Synthesis of two novel flavonoid derivatives with extended φ-system: Possible UV-B and UV-A sunscreens
Two novel flavonoid derivatives 5 and 6 were synthesized and characterized by IR, 1H, 13C NMR spectroscopy and mass spectrometry. The core structure of the two flavonoids was constructed by applying Baker-Venkataraman rearrangement on 2-Acylphenyl ester intermediate. The two compounds exhibited remarkable UV-visible absorption activities compared to flavone. Flavonoid 5 showed a bathochromic shift of 75.6 nm when the size of the cinnamic acid was increased by phenylbutadienyl group and hence it is a good UVA sunscreen. The 4-nitrostyryl group introduced in the cinnamic acid subchromophore of flavonoid 6 causes the compound to absorb at 308.3 and at 345.8 nm which will make it a broad-spectrum sunscreen.
Al-Busafi, Saleh N.,Al-Buraiki, Asma M.,Al-Qarni, Monther H.
Synthesis and evaluation of stilbenylbenzoxazole and stilbenylbenzothiazole derivatives for detecting β-amyloid fibrils
This paper describes a novel series of stilbenylbenzoxazole (SBO) and stilbenylbenzothiazole (SBT) derivatives for β-amyloid specific binding probes. These 24 compounds were synthesized and evaluated by competitive binding assay against β-amyloid 1-42 (Aβ42) aggregates using [125I]TZDM. All the derivatives displayed higher binding affinities with Ki value in the subnanomolar range (0.10-0.74 nM) than Pittsburgh Compound-B (PIB) (0.77 nM). Among these derivatives, SBT-2, 5-fluoroethoxy-2-{4-[2-(4-methylaminophenyl)vinyl]phenyl}benzothiazole, showed lowest Ki value (0.10 nM). In conclusion, the preliminary results suggest that these compounds are implying a possibility as a probe for detection of Aβ fibrils in Alzheimer's disease (AD) patients.
Lee, Ji Hoon,Byeon, Seong Rim,Lim, Soo Jeong,Oh, Seung Jun,Moon, Dae Hyuk,Yoo, Kyung Ho,Chung, Bong Young,Kim, Dong Jin
p. 1534 - 1537
(2008/12/20)
Metabolic N-Hydroxylation. Use of Substituent Variation to Modulate the in Vitro Bioactivation of 4-Acetamidostilbenes
N-Hydroxylation is an obligate step in the bioactivation of carcinogenic aryl amides.Previous reports from this laboratory demonstrated that variation of the 4' substituent of trans-4-acetamidostilbene (1) has a marked effect on the rate of its in vitro m
Hanna, Patrick E.,Gammans, Richard E.,Sehon, Russell D.,Lee, Man-Kil
p. 1038 - 1044
(2007/10/02)
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