Experimental design approach for the quantitative analysis of multicomponents by single marker and HPLC fingerprinting of Thunbergia laurifolia aqueous extract.

INTRODUCTION: Thunbergia laurifolia is used in traditional Thai medicine to reduce fever and treat mouth ulcers. However, the quantitative analysis of chemical markers has not yet been officially defined. OBJECTIVE: The objective of this study is to develop a high-performance liquid chromatography (HPLC) method using a design of experiment (DoE) for the quantitative analysis of multicomponents by single marker (QAMS) and fingerprinting of the T. laurifolia aqueous extract. MATERIALS AND METHODS: Critical variables were screened using a two-level fractional factorial design, followed by the optimization of the selected variables using a central composite design. The validated method was applied for quality assessment based on QAMS and fingerprinting of the extract. RESULTS: Optimum conditions of DoE for the analysis of caffeic acid, vicenin-2, and rosmarinic acid were determined. The relative correction factors for caffeic acid and vicenin-2 were calculated using rosmarinic acid as an internal reference standard, and their contents in 30 samples were determined. The differences between the external standard method (ESM) and QAMS were compared. No significant difference was observed in the quantitative determination, proving the consistency QAMS and ESM. HPLC fingerprints of T. laurifolia were established with 8 of 12 characteristic peaks that were structurally characterized using HPLC-diode array detection-electrospray ionization/tandem mass spectrometry. The similarity of the fingerprints in all samples was ≥0.74, and the pattern recognition of the characteristic peaks was satisfied. CONCLUSION: The proposed method efficiently detected multiple components of the T. laurifolia extract. Thus, the method is beneficial in providing references for enhancing the quality control of other herbal medicines.

Evaluation of inflammatory biomarkers and vitamins in hospitalized patients with SARS-CoV-2 infection and post-COVID syndrome.

OBJECTIVES: Concentrations of neopterin, kynurenine and kynurenine/tryptophan ratios predict prognosis and the need for oxygen therapy in patients hospitalized for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The aims of the present study were to evaluate the changes of these biomarkers early in the course of infection, the association with the prior coronavirus disease (COVID-19) vaccination and therapeutic administration of Anti-SARS-CoV-2 monoclonal antibodies, investigation of other potential biomarkers including neuropilin, 8-hydroxy-2-deoxyguanosine and 8-hydroxyguanosine in patients hospitalized with SARS-CoV-2 infection and an assessment of these biomarkers and vitamins A, E and D in patients with post-COVID syndrome. METHODS: Urine and blood samples were obtained on the 1st to the 4th day and 4th to 7th day from 108 patients hospitalized with COVID-19. Chromatography tandem mass spectrometry methods were used to analyse neopterin, kynurenine, tryptophan, liposoluble vitamins, and DNA damage biomarkers. RESULTS: A statistically significant decrease of neopterin, kynurenine and kynurenine/tryptophan ratios was observed on after 4th to 7th day of hospitalization, and concentrations of these biomarkers were increased in patients with poor prognosis and subsequent post-COVID syndrome. The concentrations of remaining biomarker and vitamins were not associated with outcomes, although markedly decreased concentrations of vitamin A, E and D were noted. CONCLUSIONS: The concentrations of neopterin, kynurenine and kynurenine/tryptophan ratios decrease during the course of infection SARS-CoV-2 and are associated with the post-COVID syndrome. No other prognostic biomarkers were identified.

Chemometrics-assisted spectroscopic methods for rapid analysis of combined anti-malarial tablets.

