The ATR-FTIR quantitation of azithromycin in three products of commercial tablets was carried out on product specific quantitative regression models using powdered paracetamol as matrix modifier to overcome the variation of spectral response and influence of sample matrix. For each product, a PLS quantitative regression model was established using training infrared spectra obtained from reference mixtures (reference powders with known mass content (%, w/w) of azithromycin mixed homogenously with paracetamol to have mass percentage of azithromycin over total mass of azithromycin and paracetamol (P) from 30% to 70%). The spectral data were collected in wavenumber range depending on commercial product within the wavenumber zone from 1300 cm to 1750 cm to build quantitative regression models.
View Article and Find Full Text PDFA simple, easy-to-implement, and green infrared spectroscopic method was developed and validated for the quantitative determination of sildenafil citrate in tablets of unknown manufacturing formula. Homogenized tablet powder with known mass content (%, m/m) of sildenafil citrate was mixed with paracetamol to form standard mixtures with different percentages of sildenafil citrate on the total quantity of sildenafil citrate and paracetamol (designated as R). Unknown tablet samples were finely ground and mixed with paracetamol to form test mixtures having values about 50%.
View Article and Find Full Text PDFA new coumarin derivative, coumacasia (1) and eight known compounds, coumarin (2), cinnamaldehyde (3), 2-methoxycinnamaldehyde (4), 2-hydroxycinnamaldehyde (5), coniferaldehyde (6), cinnamic acid (7), 2-hydroxycinnamic acid (8), and cinnamic alcohol (9), were isolated from the methanol extract of Cinnamomum cassia. Their structures were elucidated by spectral data and by comparison with the reported literature. The cytotoxic activities of compounds 1-9 were evaluated with two human cancer cell lines, HL-60 and A-549.
View Article and Find Full Text PDFA methanol extract of the twigs of Cinnamomum cassia was found to inhibit xanthine oxidase. Purification of the methanol extract afforded three new phenolic glycosides, cinnacasolide A-C (11-13), together with 10 known compounds (1-10). The structures of the three new compounds were determined by interpretation of spectroscopic data.
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