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.

2.2.1. Polyisocyanates 6117 2.2.2. Polysilanes 6118 2.2.3. Polyacetylenes 6120 2.3. Foldamer-Based Helical Polymers 6124 2.3.1. Click Polymerization 6126 2.3.2. Ring-Closing Reaction 6126 2.4. Other Types of Helical Polymers 6127 2.4.1. π-Conjugated Helical Polymers 6127 2.4.2. Metallosupramolecular Helical Polymers 6128 2.5. Induced Helical Polymers 6130 2.5.1. Induced Helical Polyacetylenes 6130 2.5.2. Other Induced Helical Polymers and Oligomers 6132

Helical polymers: synthesis, structures, and functions

A simple technique for precisely controlling the interfacial energies and wetting behavior of polymers in contact with solid surfaces is described. End-functionalized statistical random copolymers of styrene and methylmethacrylate were synthesized, with the styrene fraction f varying from 0 to 1, and were end-grafted onto silicon substrates to create random copolymer brushes about 5 nanometers thick. For f < 0.7, polystyrene (PS) films (20 nanometers thick) rapidly dewet from the brushes when heated well above the glass transition temperature. The contact angle of the resulting polymer droplets increased monotonically with decreasing f . Similar behavior was observed for poly(methylmethacrylate) (PMMA) films but with an opposite dependence on f . The interfacial energies of the random copolymer brushes with PS and PMMA were equal when f was about 0.6. Thus, precise control of the relative surface affinities of PS and PMMA was possible, demonstrating a way to manipulate polymer-surface interactions.

https://science.sciencemag.org/content/sci/275/5305/1458.full.pdf

Controlling Polymer-Surface Interactions with Random Copolymer Brushes

In this review, we describe the recent advances in supramolecular helical assemblies formed from chiral and achiral small molecules, oligomers (foldamers), and helical and nonhelical polymers from the viewpoints of their formations with unique chiral phenomena, such as amplification of chirality during the dynamic helically assembled processes, properties, and specific functionalities, some of which have not been observed in or achieved by biological systems. In addition, a brief historical overview of the helical assemblies of small molecules and remarkable progress in the synthesis of single-stranded and multistranded helical foldamers and polymers, their properties, structures, and functions, mainly since 2009, will also be described.

Supramolecular Helical Systems: Helical Assemblies of Small Molecules, Foldamers, and Polymers with Chiral Amplification and Their Functions

The structural and mechanical properties of gels formed from biopolymers are discussed both in terms of the techniques used to characterise these systems, and in terms of the systems themselves The techniques included are spectroscopic, chiroptical and scattering methods, optical and electron microscopy, thermodynamic and kinetic methods and rheological characterisation The systems considered are presented in order of increasing complexity of secondary, tertiary and quaternary structure, starting with gels which arise from essentially ‘disordered’ biopolymers via formation of ‘quasicrystalline’ junction zones (eg gelatin, carrageenans, agarose, alginates etc), and extending to networks derived from globular and rod-like species (fibrin, globular proteins, caseins, myosin) by a variety of crosslinking mechanisms Throughout the text, efforts are made to pursue the link (both from experiment and from theory) between the structural methods and mechanical measurements As far as we are aware this is the first major Review of this area since that of J D Ferry in 1948 — The interest shown by polymer physicists in more complex biochemical systems, and the multi-disciplinary approaches now being applied in this area, make the format adopted here, in our opinion, the most logical and appropriate

Structural and mechanical properties of biopolymer gels

Triple Helix of Schizophyllum commune Polysaccharide in Dilute Solution. 3. Hydrodynamic Properties in Water

From sedimentation equilibrium, light scattering, and viscosity measurements on a series of native and sonicated samples of schizophyllan, and extracellular β-1,3-D-glucan, the following results were obtained: (i) weight-average and z-average molecular weights (Mw and Mz) in water are about three times as large as those in dimethylsulfoxide (DMSO); (ii) the exponent in the Houwink-Mark-Sakurada intrinsic viscosity relation in water is close to 1.7, whereas in DMSO it is 0.68; (iii) intrinsic viscosities of samples with Mw below 5 × 105 in water at 25°C can be fitted by Yamakawa's theory for along rigid rod if the pitch (1.836 nm) of the triple helix of Atkins et al. and the diameter (3 nm) estimated from the model triple helix are used; (iv) intrinsic viscosities in water-DMSO mixtures at 25°C undergo and almost discontinuous decrease when the weight fraction of DMSO in the mixture increases to about 87%. These results combined lead to the conclusion that schizophyllan dissolves in water as a triple helix similar to that proposed by Atkins et al. and that the triple helix in aqueous DMSO solution “melts” abruptly to single chains when the DMSO coposition reaches about 87 wt%. It was also found that the triple helix is not recoverable once it is broken in DMSO.

Triple helix of aschizophyllum commune polysaccharide in aqueous solution

Double-stranded helix of xanthan: dimensional and hydrodynamic properties in 0.1 M aqueous sodium chloride

Dimensional and Hydrodynamic Properties of Poly(hexyl isocyanate) in Hexane

A sample of xanthan, a bacterial β-1,4-D-glucan with ionic side chains, and its sonicated fragments in 0.1 M aqueous NaCl and cadoxen at 25°C were studied by light scattering. Radii of gyration ‹S2›1/2 as a function of weight-average molecular weight Mw in these two solvents, combined with the values of about 2 for the ratio Mw (in 0.1 M NaCl)/Mw (in cadoxen), showed that xanthan dissolves as rodlike dimers in 0.1 M aqueous NaCl and as single flexible chains in cadoxen. The contour length per main chain glucose residue of the xanthan dimer was found to be 0.47±0.01 nm, which agreed with the pitch (per glucose residue) of the 51 double-stranded helix proposed for the crystalline structure of xanthan. Thus, it was concluded that the xanthan dimer in 0.1 M aqueous NaCl has the 51 double-stranded helical structure.

/pdf/double-stranded-helix-of-xanthan-in-dilute-solution-evidence-50pwxkd13p.pdf

Takashi Norisuye

Papers

Triple Helix of Schizophyllum commune Polysaccharide in Dilute Solution. 3. Hydrodynamic Properties in Water

Triple helix of aschizophyllum commune polysaccharide in aqueous solution

Double-stranded helix of xanthan: dimensional and hydrodynamic properties in 0.1 M aqueous sodium chloride

Dimensional and Hydrodynamic Properties of Poly(hexyl isocyanate) in Hexane

Double-stranded Helix of xanthan in dilute solution: evidence from light scattering