Combination of piperaquine (PQ) (320mg) and dihydroartemisinin (DHA) (40 mg) is an anti-malarial formulation, which is recommended by World Health Organization (WHO). Simultaneous analysis of PQ and DHA can be problematic due to the lack of chromophores or fluorophores in DHA molecule. Whereas PQ possesses strong UV absorption and it presents in 8 times of DHA contents in the formulation. In this study, two spectroscopic methods, Fourier transform infrared (FTIR) and Raman spectroscopy, were developed for the determination of both drugs in combined tablets. The FTIR and Raman spectra were recorded in the attenuate total reflectance (ATR) and scattering modes, respectively. The original and pretreated spectra from FTIR and handheld-Raman were subjected to Unscrambler® program to construct partial least squares regression (PLSR) model comparing with references values obtained from high performance liquid chromatography (HPLC)-UV method. The optimal PLSR models of PQ and DHA from FTIR spectroscopy were obtained from orthogonal signal correction (OSC) pretreatment at the wavenumbers 400-1,800 cm-1 and 1,400-4,000 cm-1, respectively. For Raman spectroscopy of PQ and DHA, the optimal PLSR models were obtained from standard normal variate (SNV) pretreatment at the wavenumbers 1,200-2,300 cm-1 and OSC pretreatment at the wavenumber 400-2,300 cm-1, respectively. Determination of PQ and DHA in tablets from the optimum model was compared with HPLC-UV method. Results were not significantly different at 95% confidence limit (p-value >0.05). The chemometrics-assisted spectroscopic methods were fast (1-3 min), economical and less labor intensive. Moreover, the handheld Raman spectrometer is portable and can be utilized for onsite analysis to facilitate the detection of counterfeit or substandard drugs at ports of entry.

Effective, convenient, and green sample preparation for the determination of retinol and retinol acetate in human serum using pipette tip microextraction.

An efficient sample preparation based on pipette tip microextraction that can be used for the analysis of retinol in human serum has been developed. Altogether, nine commercial pipette tips were compared based on recovery, sample volume, use of organic solvent, handling difficulty, duration of the preparation process, price, and greenness of the method. Retinol acetate was used as the internal standard. The extraction efficiency for both compounds was evaluated to optimize and select the best pipette tip for sample preparation, which was the WAX-S XTR pipette tip containing an ion exchanger and salt. This tip combined solid phase extraction and salting-out assisted liquid‒liquid extraction. Satisfying recoveries of 100 and 80% for retinol and retinol acetate, respectively, and good repeatability were demonstrated. The action of this pipette tip was based on the clean-up workflow in which the interferences were retained on the sorbent. The presence of residual interferences in the extracted samples did not affect the HPLC separation of compounds of interest. The simplicity of the clean-up workflow reduced the time of the sample preparation compared to the bind-wash-elute counterpart workflow. The advantages of our technique are its environmental friendliness and cost effectiveness. The selected pipette tip with an excellent microextraction efficiency enables sample preparation in both clinical research and practice.

Portable near-infrared and Raman spectroscopic devices as complementary tools for instantaneous quality control of turmeric powder.

INTRODUCTION: Process analytical technology (PAT) guidance is implemented in the quality assurance of phytocompounds to achieve the Industry 4.0 concept. Near-infrared (NIR) and Raman spectroscopies are feasible for rapid, reliable quantitative analysis through transparent packaging without removing the samples from their original containers. These instruments can serve PAT guidance. OBJECTIVE: This study aimed to develop online portable NIR and Raman spectroscopic methods for quantifying total curcuminoids in turmeric samples through a plastic bag. The method mimicked an in-line measurement mode in PAT compared with placing samples into a glass vessel (at-line mode). MATERIALS AND METHODS: Sixty-three curcuminoid standard-spiked samples were prepared. Then, 15 samples were randomly selected as fixed validation samples, and 40 of the 48 remaining samples were chosen as calibration set. The results obtained from the partial least square regression (PLSR) models constructed by using the spectra acquired from NIR and Raman were compared with the reference values from high-performance liquid chromatography (HPLC). RESULTS: The optimum PLSR model of at-line Raman was achieved with three latent variables and a root mean square error of prediction (RMSEP) of 0.46. Meanwhile, the PLSR model of at-line NIR with one latent variable offered an RMSEP of 0.43. For the in-line mode, PLSR models created from Raman and NIR spectra had one latent variable with RMSEP of 0.49 and 0.42, respectively. The R2 values for prediction were 0.88-0.92. CONCLUSION: The models established from the spectra from portable NIR and Raman spectroscopic devices with the appropriate spectral pretreatments allowed the determination of total curcuminoid contents through plastic bag.