Analysis of 5-Methyltryptamine,L-Tryptophan, 5-Hydroxy-L-Tryptophan, and Melatonin in the Bulbs of Garlic by Thin-Layer Chromatographic Method Coupled with Densitometric Detection

Abstract

SummaryThin-layer chromatography (TLC) methods coupled with densitometric detection were employed in analyses for the presence of nonhallucinogenic indole compounds in methanol extracts from the garlic (Allium sativum L.) bulbs originating from China, Georgia, Spain, Mexico, and Poland, and from granulated garlic in the form of seasoning (commercial product). Four indole compounds for which the garlic bulbs were analyzed, were detected: 5-methyltryptamine, L-tryptophan, 5-hydroxy-L-tryptophan, and melatonin, the amounts of which ranged from 4.2 to 199.6 mg kg −1 dry weight. In contrast, only 3 indole compounds were found in the garlic bulbs from Spain: 5-methyltryptamine, L-tryptophan and melatonin (85.7, 120.1, and 9.6 mg kg −1 dry weight, respectively). The total amount of indole compounds in the extracts from the garlic bulbs from China was the highest (415.4 mg kg −1 dry weight), while the amounts in the others (from Georgia, Spain, Mexico, Poland) were similar and ranged from 215.4 to 283 mg kg −1 dry weight. The granular, freeze-dried garlic contained the lowest content of indole compounds, and their total amount was only 207 mg kg −1 dry weight.

Anti-inflammatory activities of garlic sprouts, a source of α-linolenic acid and 5-hydroxy-l-tryptophan, in RAW 264.7 cells

“…In the studied garlic bulb samples, we found the presence of melatonin up to 0.96 mg/100 g d.w. in garlic bulbs from Mexico (Muszyńska et al, 2014), and they were particularly lower compared to the content of this compound in sprouts (up to 1.60 mg/100 g d.w.), and comparable to their content in seeds (0.83 mg/100 g d.w.). Melatonin (N-acetyl-5-methoxytryptamine) is produced in pinealocytes of the pineal gland, in the retina and the gastrointestinal tract.…”