Quantitative determination and characterization of polyphenols from Cissus quadrangularis L. and dietary supplements using UHPLC-PDA-MS, LC-QToF and HPTLC

Stem and leaf of Cissus quadrangularis L. (Vitaceae), indigenous to Asia and Africa, were used for medicinal and dietary purposes with limited information about the plant's phytochemistry. Stem and leaf samples were assessed for the simultaneous determination of polyphenolic compounds (catechin, epicatechin, quercetin-3-O-β-glucopyranoside, kaempferol-3-O-β-glucoside, quercetin-3-O-β-rhamnoside, leachianol F, amurensin A, pallidol, resveratrol, and quadrangularin A), using UHPLC-PDA-MS. The validation data showed that the method is precise, specific, accurate, and linear over the range of 0.5-100 μg/mL. Reversed-phase ultra-high performance liquid chromatography (UHPLC) fingerprints of the crude methanolic stem and leaf extracts of C. quadrangularis were obtained at different wavelengths based on their λ_max. Polyphenolics were characterized using both UHPLC-PDA-MS and LC-QToF analysis. From liquid chromatography quadrupole time of flight-electrospray ionization mass spectrometry (LC-QToF) spectra, over 40 components were structurally correlated, and confirmation was based on the fragmentation characteristics and also from the information available in the literature. In addition to the LC-QToF method, a simple, fast HPTLC method was developed as a visual aid for the rapid qualitative analytical tool to help establish the quality assessment of botanical raw materials and dietary supplements claiming to contain Cissus.

Phenoxychromone and 4-hydroxyisoflavans from the roots of Glycyrrhiza uralensis

In an attempt to find species specific markers, a phenoxychromone (1) and eight isoflavonoids including six isoflavans (2-7) and two isoflavanones (8 and 9) were isolated from the root of Glycyrrhiza uralensis. Among the isolated phenolic compounds, glycyurelone (1), glycyurelvanins A and B (2 and 3) were found to be undescribed while others, (-)-vestitol (4), conferol A (5), glyasperin C (6), glyasperin D (7), (-)-licoisoflavanone (8), and (-)-3'-(γ,γ-dimethylallyl)kievitone (9) were previously reported. All compounds except 4 and 5 were prenylated and majority of these possess isoflavan scaffold with highly conserved stereo specificity at C-3 center. Structure elucidation was mainly based on extensive NMR, ECD and mass spectral data analysis.

Modulation of CYP3A4 and CYP2C9 activity by Bulbine natalensis and its constituents: An assessment of HDI risk of B. natalensis containing supplements

BACKGROUND

Bulbine natalensis is an African-folk medicinal plant used as a dietary supplement for enhancing sexual function and muscle strength in males by presumably boosting testosterone levels, but no scientific information is available about the possible herb-drug interaction (HDI) risk when bulbine-containing supplements are concomitantly taken with prescription drugs.

PURPOSE

This study was aimed to investigate the HDI potential of B. natalensis in terms of the pregnane X receptor (PXR)-mediated induction of major drug-metabolizing cytochrome P450 enzyme isoforms (i.e., CYP3A4 and CYP2C9) as well as inhibition of their catalytic activity.

RESULTS

We found that a methanolic extract of B. natalensis activated PXR (EC₅₀ 6.2 ± 0.6 µg/ml) in HepG2 cells resulting in increased mRNA expression of CYP3A4 (2.40 ± 0.01 fold) and CYP2C9 (3.37 ± 0.3 fold) at 30 µg/ml which was reflected in increased activites of the two enzymes. Among the constituents of B. natalensis, knipholone was the most potent PXR activator (EC₅₀ 0.3 ± 0.1 µM) followed by bulbine-knipholone (EC₅₀ 2.0 ± 0.5 µM), and 6'-methylknipholone (EC₅₀ 4.0 ± 0.5 µM). Knipholone was also the most effective in increasing the expression of CYP3A4 (8.47 ± 2.5 fold) and CYP2C9 (2.64 ± 0.3 fold) at 10 µM. Docking studies further confirmed the unique structural features associated with knipholones for their superior inductive potentials in the activation of PXR compared to other anthraquinones. In a CYP inhibition assay, the methanolic extract as well as the anthraquinones strongly inhibited the catalytic activity of CYP2C9 while, inhibition of CYP3A4 was weak.

