-
IScience Sep 2022Propylene glycol is a ubiquitous sustainable chemical that have several industrial applications. It can be used as a non-toxic antifreeze, moisturizers, and in cosmetics... (Review)
Review
Propylene glycol is a ubiquitous sustainable chemical that have several industrial applications. It can be used as a non-toxic antifreeze, moisturizers, and in cosmetics products. Commercial production of propylene glycol uses petroleum-based propylene oxide. Therefore, there is a need to develop alternative and renewable propylene glycol production routes. Renewable propylene glycol can be produced from catalytic hydrogenolysis of glycerol. This study reviews different catalyst for glycerol hydrogenolysis, the reaction mechanism, and process challenges. Additionally, previous studies related to the economic and environmental assessment of propylene glycol production are presented in detail. The technology readiness level of different production pathways were outlined as well as the challenges and future direction of propylene glycol production from glycerol and other renewable feedstocks. Catalytic transfer hydrogenolysis, a process that uses renewable H-donors in liquid medium for hydrogenolysis reaction is also discussed and compared with conventional hydrogenolysis.
PubMed: 36039303
DOI: 10.1016/j.isci.2022.104903 -
Frontiers in Chemistry 2021Hydrogenolysis of glycerol to propylene glycol represents one of the most promising technologies for biomass conversion to chemicals. However, conventional...
Hydrogenolysis of glycerol to propylene glycol represents one of the most promising technologies for biomass conversion to chemicals. However, conventional hydrogenolysis processes are often carried out under harsh H pressures and temperatures, leading to intensive energy demands, fast catalyst deactivation, and potential safety risks during H handling. Catalytic transfer hydrogenolysis (CTH) displays high energy and atom efficiency. We have studied a series novel solid catalysts for CTH of glycerol. In this work, detailed studies have been conducted on energy optimization, tech-economic analysis, and environmental impact for both processes. The key finding is that relatively less energy demands and capital investment are required for CTH process. CO emission per production of propylene glycol is much lower in the case of transfer hydrogenolysis. The outcome of this study could provide useful information for process design and implementation of novel hydrogenolysis technologies for other energy and environmental applications.
PubMed: 35127642
DOI: 10.3389/fchem.2021.778579 -
European Journal of Pharmaceutics and... Mar 2024Glycols stand out as one of the most commonly employed safe and effective excipients for pharmaceutical and cosmeceutical products. Their widespread adoption can be... (Review)
Review
Glycols stand out as one of the most commonly employed safe and effective excipients for pharmaceutical and cosmeceutical products. Their widespread adoption can be attributed to their exceptional solvency characteristics and their ability to interact effectively with skin lipids and keratin for permeation enhancement. Notably, propylene glycol enjoys significant popularity in this regard. Ongoing research endeavours have been dedicated to scrutinising the impact of glycols on dermal drug delivery and shedding light on the intricate mechanisms by which glycols enhance skin permeation. This review aims to mitigate the discordance within the existing literature, assemble a holistic understanding of the impact of glycols on the percutaneous absorption of active compounds and furnish the reader with a profound comprehension of the foundational facets pertaining to their skin permeation enhancement mechanisms, while simultaneously delving deeper into the intricacies of these processes.
Topics: Solvents; Administration, Cutaneous; Glycols; Skin; Skin Absorption; Propylene Glycol; Propylene Glycols
PubMed: 38224756
DOI: 10.1016/j.ejpb.2024.114182 -
The American Journal of Emergency... May 2023Toxic alcohol ingestion is a rare but serious condition that carries with it a high rate of morbidity and mortality. (Review)
Review
INTRODUCTION
Toxic alcohol ingestion is a rare but serious condition that carries with it a high rate of morbidity and mortality.
OBJECTIVE
This review highlights the pearls and pitfalls of toxic alcohol ingestion, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence.
DISCUSSION
Toxic alcohols include ethylene glycol, methanol, isopropyl alcohol, propylene glycol, and diethylene glycol. These substances can be found in several settings including hospitals, hardware stores, and the household, and ingestion can be accidental or intentional. Toxic alcohol ingestion presents with various degrees of inebriation, acidemia, and end-organ damage depending on the substance. Timely diagnosis is critical to prevent irreversible organ damage or death and is based primarily on clinical history and consideration of this entity. Laboratory evidence of toxic alcohol ingestion includes worsening osmolar gap or anion-gap acidemia and end organ injury. Treatment depends on the ingestion and severity of illness but includes alcohol dehydrogenase blockade with fomepizole or ethanol and special considerations for the initiation of hemodialysis.
