Flavonoid aglycones from the leaf surfaces of someLabiatae species

1990 ◽  
Vol 173 (3-4) ◽  
pp. 109-118 ◽  
Author(s):  
F. A. Tom�s-Barber�n ◽  
E. Wollenweber
1986 ◽  
Vol 26 (1) ◽  
pp. 181-182 ◽  
Author(s):  
E. Wollenweber ◽  
K.M. Valant-Vetschera ◽  
S. Ivancheva ◽  
B. Kuzmanov

2008 ◽  
Vol 3 (8) ◽  
pp. 1934578X0800300
Author(s):  
Eckhard Wollenweber ◽  
Rüdiger Wehde ◽  
Matthias Christ ◽  
Marion Dörr

Exudate flavonoids have been found on the green fruits of Catalpa ovata (Bignoniaceae) and Paulownia tomentosa (Scrophulariaceae) and on the leaf surfaces of Greyia sutherlandii (Melianthaceae) and Paulownia tomentosa, respectively. The flavonoid aglycones are mostly flavone and flavonol methyl ethers, including some rare natural products. Several flavanones and 2 dihydrochalcones have also been detected, the flavanones produced by Paulownia being geranylated products. The occurrence of exudate flavonoids on fruit tissue has been rarely noticed in the past.


2006 ◽  
Vol 1 (11) ◽  
pp. 1934578X0600101 ◽  
Author(s):  
Karin M. Valant-Vetschera ◽  
Brigitte Brem

Chemodiversity, as a new research concept, is highlighted by a discussion of selected publications of Professor Dr E. Wollenweber. Excretion phenomena of flavonoid aglycones are addressed, such as localization, chemosystematic, and applied aspects. Various classes of flavonoids have been reported from exudates; even flavonoid glycosides and biflavonoids were accumulated on the leaf surfaces of plants. The production of other exudate constituents outside the flavonoid pathway is briefly addressed. The connective role to biological disciplines is stressed, particularly as far as secretory structures are concerned.


1995 ◽  
Vol 50 (5-6) ◽  
pp. 353-357 ◽  
Author(s):  
Karin M. Valant-Vetschera ◽  
Eckhard Wollenweber

Abstract Several species of the large genus Artemisia have been analysed for the flavonoid aglycone composition of their leaf exudates. These species belong to different taxonomic groups within Artemisia. Flavone and flavonol aglycones were found as the major flavonoid constituents of the leaf exudates. Many of these compounds were 6-methoxylated, with additional substitutions at the 7-, 3′-and 4′-position of the molecule. In addition, 7,4′-substituted apigenin and luteolin derivatives and rarely also coumarin derivatives were encountered in some species. The observed substitution trends are in accordance with literature data. Taxonomic and eco­logical aspects are briefly discussed.


Biofouling ◽  
2021 ◽  
pp. 1-13
Author(s):  
Md. Furkanur Rahaman Mizan ◽  
Hye Ran Cho ◽  
Md. Ashrafudoulla ◽  
Junbin Cho ◽  
Md. Iqbal Hossain ◽  
...  

Foods ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 575
Author(s):  
Songsirin Ruengvisesh ◽  
Chris R. Kerth ◽  
T. Matthew Taylor

Spinach and other leafy green vegetables have been linked to foodborne disease outbreaks of Escherichia coli O157:H7 and Salmonella enterica around the globe. In this study, the antimicrobial activities of surfactant micelles formed from the anionic surfactant sodium dodecyl sulfate (SDS), SDS micelle-loaded eugenol (1.0% eugenol), 1.0% free eugenol, 200 ppm free chlorine, and sterile water were tested against the human pathogens E. coli O157:H7 and Salmonella Saintpaul, and naturally occurring microorganisms, on spinach leaf surfaces during storage at 5 °C over 10 days. Spinach samples were immersed in antimicrobial treatment solution for 2.0 min at 25 °C, after which treatment solutions were drained off and samples were either subjected to analysis or prepared for refrigerated storage. Whereas empty SDS micelles produced moderate reductions in counts of both pathogens (2.1–3.2 log10 CFU/cm2), free and micelle-entrapped eugenol treatments reduced pathogens by >5.0 log10 CFU/cm2 to below the limit of detection (<0.5 log10 CFU/cm2). Micelle-loaded eugenol produced the greatest numerical reductions in naturally contaminating aerobic bacteria, Enterobacteriaceae, and fungi, though these reductions did not differ statistically from reductions achieved by un-encapsulated eugenol and 200 ppm chlorine. Micelles-loaded eugenol could be used as a novel antimicrobial technology to decontaminate fresh spinach from microbial pathogens.


2019 ◽  
Vol 7 (5) ◽  
pp. 122 ◽  
Author(s):  
Qiuya Gu ◽  
Guoliang Duan ◽  
Xiaobin Yu

The flowering process has been reported to play crucial roles in improving the flavor and efficacy of fermented tea. Hippophae rhamnoides leaves containing many beneficial ingredients are a suitable plant source for tea processing. In this study, we isolated a β-glucosidase-producing fungus Eurotium amstelodami BSX001 from the fermented tea and used Hippophae rhamnoides leaves (HRL) as a substrate to explore the detailed process of bioconversion of some important functional factors. The results show that the contents of total phenolic compounds and flavonoids increased significantly after seven days, especially flavonoid aglycones (e.g., quercetin, kaempferol, and isorhamnetin). Such compounds greatly enhance the antioxidative activity of fermented products. Metabolic analysis of the standard compounds (rutin, quercetin-3-glucoside, kaempferol-3-glucoside, quercetin, isorhamnetin-3-glucoside, isorhamnetin, and kaempferol) further confirmed the effective biotransformation by E. amstelodami. Mechanisms of the bioconversion could be involved in deglycosylation, dihydroxylation, and O-methylation. Our findings expand the understanding of tea fermentation process and provide further guidance for the fermented tea industry.


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