A new single-reference quantitative method using liquid chromatography with relative molar sensitivity based on 1H-qNMR for khellactone esters from Peucedanum japonicum root extract.

Khellactone ester (KLE) quantification using the absolute calibration method is difficult owing to the unavailability of standard reagents that can guarantee purity. Herein, a new method was developed to quantify KLEs from Peucedanum japonicum root extracts using liquid chromatography (LC) without utilizing standards. This method used relative molar sensitivity (RMS) and 7-ethoxy-4-methylcoumarin as a single-reference (SR) compound instead of KLE standards. RMS is the sensitivity ratio of SR to analytes, determined using an offline combination of quantitative NMR and LC. LC was performed using a triacontylsilyl silica gel column of superficially porous particles with a ternary mobile phase. The range of the method was 2.60-509 µmol/L. The accuracy and precision were reasonable. This is the first study to apply the RMS method to both conventional LC and ultra-high-performance liquid chromatography using the same mobile phase and column. This method may aid the quality assurance of foods containing KLEs.

Simultaneous quantitation of nine carbazole alkaloids from Murraya koenigii (L.) Spreng by 1H qNMR spectroscopy.

Murraya koenigii leaves are widely used as a spice and also have several biological activities. The major active constituents are carbazole alkaloids. Quantitation by HPLC or HPTLC requires pure marker compounds, whereas nuclear magnetic resonance spectroscopy can be used as a quantitative technique without the requirement of a pure marker compound. An alkaloid-rich fraction was prepared from the leaves and a validated qNMR method was developed for the quantitation of nine carbazole alkaloids, namely mahanimbine, girinimbine, koenimbine, koenine, kurrayam, mukonicine, isomahanimbine, euchristine B and bismahanine. One of the major compounds, koenimbine, was isolated and quantified by HPTLC to compare the results. The results obtained by qNMR were compared with the reported yields of these compounds.

New trends of new psychoactive substances (NPS)-infused chocolate: Identification and quantification of trace level of NPS in complex matrix by GC-MS and NMR.

For the first time, the identification and quantification of trace level of new psychoactive substances (NPS) in a complex chocolate matrix have been reported. Since the beginning of 2022, suspected NPS-infused chocolate samples confiscated in inbound packages have been continuously sent to our laboratory for analysis. The qualitative gas chromatography-mass spectrometry (GC-MS) results were verified by 1H nuclear magnetic resonance (1H NMR) and 19F NMR to distinguish between potential aromatic isomers. A total of 11 NPS including deoxymethoxetamine, 3-OH-PCP, 6-APB, 4-APB, 4-OH-MiPT, 3-FEA, 2-FEA, 3-MMC, bromazolam, 2-FDCK, and ADB-BUTINACA were detected in 65 seized chocolate samples. A general 1H quantitative NMR (1H qNMR) method for quantification of 297 types of NPS in complex chocolate matrixes was devised for the first time after rigorous analysis of various critical features of merit, including suitable deuterated solvent, internal standard, quantitative peaks, and instrument acquisition parameters. Validation of the method using six different types of NPS afforded limits of detection of 0.05-0.1 mg/mL, limits of quantification of 0.01-0.03 mg/mL, repeatability and reproducibility lower than 0.5% and 3.6%, recoveries of 91.7%∼104.4%, and absence of matrix effect. The quantitative analysis of 65 seized chocolate samples by 1H qNMR and 19F qNMR showed that the content of NPS was in the range of 0.5 mg/g∼44.1 mg/g. Generally, the developed qNMR method was simple, fast, precise, and can be performed without reference materials of NPS. Since the type and content of NPS are relatively random, chocolate consumers will face huge health risks. Therefore, this new trend of NPS-infused chocolate deserves and requires more attention from national NPS monitoring departments as well as forensic laboratories.

[Quantitative Analysis of Bisacurone in Turmeric by HPLC Using Relative Molar Sensitivity].

