Quantitative Determination of Triterpenes from Amphiptherygium adstringens by Liquid Chromatography and Thin-Layer Chromatography and Morphological Analysis of Cuachalalate Preparations

Amphiptherygium adstringens (Anacardiaceae/Julianaceae), local name cuachalalate, is used in folk medicine for the treatment of cholelithiasis, fevers, fresh wounds, hypercholesterolemia, gastritis, gastric ulcers, and cancer of the gastrointestinal tract. The development of column high-performance liquid chromatographyphotodiode array detector (LC-PDA) and high-performance thin-layer chromatography (HPTLC)densitometry methods for the determination of masticadienonic acid and 3-hydroxymasticadienonic acid in cuachalalate preparations is described in this paper. Good separation of the compounds could be achieved by both methods. Either might be preparable depending on the requirements. The LC separation was performed on a Phenomenex Synergi MAX-RP 80A reversed-phase column operated at 40C with detection at 215 nm. The plant materials were extracted with methanol by sonication. The triterpenes present in the plant material and commercial extracts were separated with an acetonitrilewater reagent alcohol isocratic system. The limit of detection was 0.10.2 g/mL. The relative standard deviation values for the determination of triterpenes in plant extracts were less than 1.00%. This is the first report of an analytical method developed for the quantitative analysis of triterpenes from Amphiptherygium adstringens by LC-PDA and HPTLC. The stem bark showed higher amounts of triterpenes, and low amounts in root and stem root. The microscopic description of the crude drug of cuachalalate was also provided.

Simultaneous Quantification of Adrenergic Amines and Flavonoids in C. aurantium, Various Citrus Species, and Dietary Supplements by Liquid Chromatography

An analytical method was developed for the simultaneous quantitative analysis of 6 amines and 20 flavonoids in fruits and extracts of 30 Citrus species, including C. aurantium, near-Citrus relatives, and dietary supplements by liquid chromatography with photodiode array detection. The separation was achieved with a Phenomenex Synergi Hydro reversed-phase column using gradient mobile phase of sodium acetate buffer (pH 5.5) and acetonitrile. Elution was run at a flow rate of 1.0 mL/min and UV at 254, 280, and 330 nm. Among the amines analyzed, synephrine, the main component, was present in the levels from 0.11 to 2.0 mg/g dry weight in 21 Citrus species and 0.07 to 18.62% in dietary supplements claiming to contain C. aurantium. The flavanones and flavones were analyzed in the same Citrus samples and were species-specific. The levels of flavones were very low compared with those of flavanones. The method facilitated the simultaneous quantification of 6 amines and 20 flavonoids in various Citrus species, the distinction between the different Citrus species, and the analysis of dietary supplements containing C. aurantium.

Determination of the Appetite Suppressant P57 in Hoodia gordonii Plant Extracts and Dietary Supplements by Liquid Chromatography/Electrospray Ionization Mass Spectrometry (LC-MSD-TOF) and LC-UV Methods

Hoodia gordonii is traditionally used in South Africa for its appetite suppressant properties. P57AS3 (P57), an oxypregnane steroidal glycoside, is the only reported active constituent from this plant as an appetite suppressant. Effective quality control of these extracts or products requires rapid methods to determine P57 content. New methods of liquid chromatography/mass spectrometry (LC/MS) and LC-UV for analysis of P57 from H. gordonii have been developed. The quantitative determination of P57 was achieved with a Phenomenex Gemini (Torrance, CA) reversed-phase column using gradient mobile phase of water and acetonitrile, both containing 0.1% acetic acid. The method was validated for linearity, repeatability, and limits of detection and quantification. Good results were obtained in terms of repeatability (relative standard deviation <5.0%) and recovery (98.5103.5%). The developed methods were applied to the determination of P57 for H. gordonii plant samples, one related genus (Opuntia ficus-indica), and dietary supplements that claim to contain H. gordonii.

Chemical Fingerprinting of Hoodia Species and Related Genera: Chemical Analysis of Oxypregnane Glycosides Using High-Performance Liquid Chromatography with UV Detection in Hoodia gordonii

Hoodia gordonii, family Asclepiadaceae, is a succulent plant and is traditionally used in southern Africa for its appetite-suppressant properties. A high-performance liquid chromatographic (HPLC) method with UV detection for analysis of 11 oxypregnane glycosides from H. gordonii has been developed. The simultaneous analysis of 11 oxypregnane glycosides was achieved with a Phenomenex (Torrance, CA) reversed-phase C18 column using gradient mobile phase of water and acetonitrile, both containing 0.025 trifluoroacetic acid. The developed method was applied to the identification of oxypregnane glycosides in 3 different species of Hoodia and 23 related genera. The HPLC profiles of various plant samples were compared for the presence of oxypregnane glycosides.