CONCLUSIONS

These results suggest that consumption of B. natalensis may pose a potential risk for HDI if taken with conventional medications that are substrates of CYP3A4 and CYP2C9 and may contribute to unanticipated adverse reactions or therapeutic failures. Further studies are warranted to validate these findings and establish their clinical relevancy.

Liver injury associated with kratom, a popular opioid-like product: Experience from the U.S. drug induced liver injury network and a review of the literature

BACKGROUND

Kratom is a botanical product used as an opium substitute with abuse potential.

METHODS

Assessment of suspected cases of kratom-induced liver injury in a prospective US cohort.

RESULTS

Eleven cases of liver injury attributed to kratom were identified with a recent increase. The majority were male with median age 40 years. All were symptomatic and developed jaundice with a median latency of 14 days. The liver injury pattern was variable, most required hospitalization and all eventually recovered. Biochemical analysis revealed active kratom ingredients.

CONCLUSION

Kratom can cause severe liver injury with jaundice.

Comparative study and quality evaluation regarding morphology characters, volatile constituents, and triglycerides in seeds of five species used in traditional Chinese medicine

Volatile compounds (VCs) and triglycerides (TGs) are the primary groups of constituents in the fruits of five well-known species used in traditional Chinese medicine (TCM), viz. Alpinia oxyphylla Miq. (AO), Alpinia katsumadai Hayata (AK), Amomum villosum Lour. (FAL), Amomum villosum Lour. var. xanthioides T. L. Wu et Senjen (FALX), and Amomum longiligulare T. L. Wu (FALO). The fruits of these species are morphologically similar and commonly used in both foods and TCM. Each species is purportedly endowed with different medicinal properties. Efficient and environmentally friendly methods are desirable for the quality control of these species. The current study attempted to establish both comprehensive profiles and quality standards for the five TCM species. External morphology characters were provided to distinguish 18 fruit samples belonging to the five species, which were collected from different geographical regions of China. The VCs of each sample were analyzed by SPME GC/Q-ToF. The identification of marker compounds from each species allowed for the differentiation of the fruits from the five plants. Characterization and quantification of 21 TGs were achieved using SFC/MS with an analysis time of less than 15 min. The complex TGs were unambiguously identified using the MS detection with correct attribution of the acyl group to the sn-2 position. Moreover, the quantification of TGs was improved by using reference standards whenever possible or a single standard strategy to determine multiple TGs. The validity of the proposed SFC/MS method was assessed by analyzing fatty acids from the hydrolysis and transesterification products of the same sample set using GC/MS. The quantification results from both TGs and fatty acids were consistent, and were further substantiated by chemometric analysis. To our knowledge, this is the first comprehensive study utilizing the morphology, VCs, and TGs for quality evaluation purpose of these five TCM species.

Potential Modulation of Human NAD[P]H-Quinone Oxidoreductase 1 (NQO1) by EGCG and Its Metabolites-A Systematic Computational Study

At high doses, green tea extracts and green tea's major active constituent, (-)-epigallocatechin gallate (EGCG), despite their generally perceived health benefits, have been suspected to cause hepatotoxicity in certain human populations. It has been reported that o-quinone metabolites of gallic acid or EGCG are causative agents for this hepatotoxicity. However, no experimental information is available at the molecular level on the possible role of NQO1 in the detoxification of EGCG and its metabolites, including reactive intermediates. In the present study, we investigated the possibility of NQO1 inhibition by EGCG and its metabolites by studying their interaction profiles and binding mechanism at the active site of NQO1 using molecular docking, binding free energy calculations, and molecular dynamics (MD) simulations. The binding free energy calculations showed that some metabolites exhibited strong predicted binding affinity and found that the binding orientation of the EGCG metabolites overlapped with that of dicoumarol found in an NQO1 X-ray crystal structure. The results suggest that these metabolites may act as strong NQO1 inhibitors, highlighting the need for experimental validation of this with appropriate biological methods. The Prime MM-GBSA computed average binding free energies after MD simulations of compounds 1, 2, 24, 31, and 33 revealed that these compounds highly favored van der Waals (VdW) and Coulombic interactions with NQO1. In addition, the MD results revealed that selected EGCG metabolites formed a stable and strong complex with NQO1, with amino acids W105, Y126, Y128, H161, F178, H194, F232, and F236 being critical for potential NQO1 binding. The current results together with experimental data as well as studies of the polymorphisms of NQO1 (especially C609T) may explain the observed idiosyncratic hepatotoxicity caused by the consumption of green tea and its constituents.

