The number of mushrooms on Earth is estimated at 140,000, yet maybe only 10% (approximately 14,000 named species) are known. Mushrooms comprise a vast and yet largely untapped source of powerful new pharmaceutical products. In particular, and most importantly for modern medicine, they represent an unlimited source of polysaccharides with antitumor and immunostimulating properties. Many, if not all, Basidiomycetes mushrooms contain biologically active polysaccharides in fruit bodies, cultured mycelium, culture broth. Data on mushroom polysaccharides have been collected from 651 species and 7 infraspecific taxa from 182 genera of higher Hetero- and Homobasidiomycetes. These polysaccharides are of different chemical composition, with most belonging to the group of β-glucans; these have β-(1→3) linkages in the main chain of the glucan and additional β-(1→6) branch points that are needed for their antitumor action. High molecular weight glucans appear to be more effective than those of low molecular weight. Chemical modification is often carried out to improve the antitumor activity of polysaccharides and their clinical qualities (mostly water solubility). The main procedures used for chemical improvement are: Smith degradation (oxydo-reducto-hydrolysis), formolysis, and carboxymethylation. Most of the clinical evidence for antitumor activity comes from the commercial polysaccharides lentinan, PSK (krestin), and schizophyllan, but polysaccharides of some other promising medicinal mushroom species also show good results. Their activity is especially beneficial in clinics when used in conjunction with chemotherapy. Mushroom polysaccharides prevent oncogenesis, show direct antitumor activity against various allogeneic and syngeneic tumors, and prevent tumor metastasis. Polysaccharides from mushrooms do not attack cancer cells directly, but produce their antitumor effects by activating different immune responses in the host. The antitumor action of polysaccharides requires an intact T-cell component; their activity is mediated through a thymus-dependent immune mechanism. Practical application is dependent not only on biological properties, but also on biotechnological availability. The present review analyzes the pecularities of polysaccharides derived from fruiting bodies and cultured mycelium (the two main methods of biotechnological production today) in selected examples of medicinal mushrooms.

https://www.xn--c1atere.xn--p1ai/upload/files/_wasser_polysaccharide.pdf

Medicinal mushrooms as a source of antitumor and immunomodulating polysaccharides.

The protein content in foodstuffs is estimated by multiplying the determined nitrogen content by a nitrogen-to-protein conversion factor. Jones' factors for a series of foodstuffs, including 6.25 as the standard, default conversion factor, have now been used for 75 years. This review provides a brief history of these factors and their underlying paradigm, with an insight into what is meant by "protein." We also review other compelling data on specific conversion factors which may have been overlooked. On the one hand, when 6.25 is used irrespective of the foodstuff, "protein" is simply nitrogen expressed using a different unit and says little about protein (s.s.). On the other hand, conversion factors specific to foodstuffs, such as those provided by Jones, are scientifically flawed. However, the nitrogen:protein ratio does vary according to the foodstuff considered. Therefore, from a scientific point of view, it would be reasonable not to apply current specific factors any longer, but they have continued to be used because scientists fear opening the Pandora's box. But because conversion factors are critical to enabling the simple conversion of determined nitrogen values into protein values and thus accurately evaluating the quantity and the quality of protein in foodstuffs, we propose a set of specific conversion factors for different foodstuffs, together with a default conversion factor (5.6). This would be far more accurate and scientifically sound, and preferable when specifically expressing nitrogen as protein. These factors are of particular importance when "protein" basically means "amino acids," this being the principal nutritional viewpoint.

/pdf/converting-nitrogen-into-protein-beyond-6-25-and-jones-411vf4lh1d.pdf

Converting nitrogen into protein--beyond 6.25 and Jones' factors.

