Chns 932

Soils were tested for their particle size distribution and organic matter content. The particle size distribution was determined using the pipette method together with dry sieving²⁵ , whereas organic matter was determined by the loss on ignition method²⁵ . Soil chemical tests involved the pH (H₂O), plant nutrient contents (Ca, Mg, K, and P), organic carbon content, electrical conductivity, and metal ions. The soil pH in water was determined at soil: solution ratio (1/2.5) and measured using a pH meter (Model: Metrohm 827, Riverview, FL, USA). Organic carbon was measured with the Walkley and Black method^{26 (link)}. Electrical conductivity was measured in saturated gypsum extracts^{27 (link)} (Model: Mettler Toledo SevenEasyTM Conductivity Meter S30, Hamilton, New Zealand). The total C, N, and S were measured using a CHNS analyzer (Model: LECO CHNS-932).

All chemicals were obtained from Aldrich/Merck (St. Louis, MO, USA), VWR (Radnor, PA, USA), Fluorochem (Derbyshire, UK), and ABCR (Karlsruhe, Germany). TLC analyses were performed on Merck silica gel 60 F254 plates using phosphomolybdic acid or anisaldehyde and heat for detection. Silica gel NORMASIL 60 40–63 μm was used for flash chromatography. NMR spectra were recorded on a Bruker spectrometer (400 MHz or 300 MHz for ¹H and 100 MHz or 75 MHz for ¹³C), (Billerica, MA, USA). Chemical shifts are reported in δ ppm referenced to CDCl₃ (δ = 7.26 for ¹H and 77.00 for ¹³C), CD₃OD (δ = 3.31 for ¹H and 49.00 for ¹³C), or D₂O (δ = 4.79 for ¹H). Bidimensional spectra (HMQC, HMBC, COSY, and NOESY) were recorded in order to carry out the assignment. Infrared spectra were done in a Perkin-Elmer spectrum 100 (Agilent, Santa Clara, CA, USA). Specific optical rotation was measured in a Polarimeter Anton Paar MCP 100 (Anton Paar, Graz, Austria). Melting points of solid compounds were determined using a Stuart Scientific Melting Point Apparatus SMP3 (Stuart, Staffordshire, UK). Microanalyses were done on a LECO CHNS-932 (LECO, St. Joseph, MI, USA). Absorbance of p-nitrophenoxyde released in the enzymatic reactions was measured at 405 nm in a Perkin-Elmer Lamba25 (PerkinElmer, Waltham, MA, USA).

All chemicals were obtained from Aldrich/Merck (St. Louis, MO, USA), VWR (Radnor, PA, USA) and Fluorochem (Derbyshire, UK). TLC analyses were performed on Merck silica gel 60 F254 plates using phosphomolybdic acid or anisaldehyde and heat for detection. Silica gel NORMASIL 60 40–63 μm was used for flash chromatography. NMR spectra were recorded on a Bruker spectrometer (400 MHz or 300 MHz for ¹H and 100 MHz or 75 MHz for ¹³C). Chemical shifts are reported in δ ppm referenced to CDCl₃ (δ = 7.26 for ¹H and 77.00 for ¹³C). Infrared spectra were performed in a Perkin-Elmer spectrum 100 (Agilent, Santa Clara, CA, USA). Melting points of solid compounds were determined using a Stuart Scientific Melting Point Apparatus SMP3 (Stuart, Staffordshire, UK). Microanalyses were done on a LECO CHNS-932 (LECO, St. Joseph, MI, USA).