Identification of Antifungal Bisphosphocholines from Medicinal Gentiana Species

Gentiana species including G. crassicaulis, G. macrophylla, G. dahurica, and G. straminea are used in traditional Chinese medicine as "Qinjiao" for the treatment of rheumatism, hepatitis, and pain. Four antifungal bisphosphocholines [irlbacholine (2) and three new analogues, gentianalines A-C (1, 3, and 4)] were identified from G. crassicaulis by a bioassay-guided fractionation and structure elucidation approach. Subsequent chemical analysis of 56 "Qinjiao" samples (45 from G. crassicaulis, five from G. macrophylla, three from G. dahurica, and three from G. straminea) showed that bisphosphocholines were present in all four Gentiana species, with irlbacholine as the major compound ranging from 2.0 to 6.2 mg per gram of dried material. Irlbacholine exhibited potent in vitro antifungal activity against Cryptococcus neoformans, Aspergillus fumigatus, Candida albicans, and Candida glabrata with minimum inhibitory concentration (MIC) values of 0.63, 1.25, 10.0, and 5.0 μg/mL, respectively. Identification of the bisphosphocholines, a rare class of antifungal natural products, in these medicinal plants provides scientific evidence to complement their medicinal use. The bisphosphocholines carrying a long aliphatic chain possess amphiphilic molecule-like properties with a tendency of retention in both normal and reversed-phase silica gel column chromatography and thereby may be neglected in natural products discovery. This report may stimulate interest in this class of compounds, which warrant the further study of other biological activities as well.

Quantification and Characterization of Phenolic Compounds from Northern Indian Propolis Extracts and Dietary Supplements

BACKGROUND

Propolis is a resinous substance produced by bees. Propolis extracts have been used for anti-inflammatory and antimicrobial activities. The use of propolis dietary supplements has been increasing in the United States and the rest of the world.

OBJECTIVE

A simple, economic, and valid analytical method is needed for quality assessment of dietary supplements and extracts claiming to contain propolis.

METHODS

A ultra-high performance liquid chromatography (UHPLC) quadropole time-of-flight-MS method was used to characterize the chemical composition of northern Indian propolis. Fourteen major phenolic compounds were quantified using a UHPLC-DAD method. An HPTLC method was used to develop chemical fingerprinting profiles for propolis extracts and dietary supplements. The seven propolis extracts and 14 dietary supplements purchased in the U.S. were analyzed using the UHPLC-DAD-QToF method.

RESULTS

Fifty-seven compounds belonging to phenolic, coumarin, fatty acid, and terpene classes were identified in propolis extracts. Based on quantification results, the content of 14 phenolic compounds in propolis extracts varied from 19-32% in dietary supplements, a significant variation to the recommended daily intake (0.2-94 mg/day).

CONCLUSIONS/HIGHLIGHTS

The developed analytical methods can be used for quality assessment of propolis extracts and dietary supplements.

Licochalcone L, an undescribed retrochalcone from Glycyrrhiza inflata roots

Glycyrrhiza inflata Batalin is among the three glycyrrhizin producing Glycyrrhiza species and can be distinguished from other species with regard to its retrochalcone contents. Seven retrochalcones, echinatin and licochalcones A, C, D, E, K, and L were isolated and characterized from the chloroform extract of G. inflata roots. Among the isolates, licochalcone L was found to be previously undescribed. Structure elucidation of these specialised metabolites was achieved through NMR and mass spectroscopic data analyses.

Green Tea Extract as a Safe and Effective Dietary Supplement: Lessons Learned from Mice

Objectives

Green tea extracts (GTEs) are common ingredients among dietary supplements marketed for weight loss and weight management. However, GTEs and their various catechin polyphenols have also been linked to a number of hepatotoxicity cases.

Methods

The purpose of this study was to investigate, using various mouse models, the hepato- and cardiotoxic potential of a well-characterized GTE; its ability to promote weight loss; and its effect on the gut microbiome.

