No abstract

Three cationic water-soluble chlorin e(6) derivatives, that is, 6a-,gammab-,7c-tris(2-trimethylammonioethyl)chlorin e(6) (1), 6a-,gammab-,7c-tris(3-methylpyridiniummethyl)chlorin e(6) (2), and 6a-,gammab-, 7c-tris(2-trimethylammonioethyl)-2-(3-trimethylammonioprop-1-enyl)chlorin e(6) (3), have been designed and synthesized to allow the study of their DNA-binding and -photocleavage activities. The DNA-unwinding assay, measurements of melting temperatures of double-stranded DNA, and the induced CD and visible absorption spectra have revealed that 1 and 3 are intercalated into the base pairs of the double-helical DNA, while 2 is bound to outside the minor groove of the double-helical DNA. The cationic water-soluble chlorin e(6) derivatives effectively cleave the double-helical DNA under photoirradiation and the DNA-photocleavage activity increases in the order 3>1>2. The DNA-binding and -photocleavage characteristics of the three cationic water-soluble chlorin e(6) derivatives are influenced by aspects of their molecular structure, such as the kind, number, and position of the cationic substituents.

Background: Many patients with atopic dermatitis (AD) know that harsh rubbing of their skin might worsen their skin symptoms. They consider that the force they use to rub their skin when removing their makeup cosmetics should not be hard and their cleansing habits could worsen their skin symptoms. However, we presume that the force they use to rub their skin may still be strong and might worsen their skin symptoms. Aims:We characterized the effects of rubbing the skin of AD patients during cleansing of makeup cosmetics.Patients/Methods: A cleansing oil which has a higher cleansing ability compared the cleansers used daily by the subjects but required less rubbing force was used. We performed a 4-week clinical trial of this cleansing oil on 35 female subjects who had mild AD skin symptoms on their faces. Each subject used the cleansing oil instead of their usual makeup remover without changing their other facial skin care habits. Prior to the study, and at the end of weeks 1 and 4, the skin conditions of each subject were evaluated.Results: Four weeks of usage of this cleansing oil significantly decreased skin dryness, scaling, irritation, erythema, and itchiness. Higher improvements were observed for subjects who had previously used cleansers with less cleansing ability. Accompanying those improvements, a significant increase in moisture-retention ability and a significant decrease in transepidermal water loss were observed. Conclusion:These results suggest that many AD patients cleanse their face with hard rubbing of their skin because of the low cleansing ability of their skin cleansers and may worsen their AD skin symptoms without realizing it.

A series of mono-, di-, tetra- and hexacationic esters of pyropheophorbide a/b have been designed and synthesized to explore the intercalation of their phorbine ring between the base pairs of double-helical DNA and the influence of their peripheral substituents on the DNA interactions. Mono-(1), di-(2, 3) and tetra-(4, 5) cationic pyropheophorbides are soluble as an oligomeric aggregate in HEPES buffer, but hexa-(6) cationic pyropheophorbide is soluble as a monomer at lower concentrations. The interaction of these cationic pyropheophorbide derivatives with DNA has been investigated by DNA unwinding assay, fluorescence energy transfer, and measurements of the melting temperature of the double-helical DNA and visible absorption spectra. Dicationic 2 and 3 bind outside the double-helical DNA without and/or with self-aggregation and with self-aggregation, respectively, because they cannot intercalate between the base-pairs due to their aggregation. On the other hand, tetracationic 4 and 5 and hexacationic 6 intercalate between the base pairs of the double-helical DNA. The binding mode of the cationic pyropheophorbides a/b is strongly dependent on the number and position of the cationic peripheral substituents of the pyropheophorbides.