The rhizomes of Alpinia pahangensis yielded a new bis-labdanic diterpene for which the name pahangensin C (1) was proposed along with twelve known analogues (2-13). The structure of 1 was elucidated via spectroscopic methods including 1D and 2D NMR techniques and LCMS-IT-TOF analysis. Compounds 2 and 12 were isolated for the first time from the genus Alpinia. This is the second occurrence of co...

A spectrophotometric method for the direct determination of microgram quantities of calcium in serum is presented. In this procedure, 0.02 ml. of serum is interacted with buffered glyoxal bis (2-hydroxyanil) solution (GBHA) at pH 12.6. The resultant red calcium-GBHA complex is diluted in methanol-acetone-water solution, and the absorbance determined at 520 m . The effects of pH, temperature, CB...

The binding properties of the cucurbit[7]uril host with three structurally related ferrocene-containing guests, ferrocenyltrimethylammonium, ferrocenylmethyltrimethylammonium and ferrocenylethyltrimethylammonium, have been investigated using (1)H NMR spectroscopy, mass spectrometry, voltammetry and computational methods. The experimental and computational data indicate that the stability of the...

1. The oxidation of p-dimethylaminomethylbenzylamine by purified placental diamine oxidase was followed by measuring the change in E250 caused by the production of p-dimethylaminomethylbenzaldehyde. 2. The inhibition of this reaction by substrate analogues such as isothiouronium, guanidinium, dimethylsulphonium and trimethylammonium compounds was extensively studied. 3. The type and degree of i...

Use of an 125I radioimmunoassay involving antiserum coupled to magnetizable cellulose, after prednisolone-21-phosphate interference is removed by dichloromethane extraction at pH 7.4 and endogenous glucocorticoid interference is removed by selective chemical derivatization with Girard's Reagent T [(carboxymethyl)trimethylammonium chloride hydrazide], allows determination of prednisolone in 10 m...