Results

Gavaging GTE over a range of 1X–10X mouse equivalent doses (MED) for up to 2 weeks did not elicit significant histomorphological, physiological, biochemical or molecular alterations in the livers of lean B6C3F1 mice. Similarly, no evidence of hepato- or cardiotoxicity was noted when GTE was administered to obese NZO/HlLtJ mice for 8 weeks, either alone or in combination with caffeine (CAF) and/or exercise (EX). Eight weeks of GTE administration in combination with CAF resulted in significant body weight reduction in obese mice, which was further enhanced by EX. Furthermore, GTE/CAF combinations partially mitigated obesity-associated small and large droplet steatosis and decreased both portal and lobular inflammation, demonstrating hepatoprotective capabilities. Administration of GTE at MEDs comparable to those consumed by humans resulted in significant modulation of gut microflora, with increases in beneficial Akkermansia spp. among lean mouse phenotypes being most pronounced. This favorable change in the gut microbiome may provide a mechanistic link to weight loss management.

Conclusions

Results of this study demonstrate that appropriate doses of caffeinated GTE can serve as a useful adjunct in weight management strategies. Furthermore, clinically relevant doses of GTE/CAF combinations did not produce hepato- or cardiotoxicity, but rather show significant potential to promote liver health by reversing early signs of non-alcoholic fatty liver disease and hepatosteatosis.

Funding Sources

NIGMS 1P20 GM109005.

Carboxyvinyl Polymer and Guar-Borate Gelling System Containing Natamycin Loaded PEGylated Nanolipid Carriers Exhibit Improved Ocular Pharmacokinetic Parameters

Purpose: Natamycin (NTM) ophthalmic suspension is the only FDA-approved formulation commercially available for treating ocular fungal infections. However, precorneal residence times and losses/drainage remain the foremost challenges associated with current ocular antifungal pharmacotherapy. In our previous investigations, NTM loaded polyethylene glycol nanolipid carriers (NTM-PNLCs) showed enhanced corneal permeation, both in vitro and in vivo. To further improve the corneal retention of NTM-PNLCs, this study aimed to develop a gelling system composed of carboxyvinyl polymer, guar gum, and boric acid in which the NTM-PNLCs were loaded. Methods: A 2³ factorial design was employed in formulating and optimizing the gelling system for NTM-PNLCs, where the independent factors were the gelling excipients (guar gum, boric acid, and Carbopol^® 940) and dependent variables were gelling time, gel depot collapse time, rheology, firmness, and work of adhesion. Optimized gel was evaluated for transcorneal permeation using rabbit cornea, in vitro; and tear pharmacokinetics and ocular biodistribution in male New Zealand White rabbits, in vivo. Results: Optimized NTM-PNLC-GEL was found to exhibit shear thinning rheology, adequate firmness, and spreadability, and formed a depot that did not collapse immediately. In addition, the in vitro transcorneal evaluation studies indicated that the NTM-PNLC-GEL exhibited a lower/slower flux and rate in comparison to Natacyn^® suspension. NTM-PNLC-GEL (0.3%), at a 16-fold lower dose, exhibited mean residence time and elimination half-life comparable to Natacyn (5%), and provided similar in vivo concentrations in the innermost tissues of the eye. Conclusion: The data indicate that the NTM-PNLC-GEL formulation could serve as an alternative during ophthalmic antifungal therapy.

Ashwagandha-induced liver injury: A case series from Iceland and the US Drug-Induced Liver Injury Network

BACKGROUND & AIMS

Ashwagandha (Withania somnifera) is widely used in Indian Ayurvedic medicine. Several dietary supplements containing ashwagandha are marketed in the US and Europe, but only one case of drug-induced liver injury (DILI) due to ashwagandha has been published. The aim of this case series was to describe the clinical phenotype of suspected ashwagandha-induced liver injury.

METHODS

Five cases of liver injury attributed to ashwagandha-containing supplements were identified; three were collected in Iceland during 2017-2018 and two from the Drug-Induced Liver Injury Network (DILIN) in 2016. Other causes for liver injury were excluded. Causality was assessed using the DILIN structured expert opinion causality approach.

