Therapeutic benefit of combining calorie-restricted ketogenic diet and glutamine targeting in late-stage experimental glioblastoma.

Glioblastoma (GBM) is an aggressive primary human brain tumour that has resisted effective therapy for decades. Although glucose and glutamine are the major fuels that drive GBM growth and invasion, few studies have targeted these fuels for therapeutic management. The glutamine antagonist, 6-diazo-5-oxo-L-norleucine (DON), was administered together with a calorically restricted ketogenic diet (KD-R) to treat late-stage orthotopic growth in two syngeneic GBM mouse models: VM-M3 and CT-2A. DON targets glutaminolysis, while the KD-R reduces glucose and, simultaneously, elevates neuroprotective and non-fermentable ketone bodies. The diet/drug therapeutic strategy killed tumour cells while reversing disease symptoms, and improving overall mouse survival. The therapeutic strategy also reduces edema, hemorrhage, and inflammation. Moreover, the KD-R diet facilitated DON delivery to the brain and allowed a lower dosage to achieve therapeutic effect. The findings support the importance of glucose and glutamine in driving GBM growth and provide a therapeutic strategy for non-toxic metabolic management.

DART-MS in-source collision induced dissociation and high mass accuracy for new psychoactive substance determinations.

The influx of new psychoactive substances is a problem that is challenging the analytical capabilities of enforcement agencies. Cathinone designer drugs are less likely to be included in routine drug screens and typical drug formulations are commonly mixtures with continually shifting components. Ambient ionization mass spectrometry employs relatively mild conditions to desorb and ionize solid samples, imparting much less energy than that associated with conventional mass spectrometry methods. Direct analysis in real time mass spectrometry (DART-MS) is an ambient ionization method that was employed to rapidly screen cathinones, alone and in mixtures, readily enabling differentiation of the active drug(s) from various cutting agents. Accurate mass determinations provided preliminary identification of the various components of drug mixtures. The data generated in forensic mass spectrometry can be used for both elemental composition formulations and isotope abundance calculations for determination of unknown psychoactive substances, and we demonstrate how this data could be applied to the presence of new drugs as the active components shift in response to regulations. Isotope abundance calculations were used to develop a candidate pool of possible molecular formulas associated with cathinones as a specific class of designer drugs. Together, the combination of a time-of-flight (TOF) mass analyzer along with in-source collision-induced dissociation (CID) spectra were used to drastically narrow the pool of candidates to a single molecular formula. The [M+H](+) and product ion peaks provided data for presumptive analysis of various substituted synthetic cathinones in a manner that is complementary to conventional GC-MS analysis of new psychoactive substances.

DART-MS for rapid, preliminary screening of urine for DMAA.

Dimethylamylamine (DMAA) is a sympathomimetic amine found in weight-loss/workout supplements or used as an appetite suppressant. DMAA is a stimulant that is banned by the World Anti-Doping Agency (WADA). Adverse health effects as well as fatalities have been implicated with its use. Direct analysis in real time mass spectrometry (DART-MS) is an ambient ionization method that was employed to rapidly identify the presence of DMAA in various samples without any extraction or preparations whatsoever. DMAA was first identified in supplements, sampled directly in their solid forms. Furthermore, DMAA was detected directly in urine over 48 h as a means of indicating recent abuse of the substance. DART-MS analysis is instantaneous, and coupled with the high mass accuracy associated with the time-of-flight mass analyzer, results in unequivocal identification of the presence of DMAA. These features demonstrate DART-MS as an attractive potential alternative screening method for the presence of drugs and medications or for toxicological investigations.

DART-MS as a preliminary screening method for "herbal incense": chemical analysis of synthetic cannabinoids.

Direct analysis in real time mass spectrometry (DART-MS) served as a method for rapid high-throughput screening of six commercially available "Spice" products, detecting various combinations of five synthetic cannabinoids. Direct analysis in real time is an ambient ionization process that, along with high mass accuracy time-of-flight (TOF)-MS to 0.0001 Da, was employed to establish the presence of cannabinoids. Mass spectra were acquired by simply suspending a small portion of sample between the ion source and the mass spectrometer inlet. The ability to test minute amounts of sample is a major advantage when very limited amounts of evidentiary material are available. In addition, reports are widespread regarding the testing backlogs that now exist because of the large influx of designer drugs. This method circumvents time-consuming sample extraction, derivatization, chromatographic, and other sample preparative steps required for analysis by more conventional mass spectrometric methods. Accordingly, the synthetic cannabinoids AM-2201, JWH-122, JWH-203, JWH-210, and RCS-4 were identified in commercially available herbal Spice products, singly and in tandem, at concentrations within the range of 4-141 mg/g of material. Direct analysis in real time mass spectrometry decreases the time necessary to triage analytical evidence, and therefore, it has the potential to contribute to backlog reduction and more timely criminal prosecution.

Direct analysis in real time mass spectrometry (DART-MS) of "bath salt" cathinone drug mixtures.