Simultaneous Analysis of Adrenergic Amines and Flavonoids in Citrus Peel Jams and Fruit Juices by Liquid Chromatography: Part 2

Citrus species are rich sources for various bioactive compounds such as flavonoids, adrenergic amines, limonoids, and coumarins. Six adrenergic amines and 20 flavonoids in the jams and juices of Citrus species were analyzed by high-performance liquid chromatography with a C18 reversed-phase column using gradient mobile phase of sodium acetate buffer (pH 5.5) and acetonitrile at a flow rate of 1.0 mL/min with detection at 254, 280, and 330 nm. Synephrine was present in levels from 3.65 to 60.66 mg/L in 48 Citrus juices and 0.0181.02 mg per serving in 32 Citrus jams. The content of these amines and flavonoids varied to a large extent depending on the type of the Citrus species used. The method has been successfully applied to the determination of adrenergic amines and flavonoids in several samples of Citrus fruit juices and jams.

Simultaneous Identification and Quantification of Anthraquinones, Polydatin, and Resveratrol in Polygonum multiflorum, Various Polygonum Species, and Dietary Supplements by Liquid Chromatography and Microscopic Study of Polygonum Species

A high-performance liquid chromatographic (HPLC) method with ultraviolet absorption detection was developed to determine the presence of anthraquinones, polydatin, and resveratrol in Polygonum multiflorum Thunb. as well as other medicinal Polygonum species, viz., P. cuspidatum, P. oriental, P. aviculare, and P. vulgare, as well as commercial products that claim to contain P. multiflorum. The best results were obtained with a Phenomenex Gemini C18 column using gradient mobile phase composed of water (0.1 acetic acid) and acetonitrile (0.1 acetic acid). Elution was at a flow rate of 1.0 mL/min. The detection wavelength was 280 nm for anthraquinones and 320 nm for polydatin and resveratrol. The main anthraquinones identified were emodin and physcion. The HPLC pattern of P. multiflorum was also compared with 5 other species of Polygonum. The method was validated for precision, repeatability, and accuracy. The relative standard deviation was between 0.9 and 1.6. The method was sensitive, quick, and accurate for determination of anthraquinones, polydatin, and resveratrol in 6 different species of Polygonum and can be used for quality control of P. multiflorum. The commercial samples and the 6 Polygonum species were compared microscopically, and a detailed description is provided for P. multiflorum.

Determination of the Anthraquinones Aloe-Emodin and Aloin-A by Liquid Chromatography with Mass Spectrometric and Diode Array Detection

Methods using liquid chromatography/mass spectrometry (LC/MS) and LC with diode array detection (DAD) in the UV range (LC/UV) were developed for the determination of low levels of the anthraquinones aloe-emodin and aloin-A (barbaloin) in aloe-based products. The methods were used to analyze several commercial products (liquids, semisolids, and solids) for the 2 anthraquinones. The wavelengths used for quantification of aloin-A, aloe-emodin, and emodin (internal standard) by DAD were 357, 257, and 289 nm, respectively. The on-column sensitivities were 0.25 and 0.05 ng by LC/UV and 0.01 and 0.025 ng by LC/MS for aloin-A and aloe-emodin, respectively. The methods are simple and sensitive and provide reproducible results; therefore, they are suitable for the determination of these anthraquinones in various aloe-based products.