RESULTS

Among the five patients, three were males; mean age was 43 years (range 21-62). All patients developed jaundice and symptoms such as nausea, lethargy, pruritus and abdominal discomfort after a latency of 2-12 weeks. Liver injury was cholestatic or mixed (R ratios 1.4-3.3). Pruritus and hyperbilirubinaemia were prolonged (5-20 weeks). No patient developed hepatic failure. Liver tests normalized within 1-5 months in four patients. One patient was lost to follow-up. One biopsy was performed, showing acute cholestatic hepatitis. Chemical analysis confirmed ashwagandha in available supplements; no other toxic compounds were identified. No patient was taking potentially hepatotoxic prescription medications, although four were consuming additional supplements, and in one case, rhodiola was a possible causative agent along with ashwagandha.

CONCLUSIONS

These cases illustrate the hepatotoxic potential of ashwagandha. Liver injury is typically cholestatic or mixed with severe jaundice and pruritus, but self-limited with liver tests normalizing in 1-5 months.

Characterization, Quantification and Quality Assessment of Avocado (Persea americana Mill.) Oils

Avocado oil is prized for its high nutritional value due to the substantial amounts of triglycerides (TGs) and unsaturated fatty acids (FAs) present. While avocado oil is traditionally extracted from mature fruit flesh, alternative sources such as avocado seed oil have recently increased in popularity. Unfortunately, sufficient evidence is not available to support the claimed health benefit and safe use of such oils. To address potential quality issues and identify possible adulteration, authenticated avocado oils extracted from the fruit peel, pulp and seed by supercritical fluid extraction (SFE), as well as commercial avocado pulp and seed oils sold in US market were analyzed for TGs and FAs in the present study. Characterization and quantification of TGs were conducted using UHPLC/ESI-MS. Thirteen TGs containing saturated and unsaturated fatty acids in avocado oils were unambiguously identified. Compared to traditional analytical methods, which are based only on the relative areas of chromatographic peaks neglecting the differences in the relative response of individual TG, our method improved the quantification of TGs by using the reference standards whenever possible or the reference standards with the same equivalent carbon number (ECN). To verify the precision and accuracy of the UHPLC/ESI-MS method, the hydrolysis and transesterification products of avocado oil were analyzed for fatty acid methyl esters using a GC/MS method. The concentrations of individual FA were calculated, and the results agreed with the UHPLC/ESI-MS method. Although chemical profiles of avocado oils from pulp and peel are very similar, a significant difference was observed for the seed oil. Principal component analysis (PCA) based on TG and FA compositional data allowed correct identification of individual avocado oil and detection of possible adulteration.

A Public Health Issue: Dietary Supplements Promoted for Brain Health and Cognitive Performance

Background: Dietary supplements targeting brain health have quickly emerged in the marketplace as cognitive performance becomes an important public health issue. While manufacturers are required to report the exact ingredients and formulations listed on the Supplement Facts labels of products, many reports have indicated such labels are not always truthful, and the content of some products is inconsistent with the ingredients listed on the Supplement Facts label.

Objectives: To identify dietary supplement products and ingredients marketed for brain health and cognitive performance and perform analyses of select products to verify whether purported claims are truthful and product labels accurate.

Design: A scoping review was performed to identify products and ingredients. Products were selected for content analysis, investigated for scientific-sounding claims made, and assessed using an educational tool for potential red flags when reading Supplement Facts labels.

Results: Twelve products were selected from the 650 products being marketed for brain health and queried about by Service Members. Eight (67%) had at least one ingredient listed on the Supplement Facts label not detected through analysis. Compounds not reported on the label were detected in 10 (83%) products. Scientific-sounding claims made are not supported by science and red flags are presented.

Conclusions: There are dietary supplements targeting brain health being marketed to consumers that should be considered adulterated and misbranded. Advertisements and product labels may be deceiving and could put the public at risk. Education is required so that the public can recognize red flags while the U.S. Food and Drug Administration works to “modernize” the current regulations for dietary supplements.

