Analysis of Xanthophylls in Corn by HPLC
An HPLC method was developed using the C-30 carotenoid column to separate and identify the major xanthophylls in corn (lutein, zeaxanthin, and β-cryptoxanthin). A photodiode array detector and a mobile phase consisting of methyl tert-butyl ether/methanol/water was used. All three xanthophylls eluted in less than 25 min. Yellow dent corn had a total xanthophyll content of 21.97 μg/g with lutein content of 15.7 μg/g, zeaxanthin content of 5.7 μg/g, and β-cryptoxanthin of 0.57 μg/g. Commercial corn gluten meal had a 7 times higher concentration of xanthophylls (145 μg/g), and deoiled corn contained 18 μg/g, indicating that the xanthophylls are probably bound to the zein fraction of corn proteins. 
HPLC Profile of Longan (cv. Shixia) Pericarp-Sourced Phenolics and Their Antioxidant and Cytotoxic Effects
Longan (Dimocarpus longan Lour.) pericarp, the main by-product of aril and pulp processing, is abundant in phenolic compounds and worthy of further utilization. The present work firstly reported HPLC analysis and in vitro antioxidant evaluation of longan (cv. Shixia) pericarp-derived phenolics (LPPs), the purified longan pericarp extract (LPE), as well as their cytotoxic effect on lung cancer cell line, A549. The results indicated that the purified LPE had significant amounts of phenolics, with content of 57.8 ± 0.6 mg of gallic acid equivalents per gram of dry longan pericarp (mg GAE·g−1 DLP), which consisted of six phenolic compounds (A–F), including protocatechuic acid (A), isoscopoletin (B), quercetin (C), ellagic acid (D), corilagin (E), and proanthocyanidins C1 (F). Antioxidant assays showed that LPPs (10 μM) and LPE (1.0 mg·mL−1) had certain antioxidant activities, in which corilagin (E) possessed the best DPPH radical scavenging rate 71.8 ± 0.5% and •OH inhibition rate 75.9 ± 0.3%, and protocatechuic acid (A) exhibited the strongest Fe2+ chelating ability 36.4 ± 0.7%. In vitro cytotoxic tests suggested that LPPs had different effect on A549 cell line, in which corilagin (E) exhibited potent cytotoxicity with an IC50 value of 28.8 ± 1.2 μM. These findings were further confirmed by cell staining experiments. 
HPLC method for amino acids profile in biological fluids and inborn metabolic disorders of aminoacidopathies
Quantification of total and individual amino acids in biological fluids such as plasma, urine and cerebrospinal fluid has an important diagnostic implication in laboratory medicine. The present paper describes protocols for the assay of total amino acids by modified method based on dinitrophenyl and HPLC profile involving pre-column derivatization with o-pthalaldehyde (OPA) derivatization, respectively. The method, based on the alkylation of-SH groups prior to OPA derivatization of amino acids followed by reverse phase high performance liquid chromatography, provide a comprehensive profile of more than twenty amino acids (including-SH group containing) in a single run lasting about 45 minutes. The present study, apart from establishing the normal profile of amino acids in plasma of Indian sub population, also presents HPLC profile for some of the rare amino acidopathies. 
Antioxidant Activity and HPLC Fingerprinting Profile of Ethanolic Extract of Euphorbia cotinifolia Bark from Bangladesh
Aims: The present study was designed to investigate the antioxidant activity and High Performance Liquid Chromatography (HPLC) fingerprinting profiles of the ethanolic stem bark extract of Euphorbia cotinifolia growing in Bangladesh.
Methodology: In-vitro antioxidant activity of the ethanol extract was carried out using ABTS (2, 2′-Azino-Bis-3-Ethylbenzothiazoline-6-Sulfonic Acid) radical scavenging activity, reducing power assay, total antioxidant activity, total phenolic and flavonoid content determination. The polyphenolics content in the ethanol extract was identified and quantified through HPLC with Diode-Array Detection method.