Mercury poisoning has become a problem of current interest as a result of environmental pollution on a global scale. Natural emissions of mercury form two-thirds of the input; manmade releases form about one-third. Considerable amounts of mercury may be added to agricultural land with sludge, fertilizers, lime, and manures. The most important sources of contaminating agricultural soil have been the use of organic mercurials as a seed-coat dressing to prevent fungal diseases in seeds. In general, the effect of treatment on germination is favorable when recommended dosages are used. Injury to the seed increases in direct proportion to increasing rates of application. The availability of soil mercury to plants is low, and there is a tendency for mercury to accumulate in roots, indicating that the roots serve as a barrier to mercury uptake. Mercury concentration in aboveground parts of plants appears to depend largely on foliar uptake of Hg0 volatilized from the soil. Uptake of mercury has been found to be plant specific in bryophytes, lichens, wetland plants, woody plants, and crop plants. Factors affecting plant uptake include soil or sediment organic content, carbon exchange capacity, oxide and carbonate content, redox potential, formulation used, and total metal content. In general, mercury uptake in plants could be related to pollution level. With lower levels of mercury pollution, the amounts in crops are below the permissible levels. Aquatic plants have shown to be bioaccumulators of mercury. Mercury concentrations in the plants (stems and leaves) are always greater when the metal is introduced in organic form. In freshwater aquatic vascular plants, differences in uptake rate depend on the species of plant, seasonal growthrate changes, and the metal ion being absorbed. Some of the mercury emitted from the source into the atmosphere is absorbed by plant leaves and migrates to humus through fallen leaves. Mercury-vapor uptake by leaves of the C3 speciesoats, barley, and wheat is five times greater than that by leaves of the C4 species corn, sorghum, and crabgrass. Such differential uptake by C3 and C4 species is largely attributable to internal resistance to mercury-vapor binding. Airborne mercury thus seems to contribute significantly to the mercury content of crops and thereby to its intake by humans as food. Accumulation, toxicity response, and mercury distribution differ between plants exposed through shoots or through roots, even when internal mercury concentrations in the treated plants are similar. Throughfall and litterfall play a significant role in the cycling and deposition of mercury. The possible causal mechanisms of mercury toxicity are changes in the permeability of the cell membrane, reactions of sulphydryl (-SH) groups with cations, affinity for reacting with phosphate groups and active groups of ADP or ATP, and replacement of essential ions, mainly major cations. In general, inorganic forms are thought to be more available to plants than are organic ones.

Mercury toxicity in plants

https://www.massey.ac.nz/%7Eychisti/BrTechMC.pdf

Protein measurements of microalgal and cyanobacterial biomass.

Nutritional and medicinal value of specialty mushrooms

Purines are natural substances found in all of the body’s cells and in virtually all foods. In humans, purines are metabolized to uric acid, which serves as an antioxidant and helps to prevent damage caused by active oxygen species. A continuous supply of uric acid is important for protecting human blood vessels. However, frequent and high intake of purine-rich foods reportedly enhances serum uric acid levels, which results in gout and could be a risk factor for cardiovascular disease, kidney disease, and metabolic syndrome. In Japan, the daily intake of dietary purines is recommended to be less than 400 mg to prevent gout and hyperuricemia. We have established an HPLC method for purine analysis and determined purines in a total of 270 foodstuffs. A relatively small number of foods contained concentrated amounts of purines. For the most part, purine-rich foods are also energy-rich foods, and include animal meats, fish meats, organs such as the liver and fish milt, and yeast. When the ratio of the four purine bases (adenine, guanine, hypoxanthine, and xanthine) was compared, two groups of foods were identified: one that contained mainly adenine and guanine and one that contained mainly hypoxanthine. For patients with gout and hyperuricemia, the amount of total purines and the types of purines consumed, particularly hypoxanthine, are important considerations. In this context, the data from our analysis provide a purine content reference, and thereby clinicians and patients could utilize that reference in nutritional therapy for gout and hyperuricemia.

