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and J J Pfiffner

Bio: and J J Pfiffner is an academic researcher. The author has contributed to research in topics: Water-Soluble Vitamin. The author has an hindex of 2, co-authored 2 publications receiving 13 citations.

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Book ChapterDOI
TL;DR: In general, complexing of the acidic aminopolysaccharides with protein is believed to be through predominantly ionic linkages that can be relatively easily split at high ionic strength or pH, while in mucoproteins and mucopolysacCharides, the carbohydrate is bound to the protein by firmer, presumably covalent, bonds.
Abstract: Publisher Summary The chapter deals with two main types of complexes of protein–carbohydrate. The first type consists of the relatively loose complexes formed between proteins and acidic aminopolysaccharides, containing hexosamine together with hexuronic acid or ester sulfate or both. The second type is called the “mucoproteins” and “mucopolysaccharides,” where the carbohydrate is firmly linked to protein and contains hexosamine, neutral sugar, and often sialic acid, but not uronic acid or ester sulfate. In general, complexing of the acidic aminopolysaccharides with protein is believed to be through predominantly ionic linkages that can be relatively easily split at high ionic strength or pH, while in mucoproteins and mucopolysaccharides, the carbohydrate is bound to the protein by firmer, presumably covalent, bonds. Acid aminopolysaccharides containing uronic acid or sulfate, or both—occur in animals often—if not always, associated with protein. The interaction of acid aminopolysaccharides with proteins takes place, in most cases, through forces weaker than covalent bonds.

56 citations

Journal ArticleDOI
TL;DR: The exhaustive review of rat studies investigating phytochemical effect on hepatic lipid metabolism suggests that some fatty acids, acetic acid, melatonin, phytic acid, some fiber compounds, oligofructose, resistant starch, some phenolic acids, flavonoids, lignans, stilbenes, curcumin, saponins, coumarin, some plant extracts, and some solid foods may be lipotropic.
Abstract: Increased consumption of plant products is associated with lower chronic disease prevalence. This is attributed to the great diversity of healthy phytochemicals present in these foods. The most investigated physiological effects have been their antioxidant, anti-carcinogenic, hypolipidemic, and hypoglycemic properties. Although less studied in humans, some compounds were very early on shown to be lipotropic in animals, i.e., the capacity to hasten the removal of fat from liver and/or reduce hepatic lipid synthesis or deposits by mainly increasing phospholipid synthesis via the transmethylation pathway for triglyceride-rich lipoprotein exportation from the liver and enhanced fatty acid β-oxidation and/or down- and up-regulation of genes involved in lipogenic and fatty acid oxidation enzyme synthesis, respectively. The main plant lipotropes are choline, betaine, myo-inositol, methionine, and carnitine. Magnesium, niacin, pantothenate, and folates also indirectly support the overall lipotropic effect. The exhaustive review of rat studies investigating phytochemical effect on hepatic lipid metabolism suggests that some fatty acids, acetic acid, melatonin, phytic acid, some fiber compounds, oligofructose, resistant starch, some phenolic acids, flavonoids, lignans, stilbenes, curcumin, saponins, coumarin, some plant extracts, and some solid foods may be lipotropic. However, this remains to be confirmed in humans, for whom intervention studies are practically non-existent. Supplemental materials are available for this article. Go to the publisher's online edition of Critical Reviews in Food Science and Nutrition® to view the free supplemental file.

45 citations

Book ChapterDOI
TL;DR: This chapter discusses the chemistry of the antipernicious anemia factor, vitamin B 12, by reviewing results published between the date of its appearance and September, 1956.
Abstract: Publisher Summary Since the chemistry of the antipernicious anemia factor, vitamin B 12 , was last reviewed in “Vitamins and Hormones” by Folkers and Wolf, outstanding progress has been made, resulting in the complete structural elucidation of the vitamin. It is the purpose of this chapter to bring that review up t o date by reviewing results published between the date of its appearance and September, 1956. The demand for vitamin B 12 has increased, and many recent papers on the preparation of the vitamin are concerned with commercial production which depends on fermentation methods; in fact vitamin B 12 is synthesized almost entirely by microorganisms in nature. It is now more usual to employ special organisms for B 12 production than to isolate it as a by-product from antibiotic fermentations. Various species of Streptomyces have been recommended for the preparation of vitamin B12, for example S. olivaceus, as well as Bacillus megatherium, although no outstanding improvements have been reported in its isolation.

35 citations

Journal ArticleDOI
TL;DR: A study of the growth factor requirements of representatives of six genera of fruit-rotting fungi found that Gloeosporium musarum, Nigrospora sphaerica, Thielaviopsis paradoxa, and Verticillium theobromae all required biotin for growth.
Abstract: Esposito, R. G. (United Fruit Co., Norwood, Mass.), H. Greenwood, and A. M. Fletcher. Growth factor requirements of six fungi associated with fruit decay. J. Bacteriol. 83:–250–255. 1962.—A study of the growth factor requirements of representatives of six genera of fruit-rotting fungi has been made. Gloeosporium musarum, Nigrospora sphaerica, Thielaviopsis paradoxa, and Verticillium theobromae all required biotin for growth. Under certain conditions in nitrate medium, Fusarium roseum appeared to be partially dependent on biotin. T. paradoxa also required thiamine for growth. In addition to biotin, N. sphaerica required an unknown material contained in extracts of yeast. Twenty-one known growth factors were tested and found to be inactive. Thiamine inhibited the growth of F. roseum, apparently by stimulating the formation of ethanol. Biotin reversed the effect of thiamine on growth and ethanol formation.

16 citations

Book ChapterDOI
TL;DR: Physical methods that have been employed in vitamin and hormone studies include: visible-and ultraviolet-absorption spectrophotometry, photochemical techniques, colorimetry, fluorescence spectroscopy, fluorophotometry and isotopic tracer methods.
Abstract: Publisher Summary Physical methods that have been employed in vitamin and hormone studies include: visible- and ultraviolet-absorption spectrophotometry, photochemical techniques, colorimetry, fluorescence spectroscopy, fluorophotometry, infrared and Raman spectroscopy, x-ray diffraction studies, manometric techniques, polarography, and isotopic tracer methods. Of these techniques, some have had limited application and others are not universally regarded as physical. As this chapter is limited to methods that are both essentially physical, and of broad application in the vitamin and hormone field, only the following topics are included: visible- and ultraviolet-absorption spectrophotometry, colorimetry, fluorescence spectroscopy, and fluorophotometry. It has not been practicable to consider all aspects of these techniques. In discussing colorimetry, for example, it has been necessary to omit reference to the many chemical problems concerned with the devising of color reactions and of procedures for eliminating interfering substances. In deciding what material to include and what to exclude, preference has been given to the quantitative and physical aspects of the methods discussed.

12 citations