Quantitative determination and pharmacokinetic study of fusaricidin A in mice plasma and tissues using ultra-high performance liquid chromatography-tandem mass spectrometry

Fusaricidins are a family of cyclic lipodepsipeptides that convey antifungal and antibacterial activity. Fusaricidin A (FA) is one of the Fusaricidins major compounds and it is showing promising activity against fungi and bacteria. In the present study, a fast and sensitive ultra-high performance liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-MS/MS) method was developed for the analysis of FA in mice plasma, liver, kidney and brain tissues. The instrument was operated in positive electrospray ionization mode. Multiple reaction monitoring (MRM) mode was performed with ion pairs of m/z: 883.5→256.3, 883.5→197.2 and 883.5→72.1 for FA. The method was validated for linearity, repeatability, accuracy, stability, limits of detection (LOD) and limits of quantification (LOQ). The LOD and LOQ were 0.01 and 0.05 ng/mL for plasma and tissues, respectively. The calibration curve (10-200 ng/mL) was linear ( r² = 0.99). Precision and accuracy values were found to be < 10% (within acceptable limit). The pharmacokinetic and tissue distribution characteristics of FA were determined in plasma, liver, kidney and brain of CD1 mice after I.V. administration of a single dose of 15 mg/kg body weight. Highest plasma concentration (C_max) was calculated to be 4169.97 ± 50 ng/mL with a t_max of 0.08 h. The plasma clearance rate of FA was 397.6 ± 203 mL/h with a t_1/2 of 2.2 ± 0.5 h and apparent volume of distribution during the terminal phase (V_z) of 979.2 ± 318 mL. The highest tissue concentration (C_max) was found in the liver (219 ± 14 ng/mg) at a t_max of 0.08 h followed by the kidneys (38.6 ± 16 ng/mg) at t_max of 0.2 h. FA was poorly distributed to the brain with a C_max of 0.45 ± 0.2 ng/mg and a t_max of 0.08 h. The method for quantitative analysis and pharmacokinetic data provided will support the development of various formulation approaches and therapeutic application for future clinical studies.

Severe and protracted cholestasis in 44 young men taking bodybuilding supplements: assessment of genetic, clinical and chemical risk factors

BACKGROUND

Bodybuilding supplements can cause a profound cholestatic syndrome.

AIM

To describe the drug-Induced liver injury network's experience with liver injury due to bodybuilding supplements.

METHODS

Liver injury pattern, severity and outcomes, potential genetic associations, and exposure to anabolic steroids by product analysis were analysed in prospectively enrolled subjects with bodybuilding supplement-induced liver injury with causality scores of probable or higher.

RESULTS

Forty-four males (mean age 33 years) developed liver injury with a median latency of 73 days. Forty-one per cent presented with hepatocellular pattern of liver injury as defined by the R > 5 ([Fold elevation of ALT] ÷ [Fold elevation of Alk Phos] (mean, range = 6.4, 0.5-31.4, n = 42) despite all presenting with clinical features of cholestatic liver injury (100% with jaundice and 84% with pruritus). Liver biopsy (59% of subjects) demonstrated a mild hepatitis and profound cholestasis in most without bile duct injury, loss or fibrosis. Seventy-one per cent were hospitalised, and none died or required liver transplantation. In some, chemical analysis revealed anabolic steroid controlled substances not listed on the label. No enrichment of genetic variants associated with cholestatic syndromes was found, although mutations in ABCB11 (present in up to 20%) were significantly different than in ethnically matched controls.

CONCLUSIONS

Patients with bodybuilding supplements liver injury uniformly presented with cholestatic injury, which slowly resolved. The ingested products often contained anabolic steroids not identified on the label, and no enrichment in genetic variants was found, indicating a need for additional studies.

Decaffeinated Green Tea Extract Does Not Elicit Hepatotoxic Effects and Modulates the Gut Microbiome in Lean B6C3F₁ Mice

The main purpose of this study was to investigate the hepatotoxic potential and effects on the gut microbiome of decaffeinated green tea extract (dGTE) in lean B6C3F₁ mice. Gavaging dGTE over a range of 1X–10X mouse equivalent doses (MED) for up to two weeks did not elicit significant histomorphological, physiological, biochemical or molecular alterations in mouse livers. At the same time, administration of dGTE at MED comparable to those consumed by humans resulted in significant modulation of gut microflora, with increases in Akkermansia sp. being most pronounced. Results of this study demonstrate that administration of relevant-to-human-consumption MED of dGTE to non-fasting mice does not lead to hepatotoxicity. Furthermore, dGTE administered to lean mice, caused changes in gut microflora comparable to those observed in obese mice. This study provides further insight into the previously reported weight management properties of dGTE; however, future studies are needed to fully evaluate and understand this effect.