/pdf/total-purine-and-purine-base-content-of-common-foodstuffs-3jz2859hqs.pdf

Total Purine and Purine Base Content of Common Foodstuffs for Facilitating Nutritional Therapy for Gout and Hyperuricemia

Twenty (JAPANESE) vegetables in Japan were analyzed for total nitrogen, amino acid nitrogen, amide nitrogen, and nonprotein nitrogen and then calculated nitrogen-to-protein conversion factors were calculated. The average conversion factor based on quantitative amino acid composition data was 6.00. However, the use of this factor for estimating protein content led to a considerable difference from estimates based on amino acid residue concentrations, due to the presence of high levels of nonprotein nitrogen. The distribution of protein nitrogen to total nitrogen averaged 73%. Adjusted conversion factors, defined as the proportion of amino acid nitrogen to total nitrogen, averaged 4.39. Protein contents estimated with this factor agreed well with contents determined by amino acid residues. La composition en azote total, en azote contenu dans les aminoacides, les amides et l'azote non proteique a ete ananalysees dans 20 vegetaux japonais, puis le facteur de conversion azote/proteine a ete calcule. La valeur moyenne obtenue est 6.00. La distribution de l'azote proteique par rapport a l'azote total est de 73%. La valeur du facteur de conversion corrige est definie comme la proportion d'azote des acides amines par rapport a l'azote total est de 4,39.

Nitrogen-to-Protein Conversion Factors for Common Vegetables in Japan

To evaluate a practical method of determining more accurately conversion factors for calculating the protein contents of foods from the total nitrogen content, 19 cereal products found in Japan were analyzed for total nitrogen, amino acid nitrogen, and amide nitrogen, and then the nitrogen-to-protein conversion factors were calculated. The average conversion factors were 5.75 for rice, 5.81 for wheat, and 5.95 for others. These values, corresponding to the proportion of the amino acid residue to amino acid nitrogen recovered from 20 amino acids, were lower than the currently applied factors to these foods, except for wheat flour and amaranth. The use of this factor for estimating the protein content results in a considerable difference from the estimate based on amino acid residue concentrations, due to the wide variations in amino acid composition and to the presence of a significant level of nonprotein nitrogen. The distribution of the protein nitrogen recovered from the amino acids to total nitrogen averaged 93%. Adjusted conversion factors corresponding to the proportion of the amino acid residue to total nitrogen averaged 5.26 for rice, 5.47 for wheat, and 5.54 for other cereal products. Protein contents estimated using these factors are in good agreement with the contents defined as amino acid residues.

Nitrogen-to-protein conversion factors for some cereal products in Japan.

The inhibitory activity of angiotensin I-converting enzyme (ACE) was extracted with 80% ethanol from the leaves of Ashitaba (Angelica keiskei). The present ACE inhibitor was fractionated and separated with various chromatographies. The antihypertensive effects of the sample (G fraction) from Ashitaba on spontaneously hypertensive rats (SHR) were observed by long-term administration for 10 wk. Another sample (S fraction) from Ashitaba also had antihypertensive effects after a single intravenous administration to SHR. The sample was further purified by using several chromatographies. The ACE inhibitor fraction was characterized as follows: no significant absorbance, a zwitterion, a water-soluble substance and a positive ninhydrin reaction. According to a mass spectrum analysis, the molecular weight of the ACE inhibitor was determined to be 303 and Na-salt ions of carboxyl groups were detected. The ACE inhibitor from Ashitaba contained in the anti-hypertensive fraction was speculated to be very similar to authentic nicotianamine based on a comparative study of inhibitory activity, mass spectrum analysis and thin-layer chromatographies.

Yasuo Aoyagi

Papers

Total Purine and Purine Base Content of Common Foodstuffs for Facilitating Nutritional Therapy for Gout and Hyperuricemia

Nitrogen-to-Protein Conversion Factors for Common Vegetables in Japan

Nitrogen-to-protein conversion factors for some cereal products in Japan.

Effects of angiotensin I-converting enzyme inhibitor from Ashitaba (Angelica keiskei) on blood pressure of spontaneously hypertensive rats.

An angiotensin-I converting enzyme inhibitor from buckwheat (Fagopyrum esculentum Moench) flour.