Medicinal Properties and Bioactive Compounds from Wild Mushrooms Native to North America

Mushrooms, the fruiting bodies of fungi, are known for a long time in different cultures around the world to possess medicinal properties and are used to treat various human diseases. Mushrooms that are parts of traditional medicine in Asia had been extensively studied and this has led to identification of their bioactive ingredients. North America, while home to one of the world’s largest and diverse ecological systems, has not subjected its natural resources especially its diverse array of mushroom species for bioprospecting purposes: Are mushrooms native to North America a good source for drug discovery? In this review, we compile all the published studies up to September 2020 on the bioprospecting of North American mushrooms. Out of the 79 species that have been investigated for medicinal properties, 48 species (60%) have bioactivities that have not been previously reported. For a mere 16 selected species, 17 new bioactive compounds (10 small molecules, six polysaccharides and one protein) have already been isolated. The results from our literature search suggest that mushrooms native to North America are indeed a good source for drug discovery.     

Magnetic-field effects on the size of vortices below the surface of NbSe2 detected using low energy beta-NMR

A low energy radioactive beam of polarized 8Li has been used to observe the vortex lattice near the surface of superconducting NbSe2. The inhomogeneous magnetic-field distribution associated with the vortex lattice was measured using depth-resolved beta-detected NMR. Below Tc, one observes the characteristic line shape for a triangular vortex lattice which depends on the magnetic penetration depth and vortex core radius. The size of the vortex core varies strongly with the magnetic field. In particular, in a low field of 10.8 mT, the core radius is much larger than the coherence length. The possible origin of these giant vortices is discussed.     

Structural phase transition of vanadium at 69 GPa

A phase transition was observed at 63-69 GPa and room temperature in vanadium with synchrotron x-ray diffraction. The transition is characterized as a rhombohedral lattice distortion of the body-centered-cubic vanadium without a discontinuity in the pressure-volume data, thus representing a novel type of transition that has never been observed in elements. Instead of driven by the conventional s-d electronic transition mechanism, the phase transition could be associated with the softening of C44 trigonal elasticity tensor that originates from the combination of Fermi surface nesting, band Jahn-Teller distortion, and electronic topological transition.     

Pigmentation Chemistry and Radical‐Based Collagen Degradation in Alkaptonuria and Osteoarthritic Cartilage

Alkaptonuria (AKU) is a rare disease characterized by high levels of homogentisic acid (HGA); patients suffer from tissue ochronosis: dark brown pigmentation, especially of joint cartilage, leading to severe early osteoarthropathy. No molecular mechanism links elevated HGA to ochronosis; the pigment's chemical identity is still not known, nor how it induces joint cartilage degradation. Here we give key insight on HGA‐derived pigment composition and collagen disruption in AKU cartilage. Synthetic pigment and pigmented human cartilage tissue both showed hydroquinone‐resembling NMR signals. EPR spectroscopy showed that the synthetic pigment contains radicals. Moreover, we observed intrastrand disruption of collagen triple helix in pigmented AKU human cartilage, and in cartilage from patients with osteoarthritis. We propose that collagen degradation can occur via transient glycyl radicals, the formation of which is enhanced in AKU due to the redox environment generated by pigmentation.     

Improved estimation of PM2.5 brown carbon contributions to filter light attenuation

Multiwavelength light attenuation measurements have been acquired as part of thermal/optical carbon analysis in the U.S.Chemical Speciation Network(CSN)and the ...     

Extraction of aromatic organic compounds by polyurethane foam

The mechanism of extraction of organic compounds by open-cell polyurethane foam has been investigated through a detailed study with simple aromatic compounds. Comparison with identical extractions into diethyl ether suggests that the basic extraction mechanism is an ether-like solvent extraction process. The addition of salt increases the extraction and changing the dielectric constant of the aqueous solution also affects the extraction. For organic compounds which have a group capable of hydrogen bonding, some additional factor appears to influence the extraction. This appears to be hydrogen bonding with the polyurethane foam; it is stronger with polyether foam and reduced by the presence of a strong intramolecular hydrogen-bonding group placed ortho to the hydrogen-bonding group. Thermodynamic studies support these conclusions.     

Extraction of zirconium and hafnium thiocyanate with polyurethane foam

Conditions for the extraction of zirconium and hafnium thiocyanate by polyether-type polyurethane foam were studied in detail. The composition of the extractable species was found to be dependent on both the thiocyanate and metal-ion concentrations. The extraction efficiency for zirconium and hafnium depended on the size of the counter-cation as well as on the type of anion.     

Type 2 intramolecular N-acylnitroso diels-alder reaction: stereoselective synthesis of bridged bicyclic oxazinolactams

[reaction: see text] The type 2 intramolecular N-acylnitroso Diels-Alder reaction has been employed for the synthesis of substituted bridged bicyclic oxazinolactams. Upon oxidation of hydroxamic acid 6, a 3-benzylated oxazinolactam (7) was synthesized with complete diastereoselectivity. Elaboration of cycloadduct 7 liberated a cis-3,7-disubstituted azocin-2-one (9).