The bell-shaped pH rate profile for the reaction of tetrahydrofolic acid with formaldehyde to form 5, lo-methylene tetrahydrofolic acid has been shown to result from a change in rate-determining step with changing acidity. In alkaline solution, the rate-determining step is the acid-catalyzed dehydration of hydroxymethyl tetrahydrofolic acid and its conjugate base. This step is subject to genera...

It has been reported (1) and confirmed (2) that the production of uroporphyrin III from porphobilinogen, either by heating in acid solution or enzymatically by hemolyzed avian erythrocytes, is accompanied by the formation of formaldehyde from the aminomethyl group of the pyrrole. These observations have been cited as evidence in support of two hypotheses on the mechanism of uroporphyrin III for...

A promising strategy for the prevention of Alzheimer's disease (AD) is the identification of age-related changes that place the brain at risk for the disease. Additionally, AD is associated with chronic dehydration, and one of the significant changes that are known to result in metabolic dysfunction is an increase in the endogenous formaldehyde (FA) level. Here, we demonstrate that the levels o...

Different resol phenol-formaldehyde prepolymer resins have been synthesized with different formaldehyde / phenol ratios. The phenolic resin composition depends on monomer ratio, catalyst, reaction conditions, and residual free monomers. Temperature and pH conditions under which reactions of phenols with formaldehyde are carried out have a profound effect on the characteristics of the resulting ...

Formaldehyde is an economically important chemical, to which more than 2 million U.S. workers are occupationally exposed. Substantially more people are exposed to formaldehyde environmentally, as it is generated by automobile engines, is a component of tobacco smoke and is released from household products, including furniture, particleboard, plywood, and carpeting. The International Agency for ...

Concern has been expressed about the safety of formocresol use in pediatric dentistry Formaldehyde, a primary component in formocresol, is a hazardous substance and is considered a probable human carcinogen by the International Agency for Research on Cancer, Health Canada, the Agency for Toxic Substances and Disease Registry in the U.S. Department of Health and Human Services, and the U.S. Envi...

Following the detection of formaldehyde in cultivated mushrooms, an evaluation was carried out to assess whether its presence in food poses a risk to public health. Formaldehyde, a carcinogenic chemical, has a broad range of industrial applications and, hence, exposure to formaldehyde is ubiquitous through diverse consumer goods, food, the air, etc. The observed levels of formaldehyde in mushro...

Background Formaldehyde is a chemical precursor, flammable and colorless which is widely used in different industries. Previous studies, have reported that Formaldehyde has destructive effects on reproductive system of female mice. In the present study we aimed at evaluating the protective effects of Rosa damascene on the toxic effects of Formaldehyde on sex hormones, ovary parameters and folli...

conclusions exposure to formaldehyde vapor can destroy testicular structure and decrease percentages of sperm count and progressive motility. the present study indicated that a reduction in the percentage of progressive motile sperm may be potentiated by noise (700-5700 hz) in the simultaneous exposure to formaldehyde and noise group. thus, it can be anticipated that simultaneous exposure to fo...