Isoflavonoids

HANOI UNIVERSITY OF SCIENCE - VNU
FACULTY OF CHEMISTRY
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Scientific Report

AN OVERVIEW OF isoflavonoids
Field of Study: Pharmaceutical Chemistry

Student: Nguyễn Bảo Ninh
Supervisor: Prof. Dr. Sci.Nguyễn Văn Đậu












Hanoi , 2011


Acknowledgement
I am very grateful to Prof. Dr. Sci.Nguyễn Văn Đậu who has dedicated guidance and instructions so I can finish this report. Besides, Mr Nguyen Van Cuong who helped me find some documents

































Terms


Acknowledgement
I.Introduction

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II. Classification

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 1. flavonoids

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 2. isoflavonoids

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 3.Neoflavonoids

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 4.Minor Flavonoids

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 5.Chalcones, Dihydrochalcones, and Racemic Flavonoids and others

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 5.1.Asymmetric Epoxidation of Chalcones
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 5.2 . α- and β-Hydroxydihydrochalcones

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 5.3 . Dihydroflavonols

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 5.4 Flavan-3-ols and Flavan-3,4-diols
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 5.5 . Isoflavonoids
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III Analysis and Extraction

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 1. Qualitative methods and quantitative
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 1.1 Quantitative
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 1.2 Qualitative methods
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 1.3 For example
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 2.The method extracts and synthetic flavonoid
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 2.1Refractive index
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 3.Biological effects and applications
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 3.1 Biological effects
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 3.2 Applications
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IV-Conclusions

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V-References

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Introduction
In this paper, I will introduce one of the compounds have very high biological effects: isoflavonoids.
The distribution of isoflavo-noids among plants is relatively sparse they nevertheless form a large and very distinctive subclass of the flavonoid family
with a wide variety of structural variations encountered in nature.
Flavonoids and their conjugates form a very large group of natural products. They are found in many plant tissues, where they are present inside the cells or on the surfaces of different plant organs. The chemical structures of this class of compounds are based on a C6-C3-C6 skeleton. They differ from the saturation of the heteroatomic ring C, in the placement of the aromatic ring B at the positions C-2 or C-3 of ring C, and in the overall hydroxylation patterns (Figure 2.1). The flavonoids may be modified by hydroxylation, methoxylation, or O-glycosylation of hydroxyl groups as well as C-glycosylation directly to carbon atom of the flavonoid skeleton.In addition, alkyl groups (often prenyls) may be covalently attached to the flavonoid moieties, and sometimes additional rings are condensed to the basic skeleton of the flavonoid core. The last modification takes place most often in the case of isoflavonoids, where the B ring is condensed to the C-3 carbon atom of the skeleton.Flavonoid glycosides are frequently acylated with aliphatic or aromatic acid molecules. These derivatives are thermally labile and their isolation and further purification without partial degradation is difficult. The multiplicity of possible modifications of flavonoids result in more than 6,000 different compounds from this class were known in the end of the last century and this number continues to increase (Harborne and Williams, 2000). Condensed tannins create a special group of flavonoid compounds formed by polymeric compounds built of flavan-3-ol units, and their molecular weights often exceeding 1,000 Da.
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1- Somes picture
In the plant kingdom, different plant families have characteristic patterns of flavonoids and their conjugates. All these compounds play important biochemical and physiological roles in the various cell types or organs (seed, root,green part, fruit) where they accumulate. Different classes of flavonoids and their conjugates have numerous functions during the interactions of plant with the environment, both in biotic and abiotic stress conditions (Dixon and Paiva, 1995; Shirley, 1996). Additionally, flavonoid conjugates, because of their common presence in plants, are important components of human and animal diet. Due to the different biological activities of plant secondary metabolites, their regular consumption may have serious consequences for health, both positive and negative (Beck et al., 2003; Le March, 2002; Boue et al., 2003; Fritz et al., 2003; Nestel,2003). For the mentioned reasons, ethods or the efficient and reproducibleanalysis of flavonoids play a crucial role in research conducted in different fields
of the biological and medical sciences.
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Flavonoids have long sparked the interest of scientists and nonscientists alike, largely because these metabolites account for