CONCLUSIONS
An understanding of toxic alcohol ingestion can assist emergency clinicians in diagnosing and managing this potentially deadly disease.
Topics: Humans; Prevalence; Ethanol; Methanol; Fomepizole; Acidosis; Eating
PubMed: 36796238
DOI: 10.1016/j.ajem.2023.01.048 -
BMC Chemistry Apr 2023This work aims to obtain the solubility, density and thermodynamic parameters of deferiprone in propylene glycol and ethanol. For this purpose, a shake-flask technique...
This work aims to obtain the solubility, density and thermodynamic parameters of deferiprone in propylene glycol and ethanol. For this purpose, a shake-flask technique was applied for solid-liquid equilibration and the spectrophotometry method was employed for solubility measurement. Solubility and density of deferiprone in non-aqueous mixtures of propylene glycol and ethanol were measured in the temperatures 293.2-313.2 K. Some equations including van't Hoff, the Jouyban-Acree, the Jouyban-Acree-van't Hoff, the mixture response surface and modified Wilson equations were used for the mathematical data modeling. The apparent thermodynamic parameters of the deferiprone dissolution process were computed and reported.
PubMed: 37061696
DOI: 10.1186/s13065-023-00950-1 -
Bioorganic Chemistry Dec 2023Xeno nucleic acids (XNA) are an increasingly important class of hypermodified nucleic acids with great potential in bioorganic chemistry and synthetic biology. Glycol... (Review)
Review
Xeno nucleic acids (XNA) are an increasingly important class of hypermodified nucleic acids with great potential in bioorganic chemistry and synthetic biology. Glycol nucleic acid (GNA) is constructed from a three-carbon 1,2-propanediol (propylene glycol) backbone attached to a nucleobase entity, representing the simplest known XNA. This review is intended to present GNA nucleosides from a synthetic chemistry perspective-a perspective that serves as a starting point for biological studies. Therefore this account focuses on synthetic methods for GNA nucleoside synthesis, as well as their postsynthetic chemical transformations. The properties and biological activity of GNA constituents are also highlighted. A literature survey shows four major approaches toward GNA nucleoside scaffold synthesis. These approaches pertain to glycidol ring-opening, Mitsunobu, S2, and dihydroxylation reactions. The general arsenal of reactions used in GNA chemistry is versatile and encompasses the Sonogashira reaction, Michael addition, silyl-Hilbert-Johnson reaction, halogenation, alkylation, cyclization, Rh-catalyzed N-allylation, Sharpless catalytic dihydroxylation, and Yb(OTf)-catalyzed etherification. Additionally, various phosphorylation reactions have enabled the synthesis of diverse types of GNA nucleotides, dinucleoside phosphates, phosphordiamidites, and oligos. Furthermore, recent advances in GNA chemistry have resulted in the synthesis of previously unknown redox-active (ferrocenyl) and luminescent (pyrenyl and phenanthrenyl) GNA nucleosides, which are also covered in this review.
Topics: Nucleic Acids; Nucleosides; Glycols; Nucleotides; Propylene Glycol
PubMed: 37871392
DOI: 10.1016/j.bioorg.2023.106921 -
Chemical & Pharmaceutical Bulletin 2023Propan-1,3-diol (PD) and propan-1,2-diol (propylene glycol, PG) are very similar compounds because their structures, safety data, and anti-microbial activities are...
Propan-1,3-diol (PD) and propan-1,2-diol (propylene glycol, PG) are very similar compounds because their structures, safety data, and anti-microbial activities are almost the same. Actually, both compounds are made up of three carbon atoms and two hydroxyl groups. Regarding their safety, they do not have serious hazard data for animals, and LD values (in rats) of both are similar. As for the anti-microbial activity, minimum inhibitory concentration (MIC) values of both PD and PG are approximately 10% (v/v). In this study, we used the preservatives-effectiveness test (PET) to evaluate the anti-microbial activities of PD and PG, because both compounds are used in cosmetics as preservatives. The results indicated that PD was more effective as an anti-microbial agent compared with PG, and the effect of PD was marked against Escherichia coli and Pseudomonas aeruginosa. Scanning electron microscopy (SEM) images showed that the membrane of Escherichia coli was injured by PD and PG, but the damage by PD was more marked. The damage of the cell membrane may be the cause of high anti-microbial activity of PD in PET. These results suggest that PD has greater potential as a preservative, and PD should be recommended as an additive for food and medicine.