A novel method was developed for quantification of bisacuron (BC) and dehydrozingerone (DZ), the functional component of turmeric (Curcuma longa.L)-containing foods, using a relative molar sensitivity (RMS) method based on the combination of HPLC-UV and 1H-NMR. The RMSs of BC and DZ using 4-hydroxybenzoic acid ethyl ester (HBE) as the internal standard were calculated to 1.66 and 2.55, respectively. Analysis of fourteen beverage products showed the high correlations between the concentrations of BC and DZ quantified by the RMS method and those quantified by absolute calibration curve method. A collaborative study was conducted by four laboratories on one beverage and one tablet products. The repeatable relative standard deviation (RSDr) of intra-laboratories ranged from 0.7 to 1.7%, and the reproducible relative standard deviation (RSDR) of inter-laboratories ranged from 2.0 to 7.3%. The RMS method enabled the quantification of analytes for which difficultly obtain standard materials such as BC and DZ, using an internal standard for which obtain routinely readily available. This RMS method is expected to be applied to quality control for food products containing turmeric.

Development of a comprehensive method based on quantitative 1H NMR for quality evaluation of Traditional Chinese Medicine injection: a case study of Danshen Injection.

OBJECTIVES: This study aimed to establish a rapid and comprehensive method for quantitative determination of complex ingredients in Traditional Chinese Medicine injections. METHODS: A 1H quantitative nuclear magnetic resonance method was developed to simultaneously quantify comprehensive chemical components in Danshen Injection. Multivariate statistical analysis technique was applied to quality evaluation of multiple batches of Danshen injection. KEY FINDINGS: A complete signal attribution to the 1H nuclear magnetic resonance spectrum of Danshen injection was developed and performed for the first time. A total of 32 chemical components were identified from Danshen Injection. Among them, 20 were quantified simultaneously, accounting for up to 80% (w/w) of the total solids and 95% (w/w) of total organic matter, representing success compared to the previous studies. The developed method was further applied to analyze 13 batches of Danshen Injection from three manufacturers to make a realistic analysis. CONCLUSION: It was found that the comprehensive chemical information provides an adequate characterization for quality profiles among different commercial batches of Danshen Injection. The developed method further offered a guarantee for improving the consistency and safety of Traditional Chinese Medicine injections.

[~1H-qNMR quantification of total ginsenosides in Shenmai Injection].

A content determination method based on ~1H-qNMR was developed for the determination of total ginsenosides in Shenmai Injection. The parameters were optimized with CD_3OD as the solvent, dimethyl terephthalate as the internal standard, the peak at δ 8.11 as the internal standard peak, and the peaks at δ 1.68 and δ 0.79 as quantitative peaks of total ginsenosides. The developed ~1H-qNMR-based method was validated methodologically. The results showed that the method could achieve accurate measurement of total ginsenosides in Shenmai Injection in the range of 0.167 6-3.091 1 mmol·L~(-1). The developed ~1H-qNMR-based method for total ginsenosides is simple in operation, short in analysis time, strong in specificity, independent of accompanying standard curve, and small in sample volume, which can serve as a reliable mean for the quality control of Shenmai Injection. This study is expected to provide new ideas for the development of quantification methods of total ginsenosides.

Phase Behavior of Drug-Lipid-Surfactant Ternary Systems toward Understanding the Annealing-Induced Change.

The present study systematically investigates the effect of annealing conditions and the Kolliphor P 407 content on the physicochemical and structural properties of Compritol (glyceryl behenate) and ternary systems prepared via melt cooling (Kolliphor P 407, Compritol, and a hydrophilic API) representing solid-lipid formulations. The physical properties of Compritol and the ternary systems with varying ratios of Compritol and Kolliphor P 407 were characterized using differential scanning calorimetry (DSC), small- and wide-angle X-ray scattering (SWAXS) and infrared (IR) spectroscopy, and hot-stage microscopy (HSM), before and after annealing. The change in the chemical profiles of different Compritol components as a function of annealing was evaluated using 1H NMR spectroscopy. While no change in the polymorphic form of API and Kolliphor P 407 occurred during annealing, a systematic conversion of the α- to ß-form was observed in the case of Compritol. Furthermore, the polymorphic transformation of Compritol was found to be dependent on the Kolliphor P 407 content. As per the Flory-Huggins mixing theory, higher miscibility was observed in the case of monobehenin-Kolliphor P 407, monobehenin-dibehenin, and dibehenin-tribehenin binary mixtures. The miscibility of Kolliphor P 407 with monobehenin and 1,2-dibehenin was confirmed by 1H NMR analysis. The observed higher miscibility of Kolliphor P 407 with monobehenin and 1,2-dibehenin is proposed as the trigger for the physical separation from the 1,3-diglyceride and triglycerides during melt solidification of the formulations. The phase separation is postulated as the mechanism underlying the formation of a stable ß-polymorphic form (a native form of 1,3-diglyceride) of Compritol upon annealing. This finding is expected to have an important implication for developing stable solid-lipid-surfactant-based drug formulations.