Rapid and versatile direct analysis in real time mass spectrometry (DART-MS) methods were developed for detection and characterization of synthetic cathinone designer drugs, also known as "bath salts". The speed and efficiency associated with DART-MS testing of such highly unpredictable samples demonstrate the technique as an attractive alternative to conventional GC-MS and LC-MS methods. A series of isobaric and closely related synthetic cathinones, alone and in mixtures, were differentiated using high mass accuracy and in-source collision induced dissociation (CID). Crime laboratories have observed a dramatic rise in the use of these substances, which has caused sample testing backlogs, particularly since the myriad of structurally related compounds are challenging to efficiently differentiate. This challenge is compounded by the perpetual emergence of new structural variants as soon as older generation derivatives become scheduled. Because of the numerous chemical substances that fall into these categories, along with the varying composition and complexity of mixtures of these drugs, DART-MS CID has the potential to dramatically streamline sample analysis, minimize the number of sample preparation steps, and enable rapid characterization of emerging structural analogs.

Direct analysis in real time mass spectrometry with collision-induced dissociation for structural analysis of synthetic cannabinoids.

RATIONALE: The emergence of numerous cannabinoid designer drugs has been tied to large spikes in emergency room visits and overdoses. Identifying these substances is difficult for the following reasons: (1) the compounds are novel, closely structurally related, and do not usually test positive in drug screens; (2) novel analogs rapidly appear on the market; (3) no standard protocols exist for their identification; and (4) customized and extensive sample preparation/extraction and analysis procedures are required to demonstrate their presence. METHODS: Direct analysis in real time mass spectrometry (DART-MS) employing collision-induced dissociation (CID) provided confirmatory structural information that was useful in characterizing the various cannabinoid analogs, including those contained in mixtures. CID analysis illustrated that, although closely related compounds fragment in a similar fashion, their structural differences still resulted in multiple diagnostic peaks that provided additional confidence towards structural identification. RESULTS: DART-MS spectra were acquired under CID conditions to rapidly differentiate among five synthetic cannabinoids contained within 'herbal' products purchased locally in New York State (USA). The spectra exhibited [M+H](+) ions and product ions unique to each cannabinoid that corresponded to major structural features. Five different cannabinoid analogs, alone and as mixtures of at least two cannabinoids, were identified in six herbal products and differentiated by their CID product ion patterns. CONCLUSIONS: Illicit synthetic cannabinoid products continue to be readily available despite national and international restrictions. These products contain a wide range of active components, and, in many cases, multiple active ingredients. DART-MS allows rapid analyses of these synthetic cannabinoids based on the exact masses of their [M+H](+) ions and product ion peaks generated using CID.

Rapid identification of synthetic cannabinoids in herbal samples via direct analysis in real time mass spectrometry.

RATIONALE: Dozens of synthetic cannabinoid analogs purposefully meant to circumvent legal restrictions associated with controlled substances continue to be manufactured and promoted as producing 'legal highs'. These designer drugs are difficult to identify in conventional drug screens not only because routine protocols have not been developed for their detection, but also because their association with complex plant matrices during manufacture generally requires labor-intensive extraction and sample preparation for analysis. To address this new and important challenge in forensic chemistry, Direct Analysis in Real Time Mass Spectrometry (DART-MS) is applied to the analysis of these designer drugs. METHODS: DART-MS was employed to sample synthetic cannabinoids directly on botanical matrices. The ambient ionization method associated with DART-MS permitted the analysis of solid herbal samples directly, without the need for extraction or sample preparation. The high mass resolution time-of-flight analyzer allowed identification of these substances despite their presence within a complex matrix and enabled differentiation of closely related analogs. RESULTS: DART-MS was performed to rapidly identify the synthetic cannabinoids AM-251 and JWH-015. For each cannabinoid, three hundred micrograms (300 µg) of material was easily detected within an excess of background matrix by mass. CONCLUSIONS: New variations of herbal blends containing a wide range of base components and laced with synthetic cannabinoids are being produced, making their presence difficult to track by conventional methods. DART-MS permits rapid identification of trace synthetic cannabinoids within complex biological matrices, with excellent sensitivity and specificity compared with standard methods.

Routine analysis and characterization of highly insoluble polycyclic aromatic compounds by direct analysis in real time mass spectrometry (DART).

Direct Analysis in Real Time (DART), is used for the first time for the routine rapid analysis of highly insoluble polycyclic aromatic compounds. Direct analysis of such compounds as solid samples under solvent-free conditions shows that DART is a powerful analytical platform capable of providing high-throughput analysis for these complex samples, requiring no special sample pre-treatment or instrument setup.

HRMS directly from TLC slides. A powerful tool for rapid analysis of organic mixtures.

High-resolution mass spectra (HRMS) of individual spots on thin-layer chromatography (TLC) slides can now be obtained quickly and easily at atmospheric pressure, with zero sample preparation, using commercially available instrumentation. The method is complementary to GC-mass spectrometry but is not limited to compounds of high volatility and high thermal stability. TLC-HRMS can be used to monitor chemical reactions in real time and has the capacity thereby to accelerate significantly the pace of synthetic organic chemistry.