Butylated hydroxytoluene (BHT), also known as dibutylhydroxytoluene, is a lipophilic organic compound, chemically a derivative of phenol, that is useful for its antioxidant properties. BHT is widely used to prevent free radical-mediated oxidation in fluids and other materials, and the regulations overseen by the U.S. F.D.A.—which considers BHT to be "generally recognized as safe"—allow small amounts to be added to foods. Despite this, and the earlier determination by the National Cancer Institute that BHT was noncarcinogenic in an animal model, societal concerns over its broad use have been expressed. BHT has also been postulated as an antiviral drug, but as of December 2022, use of BHT as a drug is not supported by the scientific literature and it has not been approved by any drug regulatory agency for use as an antiviral.
An antimicrobial is an agent that kills microorganisms (microbicide) or stops their growth. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against. For example, antibiotics are used against bacteria, and antifungals are used against fungi. They can also be classified according to their function. The use of antimicrobial medicines to treat infection is known as antimicrobial chemotherapy, while the use of antimicrobial medicines to prevent infection is known as antimicrobial prophylaxis.
The innate, or nonspecific, immune system is one of the two main immunity strategies in vertebrates. The innate immune system is an alternate defense strategy and is the dominant immune system response found in plants, fungi, prokaryotes, and invertebrates.
Palivizumab, sold under the brand name Synagis, is a monoclonal antibody produced by recombinant DNA technology used to prevent severe disease caused by respiratory syncytial virus (RSV) infections. It is recommended for infants at high-risk for RSV due to conditions such as prematurity or other medical problems including heart or lung diseases.
Gliotoxin is a sulfur-containing mycotoxin that belongs to a class of naturally occurring 2,5-diketopiperazines produced by several species of fungi, especially those of marine origin. It is the most prominent member of the epipolythiopiperazines, a large class of natural products featuring a diketopiperazine with di- or polysulfide linkage. These highly bioactive compounds have been the subject of numerous studies aimed at new therapeutics. Gliotoxin was originally isolated from Gliocladium fimbriatum, and was named accordingly. It is an epipolythiodioxopiperazine metabolite that is one of the most abundantly produced metabolites in human invasive Aspergillosis (IA).
Protocatechuic acid (PCA) is a dihydroxybenzoic acid, a type of phenolic acid. It is a major metabolite of antioxidant polyphenols found in green tea. It has mixed effects on normal and cancer cells in in vitro and in vivo studies.
Vermilacinia, a genus of lichenized fungi in the family Ramalinaceae, is a yellow-green fruticose type of lichen with about 30 species that grow on rocks, trees, and soil within the fog zone along the Pacific Coast of North America and South America. The genus name refers to the thallus being divided into narrow worm-like (vermis) branches (lacinia);the latter part of the name (lacinia) generally applied in descriptions and taxonomic keys such as exemplified in a key to Sonoran Desert species of Ramalina.
In biochemistry, naturally occurring phenols are natural products containing at least one phenol functional group. Phenolic compounds are produced by plants and microorganisms. Organisms sometimes synthesize phenolic compounds in response to ecological pressures such as pathogen and insect attack, UV radiation and wounding. As they are present in food consumed in human diets and in plants used in traditional medicine of several cultures, their role in human health and disease is a subject of research. Some phenols are germicidal and are used in formulating disinfectants.
Marine fungi are species of fungi that live in marine or estuarine environments. They are not a taxonomic group, but share a common habitat. Obligate marine fungi grow exclusively in the marine habitat while wholly or sporadically submerged in sea water. Facultative marine fungi normally occupy terrestrial or freshwater habitats, but are capable of living or even sporulating in a marine habitat. About 444 species of marine fungi have been described, including seven genera and ten species of basidiomycetes, and 177 genera and 360 species of ascomycetes. The remainder of the marine fungi are chytrids and mitosporic or asexual fungi. Many species of marine fungi are known only from spores and it is likely a large number of species have yet to be discovered. In fact, it is thought that less than 1% of all marine fungal species have been described, due to difficulty in targeting marine fungal DNA and difficulties that arise in attempting to grow cultures of marine fungi. It is impracticable to culture many of these fungi, but their nature can be investigated by examining seawater samples and undertaking rDNA analysis of the fungal material found.
α-Cadinol or 10α-hydroxy-4-cadinene is an organic compound, a sesquiterpenoid alcohol.