1H NMR and HPLC-DAD-MS for the characterization of ellagitannins and triterpenoids of less investigated Anogeissus leiocarpus DC (Combretaceae) stem bark.

Anogeissus leiocarpus DC is an evergreen tree, widely distributed in Asia and Africa. The stem bark is used in traditional medicine, and as chewing sticks and infusion. Nowadays, it is becoming increasingly important to define the phytochemical profile of less studied edible plants. Aim of this research was a first complete characterization of ellagitannins and triterpenoids profiles by HPLC-DAD-MS and 1H NMR and analyses. A total of 59 compounds were identified including 43 ellagitannins and 16 triterpenoids, mainly oleane derivatives and glycosylated forms. Among ellagitannins, roburin, vescalin and castalin were found for the first time. Tannins accounted for 38.9% whereas triterpenoids were 4.8%, both estimated on dry decoction. The decoction was preliminary tested against osteoarthritis in rats. The characterization of the main phytochemicals of Anogeissus leiocarpus DC stem bark decoction is a necessary step to evaluate nutraceutical properties, paving the way for possible food applications of this plant.

[NMR method for simultaneous determination of 21 chemical components in Danhong Injection].

Danhong Injection, a compound Chinese medicine injection prepared from Salviae Miltiorrhizae Radix et Rhizoma and Carthami Flos, is used in the clinical treatment of coronary heart disease, cerebral thrombosis, myocardial infarction, angina pectoris and other cardiovascular and cerebrovascular diseases. In this study, a quantitative method for simultaneous determination of multiple components in Danhong Injection was developed based on ~1H-qNMR technology and then methodological verification was carried out. The results showed that the established method had good methodological indexes. This method can simultaneously determine the content of 21 chemical components including 6 amino acids, 4 small molecular organic acids, 5 sugars and their derivatives, 1 nucleoside, and 5 aromatic compounds in Danhong Injection. The total content accounted for about 85% of the total solid mass, which reflected the great advantage of ~1H-qNMR method in the analysis of Chinese medicine injections. The ~1H-qNMR method for simultaneous determination of multiple components in Danhong Injection developed in this study has simple operation, short analysis time, and wide application range, which has practical significance for the quality evaluation of Danhong Injection and provides reference for the development of quality control methods for Chinese medicine injections.

~1H-qNMR quantification of total ginsenosides in Shenmai Injection / 中国中药杂志

A content determination method based on ~1H-qNMR was developed for the determination of total ginsenosides in Shenmai Injection. The parameters were optimized with CD_3OD as the solvent, dimethyl terephthalate as the internal standard, the peak at δ 8.11 as the internal standard peak, and the peaks at δ 1.68 and δ 0.79 as quantitative peaks of total ginsenosides. The developed ~1H-qNMR-based method was validated methodologically. The results showed that the method could achieve accurate measurement of total ginsenosides in Shenmai Injection in the range of 0.167 6-3.091 1 mmol·L~(-1). The developed ~1H-qNMR-based method for total ginsenosides is simple in operation, short in analysis time, strong in specificity, independent of accompanying standard curve, and small in sample volume, which can serve as a reliable mean for the quality control of Shenmai Injection. This study is expected to provide new ideas for the development of quantification methods of total ginsenosides.

Quantitative proton nuclear magnetic resonance method for simultaneous analysis of fluticasone propionate and azelastine hydrochloride in nasal spray formulation.