The Contents of Herbal and Dietary Supplements Implicated in Liver Injury in the United States Are Frequently Mislabeled

The U.S. Drug Induced Liver Injury Network assayed the contents of herbal and dietary supplements collected from patients enrolled into its prospective study. The aim was to determine the accuracy of product labels, and to identify known hepatotoxins. Using high‐performance liquid chromatography coupled with mass spectrometry to assay 272 product, 51% were found to be mislabeled; that is, to have chemical contents that did not match the label. Appearance enhancement, sexual performance, and weight loss products were most commonly mislabeled. Whether the mislabeling contributed to liver injury is under study; however, the high mislabeling rate underscores the need for more stringent regulation of supplements.

Herbal and dietary supplements can cause liver injury. The precise cause for injury due to supplements is difficult to determine, as this studies shows that labels are largely unreliable.

Pharmacokinetics and Tissue Distribution of Aegeline after Oral Administration in Mice

Aegeline is claimed to be a biologically active constituent of Aegle marmelos. Preclinical studies have reported possible therapeutic potential for aegeline against obesity and diabetes. In recent years, aegeline has been added to several weight loss products. However, the consumption of aegeline-containing supplements such as OxyELITE Pro and VERSA-1 has been linked to multiple cases of acute and chronic liver failure. This study was carried out to evaluate the pharmacokinetics and tissue distribution of aegeline in ND4 mice. Two doses of aegeline, a human equivalent dose (1×) 30 mg/kg and a 10× dose (300 mg/kg), were orally administered to the mice, and blood and tissue samples were collected over 8 h. The quantitative analysis of plasma and tissue homogenates (liver, kidney, and brain) was done by UHPLC-QTOF to determine aegeline concentrations. The peak plasma level of aegeline was achieved at a T_max of 0.5 h, indicating its rapid absorption from the gastrointestinal tract. Aegeline was not detected in the plasma at 8 h after oral administration, with a half-life of 1.4 ± 0.01 and 1.3 ± 0.07 h for the 30 and 300 mg/kg doses, respectively. The half-life of aegeline in the liver was 1.2 h and 1.7 h for 30 and 300 mg/kg doses, respectively, with a T_max of 1.9 h, which indicates relatively fast elimination of aegeline from the liver.

Structural Characterization of Cranberry Arabinoxyloglucan Oligosaccharides

Cranberry ( Vaccinium macrocarpon) products are widely available in North American food, juice, and dietary supplement markets. The use of cranberry is popular for the prevention of urinary tract infections (UTIs) and other reported health benefits. Preliminary findings by our research group indicate that arabinoxyloglucan oligosaccharides are present in cranberry products and may contribute to the antiadhesion properties of urine produced after cranberry consumption, but relatively little is known regarding the oligosaccharide components of cranberry. This report describes the isolation from two cranberry sources and the complete structure elucidation of two arabinoxyloglucan oligosaccharides through the use of carbohydrate-specific NMR spectroscopic and chemical derivatization methods. These compounds were identified as the heptasaccharide β-d-glucopyranosyl-(1→4)-[α-d-xylopyranosyl-(1→6)]-β-d-glucopyranosyl-(1→4)-β-d-glucopyranosyl-(1→4)-[α-l-arabinofuranosyl-(1→2)-α-d-xylopyranosyl-(1→6)]-β-d-glucopyranose (1) and the octasaccharide β-d-glucopyranosyl-(1→4)-[α-l-arabinofuranosyl-(1→2)-α-d-xylopyranosyl-(1→6)]-β-d-glucopyranosyl-(1→4)-β-d-glucopyranosyl-(1→4)-[α-l-arabinofuranosyl-(1→2)-α-d-xylopyranosyl-(1→6)]-β-d-glucopyranose (2). Selected fractions and the isolated compounds were subjected to antimicrobial, cell viability, and E. coli antiadhesion assays. Results indicated that enriched fractions and purified compounds lacked antimicrobial and cytotoxic effects, supporting the potential use of such compounds for disease prevention without the risk for resistance development. Preliminary antiadhesion results indicated that mixtures of oligosaccharides exhibited greater antiadhesion properties than purified fractions or pure compounds. The potential use of cranberry oligosaccharides for the prevention of UTIs warrants continued investigations of this complex compound series.