Cerevisterol (5α-ergosta-7,22-diene-3β,5,6β-triol) is a sterol. Originally described in the 1930s from the yeast Saccharomyces cerevisiae, it has since been found in several other fungi and, recently, in deep water coral. Cerevisterol has some in vitro bioactive properties, including cytotoxicity to some mammalian cell lines.
Ramalina hyrcana is a species of fruticose lichen in the family Ramalinaceae. Found in the Hyrcanian forest area along the Caspian coast in Iran, it was described as new to science in 2011.
Lepraria sekikaica is a species of leprose (powdery) lichen in the family Lecanoraceae. Found in Western Australia, it was formally described as a new species by lichenologist John Elix. It was one of 100 new lichen species published in a single article, helping to highlight the extent of undiscovered global biodiversity. The type specimen was collected by the author in the Boyagin Rock Nature Reserve. It is known from several locations in Western Australia, where it grows on the ground under sheltered rock ledges. The lichen products made by Lepraria sekikaica include atranorin, homosekikaic acid, 4'-O-demethylsekikaic acid, and fragilin as minor products, and sekikaic acid as a major metabolite. The specific epithet refers to the latter compound; Lepraria sekikaica is the first known in genus Lepraria to contain this substance.
EICAR (5-Ethynyl-1-beta-D-ribofuranosylImidazole-4-CARboxamide) is a nucleoside analogue which has both anti-cancer and antiviral effects, and was originally developed for the treatment of leukemia, but was unsuccessful in human clinical trials. It has broad spectrum antiviral effects with activity against pox viruses, Semliki forest virus, Junin virus, reovirus, influenza, measles virus and respiratory syncytial virus among others, although it is not active against coronaviridae such as SARS-CoV-1. This useful spectrum of activity means that EICAR and related derivatives continue to be investigated for the treatment of viral diseases.
Isolichenan, also known as isolichenin, is a cold-water-soluble α-glucan occurring in certain species of lichens. This lichen product was first isolated as a component of an extract of Iceland moss in 1813, along with lichenin. After further analysis and characterization of the individual components of the extract, isolichenan was named in 1881. It is the first α-glucan to be described from lichens. The presence of isolichenan in the cell walls is a defining characteristic in several genera of the lichen family Parmeliaceae. Although most prevalent in that family, it has also been isolated from members of the families Ramalinaceae, Stereocaulaceae, Roccellaceae, and Cladoniaceae. Experimental studies have shown that isolichenan is produced only when the two lichen components – fungus and alga – are growing together, not when grown separately. The biological function of isolichenan in the lichen thallus is unknown.
Lepraria incana is a species of dust lichen in the family Stereocaulaceae. First described scientifically by Johann Jacob Dillenius in 1741, and then formally by Carl Linnaeus in 1753, it is the type species of the genus Lepraria. The thallus of this species is green to greyish-green, and powdery – as if made of tiny granules. These granules are soredia, which are asexual reproductive structures. Like most members of genus Lepraria, the lichen has few distinguishing features, lacking both a medulla and sexual reproductive structures (apothecia). Chemically, the lichen is characterised by the presence of the secondary chemicals known as divaricatic acid and zeorin.
Salazinic acid is a depsidone with a lactone ring. It is found in some lichens, and is especially prevalent in Parmotrema and Bulbothrix, where its presence or absence is often used to help classify species in those genera.
Lichexanthone is an organic compound in the structural class of chemicals known as xanthones. Lichexanthone was first isolated and identified by Japanese chemists from a species of leafy lichen in the 1940s. The compound is known to occur in many lichens, and it is important in the taxonomy of species in several genera, such as Pertusaria and Pyxine. More than a dozen lichen species have a variation of the word lichexanthone incorporated as part of their binomial name. The presence of lichexanthone in lichens causes them to fluoresce a greenish-yellow colour under long-wavelength UV light; this feature is used to help identify some species. Lichexanthone is also found in several plants, and some species of fungi that do not form lichens.
Lichen products, also known as lichen substances, are organic compounds produced by a lichen. Specifically, they are secondary metabolites. Lichen products are represented in several different chemical classes, including terpenoids, orcinol derivatives, chromones, xanthones, depsides, and depsidones. Over 800 lichen products of known chemical structure have been reported in the scientific literature, and most of these compounds are exclusively found in lichens. Examples of lichen products include usnic acid, atranorin, lichexanthone, salazinic acid, and isolichenan, an α-glucan. Many lichen products have biological activity, and research into these effects is ongoing.
Barbatic acid is an organic compound that is made by some lichens. It is in the structural class known as depsides. It is particularly common in the genera Usnea and Cladonia.