A facile, rapid, accurate and selective quantitative proton nuclear magnetic resonance (1H-qNMR) method was developed for the simultaneous determination of fluticasone propionate (FLP) and azelastine hydrochloride (AZH) in pharmaceutical nasal spray for the first time. The 1H-qNMR analysis of the studied analytes was performed using inositol as the internal standard and dimethyl sulfoxide-d6 (DMSO-d6) as the solvent. The quantitative selective proton signal of FLP was doublet of doublet at 6.290, 6.294, 6.316 and 6.319 ppm, while that of AZH was doublet at 8.292 and 8.310 ppm. The internal standard (inositol) produced a doublet signal at 3.70 and 3.71 ppm. The method was rectilinear over the concentration ranges of 0.25-20.0 and 0.2-15.0 mg ml-1 for FLP and AZH, respectively. No labelling or pretreatment steps were required for NMR analysis of the studied analytes. The proposed 1H-qNMR method was validated efficiently according to the International Council on Harmonisation guidelines in terms of linearity, limit of detection, limit of quantification, accuracy, precision, specificity and stability. Moreover, the method was applied to assay the analytes in their combined nasal spray formulation. The results ensured the linearity (r 2 > 0.999), precision (% RSD < 1.5), stability, specificity and selectivity of the developed method.

[Determination of Allyl Isothiocyanate in Mustard and Horseradish Extracts by Single Reference GC and HPLC Based on Relative Molar Sensitivities].

The main component of the Mustard and Horseradish extracts, which are used as natural food additives in Japan, is allyl isothiocyanate (AITC). The determination of AITC using GC-FID is the official method employed in the quality control assessments for these products. In this method, a commercially available AITC reagent is used as a calibrant. However, 1H-quantitative NMR (qNMR) analysis revealed that the AITC reagents contain impurity. Therefore, we examined the GC-FID and HPLC-refractive index detector (LC-RID) method based on relative molar sensitivities (RMSs) to high-purity single reference (SR). The RMSs of AITC/SR under the GC-FID and LC-RID conditions were accurately determined using qNMR. The AITC in two types of food additives was quantified using qNMR, SR GC-FID, and SR LC-RID methods. Both SR GC-FID and SR LC-RID showed good agreement within 2% with the AITC content determined by direct qNMR.

Graphene Assisted in the Analysis of Coumarins in Angelicae Pubescentis Radix by Dispersive Liquid-Liquid Microextraction Combined with 1H-qNMR.

The content of active components in traditional Chinese medicine is relatively small, and it is difficult to detect some trace components with modern analytical instruments, so good pretreatment and extraction are very important in the experiment. Graphene was introduced by a dispersive liquid-liquid microextraction method based on solidification of floating organic drop (DLLME-SFO) with graphene/1-dodecyl alcohol used as the extractant, and this method, combined with quantitative proton nuclear magnetic resonance spectroscopy (1H-qNMR), was used to simultaneously qualitative and quantitative osthole, columbianadin and isoimperatorin in Angelicae Pubescentis Radix. In this experiment, a magnetic stirrer was used for extraction, all NMR spectra were recorded on a Bruker Advance III 600 MHz spectrometer with dimethyl sulfoxide-d6 (DMSO-d6) as deuterated solvent and pyrazine as the internal standard. The influencing factors and NMR parameters in the extraction process were investigated and optimized. In addition, the methodology of the established method was also examined. The quantitative signals of osthole, columbianadin and isoimperatorin were at a chemical shift of δ6.25-δ6.26 ppm, δ6.83-δ6.85 ppm, and δ6.31-δ6.32 ppm. The linear ranges of osthole, columbianadin and isoimperatorin were all 0.0455-2.2727 mg/mL, and R2 were 0.9994, 0.9994 and 0.9995, respectively. The limits of detection of osthole, columbianadin and isoimperatorin were 0.0660, 0.0720, 0.0620 mg, and the limits of quantification of osthole, columbianadin and isoimperatorin were 0.2201, 0.2401, 0.2066 mg/mL. The solution had good stability and repeatability within 24 h. The recoveries of osthole, columbianadin and isoimperatorin were 102.26%, 99.89%, 103.28%, respectively. The established method is simple and easy to operate, which greatly reduces the cumbersome pretreatment of samples and has high extraction efficiency.

Determination of perillaldehyde in perilla herbs using relative molar sensitivity to single-reference diphenyl sulfone.

