Development of a rapid quantitative method of analysis of carbohydrate fatty acid ester reaction mixtures using 1H qNMR.

Two new analytical methods, applying absolute 1H qNMR, were developed to monitor product yield and quantify unreacted carbohydrate and fatty acid reactants, in the synthesis of carbohydrate fatty acid esters (CFAE). These methods provide a mass balance of the crude reaction mixtures and diversify the analytical screening and quantitation approaches available within the synthesis of these molecules. Both methods were validated for the model reaction of methyl α-d-glucopyranoside (MAG) and lauric acid (LA) to form the mono ester product, methyl 6-O-dodecanoyl-α-d-glucopyranoside. Analysis in CD3OD by 1H qNMR, with fumaric acid (FA) as an internal standard (IS), allowed monitoring of all reaction components. Alternatively, using CDCl3 and (E)-stilbene as IS enabled the analysis of CFAE and fatty acid. Parameters calculated for method validation included specificity and selectivity, linearity, accuracy, intermediate precision, limit of detection (LOD), limit of quantification (LOQ) and robustness. Both methods provided excellent linearity with R2 > 0.997. The accuracy, precision, and robustness of the method in CD3OD was <2 % uncertainty making it suitable for complete reaction analysis. The method completed in CDCl3 resulted in accuracy, intermediate precision, and robustness of <5 %, except for accuracy in the lowest levels of concentration (>5 %). For all related analytes in the CD3OD and CDCl3 methods, the LOD and LOQ were determined to ensure applicability for the intended use in the assessment of reaction crude composition. Finally, the system suitability was assessed in a scaled lipase catalysed CFAE synthetic reaction. The determined qNMR product yields were verified against isolated purified product yields with <5 % uncertainty.

Gestational alloimmune liver disease with alpha thalassaemia in a neonate.

A term baby presented with cholestatic jaundice since birth. She was diagnosed as gestational alloimmune liver disease-neonatal haemochromatosis (GALD-NH) on evaluation. The baby received intravenous immunoglobulin (IVIG) and recovered gradually from the illness. She was also diagnosed with alpha thalassaemia during the course of evaluation, confirmed by genetic testing. NH is a very rare disorder that results in fetal loss or neonatal death due to liver failure. NH is now known to be a phenotypic expression of GALD. Worldwide, NH is seen in less than one in a million pregnancies. The mortality rate of GALD has traditionally been around 80% with almost all babies needing liver transplantation, with advent of maternal and neonatal IVIG treatment, this has reduced significantly. There is no reported case of GALD-NH treated successfully with IVIG from India. Here, we report an interesting case of GALD-NH with alpha thalassaemia.