin conjugates 4 and 5 did not produce any cross-linked DNA under any conditions. Since the psoralen conjugates are more phototoxic than their coumarin analogues, these results suggest that DNA interstrand cross-link formation may be an important mechanism by which they exert their biological activity in cells. In addition, the enhanced photocytotoxic potency of conjugate 2 over 3 may be related to its larger binding constant, more efficient DNA cross-linking ability, and possibly to its preference for AT-rich sequences.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-2623
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1208-13
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
In vitro photoinduced cytotoxicity and DNA binding properties of psoralen and coumarin conjugates of netropsin analogues: DNA sequence-directed alkylation and cross-link formation.
pubmed:affiliation
Department of Chemistry, Furman University, Greenville, South Carolina 29613.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't