Results: The ABTS radical scavenging activity demonstrated an IC50 (Inhibitory concentration 50) of 18.50 ml, while the maximum absorbance of reducing power was found to be 0.1148 at 250 ml, respectively. The total antioxidant capacity, total phenolic and flavonoid contents were found at significant level (347.8 mg of ascorbic acid/g, 56.24 mg/g of gallic acid, and 137.4 mg/g of quercetin equivalent), respectively. Catechin, caffeic acid, epicatechin, p-coumeric acid, ellagic acid and quercetin were quantified in the ethanol extract by reverse-phase HPLC (175.50, 4.61, 67.73, 4.01, 558.31 and 4.35 mg/100g of dry extract, respectively).
Conclusion: These results may be due to the higher polyphenolics content of the ethanol extract of Euphorbia cotinifolia bark, which also accounts for the significant antioxidant activity observed. Hence, it can be suggested that bioactive polyphenolics compound in Euphorbia cotinifolia might be responsible for the antioxidant activities. 
Assessment of the Deleterious Effects of Therapeutic Antitussives on Enamel. Mapping the Chemical Profile of Over the Counter Cough Lozenges Using Analytical HPLC
Aim: 1) To evaluate and compare changes in the micro hardness of enamel after exposure to different cough lozenges.
2) To assess the pH of dissolved lozenge solutions, and
3) To analyze the number of components in cough lozenges using Analytical HPLC (High-performance liquid chromatography).
Study Design and Methods: Experimental Confirmatory Study.
Forty extracted human molars were selected for the study. The teeth were embedded in self-cured acrylic resin except a small rectangular area of 3.0 mm × 2.0 mm on the buccal surface. Micro hardness tests were carried out with a Vickers Diamond Indenter with a 50 gm load for 15 seconds. Based on the lozenges used, the samples were randomly divided into 4 groups (n=10);
Group 1: Control – No treatment
Group 2: Lozenge – A
Group 3: Lozenge – B
Group 4: Lozenge – C
Lozenges were dissolved in 20 ml of artificial saliva for 30 minutes. After complete dissolution, the samples were immersed in lozenges solution for 30 minutes at room temperature, four times a day for one week. After each exposure specimens were washed in deionized water for 20 seconds and immersed in artificial saliva until the next experimental step. At the end of 7 days, again the micro hardness of the enamel surfaces was measured with the Vickers Indenter at the same specifications.
Change in the pH of artificial saliva following dissolution of lozenges was assessed using Microprocessor pH meter.
Components of cough lozenges were separated and analyzed using Analytical HPLC.
Results: Paired t- test and ANOVA were used for statistical analysis. All experimental groups showed a significant decrease in micro hardness of tooth enamel. Analytical HPLC revealed the complex composition of these lozenges.
Conclusion: Increased consumption of cough lozenges reduces the micro hardness of teeth which may lead to erosion, sensitivity and caries susceptibility. 
 Moros, E.E., Darnoko, D., Cheryan, M., Perkins, E.G. and Jerrell, J., 2002. Analysis of xanthophylls in corn by HPLC. Journal of Agricultural and Food Chemistry, 50(21), pp.5787-5790.
 Bai, X., Pan, R., Li, M., Li, X. and Zhang, H., 2019. HPLC profile of Longan (cv. Shixia) pericarp-sourced phenolics and their antioxidant and cytotoxic effects. Molecules, 24(3), p.619.
 Babu, S.S., Shareef, M.M., Shetty, A.P.K. and Shetty, K.T., 2002. HPLC method for amino acids profile in biological fluids and inborn metabolic disorders of aminoacidopathies. Indian journal of clinical biochemistry, 17(2), pp.7-26.
 Khan, T. A., Rahman, M. M., Kabir, M. A., Rahman, S. E., Akbar, P., Hossain, H. and Jahan, I. A. (2018) “Antioxidant Activity and HPLC Fingerprinting Profile of Ethanolic Extract of Euphorbia cotinifolia Bark from Bangladesh”, Journal of Advances in Medicine and Medical Research, 27(5), pp. 1-8. doi: 10.9734/JAMMR/2018/19593.
 Sharma, R., Kaushik, M., Rana, R., Reddy, P., Mehra, N., Yadav, M. and Jain, V. (2016) “Assessment of the Deleterious Effects of Therapeutic Antitussives on Enamel. Mapping the Chemical Profile of Over the Counter Cough Lozenges Using Analytical HPLC”, Journal of Advances in Medicine and Medical Research, 18(6), pp. 1-8. doi: 10.9734/BJMMR/2016/29168.