A sensitive bioanalytical method for quantitative determination of resiniferatoxin in rat plasma using ultra-high performance liquid chromatography coupled to tandem mass spectrometry and its application in pharmacokinetic study

Resiniferatoxin (RTX) is a daphnane diterpene isolated from the latex of Euphorbia resinifera O. Berg, a potent activator of transient receptor potential vanilloid 1 (TrpV1), with a potency 10³-10⁵ times greater than pure capsaicin. Intravenous administration of RTX at very low concentration improves urodynamic parameters in patients with neurogenic detrusor overactivity and also reduces bladder pain in patients. Herein, a simple, rapid, selective and sensitive method for determination of RTX with silydianin as an internal standard was developed using ultra-high performance liquid chromatography coupled to tandem mass spectrometry with electrospray ionization source (UHPLC-ESI-MS/MS) in multiple reaction monitoring mode. The mass spectrometer was operated in positive electrospray ionization ((+) ESI) mode. Multiple reaction monitoring (MRM) mode was performed with ion pairs of m/z: 629.23→283.2 for RTX and 483.24→153.1 for IS. The limit of detection achieved in this method for RTX was 0.05 ng/mL and had good linearity in calibration range of 0.2-50 ng/mL ( r² = 0.99). Precision and accuracy values were found to be < 15% (within acceptable limit), extraction recovery (≥ 88.2%), matrix effect (≥ 89.7%) and stability were in accordance with the bioanalytical guidelines. The sensitivity of this bio-analytical method supported the successful pharmacokinetic evaluation of RTX on rat plasma (2.5 μg/kg dose; i.v.) and has demonstrated pharmacokinetic parameters V_d and AUC_0-∞ as 191.0 ± 71.31 mL/kg and 981.6 ± 137.40 min*ng/mL, respectively. The clearance was found to be 2.6 ± 0.38 mL/min/kg and half-life was 53.6 ± 23.51 min. This efficient, rapid and reliable method promises the quantification at low concentration of RTX, allowing determination of the pharmacokinetic profile, which is essential in future drug delivery and clinical application.

The power of hyphenated chromatography-Time of flight mass spectrometry for unequivocal identification of spirostanes in bodybuilding dietary supplements

A previously unidentified purported botanical ingredient was found in dietary supplements marketed for anabolic benefits. In an attempt to assess the 'naturalness' of a group of steroid-like compounds called laxogenins, a UHPLC-QToF method was developed. Several dietary supplements claim to contain 5α-hydroxy laxogenin, which is a derivative of a naturally occurring spirostane-type steroid, laxogenin. Although laxogenin has been isolated from the rhizomes of Smilax sieboldii, 5α-hydroxy laxogenin has not been isolated or reported from any natural source. These derivatives of laxogenins have untested anabolic properties. Due to the low UV absorbance of the spirostanes, a mass spectrometric method in positive ion mode was developed for unambiguous identification of laxogenin and closely related compounds. To show the utility of the developed method, twelve dietary supplements labeled to contain 5α-hydroxy laxogenin or laxogenin as 5α-hydroxy laxogenin were analyzed as a proof-of-concept. Five supplements did not contain any 5α-hydroxy laxogenin, whereas in the remaining seven samples, spirostane-type contaminants were identified along with the labeled 5α-hydroxy laxogenin. The identity of some of these contaminants was established based on reference standards along with mass fragmentation patterns. One of the unlabeled contaminants was identified as the phytosteroid saponin, diosgenin, a common starting precursor of several steroidal drugs. Several synthetic derivatives of diosgenin were identified in the eight products. These findings indicate that the labeled 5α-hydroxy laxogenin along with other spirostanes found in supplements are synthetic and signify a lack of quality controls. Additionally, an unlabeled, anabolic androgenic steroid, arimistane, an aromatase inhibitor, was also identified in one product. Laxogenin, was not detected in any of the samples analyzed during this investigation.

