Pentyl Trichoderma

An antibiotic inhibition zone often appears around Trichoderma spp. interacting with other fungi. The genus contains many species which produce secondary metabolites. Claydon et al. (23) have identified an antibiotic from T. harzianum as a volatile, 6-n-pentyl-2H-pyran-2-one this was recently shown to be an active antibiotic from T. koningii (24). The volatile appeared to be the factor responsible for the coconut smell of some biocontrol-effective strains of T. harzianum (25). However, in a Petri-plate assay, it can be difficult to be certain that antibiosis is involved. As well as competitive growth, lytic enzymes could also contribute to the action and Trichoderma has been shown to produce / -l,3-glucanase and chitinase (26-29). 

Scheme 23.18 a De novo biosynthesis of coconut-like 6-pentyl-a-pyrone by Trichoderma sp. b Production of macrocyclic musk-like lactones by a combination of microbial co-hydroxylations and co-l-hydroxylations and subsequent chemical conversion steps, c Production of macrocyclic musk fragrances initiated by terminal oxidation of hydrocarbons with Candida tropicalis... 

A fungus widely distributed in the soil, Trichoderma viride, produces an interesting compound with a coconut, peachy aroma in a non-agitated liquid medium containing potato extract and salts(52). After three to four days cultivation, the culture sporulates releasing the metabolite 6-pentyl-alpha-pyrone. The maximum level reported, however, is 0.17 gram/L. 

The compound 6-pentyl-a-pyrone was extracted from Trichoderma harzianum and analyzed on a Cjg column (A = 300nm). It was separated from other extracted compounds using a 100/0-> 80/20 (at 20 min hold 10 min) water (2.5% acetic acid)/acetonitrile gradient. The pyrone had a retention time of 21 min [1350]. 

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