Perillaldehyde (PRL) is one of the essential oil components derived from perilla plants (Perilla frutescens Britton) and is a characteristic compound of the traditional medicine "perilla herb ()" listed in the The Japanese Pharmacopoeia, 17th edition (JP17). HPLC using an analytical standard of PRL has been used to quantitatively determine the PRL content in perilla herb. However, PRL reagents have been reported to decompose easily. In this study, we utilized an alternative quantitative method using on a single reference with relative molar sensitivity (RMS) based on the results of experiments performed in two laboratories. It was possible to calculate the exact RMS using an offline combination of 1H-quantitative NMR spectroscopy (1H-qNMR) and an HPLC/photodiode array (PDA) detector (or an HPLC/variable-wavelength detector [VWD]). Using the RMS of PRL to the single-reference compound diphenyl sulfone (DFS), which is an inexpensive and stable compound, the PRL content in the perilla herb could be determined using HPLC/PDA or HPLC/VWD without the need for the analytical standard of PRL. There was no significant difference between the PRL contents of perilla herb determined using the method employing the single-reference DFS with RMS and using the JP17 assay, the calibration curve of which was generated using the analytical standard of PRL with adjusted purity measured by 1H-qNMR. These results demonstrate that our proposed method using a single reference with RMS is suitable for quantitative assays of perilla herb and can be an alternative method for the current assay method defined in the JP17.

[Quantitative Analysis of Piperine and the Derivatives in Long Pepper Extract by HPLC Using Relative Molar Sensitivity].

A novel method was developed for quantification of five major piperine derivatives (piperanine, piperine, chavicine, isopiperine, and isochavicine) in a hot water extract of long pepper fruit (LPE) using the relative molar sensitivity (RMS) based on the combination of HPLC/UV and 1H- quantitative NMR (1H-qNMR). The RMSs of piperanine, chavicine, isopiperine, and isochavicine to piperine of which the absolute purity was determined by 1H-qNMR were calculated to be 0.3693, 1.138, 0.9164, and 1.277, respectively. The total amount of piperine derivatives in LPE was quantified by both 1H-qNMR and HPLC/UV based on the RMS using piperine as a single-reference material (RMS method). The relative difference in quantitation values of 1H-qNMR and calibration curve method from the RMS method was 2.01% or less. The relative difference of the total cis-trans piperine isomers content between before and after photoirradiation in piperine solution was quantified to be 2.84% by the RMS method. In addition, the interlaboratory difference of the RMS method was confirmed in the range of 0.600 to 4.00 µg/g when analysis was performed on piperine derivatives in LPE containing tablets, while the total amount of piperine derivatives in the tablets was quantified at 606 µg/g. Our proposed method is a reliable tool for determining the contents of piperine and the derivatives in LPE and processed foods containing LPE.

[Determination of Hesperidin and Monoglucosylhesperidin Contents in Processed Foods Using Relative Molar Sensitivity Based on 1H-Quantitative NMR].

We designed an off-line combination of HPLC/photodiode array detector (PDA) and 1H-quantitative NMR (1H-qNMR) to estimate the relative molar sensitivity (RMS) of an analyte to a reference standard. The RMS is calculated as follows: a mixture of the analyte and the reference is analyzed using 1H-qNMR and HPLC/PDA. The response ratio of the analyte and the reference obtained by HPLC/PDA is then corrected using the molar ratio obtained by 1H-qNMR. We selected methylparaben (MPB), which is a certified reference material, as the reference standard and hesperidin (Hes) and monoglucosylhesperidin (MGHes) as analytes, and the RMSs of Hes283 nm/MPB255 nm and MGHes283 nm/MPB255 nm were determined as 1.25 and 1.32, respectively. We determined the contents of Hes and MGHes in processed foods by the conventional absolute calibration method and by the internal standard method employing the RMS values with respect to MPB. The differences between the values obtained with the two methods were less than 2.0% for Hes and 3.5% for MGHes.

Qualitative and quantitative control of pediatric syrups using Nuclear Magnetic Resonance and chemometrics.

