Microbial transformation of isocoronarin D by Cunninghamella echinulata NRRL 1386

The diterpene isocoronarin D (1) is a bioactive major constituent of labdane diterpene from the aerial parts of Curcuma comosa Roxb. (Zingiberaceae), the Thai medicinal plant. Microbial transformation of 1 was performed by the fungus Cunninghamella echinulata NRRL 1386 to yield three new metabolites, 3β-hydroxyisocoronarin D (2), 6α-hydroxyisocoronarin D (3) and 3β,7α-dihydroxyisocoronarin D (4). The structures of the new compounds were elucidated by spectroscopic techniques.

     

Online assay of bone specific alkaline phosphatase with a flow injection-bead injection system

Alkaline phosphatase (ALP) has been used as one of the biomarkers for bone resorption and liver diseases. Normally, total alkaline phosphatase is quantified along with other symptoms to determine the releasing source of the alkaline phosphatase. A semi-automated flow injection-bead injection system was proposed to conveniently and selectively assay bone alkaline phosphatase (BALP) based on its specific binding to wheat germ coated beads. Amount of BALP in serum was determined from the intensity of the yellow product produced from bound BALP on the retained beads and its substrate pNPP. The used beads were discarded and the fresh ones were introduced for the next analysis. The reaction cell was designed to be opened and closed using a computer controlled solenoid valve for a precise incubation time. The performance of the proposed system was evaluated by using it to assay BALP in human serum. The results were compared to those obtained by using a commercial ELISA kit. The system is proposed to be an easy and cost effective system for quantification of BALP as an alternative to batch wise wheat germ specific binding technique.     

Simple spectrophotometric flow injection system with an in-valve minicolumn for enhancement during the determination of chromium(III) using EDTA.

A simple spectrophotometric flow injection (FI) procedure for the determination of Cr(III) using ethylenediaminetetraacetic acid (EDTA) was developed. An FI system with a column packed with Amberlite IR-120(H) was employed for sample pretreatment. This leads to the possibility of a single standard calibration. A linear calibration in a range of 10-27 microg Cr(III) was obtained with a detection limit of 1 microg Cr(III) and RSD of 2% (18 microg Cr(III), n=12). The proposed procedure was applied for determination of Cr(III) in leachate and dietary supplement samples. The results agreed with those obtained by the standard methods.     

Sequential Injection Ion Chromatography with Flow Injection Post Column Derivatization Capable of Using the Unstable Reagent Murexide to Determine Calcium and Magnesium in a Mixture

A hyphenated sequential injection ion chromatography–flow injection analysis (SIIC–FIA) system is proposed for post column derivatization capable of using murexide, an unstable but commonly available reagent, for the determination of calcium and magnesium in a mixture. A short ion exchange column was modified from a 4.6 mm × 10 mm C18 monolithic guard column. Calcium/magnesium mixture and murexide were used as model analytes and derivatizing agent, respectively. The FIA post column allows the use of unstable chromogenic reagents. The continuous flow of liquid also helped to stabilize the signal baseline during detection. A single concentration based calibration graph was demonstrated. The system requires low volumes of standard/sample (5–50 µL) and mobile phase (4.50 mL), and offers sample throughput at 8 h^?1 without the need for long column calibration. Detection limits were 0.5 and 0.1 µg for Ca²⁺ and Mg²⁺, respectively. Working ranges were 1–5 µg Ca²⁺ and 0.2–1 µg Mg²⁺. Analyses of well and drinking water samples were demonstrated and validated with the standard complexometric titration.