Thousands of electronic cigarette refill fluids are commercially available. The concentrations of nicotine and the solvents, but not the flavor chemicals, are often disclosed on product labels. The ...purpose of this study was to identify and quantify flavor chemicals in 39 commercial refill fluids that were previously evaluated for toxicity. Twelve flavor chemicals were identified with concentrations ≥1 mg/ml: cinnamaldehyde, menthol, benzyl alcohol, vanillin, eugenol, p-anisaldehyde, ethyl cinnamate, maltol, ethyl maltol, triacetin, benzaldehyde, and menthone. Transfer of these flavor chemicals into aerosols made at 3V and 5V was efficient (mean transfer = 98%). We produced lab-made refill fluids containing authentic standards of each flavor chemical and analyzed the toxicity of their aerosols produced at 3V and 5V using a tank Box Mod device. Over 50% of the refill fluids in our sample contained high concentrations of flavor chemicals that transferred efficiently to aerosols at concentrations that produce cytotoxicity. When tested with two types of human lung cells, the aerosols made at 5V were generally more toxic than those made at 3V. These data will be valuable for consumers, physicians, public health officials, and regulatory agencies when discussing potential health concerns relating to flavor chemicals in electronic cigarette products.
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•The occurrence of selected contaminats was investigated in a highly urbanized area.•The environmental risk assessment was assessed for the entire mixture.•Emerging contaminats were ...ubiquitous pollutants in the urbanized area.•A panel of substances of environmental concern was identified in any sampling point.•The mixture showed a potential risk also for pollutants that individually were safe.
A complex mixture of emerging contaminants (ECs) occurs in the environment, with potential effects for aquatic organisms and human health. This study assessed the environmental risk of a mixture of ECs detected in the most urbanized and industrialized area of Italy. Water samples were collected in the Lambro river basin to the north and south of Milan, and were analyzed by liquid chromatography tandem mass spectrometry. The Environmental Risk Assessment (ERA) was performed calculating the Risk Quotients (RQs) for each EC as the ratio of Measured Concentrations (MECs) and Predicted No Effect Concentrations. The ERA was also conducted for the whole mixture of ECs by considering the RQs of the components. The results confirmed that ECs are ubiquitous in urbanized areas. The ERA for the single pollutants identified a panel of substances of environmental concern (estrogens, amoxicillin, clarythromycin, triclosan and nicotine). The ERA for the mixture indicated a potential cumulative risk for the substances that individually could be considered safe, highlighting the importance of taking the whole mixture of ECs into account for the ERA. This information may help establish EU regulations for ECs and environmental quality standards for regulatory purposes.
We identified the most popular electronic cigarette (EC) refill fluids using an Internet survey and local and online sales information, quantified their flavor chemicals, and evaluated cytotoxicities ...of the fluids and flavor chemicals. "Berries/Fruits/Citrus" was the most popular EC refill fluid flavor category. Twenty popular EC refill fluids were purchased from local shops, and the ingredient flavor chemicals were identified and quantified by gas chromatography-mass spectrometry. Total flavor chemical concentrations ranged from 0.6 to 27.9 mg/ml, and in 95% of the fluids, total flavor concentration was greater than nicotine concentration. The 20 most popular refill fluids contained 99 quantifiable flavor chemicals; each refill fluid contained 22 to 47 flavor chemicals, most being esters. Some chemicals were found frequently, and several were present in most products. At a 1% concentration, 80% of the refill fluids were cytotoxic in the MTT assay. Six pure standards of the flavor chemicals found at the highest concentrations in the two most cytotoxic refill fluids were effective in the MTT assay, and ethyl maltol, which was in over 50% of the products, was the most cytotoxic. These data show that the cytotoxicity of some popular refill fluids can be attributed to their high concentrations of flavor chemicals.
We characterized the flavor chemicals in a broad sample of commercially available electronic cigarette (EC) refill fluids that were purchased in four different countries. Flavor chemicals in 277 ...refill fluids were identified and quantified by gas chromatography-mass spectrometry, and two commonly used flavor chemicals were tested for cytotoxicity with the MTT assay using human lung fibroblasts and epithelial cells. About 85% of the refill fluids had total flavor concentrations >1 mg/ml, and 37% were >10 mg/ml (1% by weight). Of the 155 flavor chemicals identified in the 277 refill fluids, 50 were present at ≥1 mg/ml in at least one sample and 11 were ≥10 mg/ml in 54 of the refill fluids. Sixty-one% (170 out of 277) of the samples contained nicotine, and of these, 56% had a total flavor chemical/nicotine ratio >2. Four chemicals were present in 50% (menthol, triacetin, and cinnamaldehyde) to 80% (ethyl maltol) of the samples. Some products had concentrations of menthol ("Menthol Arctic") and ethyl maltol ("No. 64") that were 30 times (menthol) and 100 times (ethyl maltol) their cytotoxic concentration. One refill fluid contained cinnamaldehyde at ~34% (343 mg/ml), more than 100,000 times its cytotoxic level. High concentrations of some flavor chemicals in EC refill fluids are potentially harmful to users, and continued absence of any regulations regarding flavor chemicals in EC fluids will likely be detrimental to human health.
