The crystal structure of coclaurine hydrobromide monohydrate and the absolute configuration of coclaurine.
Abstract The structure and absolute configuration of coclaurine has been determined by X-ray analysis of its hydrobromide monohydrate. The (+)-enantiomer has the D-configuration. The chirality of the molecular structure is correlated with circular dichroism measurements.
Chemosystematics of the lauraceae
Abstract The various chemical constituents of the Lauraceae are discussed in relation to the taxonomy of the family. Although there is a great paucity of data, the variation in the arylpropanoids, alkaloids, flavanoids and terpene constituents is in general in agreement with the subdivision of the family put forward by Kostermans.
Novel method for the determination of the methoxyl content in lignin by headspace gas chromatography.
The paper reports on a headspace gas chromatographic (HS-GC) method for the determination of methoxyl in lignin. The method involves the quantitive cleavage of methoxyl with hydroiodic acid (HI) to form methyl iodide in a closed headspace sample vial at 130 °C for 30 min. After HI has been added, the sample is neutralized by injecting a sodium hydroxide solution; the methyl iodide in the vial was determined by HS-GC using a flame ionization detector. The results showed that the method has an excellent measurement precision (RSD < 0.69%) and accuracy (RSD < 3.5%) for the quantification of methoxyl content in lignin. The present method is simple and accurate and can be used for the efficient determination of methoxy1 content in lignin and related materials.