RESUMO
Two new secolignans and one new neolignan, named feddeiphenols A-C (1-3), together with eight known compounds (4-11), were isolated from the leaves and stems of Daphne feddei. Their structures were established on the base of spectroscopic methods, mainly extensive NMR, UV spectroscopy, and MS spectrometry. Compounds 1-11 were tested for their anti-human immunodeficiency virus (HIV)-1 activity and cytotoxicity. The results revealed that compounds 1, 2, 3, 7, and 9 showed therapeutic index (TI) values above 30, respectively, and the other compounds also showed weak anti-HIV-1 activity. Compound 1 showed modest cytotoxic activity. The other compounds also showed weak cytotoxic activity.
Assuntos
Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Daphne/química , Lignanas/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Fármacos Anti-HIV/isolamento & purificação , Linhagem Celular Tumoral , HIV-1/efeitos dos fármacos , Humanos , Lignanas/isolamento & purificação , Lignanas/toxicidade , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Conformação Molecular , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Caules de Planta/química , Espectrofotometria UltravioletaRESUMO
A new fluorescent probe based on pyrazolo[1,5-a]pyridine was synthesized and used to monitor the pH in cells. This probe exhibited a fast response to acidic pH (less than 10 s), a high quantum yield (φ = 0.64), and high selectivity and sensitivity. The response mechanism of the fluorescent probes relies on the ICT change.
RESUMO
The aim of the present study was to evaluate the diagnostic accuracy of low-radiation-dose and low-contrast-dose (double low-dose) coronary computed tomography angiography (CTA) for coronary artery stenosis in patients with suspected coronary artery disease (CAD).Totally 88 patients with suspected CAD were divided in the routine and double low-dose groups. Subjective image quality (IQ) was scored and diagnostic performance for detecting ≥50% stenosis was determined with the invasive coronary angiography. IQ and diagnostic performance were analyzed and compared between the 2 groups.There was no significant difference in the IQ of coronary artery between the routine and double low-dose groups, with good inter-observer agreement for the IQ. There were no significant differences in the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy on the per-patient, per-vessel, or per-segment level between the routine and double low-dose groups. The contrast medium injection volume in the double low-dose group was reduced by 37.1% compared with the routine-dose group. The effective dose in the double low dose was reduced by 44.5% compared with the routine-dose group.Double low-dose coronary CTA with IR can acquire satisfactory IQ and have high diagnostic sensitivity, specificity, and accuracy for the detection of coronary artery stenosis.