Development and Validation of a UHPLC-PDA-MS Method for the Quantitative Analysis of Anthraquinones in Bulbine natalensis Extracts and Dietary Supplements

A UHPLC-photodiode array-MS method was developed and validated for the quantification of one chromone and six anthraquinone type of compounds from Bulbine natalensis plant samples and dietary supplements. Metabolites 1:  -  7: were identified based on their retention times and electrospray ionization-MS spectra compared with a mix of previously isolated compounds. The quantification of 1:  -  7: was based on photodiode array detection. The optimized separation was achieved using a CORTECS C18 column with a gradient of water/acetonitrile as the mobile phase. Seven compounds were separated within 15 minutes with detection limits of 50 pg on the column. The analytical method was validated for linearity, repeatability, accuracy, limits of detection, and limits of quantification. The relative standard deviations for intra- and inter-day experiments were less than 5% and the recovery efficiency was 98 - 101%. Nine dietary supplements labeled as containing B. natalensis were examined. Anthraquinone-type compounds were detected in only five out of nine dietary supplements, with the total amount ranging from 11.3 to 90.4 mg per daily dose. The analytical method is simple, economic, rapid, and can be applied for quality assessment of B. natalensis and dietary supplements. Electrospray ionization-MS was used for the identification of these compounds in plant samples and dietary products.

Optimization, stabilization, and characterization of amphotericin B loaded nanostructured lipid carriers for ocular drug delivery

The current study sought to formulate, optimize, and stabilize amphotericin B (AmB) loaded PEGylated nanostructured lipid carriers (NLC) and to study its ocular biodistribution following topical instillation. AmB loaded PEGylated NLC (AmB-PEG-NLC) were fabricated by hot-melt emulsification followed by high-pressure homogenization (HPH) technique. 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)] (mPEG-2K-DSPE) was used for surface PEGylation. mPEG-DSPE with different PEG molecular weight, 1 K, 2 K, 5 K, 10 K, and 20 K, were screened for formulation stability. Furthermore, the AmB loaded PEGylated (2K) NLC (AmB-PEG2K-NLC) was optimized using Box-Behnken design with respect to the amount of AmB, castor oil, mPEG-2K-DSPE, and number of high-pressure homogenization cycles as the factors; particle size, zeta potential, PDI, entrapment efficiency, and loading efficiency as responses. Stability of the optimized AmB-PEG2K-NLC was assessed over 4 weeks, at 4 °C as well as 25 °C and effect of autoclaving was also evaluated. AmB-PEG2K-NLC were tested for their in vitro antifungal activity against Candida albicans (ATCC 90028), AmB resistant Candida albicans (ATCC 200955) and Aspergillus fumigatus (ATCC 204305). Cytotoxicity of AmB-PEG2K-NLC was studied in human retinal pigmented epithelium cells. In vivo ocular biodistribution of AmB was evaluated in rabbits, following topical application of PEGylated NLCs or marketed AmB preparations. PEGylation with mPEG-2K-DSPE prevented leaching of AmB and increased the drug load significantly. The optimized formulation was prepared with a particle size of 218 ± 5 nm; 0.3 ± 0.02 PDI, 4.6 ± 0.1% w/w drug loading, and 92.7 ± 2.5% w/w entrapment efficiency. The optimized colloidal dispersions were stable for over a month, at both 4 °C and 25 °C. AmB-PEG2K-NLCs showed significantly (p < 0.05) better antifungal activity in both wild-type and AmB resistant Candida strains and, was comparable to, or better than, commercially available parenteral AmB formulations like Fungizone™ and AmBisome®. AmB-PEG2K-NLC did not show any toxicity up to a highest concentration of 1% (v/v) (percent formulation in medium). Following topical instillation, AmB was detected in all the ocular tissues tested and statistically significant (p > 0.05) difference was not observed between the formulations tested. An optimized autoclavable and effective AmB-PEG2K-NLC ophthalmic formulation with at least one-month stability, in the reconstituted state, has been developed.

Quantitative Determination of Chemical Constituents from Seeds of Nigella sativa L. Using HPLC-UV and Identification by LC-ESI-TOF

An HPLC method was developed for the simultaneous determination of nine compounds of Nigella sativa L. The separation was achieved within 23 min by using C18 column material, a wateracetonitrile mobile phase, both containing 0.1 acetic acid gradient system and a temperature of 35C. The method was validated for linearity, repeatability, LOD, and LOQ. The LOD and LOQ of nine compounds were in the range of 0.0910 and 0.325 g/mL, respectively. The wavelength used for quantification with the diode array detector was 205 and 260 nm. LC/MS coupled with electrospray ionization interface method is described for the identification of compounds in N. sativa L. samples. This method involved the use of [MH]&lt;sup/&gt; and [MNa]&lt;sup/&gt; ions in the positive ion mode with extracted ion chromatogram.