Topics: Animals; Rats; Anti-Infective Agents; Escherichia coli; Microbial Sensitivity Tests; Phenylpropanolamine; Preservatives, Pharmaceutical; Propylene Glycol
PubMed: 36596515
DOI: 10.1248/cpb.c22-00625 -
Animals : An Open Access Journal From... Aug 2020With the improvement in the intense genetic selection of dairy cows, advanced management strategies, and improved feed quality and disease control, milk production level... (Review)
Review
With the improvement in the intense genetic selection of dairy cows, advanced management strategies, and improved feed quality and disease control, milk production level has been greatly improved. However, the negative energy balance (NEB) is increasingly serious at the postpartum stage because the intake of nutrients cannot meet the demand of quickly improved milk production. The NEB leads to a large amount of body fat mobilization and consequently the elevated production of ketones, which causes metabolic diseases such as ketosis and fatty liver. The high milk production of dairy cows in early lactation aggravates NEB. The metabolic diseases lead to metabolic disorders, a decrease in reproductive performance, and lactation performance decline, seriously affecting the health and production of cows. Propylene glycol (PG) can alleviate NEB through gluconeogenesis and inhibit the synthesis of ketone bodies. In addition, PG improves milk yield, reproduction, and immune performance by improving plasma glucose and liver function in ketosis cows, and reduces milk fat percentage. However, a large dose of PG (above 500 g/d) has toxic and side effects in cows. The feeding method used was an oral drench. The combination of PG with some other additives can improve the effects in preventing ketosis. Overall, the present review summarizes the recent research progress in the impacts of NEB in dairy cows and the properties of PG in alleviating NEB and reducing the risk of ketosis.
PubMed: 32872233
DOI: 10.3390/ani10091526 -
Journal of the American Chemical Society Mar 2024Renewable-energy-powered electrosynthesis has the potential to contribute to decarbonizing the production of propylene glycol, a chemical that is used currently in the...
Renewable-energy-powered electrosynthesis has the potential to contribute to decarbonizing the production of propylene glycol, a chemical that is used currently in the manufacture of polyesters and antifreeze and has a high carbon intensity. Unfortunately, to date, the electrooxidation of propylene under ambient conditions has suffered from a wide product distribution, leading to a low faradic efficiency toward the desired propylene glycol. We undertook mechanistic investigations and found that the reconstruction of Pd to PdO occurs, followed by hydroxide formation under anodic bias. The formation of this metastable hydroxide layer arrests the progressive dissolution of Pd in a locally acidic environment, increases the activity, and steers the reaction pathway toward propylene glycol. Rh-doped Pd further improves propylene glycol selectivity. Density functional theory (DFT) suggests that the Rh dopant lowers the energy associated with the production of the final intermediate in propylene glycol formation and renders the desorption step spontaneous, a concept consistent with experimental studies. We report a 75% faradic efficiency toward propylene glycol maintained over 100 h of operation.
PubMed: 38470826
DOI: 10.1021/jacs.4c00312 -
Aerospace Medicine and Human Performance May 2022The previous Spacecraft Maximal Allowable Concentrations (SMACs) for propylene glycol were established based on a study of rodents exposed to propylene glycol (PG)...
The previous Spacecraft Maximal Allowable Concentrations (SMACs) for propylene glycol were established based on a study of rodents exposed to propylene glycol (PG) aerosol for 6 h/d, 5 d/wk for 90 d. This study has been used as the basis for the few existing limits, but all exposure concentrations were well above the saturated vapor concentration of ∼100 ppm for pure propylene glycol at room temperature. For this reason, the Environmental Protection Agency and the Agency for Toxic Substances and Disease Registry noted that the method used to generate the aerosols for the two published studies of animal exposures are not relevant to exposure conditions for the general public, and most regulatory agencies have not established inhalation limits for propylene glycol, citing lack of data. Since publication of the PG SMACs in 2008, an acute inhalation study was conducted in healthy human subjects which allows us to revise our assessment. This manuscript provides the rationale for increasing the prior limits for PG in spacecraft air from 32 and 17 ppm to 64 and 32 ppm for off-nominal scenarios/releases (1-h and 24-h limits) and from 9, 3, and 1.5 ppm to 32 ppm for all nominal timeframes (7, 30, and 180 d). Due to a lack of longer-term exposure data, NASA has elected to eliminate the 1000-d SMAC limit at this time.
Topics: Animals; Humans; Maximum Allowable Concentration; Propylene Glycol; Spacecraft; United States
PubMed: 35551723
DOI: 10.3357/AMHP.6037.2022