UHPLC-PDA Assay for Simultaneous Determination of Vitamin D3 and Menaquinone-7 in Pharmaceutical Solid Dosage Formulation.

A newly developed method based on ultrahigh performance liquid chromatography (UHPLC) was optimized for the simultaneous determination of vitamin D3 and menaquinone-7 (MK-7) in tablet formulation in the present study. UHPLC separation of vitamin D3 and MK-7 was performed with ACE Excel 2 C18-PFP column (2 µm, 2.1 × 100 mm) at 0.6 mL min-1 flow rate, whereas the mobile phase consisted of methanol/water (19 : 1, v/v, phase A) and isopropyl alcohol (99.9%, phase B) containing 0.5% triethylamine. Isocratic separation of both the analytes was performed at 40°C by pumping the mobile phases A and B in the ratio of 50 : 50 (v/v, pH, 6.0). Both analytes were detected at a wavelength of 265 nm and the injection volume was 1.0 µL. The overall runtime per sample was 4.5 min with retention time of 1.26 and 3.64 min for vitamin D3 and MK-7, respectively. The calibration curve was linear from 5.0 to 100 µg mL-1 for vitamin D3 and MK-7 with a coefficient of determination (R2) ≥ 0.9981, while repeatability and reproducibility (expressed as relative standard deviation) were lower than 1.46 and 2.21%, respectively. The proposed HPLC method was demonstrated to be simple and rapid for the determination of vitamin D3 and MK-7 in tablets.

Curcumin: Synthesis optimization and in silico interaction with cyclin dependent kinase.

Curcumin is a natural product with enormous biological potential. In this study, curcumin synthesis was revisited using different reaction solvents, a catalyst (n-butylamine) and a water scavenger [(n-BuO)3B], to develop the optimal procedure for its rapid acquisition. During synthesis, solvent choice was found to be an important parameter for better curcumin yield and high purity. In a typical reaction, acetyl acetone was treated with boron trioxide, followed by condensation with vanillin in the presence of tri-n-butyl borate as water scavenger and n-butylamine as catalyst at 80 °C in ethyl acetate to afford curcumin. Moreover, curcumin was also extracted from turmeric powder and spectroscopic properties such as IR, MS, 1H NMR and 13C NMR with synthetic curcumin were established to identify any impurity. The purity of synthetic and extracted curcumin was also checked by TLC and HPLC-DAD. To computationally assess its therapeutic potential against cyclin dependent kinases (CDKs), curcumin was docked in different isoforms of CDKs. It was observed that it did not dock at the active sites of CDK2 and CDK6. However, it could enter into weak interactions with CDK4 protein.