Uv 2600 240 5

Sun protection factor evaluation was performed by means of a UV-VIS spectrophotometer SHIMADZU UV-2600 240 V. Test compounds were dissolved in a dimethylsulfoxide /methanol (1:10) solution at the concentration of 0,0015 (±0,0005) % and the absorbance was measured between 250-600 nm using a 1 cm quartz cell at intervals of one 1 nm using a UV-Vis Spectrophotometer (SHIMADZU UV-2600 240 V). The absorbance data were transformed in transmission data applying the Equation 2.

All commercially available solvents and reagents were used without further purification. Standard samples were purchased from Sigma-Aldrich, Milan, Italy. NMR spectra were recorded on an Inova 500 spectrometer (Varian, Palo Alto, CA, USA). The chemical shifts (δ) are reported in part per million downfield from tetramethylsilane (TMS), which was used as internal standard, and the spectra were recorded in hexadeuteriodimethylsulphoxide (DMSO-d 6 ). Infrared spectra were recorded on a Vector 22 spectrometer (Bruker, Bremen, Germany) in Nujol mulls. The main bands are given in cm - Spectrophotometric analysis for the detection of filter parameters were conducted with a UV-VIS spectrophotometer SHIMADZU UV-2600 240 V.