نتایج جستجو برای: flavanones

تعداد نتایج: 532  

2017
Jennifer K Matsui Gary A Molander

Utilizing photoredox/nickel dual catalysis, diverse flavanones have been synthesized by coupling novel 2-trifluoroboratochromanone building blocks with aryl and heteroaryl bromide partners. The newly reported trifluoroboratochromanones can be easily accessed from the corresponding chromones on multigram scale. This represents a general route for accessing natural and unnatural flavanones that w...

Journal: :Chirality 2011
Shubao Zhou Yuqiang Zhou Yalan Xing Naixing Wang Linghua Cao

An improved method of the synthesis of flavanones catalyzed by pyrrolidine and BF(3) ·Et(2) O has been developed and a lot of flavanones could be easily synthesized via this method. The asymmetric synthesis of flavanone from benzaldehyde and 5-fluoro-2-hydroxyacetophenone has been studied and flavanone with moderate enantioselectivity was obtained in one step.

2013
Martin Patzlaff Wolfgang Barz

Flavanones, Catabolites, Peroxidases, Degradation, Substitution Pattern Peroxidases were shown to be responsible for the degradation of flavanones as occuring after application of these substrates to plant cell suspension cultures. — Comparative studies with various flavanones and horseradish peroxidase showed that only 4'-hydroxyflavanones will be catabolized peroxidatically. — Intensive analy...

Journal: :Bulletin of the Chemical Society of Japan 1976

Journal: :Molecules 2010
Ales Zima Jan Hosek Jakub Treml Jan Muselík Pavel Suchý Gabriela Prazanová Ana Lopes Milan Zemlicka

Antiradical and cytoprotective activities of several flavanones isolated from Paulownia tomentosa (Thunb.) Steud. (Scrophulariaceae) have been evaluated using different in vitro and in vivo methods. The capacity of flavanones to scavenge radicals was measured in vitro by means of DPPH and ABTS assays, the inhibition of hydroxyl radicals produced in Fenton reactions, FRAP, scavenging superoxide ...

2012
Malkanthi Evans Prachi Sharma Najla Guthrie

Flavonoids are a group of polyphenolic compounds ubiquitous in many plants including fruits, vegetables, nuts, seeds, grains, tea and wine (Hollman & Katan, 1999). Flavonoids belong to two classes i) Flavanones and ii) Flavones. The most common flavanones are hesperetin from oranges and naringenin from grapefruit. The most common flavones, also known as polymethoxylated flavones, are tangeretin...

Journal: :Acta pharmaceutica 2004
Ivan Kosalec Marina Bakmaz Stjepan Pepeljnjak Sanda Vladimir-Knezević

Spectrometric analyses of flavonoids in twenty propolis samples, collected from ten different geographic localities in northern Croatia using two complementary methods, are reported. Flavones and flavonols were determined using aluminum chloride and expressed as quercetine equivalent while flavanones were determined using 2,4-dinitrophenylhydrazine and expressed as naringenin. Contents of flavo...

2015
AMANOLLAH ZAREI AHMADY MOSADEGH KESHAVARZ MARYAM KARDANI NEDA MOHTASHAM

CuO nanoparticle was found to be an efficient catalyst for the synthesis of flavanones derivatives from the reactions between 2-hydroxyacetophenones and aromatic aldehydes at room temperature. The protocol offers advantages in terms of higher yields, short reaction times, and mild reaction conditions, with reusability of the catalyst. The structures of the synthesized substituted flavanones wer...

Journal: :Organic & biomolecular chemistry 2012
Donghee Kim Kyungrok Ham Sungwoo Hong

The remarkable catalytic effects of Fe(OTf)(3) in the context of the Pd(ii)-catalyzed conjugate addition of arylboronic acids to chromones were observed to yield a variety of flavanones under mild conditions. The addition of catalytic amounts of DDQ and KNO(2) to the reactions exclusively yielded flavone analogs. The reaction scope for the transformation was fairly broad, affording good yields ...

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