Identification and Quantification of Volatile Ramson-Derived Metabolites in Humans

Abstract

Ramson (Allium ursinum) is known for its typical garlic-like aroma. Both ramson and garlic belong to the genus allium which is characterized by a high content of sulfurous compounds. However, in contrast to garlic, ramson is in general not associated with an unpleasant breath following consumption. While there is data available regarding the metabolism of volatile garlic constituents in the human body, the metabolism of ramson was not yet addressed. To elucidate if ramson has an impact on the body odor, this study aimed at identifying volatile ramson-derived metabolites in human milk and urine. Therefore, milk and urine samples were gathered before and after ramson consumption, and were analyzed sensorially by a trained human sensory panel as well as chemo-analytically applying gas chromatography-mass spectrometry/olfactometry (GC-MS/O). Sensory evaluation revealed a garlic-/cabbage like odor in milk samples obtained after ramson consumption, demonstrating that ramson consumption affected the milk aroma. Analyzes by means of GC-MS/O further confirmed excretion of three ramson-derived metabolites in milk and urine samples collected after ramson consumption, namely allyl methyl sulfide (AMS), allyl methyl sulfoxide (AMSO) and allyl methyl sulfone (AMSO2). Of these metabolites only AMS had a garlic-/cabbage-like odor, while the other two were odorless. These metabolites were subsequently quantified using stable isotope dilution assays. Nine urine sets, each comprising eight urine samples, and nine milk sets, each comprising four samples, were analyzed. In case of the urine sets a time interval of about 24 h was monitored, in case of the milk sets a time interval of up to 9 h. Despite the fact that all samples contained the same metabolites there were relevant differences found between individual subjects, especially with regard to the temporal rate of metabolite excretion. Generally, the maxima of metabolite excretion were observed in milk sets within 3 h after ramson consumption. In urine the highest AMS and AMSO amounts were observed within 2 h whereas the maximum concentration of AMSO2 was reached about 2 to 4 h after ramson ingestion. This study suggests that ramson constituents are heavily metabolized in the human body.

Quantification of Allyl Methyl Sulfide, Allyl Methyl Sulfoxide, and Allyl Methyl Sulfone in Human Milk and Urine After Ingestion of Cooked and Roasted Garlic

“…In previous studies, Scheffler and colleagues identified AMS, AMSO, and AMSO 2 as garlic-derived metabolites (10,12) and revealed their temporal excretion profiles in urine and milk after consumption of 3 g of raw garlic (16,23) and 10 g of raw ramson (30). In the present work, we showed that AMS, AMSO, and AMSO 2 are likewise excreted into urine and milk after consumption of roasted and cooked garlic.…”

“…In some sample series, a second maximum appeared about 6 h after garlic ingestion. Similar temporal excretion profiles were observed after ingestion of raw garlic and ramson (16,23,30), indicating that roasting or cooking garlic prior to ingestion does not change the temporal excretion profiles of metabolites.…”

“…Whereas, allicin is rapidly metabolized, other compounds such as diallyl disulfide or S-allyl cysteine are degraded more slowly ( 6 , 32 ). It is interesting to note that the double peak phenomenon appears to be specific to individual participants in the present study [but see Scheffler et al ( 30 ) for different temporal courses in one individual]. It might thus be related to individual expression profiles of enzymes involved in digestive and metabolic processes.…”

“…As already discussed by Scheffler et al (10,12,16,23,30), AMS, AMSO and AMSO 2 derive from allyl thiosulfinates. Allicin is the predominant allyl thiosulfinate in garlic (2) and is rapidly metabolized to allyl mercaptan as an intermediate metabolite (31,32).…”

The human allicin-proteome: S-thioallylation of proteins by the garlic defence substance allicin and its biological effects

“…It is generally considered that garlic consumption promotes health and it has been implicated in positive effects on a number of conditions such as various cancers, diabetes, and heart disease [1]. However, allicin ingested orally is rapidly hydrolysed in the stomach to 2-propenethiol which is quickly metabolised to allyl methyl sulfide, both of which are major components of garlic breath and are also excreted in the urine [66], [67], [68]. These reactions compete with the reaction of allicin with thiols, and reaction of allicin with glutathione will further reduce the amount remaining for S -thioallylation of cysteine residues in proteins.…”