Simultaneous determination of four neuroprotective compounds of Tilia amurensis by high performance liquid chromatography coupled with diode array detector

Method Development and Validation for the Determination of Caffeine: An Alkaloid from Coffea arabica by High-performance Liquid Chromatography Method

Objective:

The present study was investigated to develop and validate a reversed phase high performance liquid chromatography method for the determination of caffeine from bean material of Coffee arabica.

Materials and Methods:

The separation was achieved on a reversed-phase C18 column using a mobile phase composed of water: methanol (50:50) at a flow rate of 1.0 mlmin-1. The detection was carried out on a UV detector at 272 nm. The developed method was validated according to the requirements for International Conference on Harmonisation (ICH) guidelines, which includes specificity, linearity, precision, accuracy, limit of detection and limit of quantitation.

Results:

The developed method validates good linearity with excellent correlation coefficient (R2 > 0.999). In repeatability and intermediate precision, the percentage relative standard deviation (% RSD) of peak area was less than 1% shows high precision of the method. The recovery rate for caffeine was within 98.78% - 101.28% indicates high accuracy of the method. The low limit of detection and limit of quantitation of caffeine enable the detection and quantitation of caffeine from C. arabica at low concentrations.

Conclusion:

The developed HPLC method is a simple, rapid, precisely, accurately and widely accepted and it is recommended for efficient assays in routine work.

SUMMARY

A simple, accurate, and sensitive high-performance liquid chromatography (HPLC) method for caffeine from Coffea arabica has been developed and validated. The developed HPLC method was validated for linearity, specificity, precision, recovery, limits of detection, and limits of quantification by the International Conference on Harmonization guidelines. The results revealed that the proposed method is highly reliable. This method could be successfully applied for routine quality work analysis.

Abbreviation Used:C. arabica: Coffee arabica, ICH: International Conference on Harmonisation, % RSD: Percentage Relative Standard Deviation, R2: Correlation Coefficient, ppm: Parts per million, LOD: Limits of detection, LOQ: Limits of quantification, SD: Standard deviation, S: Slope, RP-HPLC: Reverse phase high performance liquid chromatography, v/v: Volume per volume.

Antineuroinflammatory and Antiproliferative Activities of Constituents from Tilia amurensis

As part of our ongoing search for bioactive constituents of natural Korean medicinal resources, we found in a preliminary study that the methanol (MeOH) extract from the trunks of Tilia amurensis RUPR. showed an inhibitory effect on nitric oxide (NO) production in an activated murine microglial cell line. A bioassay-guided fractionation and chemical investigation of the MeOH extract resulted in the isolation and identification of a new isoflavonoid glycoside, orobol 4'-O-β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside (1) and 16 known compounds (2-17). The structure of the new compound was determined by spectroscopic methods, i.e., one-dimensional (1D) and two-dimensional (2D)-NMR techniques and high resolution (HR)-MS, and chemical methods. The antineuroinflammatory activities of the isolated compounds were determined by measuring NO levels in the medium using murine microglial BV-2 cells. Among them, 12 compounds, including compound 1 (most active with an IC50 value of 23.42 µM), inhibited NO production in lipopolysaccharide-stimulated BV-2 cells. Moreover, compounds 1-4 showed moderate antiproliferative activities against the SK-MEL-2 cell line, with IC50 values ranging from 12.31 to 19.67 µM.

Neuroprotective compounds of Tilia amurensis

BACKGROUND

Tilia amurensis (Tiliacese) has been used for anti-tumor and anti-inflammatory in Korea, China, and Japan.

OBJECTIVE

In this study, we isolated five compounds from T. amurensis and determined whether protected neuronal cells against glutamate-induced oxidative stress in HT22 cells.

MATERIALS AND METHODS

Compounds were isolated using chromatographic techniques including silica gel, Sephadex LH-20 open column and high performance liquid chromatography analysis, and evaluated neuroprotective effect in HT22 cells by 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay.

RESULTS

β-D-fructofuranosyl α-D-glucopyranoside (1), (-)-epicatechin (2), nudiposide (3), lyoniside (4), and scopoletin (5) were isolated by bioactivity-guided fractionation from the ethyl acetate fraction of T. amurensis. Among them, (-)-epicatechin, nudiposide, lyoniside, and scopoletin had significant neuroprotective activities against glutamate-injured neurotoxicity in HT22 cells.

CONCLUSION

These results demonstrated that compound two, three, four, and five have a pronounced protective effect against glutamate-induced neurotoxicity in HT22 cells.