Shiitake mushrooms, volatile

C2H4S5, Mr 188.35, cryst., mp. 60-61 °C. L. is a component of the East Asian edible mushroom shiitake (Lentinus edodes, Basidiomycetes) and, together with the polythiepanes and 1,2,4-trithioIane shown in the formula scheme, is responsible for the characteristic odor of the mushroomPrecursors of this flavor substance are 2,4,5,7-tetrathiaoctane 2,2,7,7-tetraoxide and 2,3,5,7,9-pentathiadecane 9,9-dioxide (SE-3), the structures of which were confirmed by synthesis (see also dysoxysulfone). The cyclic flavor substances can be prepared simply by reaction of dichloromethane with NajSj.s (from NajS and sulfur)Shiitake mushrooms - cultivated on dead wood - are becoming increasingly popular in Europe and North America on account of their excellent flavor. L. is also found as a volatile component of cooked mutton and in the alga Chondria californica. ... 

Trithiolanes have received increasing attention since the identification of diastereomeric 3,5-dimethyl-l,2,4-trithiolane in the volatiles of boiled beef (13). The parent 1,2,4-trithiolane is a component of Shiitake mushrooms (14) and red algae (15). In addition to 3,5-dimethyl-l,2,4-trithiolane, Kubota et al. (16) identified 3-methyl-5-ethyl-l,2,4-trithiolane and 3,5-diethyl-l,2,4-tri-thiolane in both syn and anti forms in boiled Antarctic Gulls. Both compounds were described as garlicky. Flament and co-workers (17) reported the identification of 3-methyl-5-ethyl-l,2,4-trithiolane and 3-methyl-5-isopropyl-l,2,4-trithiolane in a commercial beef extract. ... 

Chen, C.C. et al., Effects of pH value on the formation of volatiles of shiitake (Lentinus edodes), an edible mushroom, J. Agric. Food Chem., 32, 999, 1984. 

Enzymic Formation of Volatile Compounds in Shiitake Mushroom (Lentinus edodes Sing.)... 

Volatile compounds of Shiitake mushroom (Lentinus edodes Sing.) are composed of eight-carbon containing alcohols and sulfur compounds. l-Octen-3-ol and 2-octen-l-ol are the major C8-compounds comprising the "mushroom" character of Shiitake mushroom. The characteristic "sulfurous" note of Shiitake mushroom is composed of cyclic S-compounds, such as lenthionine (C2 H4 S5, 1,2,3,5,6-pentathiepane),... 

Table I. Composition of volatile components of Shiitake mushroom blended with base hydrolysate of sunflower oil.

Tressl et al. (16, 17) had shown that linolenic acid (C 18 3) could also be enzymically converted to volatile C8-compounds. However, 1,5-octadien-3-ol and 2,5-octadien-l-ol would be two major C8-compounds formed. No significant amount of 1,5-octadien-3-ol and 2,5-octadien-l-ol could be detected in the volatile components of Shiitake mushrooms blended with sunflower oil hydrolysate (Table I). Instead, significant amount of 1,5-octadien-3-ol or 2,5-octa-dien-l-ol was observed in the sample to which soybean oil hydrolysate was added (20). This is in good agreement with the linolenic acid content in sunflower oil (trace) and soybean oil (ca. 7%). ... 

S-compounds reported in this study are new to the volatiles of Shiitake mushroom (compounds with a in Table II). 

Table II. Volatile sulfurous compounds identified in Shiitake mushroom...

Identification of Volatile Compounds in Shiitake Mushrooms Using Modern Extraction Techniques... 

Table 1 shows that the steam distillation-extraction of a large quantity of mushrooms yielded the most complete and complex sample for volatile analysis, when compared to the sorptive stirrer-bar and headspace trapping. The sorptive stirrer bar tends to extract fewer polar components and the headspace trapping is limited by volatility. A comparison of extraction techniques including supercritical fluid extraction as applied to Shiitake mushrooms is reported by Charpentier et al (18). 

Eri, S. Da Costa, N.C., Identification of volatile compounds in shiitake mushrooms using modem analytical techniques including GC-olfactometry, 7th Symposium of Flavor Chemistry and Biology, Wartburg, Germany, 2004. 

Trithiane itself has been found among the volatile sulfurous compounds of Shiitake mushrooms extracted from the homogenate of fresh mushrooms <1986JFA830> and 2,4,6-triethyl-l,3,5-trithiane was identified among the flavor compounds in the steam distillate of onions <1992MI459> analyzed by GC and characterized by GC-MS. Other than that, 1,3,5-trioxane derivatives are not found that often in natural products as their sulfur analogs. Only... 

The pentathiocane (278) has been isolated and identified by mass spectrometry as a volatile component of Shiitake mushrooms (Lentinus edodes Sing.) <86Mi 926-01 >. The compound s genesis is believed to be via methylene disulfide <86MI 926-02). 

Shiitake mushroom (Lentinus edodes Sing) is an important ingredient in the Oriental cuisine because it contributes a special aroma to foods. There were two classes of volatiles in shiitake, including eight-carbon and sulfur-containing compounds (Chen and Wu, 1984 ... 

Rather unusual sulfur-containing volatiles are formed from cysteine sulfoxide precursors in the Shiitake mushroom (Figure 4.14). Similar to the onion, the cysteine sulfoxide flavor precursor is bound to a y-glutamyl peptide. Therefore, the first step in flavor formation is the removal of glutamic acid by y-glutamyl transpeptidase. The remaining steps are also similar to onion but yield lenthionine, the major flavor component in this mushroom [45],... 

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