Current Topics in Medicinal Chemistry - Volume 13, Issue 21, 2013

The present review reports the antifungal activity of mushroom extracts and isolated compounds including high (e.g. peptides and proteins) and low (e.g. sesquiterpenes and other terpenes, steroids, organic acids, acylcyclopentenediones and quinolines) molecular weight compounds. Most of the studies available on literature focused on screening of antifungal activity of mushroom extracts, rather than of isolated compounds. Data indicate that mushroom extracts are mainly tested against different Candida species, while mushroom compounds are mostly tested upon other fungi. Therefore, the potential of these compounds might be more useful in food industry than in clinics. Oudemansiella canarii and Agaricus bisporus methanolic extracts proved to be the most active mushroom extracts against Candida spp. Grifolin, isolated from Albatrellus dispansus, seemed to be the most active compound against phytopathogenic fungi. Further studies should be performed in order to better understand the mechanism of action of this and other antifungal compounds as well as safety issues.

Global industrialization and agricultural development are related to the release of various pollutants into the environment including huge amounts of free radicals, which are associated with the occurrence of various destructive diseases and disorders. Due to different rates of metabolic activity and oxygen consumption, organisms, organs and tissues have distinct protective antioxidant systems and defence mechanisms. Although numerous synthetic antioxidants can improve defence system capacity, because of their toxic and mutagenic effects as well as rising awareness of a healthy lifestyle, preference is given to natural antioxidants. Therefore, studies of metabolites of various fungal species and their activity are currently increasing. Antioxidant features of numerous compounds isolated from mushrooms, such as phenolic compounds, vitamins, polysaccharides, peptides, proteins, organic acids, carotenoids, alkaloids, and nucleotides, have been reported. Chemical composition and antioxidant potential of mushrooms are highly-dependent on species, habitat, phase of life cycle (mycelium, young or mature fruiting body), method of processing, extraction solvent, and extract dose. Although around only 5% of fungal species have been well studied and thousands more species have potential benefit for mankind, reports on the antioxidant potentials of fungi are already numerous and these are the subject of this review.

Cyclodextrins are usually used in antifungal formulations as auxiliary substances to improve solubility, stability, or other physicochemical properties of the active compound. Nevertheless, more and more research and practical use results indicate that cyclodextrins might also act as active compounds in pharmaceutical formulations. The biological effects of cyclodextrins, important for their use within antimycotic formulations, can be divided into: effects based on the ability of cyclodextrins to form inclusion complexes with endogenous substances (membrane lipids, cellular cholesterol), effects based on formation of inclusion complexes with component parts of fungi cells, and effects based on the chemical nature of cyclodextrins and their derivatives. This review will cover the advances in research of biological activity of cyclodextrins with focus on their properties responsible for their synergistic effect with antimycotic compounds.

The last two decades are characterized by major increases in the incidence of systemic fungal infections caused by the yeast Candida albicans, particularly in immunocompromised patients. On the other hand it was observed the increased number of pathogenic microorganisms with multiple resistance to drugs. Also there is a big variety of drugs for the treatment of candidiasis, only two drugs are used for the treatment of infections from Aspergillus fumigatus. Taking into account that the long term therapy with azoles results in resistance a critical need exists for new antifungal agents with fewer side effecgts to treat these life-threatening fungal infections. This review will cover the advances in research of biological activity of different compounds from different chemical classes with focus on their antifungal properties.

Metabolic syndrome (MS) is a modern medical condition characterized by central obesity, hyperglycaemia, hypercholesterolemia and hypertension. The beneficial effects of mushrooms in lowering the symptoms of MS were known from both traditional and conventional medicine. Edible mushrooms, their extracts, polysaccharide fractions and isolated compounds possessed hypoglycaemic, cholesterol and triglyceride lowering ability, hypotensive effects, as well as weight managing activity by influencing satiety. The most active compounds are polysaccharides, called β-glucans, as well as lectines and small compounds such as eritadenin, triterpenes, sterols and phenolic compounds.

This review covers the 2003-2012 literature data published for antitumor natural products from marine-derived fungi. The focus is on new and highly potent cytotoxic compounds, together with details related to the relevant fungal species. It describes 22 promising bioactives, originating mainly from symbiotic fungi. The chemical structures of all highlighted organic molecules are briefly discussed.

Fungi are an important group of microorganisms. They are studied due to their significant impact on the environment, industry and human health. In relation to biological aspects, biogeochemical cycling of elements, the world of nature would not be possible without the contribution of fungi as the primary decomposers of organic material. On the other hand, food decay by the fungi spoilage causes considerable economic losses and constitutes a health risk for consumers due to the potential of fungi to produce mycotoxins. Mycotoxins are chemically diverse secondary metabolites that can be harmful both to animal and human health. Aflatoxins, a widely studied group of toxins among mycotoxins, are mainly biosynthesized by Aspergillus flavus and Aspergillus parasiticus. Therefore, the control of fungi and the production of aflatoxins, especially the most toxic aflatoxins B1 and G1, is essential and decisive. Over the last few decades, numerous studies have demonstrated that plants, especially their essential oils, contain diverse bioactive components that can protect crops from becoming contaminated by different mold species, Aspergillus in particular, with an emphasis on A. flavus and A. parasiticus; as well as that, they can prevent the contamination of food produce during the processing and storage and prevent the production of aflatoxins. Plant essential oils are expected to be more advantageous than synthetic compounds because of their relatively safe status, easy decomposition, environmentally friendly and non-phytotoxic properties. This paper also presents the recent research in biological control of aflatoxin contamination.

Mycotherapy is defined as the study of the use of extracts and compounds obtained from mushrooms as medicines or health-promoting agents. The present review updates the recent findings on anticancer/antitumor agents derived from mushroom extracts and their metabolites. The increasing number of studies in the past few years revealed mushroom extracts as potent antitumor agents. Also, numerous studies were conducted on bioactive compounds isolated from mushrooms reporting the heteropolysaccharides, β-glucans, α-glucans, proteins, complexes of polysaccharides with proteins, fatty acids, nucleoside antagonists, terpenoids, sesquiterpenes, lanostanoids, sterols and phenolic acids as promising antitumor agents. Also, molecular mechanisms of cytotoxicity against different cancer cell lines are discussed in this review. Findings with Antrodia camphorata and Ganoderma lucidium extracts and isolated compounds are presented, as being the most deeply studied previously.