Secondary Metabolites from Higher Fungi

Abstract

Secondary metabolites of higher fungi (mushrooms) are an underexplored resource compared to plant-derived secondary metabolites. An increasing interest in mushroom natural products has been noted in recent years. This chapter gives a comprehensive overview of the secondary metabolites from higher fungi, with 765 references highlighting the isolation, structure elucidation, biological activities, chemical syntheses, and biosynthesis of pigments, nitrogen-containing compounds, and terpenoids from mushrooms. Mushroom toxins are also included in each section.In a section on pigments of higher fungi, pigments are classified into four categories, namely, those from the shikimate-chorismate, acetate-malonate, and mevalonate biosynthetic pathways, and pigments containing nitrogen, with 145 references covering the years 2010-2016.In a section on other nitrogen-containing compounds of higher fungi, compounds are categorized primarily into nitrogen heterocycles, nucleosides, non-protein amino acids, cyclic peptides, and sphingolipids, with 65 references covering the years 2010-2016. In turn, in a section describing terpenoids of higher fungi, the sesquiterpenoids and diterpenoids are thoroughly elaborated, spanning the years 2001-2016, and 2009-2016, respectively. The divergent biosynthetic pathways from farnesyl pyrophosphate to sesquiterpenoids are also described. Selected triterpenoids with novel structures and promising biological activities, including lanostanes and ergostanes, are reported from the genus Ganoderma, and the fungi Antrodia cinnamomea and Poria cocos. In addition, cucurbitanes and saponaceolides are also compiled in this section.

Alcoholic fermentation of soursop (Annona muricata) juice via an alternative fermentation technique

“…Such results show that both S. cerevisiae and P. pulmonarius produce different metabolites, in which yeast are more prone to produce phenolic compounds compared to mushroom . According to a study by Schmidt et al ., fermented rice with a longer fermentation time showed a reduction of TPC.…”

“…This is in contrast to the results for DPPH because both DPPH and FRAP measure antioxidant activities via different mechanisms (DPPH by radical scavenging; FRAP by reducing power). Therefore, during the fermentation process, there are changes in chemicals composition, such as for polyphenols and other bioactive compounds, which affect antioxidant activities, as described above . Other factors, such as pH and temperature, did not show significant effects on FRAP activity because both S. cerevisiae and Pleurotus spp.…”

“…(d), the TPC content increased when the fermentation time was increased from 60 to 95.50 h, although it started to reduce when the fermentation time was increased from 95.50 to 131 h. On the other hand, when the mushroom culture was increased from 25% to 75%, TPC was reduced in soursop wine samples. In general, yeast has been found to be able to produce phenolic compounds, whereas mushroom produces nitrogen‐containing compounds and terpenoids as secondary metabolites, which explains the reduction of TPC with an increasing mushroom culture ratio.…”

Triterpenes from Poria cocos are revealed as potential retinoid X receptor selective agonists based on cell and in silico evidence

“…An increasing interest in secondary metabolites of fungus has been noted in recent years, such as phenolic compounds, nitrogen‐containing compounds, and terpenoids (Chen & Liu, ). Compared with plant‐derived secondary metabolites, their biological activities and mechanisms on a molecular level remain largely undefined.…”

Discerning the variation in fungal-treated wheat straw as ruminant feed

“…Fungi increased the amount of NPN (fraction A) of the treated straw. The increase of NPN is likely due to the known production of nitrogen-containing secondary metabolites compounds by these higher fungi, such as nitrogen heterocycles, nucleosides, free amino acids (not bound by peptide bonds) and cyclic peptides (Chen and Liu, 2017). Chitin is also an important NPN component of fungal biomass (Ravi Kumar, 1999).…”