Amino acids and cyclic dipeptides in stinging nettle (Urtica dioica and U. urens) homeopathic matrix tinctures

Abstract

Qualitative and quantitative contents of amino acids and N-containing substances isolated from lipophilic fractions of tinctures derived from both freshly collected plants and dried material of Urtica dioica L. and U. urens L. in accordance with homeopathic technology were studied using amino-acid analysis and GC-MS techniques. The amino-acid composition includes 18 compounds. The content of free amino acids amounted to 0.02 -0.21%; that of bound amino acids, 0.03 -0.29%, both being higher in tinctures obtained from freshly collected raw material. A comparison of the amino-acid contents before and after hydrolysis shows that amino acids are present in tinctures mostly in the free form. The analyses of tinctures showed the presence of pyrazine and pyrazole derivatives, including 4-ethyl-4,5-dihydro-5-propyl-1H-pyrazol-1-carboxyaldehyde isomers and hexahydropyrrolo[1, 2-a]pyrazin-1,4-dione derivatives with 3-alkyl and 3-phenylmethyl substituents in addition to 5,10-diethoxy-2,3,7,8-tetrahydro-1H,6H-dipyrrolo[1,2-a; 1¢,2¢-d]pyrazine. These biologically active compounds may contribute to the pharmacological effect of urtica-based phytopreparations. 650 0091-150X/08/4211-0650

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“…Histidine was also identified in the tincture, indicating that the amino acid is in bound form 19 . Arginine, isoleucine and leucine dominated among the free amino acids 20 .…”

“…In addition to the aforementioned compounds, pyrazine and pyrazole derivatives were detected for the first time in studied samples of HMT. These included 4-ethyl-4, 5-dihydro-5-propyl-1H-pyrazol-1-carboxaldehyde isomers (I) and derivatives of hexahydropyrrolo-[1, 2-a]pyrazin-1, 4-dione (II) with -3-alkyl and -3-phenylmethyl substituents in addition to 5, 10-diethoxy-2, 3, 19 .…”

“…It is a small (8.5 kDa) monomeric protein with high contents of glycine, cysteine and tryptophan 21 . Aspartic acid and Alanine amino acids were isolated from the root extract 19 . Polar extracts of the stinging nettle (Urtica dioica L.) roots were screened to have lignans (+)-neoolivil, (-)-secoisolariciresinol, dehydrodiconiferyl alcohol, isolariciresinol, pinoresinol, and 3, 4-divanillyltetrahydrofuran.…”

“…Amino acid been screened in Urtica urens were Aspartic acid, Threonine, Serine and Alanine 19 . Ethanolic extract of leaves of Urtica augustifolia had screened phytochemically for presence of steroidal saponins 37 .…”

“…Aerial part Amino acid-Aspartic acid, Threonine, Serine and Alanine 19 Chlorigenic acid 57 Anti-inflammatory 57 Hepato-protective, Antioxidant 63 Antirheumatoid arthritis 65 Root lignans -(+)-neoolivil, (-)-secoisolariciresinol, dehydrodiconiferyl alcohol, isolariciresinol, pinoresinol, and 3, 4-divanillyl-tetrahydro-furan 22 Antiprostatic hyperplasic 54 …”