Piper nigrum Oil - Determination of Selected Terpenes for Quality Evaluation

The growing demand and commercial value of black pepper (Piper nigrum) has resulted in considerable interest in developing suitable and cost-effective methods for chemical characterization and quality evaluation purposes. In the current study, an extensive set of oil samples (n = 23) that were extracted by steam distillation from black pepper seeds was investigated to compare the chemical profiles of samples originating from nine major producing countries, as well as to identify potential chemical markers for quality evaluation. The twenty-two most abundant volatile compounds, mainly terpenes, in these oils were determined by conventional GC/MS analysis. Principal component analysis with this set of data revealed distinct clusters for samples that originated from China and Malaysia. Relatively low concentrations of sabinene (< 0.2%) and high concentrations of 3-carene (10.9 - 21.1%) were observed in these samples, respectively, compared to oil samples from other countries. The enantiomeric distributions of key terpene markers, viz., β-pinene, sabinene, limonene, and terpinen-4-ol, were determined by chiral GC/MS analysis. Interestingly, for these four monoterpenes, levo-isomers were found to be predominant, emphasizing the highly conserved enzymatic processes occurring in P. nigrum. Moreover, consistent enantiomeric ratios ((-) isomer/(+) isomer) of 92.2 ± 3.0% for β-pinene, 94.8 ± 2.8% for sabinene, 60.7 ± 1.1% for limonene, and 78.3 ± 1.3% for terpinen-4-ol were observed, independent of geographical location. These results demonstrate the potential of using stereospecific compositions as chiral signatures for establishing the authenticity and quality of black pepper oil.

Formation primaquine-5,6-orthoquinone, the putative active and toxic metabolite of primaquine via direct oxidation in human erythrocytes

BACKGROUND

The activity and haemolytic toxicity associated with primaquine has been linked to its reactive metabolites. The reactive metabolites are thought to be primarily formed through the action of cytochrome P₄₅₀-mediated pathways. Human erythrocytes generally are not considered a significant contributor to drug biotransformation. As erythrocytes are the target of primaquine toxicity, the ability of erythrocytes to mediate the formation of reactive oxidative primaquine metabolites in the absence of hepatic enzymes, was evaluated.

METHODS

Primaquine and its enantiomers were incubated separately with human red blood cells and haemoglobin. Post-incubation analysis was performed with UPLC-MS/MS to identify products of biotransformation.

RESULTS

The major metabolite detected was identified as primaquine-5,6-orthoquinone, reflecting the pathway yielding putative active and haematotoxic metabolites of primaquine, which was formed by oxidative demethylation of 5-hydroxyprimaquine. Incubation of primaquine with haemoglobin in a cell-free system yielded similar results. It appears that the observed biotransformation is due to non-enzymatic processes, perhaps due to reactive oxygen species (ROS) present in erythrocytes or in the haemoglobin incubates.

CONCLUSION

This study presents new evidence that primaquine-5,6-orthoquinone, the metabolite of primaquine reflecting the oxidative biotransformation pathway, is generated in erythrocytes, probably by non-enzymatic means, and may not require transport from the liver or other tissues.

Identification and Characterization of Key Chemical Constituents in Processed Gastrodia elata Using UHPLC-MS/MS and Chemometric Methods

Gastrodia elata Blume belongs to the Orchidaceae family. G. elata is often processed when used in traditional Chinese medicine (TCM). In the current study, a traditional processing method, known as "Jianchang Bang," was applied. Steamed and dried (S&D) G. elata was processed with ginger juice for up to 5 days (GEP5D). An UHPLC-MS/MS combined with a chemometric method was developed for the analysis of processed G. elata along with the raw material as well as steamed and dried G. elata. As a result, the primary marker compounds were identified with the aid of TOF-MS and MS/MS analyses. Compared with the raw material of G. elata with GEP5D, three new parishin-type compounds were identified according to their retention time, accurate mass, and fragmentation patterns. The chromatographic peak areas for marker compounds, including S-(gastrodin)-glutathione, S-(4-hydroxybenzylamine)-glutathione, and parishin-type compounds, changed significantly. This result indicated that by applying the "Jianchang Bang" method, changes in chemical composition in G. elata contents were observed. The study also demonstrated that chemometric analysis is helpful in understanding the processing mechanism and will provide scientific support for the clinical application of G. elata.

Quantification of Phenolic Compounds from Fadogia agrestis and Dietary Supplements using UHPLC-PDA-MS

