This review presents an overview of azaphilones isolated from different species of fungi, detailing their chemical structures and biological activities as covered in the recent literature. Over 170 different azaphilone compounds occur in fungi belonging to 23 genera from 13 families: these azaphilones can be classified into ten different structural groups. Numerous azaphilone structures have been described, particularly from members of the Trichocomaceae and Xylariaceae families. Azaphilones exhibit a wide range of interesting biological activities, such as antimicrobial, antifungal, antiviral, antioxidant, cytotoxic, nematicidal and anti-inflammatory activities. Many of these effects may be explained by the reactions of azaphilones with amino groups, such as those found in amino acids, proteins and nucleic acids, resulting in the formation of vinylogous c-pyridones.
The presence of the tetracyclic diterpene 16alpha-hydroxykaurane (16alpha-hydroxy-ent-kaurane, C20H34O, CAS 5524-17-4) was detected in sterile cell cultures of the moss Physcomitrella patens (Hedw.) B.S.G. using gas chromatography and mass spectrometry. 16alpha-hydroxykaurane was found to be a major lipid compound in P. patens, with an estimated intracellular concentration of up to 0.84 mmol/l and an extracellular concentration of up to 9.3 micromol/l. The overall content of 16alpha-hydroxykaurane (in milligrams) produced per culture reached 0.37-fold that of chlorophyll a+b. In agar cultures with low air exchange, 16alpha-hydroxykaurane forms needle-like crystals on tissue and on the inner surface of the culture vessels, indicating that it is being released into the atmosphere. Solid phase microextraction confirmed the air-bound release of 16alpha-hydroxykaurane. To our knowledge this is the first report on the release of a plant-derived tetracyclic diterpene into the air.
Conifers are widespread through the northern hemisphere and many of their essential oils and oleoresins have acquired high commercial significance. After a short review of conifer taxonomy and some cytological aspects of oil secretion and accumulation, general characteristics of conifer oils and resins are discussed in more detail.
Since considerable differences can be found in literature concerning the composition of commercially important conifer oils, we have analysed some of them originating from several species of the genera Abies, Larix, Pseudotsuga, Tsuga, Picea and Pinus. The results were compared with those of self‐distilled oils from authentic botanical origin and discussed in regard to the systematic grouping of the individual conifer.
In addition to investigations of the chemistry of selected conifer oils, the paper outlines the influence of the raw material, especially the relation of needles to twigs and the effect that this variable has on the composition of an individual oil.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.