Several flavoring and sweetening agents added to excipient of pediatric syrups are not declared in the package leaflet. Therefore, the aim of this study was to develop a non-target, simple, and precise method for qualitative and quantitative evaluation of pediatric syrups using NMR spectroscopy combined with chemometrics. This approach allowed the identification of several added compounds as citric acid, cyclamate, ethanol, glycerol, propylene glycol, saccharin, sorbitol, fructose, glucose, and sucrose. Among the sugared syrups, sucrose was the main carbohydrate with approximately 59.1%, and for sweetened syrups, glycerol with 25.5%. The ethanol was found with highest concentration of 4.0%, approximately. In addition, some syrups presented both sugar and sweetener, which is inconsistent according to the purpose of the addition. Consequently, institutional structures of countries as Brazil that are in charge of public health should put additional compliance pressure on pharmaceutical companies to clearly declare in package leaflet the presence and exact amount of the main compounds (at least) existent in the pediatric excipients.

Qualitative and Quantitative NMR Approaches in Blood Serum Lipidomics.

Nuclear magnetic resonance (NMR) spectroscopy in combination with chemometrics can be applied in the analysis of complex biological samples in many ways. For example, we can analyze lipids, elucidate their structures, determine their nutritional values, and determine their distribution in blood serum. As lipids are not soluble in water, they are transported in blood as lipid-rich self-assembled particles, divided into different density assemblies from high- to very-low-density lipoproteins (HDL to VLDL), or by combining with serum proteins, such as albumins (human serum albumins (HSA)). Therefore, serum lipids can be analyzed as they are using only a 1:1 (v/v) dilution with a buffer or deuterated water prior to analysis by applying 1H NMR or 1H NMR edited-by-diffusion techniques. Alternatively, lipids can be extracted from the serum using liquid partition equilibrium and then analyzed using liquid-state NMR techniques. Our chapter describes protocols that are used for extraction of blood serum lipids and their quantitative 1H NMR (1H qNMR) analysis in lipid extracts as well as 1H NMR edited by diffusion for direct blood serum lipid analysis.

Chemometric analysis of NMR and GC datasets for chemotype characterization of essential oils from different species of Ocimum.

The genus Ocimum (Labiatae) comprises 30 species found in tropical and subtropical regions of the planet, of which species O. basilicum L. and O. gratissimum are widely used in food and traditional medicine. Phytochemical studies on Ocimum have revealed a number of essential oil chemotypes, for example, eugenol, methyl chavicol, linalool, and methyl cinnamate. Since essential oils are commercially assessed according to their content, the aim of this study was to develop a simple and precise method for their qualitative and quantitative analysis using NMR spectroscopy combined with chemometrics. Seven essential oils from different species of Ocimum, an unknown sample, and a commercial sample were evaluated and the results compared to those from established and precise GC-MS and GC-FID methods. Chemometric evaluation from both 1H NMR and GC-MS data revealed three chemotypes: eugenol for O. gratissimum, O. micranthum, and O. tenuiflorum; estragole for O. basilicum, O. basilicum var. purpuracens, and O. selloi; and methyl cinnamate for O. americanum. The unknown and commercial species were classified as cinnamate and eugenol chemotypes, respectively. Despite the corroborating results, the chemometric analysis revealed the higher robustness (better adjustment) of the 1H NMR model compared to the GC-MS method in terms of certain statistical parameters. The 1H NMR method allows for the detection and quantification of organic compounds in a complex mixture without the need for certified standard compounds. Although GC-MS and GC-FID were able to detect five compounds not observed by NMR spectroscopy, the four most important metabolites (eugenol, estragole, methyl cinnamate, and eucalyptol) were more readily detected and quantified by 1H NMR.

1H NMR spectra dataset and solid-state NMR data of cowpea (Vigna unguiculata).

In this article the NMR data from chemical shifts, coupling constants, and structures of all the characterized compounds were provided, beyond a complementary PCA evaluation for the corresponding manuscript (E.G. Alves Filho, L.M.A. Silva, E.M. Teofilo, F.H. Larsen, E.S. de Brito, 2017) [3]. In addition, a complementary assessment from solid-state NMR data was provided. For further chemometric analysis, numerical matrices from the raw 1H NMR data were made available in Microsoft Excel workbook format (.xls).