Fadogia agrestis is used in traditional African medicine as an analgesic and for anti-inflammatory and aphrodisiac activities. An ultra-high-performance liquid chromatography method was developed for the determination of 11 chemical constituents from roots and aerial parts of F. agrestis. The separation was achieved within 7 min by using C-18 column material and a water/acetonitrile mobile phase, both containing 0.1% formic acid gradient system with a temperature of 45 °C. The method was validated for linearity, repeatability, limits of detection, and limits of quantification. The limits of detection of phenolic compounds were found to be in the range from 0.025 to 0.1 µg/mL. The wavelengths used for quantification with the photodiode array detector were 238, 254, 291, and 325 nm. Twelve of 17 dietary supplements contained phenolic compounds in the range from 0.3 to 2.7 mg/d. The phenolic compounds were not detected in five dietary supplements. Liquid chromatography-mass spectrometry coupled with electrospray ionization interface method is described for the identification and confirmation of compounds from plant samples and dietary supplements claiming to contain F. agrestis. This method involved the use of [M + H]⁺ and [M + Na]⁺ ions in the positive mode and [M - H]^- ions in the negative mode with extractive ion monitoring. The developed method is simple, economic, rapid, and especially suitable for quality control and chemical fingerprint analysis of F. agrestis.

In Situ Gel of Triamcinolone Acetonide-Loaded Solid Lipid Nanoparticles for Improved Topical Ocular Delivery: Tear Kinetics and Ocular Disposition Studies

Triamcinolone acetonide (TA), an intermediate acting corticosteroid, is used in the treatment of posterior ocular diseases, such as inflammation, posterior uveitis, and diabetic macular edema. The objective of this investigation was to prepare TA-loaded solid lipid nanoparticles (TA-SLNs) and in situ gel (TA-SLN-IG) formulations for delivery into the deeper ocular tissues through the topical route. TA-SLNs were prepared by hot homogenization and ultrasonication method using glyceryl monostearate and Compritol® 888ATO as solid lipids and Tween®80 and Pluronic® F-68 as surfactants. TA-SLNs were optimized and converted to TA-SLN-IG by the inclusion of gellan gum and evaluated for their rheological properties. In vitro transcorneal permeability and in vivo ocular distribution of the TA-SLNs and TA-SLN-IG were studied using isolated rabbit corneas and New Zealand albino rabbits, respectively, and compared with TA suspension, used as control (TA-C). Particle size, PDI, zeta potential, assay, and entrapment efficiency of TA-SLNs were in the range of 200⁻350 nm, 0.3⁻0.45, -52.31 to -64.35 mV, 70⁻98%, and 97⁻99%, respectively. TA-SLN-IG with 0.3% gellan gum exhibited better rheological properties. The transcorneal permeability of TA-SLN and TA-SLN-IG was 10.2 and 9.3-folds higher compared to TA-C. TA-SLN-IG showed maximum tear concentration at 2 h, indicating an improved pre-corneal residence time, as well as higher concentrations in aqueous humor, vitreous humor and cornea at 6 h, suggesting sustained delivery of the drug into the anterior and posterior segment ocular tissues, when compared to TA-SLN and TA-C. The results, therefore, demonstrate that the lipid based nanoparticulate system combined with the in situ gelling agents can be a promising drug delivery platform for the deeper ocular tissues.

Tetra-glucopyranosyl Diterpene ent-Kaur-16-en-19-oic Acid and ent-13(S)-Hydroxyatisenoic Acid Derivatives from a Commercial Extract of Stevia rebaudiana (Bertoni) Bertoni

Stevia rebaudiana and its diterpene glycosides are one of the main focuses of food companies interested in developing novel zero calorie sugar substitutes since the recognition of steviol glycosides as Generally Recognized as Safe (GRAS) by the United States Food and Drug Administration. Rebaudioside A, one of the major steviol glycosides of the leaves is more than 200 times sweeter than sucrose. However, its lingering aftertaste makes it less attractive as a table-top sweetener, despite its human health benefits. Herein, we report the purification of two novel tetra-glucopyranosyl diterpene glycosides 1 and 3 (rebaudioside A isomers) from a commercial Stevia rebaudiana leaf extract compounds, their saponification products compounds 2 and 4, together with three known compounds isolated in gram quantities. Compound 1 was determined to be 13-[(2-O-β-d-glucopyranosyl-6-O-β-d-glucopyranosyl-β-d-glucopyranosyl) oxy]ent-kaur-16-en-19-oic acid-β-d-glucopyranosy ester (rebaudioside Z), whereas compound 3 was found to be 13-[(2-O-β-d-glucopyranosyl-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl) oxy]ent-hydroxyatis-16-en-19-oic acid -β-d-glucopyranosy ester. Two new tetracyclic derivatives with no sugar at position C-19 were prepared from rebaudiosides 1 and 3 under mild alkaline hydrolysis to afford compounds 2 13-[(2-O-β-d-glucopyranosyl-6-O-β-d-glucopyranosyl-β-d-glucopyranosyl) oxy]ent-kaur-16-en-19-oic acid (rebaudioside Z₁) and 4 13-[(2-O-β-d-glucopyranosyl-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl) oxy]ent-hydroxyatis-16-en-19-oic acid. Three known compounds were purified in gram quantities and identified as rebaudiosides A (5), H (6) and J (7). Chemical structures were unambiguously elucidated using different approaches, namely HRESIMS, HRESI-MS/MS, and 1D-and 2D-NMR spectroscopic data. Additionally, a high-quality crystal of iso-stevioside was grown in methanol and its structure confirmed by X-ray diffraction.