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•Acetobacter xylinum synthesized BC using tobacco waste extract.•Nicotine was found to be inhibitory for the synthesis of BC.•BC production increased after nicotine removal by steam ...distillation at pH 9.0.•BC production reached 5.2 g/L using two-stage fermentation by adjusting pH.•BC obtained from TWE medium has similar properties to that from HS medium.
In this study, bacterial cellulose (BC) was synthesized by Acetobacter xylinum ATCC 23767 using tobacco waste extract (TWE) as a carbon source. Nicotine was found to be an inhibitory factor for BC synthesis, but it can be removed at pH 9.0 by steam distillation. After removing nicotine, the BC production was 2.27 g/L in TWE prepared with solid-liquid (S-L) ratio at 1:10. To further enhance the BC production, two fermentation stages were performed over 16 days by re-adjusting the pH to 6.5 at 7 days, after the first fermentation stage was completed. Using this two-stage fermentation, the BC production could reach 5.2 g/L. Structural and thermal analysis by FE-SEM, FT-IR, XRD and TGA showed the properties of BC obtained from TWE were similar to that from Hestrin-Schramm (HS) medium. Considering the huge disposal tobacco waste in China, the present study provides an alternative methodology to synthesize BC.
Latar Belakang: Merokok masih menjadi faktor risiko peyebab utama masalah kesehatan dan kematian dini di dunia. Senyawa yang berperan dalam kebiasaan merokok adalah nikotin yang dapat mengakibatkan ...nikotin dependen.
Objektif: Penelitian ini dilakukan untuk mengetahui apakah terdapat hubungan faktor usia inisial merokok, lama merokok, tipe kebiasaan merokok, dan aturan merokok dengan tingkat nikotin dependen perokok pada mahasiswa laki-laki di Kota Padang.
Metode: Penelitian ini merupakan survei analitik dengan desain cross-sectional study yang dilakukan di Kota Padang dari September-Desember 2020. Sebanyak 218 mahasiswa menjadi sampel penelitian diambil dengan teknik consecutive sampling. Pengambilan data dilakukan dengan pengisian kuesioner secara online. Pengukuran tingkat nikotin dependen berdasarkan kuesioner Fagerstrom Test for Nicotine Dependence (FTND). Analisis data yang dilakukan adalah uji Mann-Whitney dan uji chi-square.
Hasil: Sebagian besar mahasiswa perokok laki-laki di Kota Padang memiliki tingkat nikotin dependen ringan (84,8%). Terdapat perbedaan rata-rata usia inisial (p=0,001) dan lama merokok (<0,001) antar tingkat nikotin dependen. Terdapat hubungan bermakna antara tipe kebiasaan merokok dan aturan merokok dengan tingkat nikotin dependen ((p<0,001, OR=9,537 (3,229-28,171); p<0,001, OR=7,635(3,466-16,820)).
Kesimpulan: Kesimpulan dari penelitian ini adalah faktor usia inisial merokok, lama merokok, tipe kebiasaan merokok, dan aturan merokok berpegaruh terhadap tingkat nikotin dependen.
Metal‐catalyzed intramolecular C−H amination of alkyl azides constitutes an appealing approach to alicyclic amines; challenges remain in broadening substrate scope, enhancing regioselectivity, and ...applying the method to natural product synthesis. Herein we report an iron(III) porphyrin bearing axial N‐heterocyclic carbene ligands which catalyzes the intramolecular C(sp3)–H amination of a wide variety of alkyl azides under microwave‐assisted and thermal conditions, resulting in selective amination of tertiary, benzylic, allylic, secondary, and primary C−H bonds with up to 95 % yield. 14 out of 17 substrates were cyclized selectively at C4 to give pyrrolidines. The regioselectivity at C4 or C5 could be tuned by modifying the reactivity of the C5–H bond. Mechanistic studies revealed a concerted or a fast re‐bound mechanism for the amination reaction. The reaction has been applied to the syntheses of tropane, nicotine, cis‐octahydroindole, and leelamine derivatives.
Reaching closure: An iron(III) porphyrin N‐heterocyclic carbene complex catalyzed the intramolecular C(sp3)–H amination of a wide variety of primary, secondary, and tertiary alkyl azides under microwave‐assisted and thermal conditions. The reaction has been applied to syntheses of tropane, nicotine, and cis‐octahydroindole and leelamine derivatives.
Understanding and predicting permeability of compounds through skin is of interest for transdermal delivery of drugs and for toxicity predictions of chemicals. We show, using a new atomistic ...molecular dynamics model of the skin's barrier structure, itself validated against near-native cryo-electron microscopy data from human skin, that skin permeability to the reference compounds benzene, DMSO (dimethyl sulfoxide), ethanol, codeine, naproxen, nicotine, testosterone and water can be predicted. The permeability results were validated against skin permeability data in the literature. We have investigated the relation between skin barrier molecular organization and permeability using atomistic molecular dynamics simulation. Furthermore, it is shown that the calculated mechanism of action differs between the five skin penetration enhancers Azone, DMSO, oleic acid, stearic acid and water. The permeability enhancing effect of a given penetration enhancer depends on the permeating compound and on the concentration of penetration enhancer inside the skin's barrier structure. The presented method may open the door for computer based screening of the permeation of drugs and toxic compounds through skin.
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