Chemical Characterization of Pseudognaphalium obtusifolium by Gas Chromatography - Mass Spectrometry (GC-MS) to Assess Potential Therapeutic Phytochemicals and Toxicological Concerns Using Simulated Use Conditions

Chemical Characterization of Pseudognaphalium obtusifolium by Gas Chromatography – Mass Spectrometry (GC-MS) to Assess Potential Therapeutic Phytochemicals and Toxicological Concerns Using Simulated Use Conditions By Regina Ballentine Virginia Commonwealth University, 2019 Director: Sarah C. Rutan, Professor, Department of Chemistry Currently, there is an increasing demand for natural therapies and herbal products to treat various ailments. It is generally believed that natural therapies have fewer side-effects than traditional western medicine; however, they are often used in different strengths and formulations without consistency of the levels of target compounds or knowledge about toxicity. Due to this growing trend, a comprehensive chemical evaluation of plants used for medicinal purposes is necessary. Pseudognaphalium obtusifolium is a plant that has been used historically by Native Americans as an herbal medicine. It is a flowering plant belonging to the Asteraceae family indigenous to the Eastern United States. There are documented accounts of the Native Americans using the herb therapeutically. Reportedly, they used the plant to prepare tea and as filler for bedding. Additionally, they smoked the plant material. To date, there has been little research published on the chemical composition of this plant. Thus, the objective of this work was to conduct a chemical survey of P. obtusifolium using methodologies that would simulate the three historical routes of administration (tea, bedding material, and smoke inhalation). To determine the types of compounds that may be found in the plant, initial experiments using pressurized solvent extraction (PSE) with an ethanolic solvent were performed followed by analysis using gas chromatography – mass spectrometry (GC-MS) in scan mode. This extraction technique enabled a broad range of compounds to be identified. For the analysis of the tea, the leaves and the flowers were ground and analyzed separately. The “tea” simulation was then performed using a water extraction which was then back extracted into dichloromethane for GC-MS analysis in Selected Ion Monitoring (SIM) mode. Seventeen target compounds (terpenes, terpinoids, flavanoids, etc.) were quantified using this method. A bedding material simulation was performed using headspace solid phase micro-extraction (HS-SPME) to collect the volatile and/or semi-volatile components of the headspace. The compounds collected on the SPME fiber were then analyzed by GC-MS in scan and SIM modes to qualitatively and quantitatively determine the types of chemical compounds (most of which were terpenes) that may be off-gassed from bedding material. This analysis compared levels of compounds in two different crop years and four terpene compounds were quantified. To simulate smoking of the plant material, the leaves and flowers were fashioned into smoking articles. Sample collection was performed by a smoking machine and smoke condensate was collected. The smoke condensate was then analyzed by GC-MS in scan mode. As combustion and pyrolysis of plant material are known to produce toxic products, specific potentially harmful compounds were investigated and quantified. This chemical analysis of P. obtusifolium identified target compounds that can be found in the three simulated usage forms. Identification of these compounds gives insight on why the Native Americans may have used P. obtusifolium as an herbal medicine. Among the detected compounds, there were many unknowns. Elucidating these unknown compounds will be important in the effort to understand the full chemical profile of this plant

Characterization of potential impurities and degradation products in electronic cigarette formulations and aerosols

AbstractE-cigarettes are gaining popularity in the U.S. as well as in other global markets. Currently, limited published analytical data characterizing e-cigarette formulations (e-liquids) and aerosols exist. While FDA has not published a harmful and potentially harmful constituent (HPHC) list for e-cigarettes, the HPHC list for currently regulated tobacco products may be useful to analytically characterize e-cigarette aerosols. For example, most e-cigarette formulations contain propylene glycol and glycerin, which may produce aldehydes when heated. In addition, nicotine-related chemicals have been previously reported as potential e-cigarette formulation impurities. This study determined e-liquid formulation impurities and potentially harmful chemicals in aerosols of select commercial MarkTen® e-cigarettes manufactured by NuMark LLC. The potential hazard of the identified formulation impurities and aerosol chemicals was also estimated. E-cigarettes were machine puffed (4-s duration, 55-mL volume, 30-s intervals) to battery exhaustion to maximize aerosol collection. Aerosols analyzed for carbonyls were collected in 20-puff increments to account for analyte instability. Tobacco specific nitrosamines were measured at levels observed in pharmaceutical grade nicotine. Nicotine-related impurities in the e-cigarette formulations were below the identification and qualification thresholds proposed in ICH Guideline Q3B(R2). Levels of potentially harmful chemicals detected in the aerosols were determined to be below published occupational exposure limits