Spd 6av spectrophotometer

The UV–visible (UV–VIS) spectra were recorded with a Hitachi U-2001 (Hitachi High-Technologies Corporation, Tokyo, Japan) in diethyl ether (Et₂O). The positive ion fast atom bombardment mass spectrometry (FAB MS) spectra were recorded using a JEOL JMS-HX 110A mass spectrometer (JEOL, Tokyo, Japan) with m-nitrobenzyl alcohol as a matrix. The positive ion electro spray ionization time of flight mass (ESI-TOF MS) spectra were recorded using a Waters Xevo G2S Q TOF mass spectrometer (Waters Corporation, Milford, CT, USA). The ¹H-NMR (500 MHz) and ¹³C-NMR (500 MHz) spectra were measured with a Varian UNITY INOVA 500 spectrometer (Agilent Technologies, Santa Clara, CA, USA) in CDCl₃. The chemical sifts are expressed in ppm relative to tetramethyl silane (TMS) (δ = 0) as an internal standard for ¹H-NMR and CDCl₃ (δ = 77) as an internal standard for ¹³C-NMR. J values are given in Hz. The CD spectra were recorded in EPA [Et₂O–isopentane–ethanol (5:5:2)] at room temperature with a Jasco J-500C spectropolarimeter (Jasco corporation, Tokyo, Japan). Preparative high-performance liquid chromatography (HPLC) was performed on a Shimadzu LC-6AD with a Shimadzu SPD-6AV spectrophotometer (Shimadzu Corporation, Kyoto, Japan) set at 450 nm. The column used was a 250mmX10mm i.d. 10 μm Cosmosil 5SL-II and 5C18 II (Nacalai tesque, Kyoto, Japan).

The AST content in the plasma and skin tissues was quantified using high performance liquid chromatography (HPLC). Blood samples were treated with EDTA and citrate-theophylline-adenosine-dipyridamole (BD Biosciences, Tokyo, Japan) and centrifuged at 2,500×g for 30 minutes to obtain plasma and then stored at −80°C until HPLC measurement. Plasma treated with 5 mL of hexane/ether (8:2, v/v) was subjected to preparative HPLC, while the skin tissues were evaporated until dry and subsequently expressed with 3 mL of acetone and homogenized. The residue was filtered, and the solution was subjected to HPLC on a Shimadzu SPD-6AV spectrophotometer (Shimadzu, Kyoto, Japan) set at 470 nm. The column used was a Cosmosil 5SL-II column (4.6×250 nm, Nacalai Tesque, Kyoto, Japan) with a mobile phase of acetone/hexane (2:8). A low rate was employed (1.0 ml/min). The AST content was quantified relative to calibration with that observed in a standard sample.