Taxonomic group: plant / Streptophyta
(Phylum: Streptophyta)
Organ / tissue: leaf
The structure was elucidated in this paperPublication DOI: 10.1073/pnas.98.2.747Journal NLM ID: 7505876Publisher: National Academy of Sciences
Correspondence: pedras
sask.usask.ca
Institutions: Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, SK, Canada S7N 5C9
To facilitate plant colonization, some pathogenic fungi produce phytotoxic metabolites that damage tissues; plants may be resistant to a particular pathogen if they produce an enzyme(s) that catalyzes detoxification of this metabolite(s). Alternaria blackspot is one of the most damaging and significant fungal diseases of brassica crops, with no source of resistance known within the Brassica species. Destruxin B is the major phytotoxin produced by the blackspot-causing fungus, Alternaria brassicae (Berkley) Saccardo. We have established that a blackspot-resistant species (Sinapis alba) metabolized 14C-labeled destruxin B to a less toxic product substantially faster than any of the susceptible species. The first metabolite, hydroxydestruxin B (14C-labeled), was further biotransformed to the β-D-glucosyl derivative at a slower rate. The structures of hydroxydestruxin B and β-D-glucosyl hydroxydestruxin B were deduced from their spectroscopic data [NMR, high resolution (HR)-MS, Fourier transform infrared (FTIR)] and confirmed by total chemical synthesis. Although these hydroxylation and glucosylation reactions occurred in both resistant (S. alba) and susceptible (Brassica napus, Brassica juncea, and Brassica rapa) species, hydroxylation was the rate limiting step in the susceptible species, whereas glucosylation was the rate limiting step in the resistant species. Remarkably, it was observed that the hydroxydestruxin B induced the biosynthesis of phytoalexins in blackspot-resistant species but not in susceptible species. This appears to be a unique example of phytotoxin detoxification and simultaneous phytoalexin elicitation by the detoxification product. Our studies suggest that S. alba can overcome the fungal invader through detoxification of destruxin B coupled with production of phytoalexins.
Structure type: monomer
Location inside paper: fig. 1, structure 5
Contained glycoepitopes: IEDB_142488,IEDB_146664,IEDB_983931,SB_192
Methods: 13C NMR, 1H NMR, TLC, FTIR, HPLC, column chromatography, HR-FAB-MS, phytotoxicity assay, optical rotation, radiolabelling, metabolic assay
Comments, role: fungal cytotoxin metabolized to a less toxic product; cultivars of B. napus appeared to transform hydroxydestruxin B to β-D-glucosyl hydroxydestruxin B substantially faster than cultivars of S. alba, whereas Cutlass (B. juncea) showed an intermediate rate
NCBI Taxonomy refs (TaxIDs): 3728,
3708,
3707
Show glycosyltransferases
There is only one chemically distinct structure:
Taxonomic group: fungi / Basidiomycota
(Phylum: Basidiomycota)
Organ / tissue: fruiting bodies
NCBI PubMed ID: 37364942Publication DOI: 10.1016/j.carbpol.2023.121108Journal NLM ID: 8307156Publisher: Elsevier
Correspondence: K. Wang <wkpzcq
163.com>
Institutions: Hubei Key Laboratory of Nature Medicinal Chemistry and Resource Evaluation, Tongji Medical College of Pharmacy, Huazhong University of Science and Technology, 430030 Wuhan, China, Department of Pharmacy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 430030 Wuhan, China, Hubei province clinical research center for precision medicine for critical illness, 430030 Wuhan, China, Department of Pharmacy, Wuhan Children's Hospital (Wuhan Maternal and Child Healthcare Hospital), Tongji Medical College, Huazhong University of Science and Technology, 430019 Wuhan, China
It had been shown that lentinan (LNT) was mainly distributed in the liver after intravenous administration. The study aimed to investigate the integrated metabolic processes and mechanisms of LNT in the liver, as these have not been thoroughly explored. In current work, 5-([4,6-dichlorotriazin-2-yl] amino) fluorescein and cyanine 7 were used to label LNT for tracking its metabolic behavior and mechanisms. Near-infrared imaging demonstrated that LNT was captured mainly by the liver. Kupffer cell (KC) depletion reduced LNT liver localization and degradation in BALB/c mice. Moreover, experiments with Dectin-1 siRNA and Dectin-1/Syk signaling pathway inhibitors showed that LNT was mainly taken up by KCs via the Dectin-1/Syk pathway and promoted lysosomal maturation in KCs via this same pathway, which in turn promoted LNT degradation. These empirical findings offer novel insights into the metabolism of LNT in vivo and in vitro, which will facilitate the further application of LNT and other beta-glucans.
lentinan, fluorescent labeling, Dectin-1, Kupffer cells, metabolic degradation
Structure type: polymer chemical repeating unit
Location inside paper: Fig. 2A, LNT (lentinan)
Trivial name: lentinan
Compound class: glucan, polysaccharide
Methods: Western blotting, HPLC, extraction, statistical analysis, flow cytometry analysis, fluorescence labeling, HPGPC, immunohistochemistry, metabolic assay, cellular uptake and degradation of FLNT
Biological activity: LNT was first phagocytosed via the Dectin-1/Syk signaling pathway in the hepatic KCs and then promoted the maturation of phagosomes in KCs through the Dectin-1/Syk signaling pathway, which in turn fostered the degradation of LNT
NCBI Taxonomy refs (TaxIDs): 5353
Show glycosyltransferases
There is only one chemically distinct structure:
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