Neolinustatin

Metabolites . 2020 Jul 14;10(7):288.

Metabolism of the Cyanogenic Glucosides in Developing Flax: Metabolic Analysis, and Expression Pattern of Genes[Pubmed: 32674262]

Cyanogenic glucosides (CG), the monoglycosides linamarin and lotaustralin, as well as the diglucosides linustatin and Neolinustatin, have been identified in flax. The roles of CG and hydrogen cyanide (HCN), specifically the product of their breakdown, differ and are understood only to a certain extent. HCN is toxic to aerobic organisms as a respiratory inhibitor and to enzymes containing heavy metals. On the other hand, CG and HCN are important factors in the plant defense system against herbivores, insects and pathogens. In this study, fluctuations in CG levels during flax growth and development (using UPLC) and the expression of genes encoding key enzymes for their metabolism (valine N-monooxygenase, linamarase, cyanoalanine nitrilase and cyanoalanine synthase) using RT-PCR were analyzed. Linola cultivar and transgenic plants characterized by increased levels of sulfur amino acids were analyzed. This enabled the demonstration of a significant relationship between the cyanide detoxification process and general metabolism. Cyanogenic glucosides are used as nitrogen-containing precursors for the synthesis of amino acids, proteins and amines. Therefore, they not only perform protective functions against herbivores but are general plant growth regulators, especially since changes in their level have been shown to be strongly correlated with significant stages of plant development.

Int J Food Microbiol . 1999 Dec 15;53(2-3):169-184.

Degradation of cyanogenic glycosides by Lactobacillus plantarum strains from spontaneous cassava fermentation and other microorganisms[Pubmed: 10634708]

Strains of Lactobacillus plantarum, Leuconostoc mesenteroides, Candida tropicalis and Penicillium sclerotiorum were screened for 19 enzymatic activities using the commercial kit API zym (Bio Mérieux). This activity was compared to the ability of degrading the toxic cyanogenic glycosides amygdalin, linamarin, and linseed cyanogens (a mixture of linustatin and Neolinustatin). Good correlation between the beta-glucosidase activity found in the API zym screening and the ability to degrade the cyanogenic glycosides was found for the first three species mentioned. P. sclerotiorum strains exhibited very high activity in the API zym test (substrate: 6-Br-2-naphthyl-beta-D-glucopyranoside), but proved unable to degrade any of the cyanogenic substrates. Among the seven strains of L. plantarum tested, a great variation was seen in the beta-glucosidase activity as well as in the ability to degrade the cyanogens. This was also the case for the strains of C. tropicalis. However, all the glucosidase positive strains of these species were also able to degrade all of the cyanogens tested and at approximately the same rate. A co-culture of the most active strain of L. plantarum and C. tropicalis seemed to degrade linamarin faster than the mono cultures. L. plantarum LPI (originally isolated from fermented cassava) was investigated in further detail. The hydrolytic activity of this strain was intracellular or cell bound, and beta-bis-glycosides such as amygdalin were hydrolysed by a two-stage sequential mechanism as follows: (1) amygdalin to prunasin and (2) prunasin to cyanohydrin. Finally, inoculation of extracted linseed meal (containing linustatin and Neolinustatin) with L. plantarum LPI resulted in hydrolysis of the glycosides.

J Nutr . 1980 Jan;110(1):145-150.

Isolation of factors in linseed oil meal protective against chronic selenosis in rats[Pubmed: 7354378]

Two new cyanogenic glycosides, linustatin and Neolinustatin, were isolated from linseed oil meal. Each of the compounds was fed to rats in a corn-based diet at levels of 0.1 and 0.2%. At the 0.2% level, both substances gave significant protection against growth depression caused by 9 ppm selenium as sodium selenite. Both compounds also promoted a significant increase in liver and kidney weight over the selenium control animals. Linustatin and Neolinustatin are closely related in structure to linamarin and lotaustralin and were found to be present in linseed oil meal at levels of 0.17 and 0.19%, respectively. Linamarin fed at the level of 0.2% also gave significant protection against growth depression and liver damage. A related cyanogenic glycoside, amygdalin, appeared to give a small but nonsignificant protective response. The isolation of the two new glycosides provides a probable explanation for the protective activity of linseed oil meal against selenium toxicity.

Yao Xue Xue Bao . 2013 Apr;48(4):521-525.

[Chemical constituents from the linseed meal][Pubmed: 23833939]

Ten compounds were isolated from the 70% ethanol extract of linseed meal (Linum usitatissimum L) through a combination of various chromatographic techniques, including silica gel, macroporous adsorbent resin, Sephadex LH-20, and preparative HPLC. On the basis of spectroscopic data analysis, they were elucidated as 1-methylethyl-2-O-beta-D-glucopyranosyl-(1" --> 6')-beta-D-glucopyanoside (1), linustatin (2), Neolinustatin (3), lotaustralin (4), linamarin (5), deoxyguanosine (6), deoxyadenosine (7), (+)-pinoresinol-4'-O-beta-D-glucopyranoside (8), 4-O-beta-D-glucopyranosylvanillyl alcohol (9) and tachioside (10), separately. Among them, compound 1 is a new compound, and compounds 6, 8 and 10 were isolated from the linseed meal for the first time.

J Nat Prod . 2015 Jun 26;78(6):1231-1242.

Dirigent Protein-Mediated Lignan and Cyanogenic Glucoside Formation in Flax Seed: Integrated Omics and MALDI Mass Spectrometry Imaging[Pubmed: 25981198]

An integrated omics approach using genomics, transcriptomics, metabolomics (MALDI mass spectrometry imaging, MSI), and bioinformatics was employed to study spatiotemporal formation and deposition of health-protecting polymeric lignans and plant defense cyanogenic glucosides. Intact flax (Linum usitatissimum) capsules and seed tissues at different development stages were analyzed. Transcriptome analyses indicated distinct expression patterns of dirigent protein (DP) gene family members encoding (-)- and (+)-pinoresinol-forming DPs and their associated downstream metabolic processes, respectively, with the former expressed at early seed coat development stages. Genes encoding (+)-pinoresinol-forming DPs were, in contrast, expressed at later development stages. Recombinant DP expression and DP assays also unequivocally established their distinct stereoselective biochemical functions. Using MALDI MSI and ion mobility separation analyses, the pinoresinol downstream derivatives, secoisolariciresinol diglucoside (SDG) and SDG hydroxymethylglutaryl ester, were localized and detectable only in early seed coat development stages. SDG derivatives were then converted into higher molecular weight phenolics during seed coat maturation. By contrast, the plant defense cyanogenic glucosides, the monoglucosides linamarin/lotaustralin, were detected throughout the flax capsule, whereas diglucosides linustatin/Neolinustatin only accumulated in endosperm and embryo tissues. A putative biosynthetic pathway to the cyanogens is proposed on the basis of transcriptome coexpression data. Localization of all metabolites was at ca. 20 μm resolution, with the web based tool OpenMSI enabling not only resolution enhancement but also an interactive system for real-time searching for any ion in the tissue under analysis.