Column Liquid Chromatography/Electrospray Ionization-Time of Flight-Mass Spectrometry and Ultraperformance Column Liquid Chromatography/Mass Spectrometry Methods for the Determination of Ginkgolides and Bilobalide in the Leaves of Ginkgo biloba and Dietary Supplements

Column liquid chromatography/electrospray ionization-time of flight-mass spectrometry (LC/ESI-TOF-MS) and ultraperformance column liquid chromatographic/MS (UPLC/MS) methods were developed for the determination of 5 terpenelactones in the leaves of Ginkgo biloba. The separation was performed using a C18 column and a mobile phase composed of water and acetonitrile. The limit of detection (LOD) values for ginkgolide J, ginkgolide C, ginkgolide B, and ginkgolide A were found to be in the range of 110 ng/mL by both methods, and the bilobalide LOD was 200 ng/mL by LC/ESI-TOF and 35 ng/mL by UPLC/MS. Using the optimized method, 4 commercial products were analyzed. Concentrations of total marker compounds in these products were in the 0.0915.4 range, with individual ginkgo terpenelactones being detected at ppb levels. LC/MS with ESI is described for the identification and quantification of ginkgolides and bilobalide in plant samples and dietary supplements that claim to contain G. biloba. These methods involve the use of the M NH4&lt;sup/&gt; and M H&lt;sup/&gt; ions of sesquiterpenoids in the positive ion mode with extractive ion monitoring by LC/ESI-TOF-MS and selected ion monitoring by UPLC/MS. The LC method coupled with MS analysis yielded well-separated peaks which resulted in a clear identification of the compounds.

Quantitative Determination of Flavonoids by Column High-Performance Liquid Chromatography with Mass Spectrometry and Ultraviolet Absorption Detection in Artemisia afra and Comparative Studies with Various Species of Artemisia Plants

A simple and specific analytical method for the quantitative determination of flavonoids from the aerial parts of the Artemisia afra plant samples was developed. By column high-performance liquid chromatography (HPLC) with UV absorption and mass spectrometry (MS) detection, separation was achieved on a reversed-phase octadecylsilyl (C18) column with water, methanol, and acetonitrile, all containing 0.1 acetic acid, as the mobile phase. These methods were used to analyze various species of Artemisia plant samples. The wavelength used for quantification of flavonoids with the diode array detector was 335 nm. The limits of detection (LOD) by HPLC/MS were found to be 7.5, 7.5, 10, 2.0, and 2.0 ng/mL; and by LC-UV the LODs were 500, 500, 500, 300, and 300 ng/mL for apigenin, chrysoeriol, tamarixetin, acacetin, and genkwanin, respectively. The HPLC/MS method was found to be 50150 times more sensitive than the HPLC-UV method. HPLC/MS coupled with an electrospray ionization interface is described for the identification and quantification of flavonoids in various plant samples. This method involved the use of the MH&lt;sup/&gt; ions of the compounds at mass-to-charge ratio of 1.0606, 301.0712, 317.0661, 285.0763, and 285.0763 (calculated mass), respectively, in the positive ion mode with extractive ion monitoring.

Chemical Fingerprinting of Valeriana Species: Simultaneous Determination of Valerenic Acids, Flavonoids, and Phenylpropanoids Using Liquid Chromatography with Ultraviolet Detection

The roots and rhizomes of various valeriana species are currently used as a sleeping aid or mild sedative. A liquid chromatography method has been developed that permits the analysis of chlorogenic acid, lignans, flavonoids, valerenic acids, and valpotrates in various valerian samples. The best results were obtained with a Phenomenex Luna C18(2) column using gradient elution with a mobile phase consisting of water and 0.05% phosphoric acid and 2100% acetonitrilemethanol (1 + 1) with 0.05% phosphoric acid. The flow rate was 0.8 mL/min and ultraviolet detection was at 207, 225, 254, 280, and 325 nm. Different valerian species and commercial products showed remarkable quantitative variations. Chlorogenic acid (0.21.2%), 3 lignans, linarin (0.0020.24%), and valepotriates were detected in all the valeriana species analyzed. Highest amounts of valerenic acids were detected in V. officinalis L., trace amounts in V. sitchensis, and none in the other species analyzed.