Impact of obesity on the toxicity of a multi-ingredient dietary supplement, OxyELITE Pro™ (New Formula), using the novel NZO/HILtJ obese mouse model: Physiological and mechanistic assessments

Herbal dietary supplement (HDS)-induced hepato- and cardiotoxicity is an emerging clinical problem. In this study, we investigated the liver and heart toxicity of HDS OxyELITE-PRO™ New Formula (OEP-NF), a dietary supplement marketed for weight loss and performance enhancement that was recently withdrawn from the market. Using a novel NZO/HlLtJ obese mouse model, we demonstrated that administration of clinically relevant mouse equivalent doses (MED) of OEP-NF produced cardio- and hepatotoxic risks following both short- and long-term administration schedules. Specifically, gavaging female NZO/HlLtJ with up to 2X MED of OEP-NF resulted in 40% mortality within two weeks. Feeding mice with either 1X or 3X MED of OEP-NF for eight weeks, while not exhibiting significant effects on body weights, significantly altered hepatic gene expression, increased the number of apoptotic and mast cells in the heart and affected cardiac function. The degree of toxicity in NZO/HlLtJ mice was higher than that observed previously in non-obese CD-1 and B6C3F1 strains, suggesting that an overweight/obese condition can sensitize mice to OEP-NF. Adverse health effects linked to OEP-NF, together with a number of other hepato- and cardiotoxicity cases associated with HDS ingestion, argue strongly for introduction of quality standards and pre-marketing safety assessments for multi-ingredient HDS.

Metabolism of primaquine in normal human volunteers: investigation of phase I and phase II metabolites from plasma and urine using ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry

BACKGROUND

Primaquine (PQ), an 8-aminoquinoline, is the only drug approved by the United States Food and Drug Administration for radical cure and prevention of relapse in Plasmodium vivax infections. Knowledge of the metabolism of PQ is critical for understanding the therapeutic efficacy and hemolytic toxicity of this drug. Recent in vitro studies with primary human hepatocytes have been useful for developing the ultra high-performance liquid chromatography coupled with high-resolution mass spectrometric (UHPLC-QToF-MS) methods for simultaneous determination of PQ and its metabolites generated through phase I and phase II pathways for drug metabolism.

METHODS

These methods were further optimized and applied for phenotyping PQ metabolites from plasma and urine from healthy human volunteers treated with single 45 mg dose of PQ. Identity of the metabolites was predicted by MetaboLynx using LC-MS/MS fragmentation patterns. Selected metabolites were confirmed with appropriate standards.

RESULTS

Besides PQ and carboxy PQ (cPQ), the major plasma metabolite, thirty-four additional metabolites were identified in human plasma and urine. Based on these metabolites, PQ is viewed as metabolized in humans via three pathways. Pathway 1 involves direct glucuronide/glucose/carbamate/acetate conjugation of PQ. Pathway 2 involves hydroxylation (likely cytochrome P450-mediated) at different positions on the quinoline ring, with mono-, di-, or even tri-hydroxylations possible, and subsequent glucuronide conjugation of the hydroxylated metabolites. Pathway 3 involves the monoamine oxidase catalyzed oxidative deamination of PQ resulting in formation of PQ-aldehyde, PQ alcohol and cPQ, which are further metabolized through additional phase I hydroxylations and/or phase II glucuronide conjugations.

CONCLUSION

This approach and these findings augment our understanding and provide comprehensive view of pathways for PQ metabolism in humans. These will advance the clinical studies of PQ metabolism in different populations for different therapeutic regimens and an understanding of the role these play in PQ efficacy and safety outcomes, and their possible relation to metabolizing enzyme polymorphisms.