Publisher Summary This chapter discusses the analysis of total phenols and other oxidation substrates and antioxidants by means of Folin-Ciocalteu reagent. Analyses of the Folin-Ciocalteu (FC) type are convenient, simple, and require only common equipment and have produced a large body of comparable data. Under proper conditions, the assay is inclusive of monophenols and gives predictable reactions with the types of phenols found in nature. Because different phenols react to different degrees, expression of the results as a single number—such as milligrams per liter gallic acid equivalence—is necessarily arbitrary. Because the reaction is independent, quantitative, and predictable, analysis of a mixture of phenols can be recalculated in terms of any other standard. The assay measures all compounds readily oxidizable under the reaction conditions and its very inclusiveness allows certain substances to also react that are either not phenols or seldom thought of as phenols (e.g., proteins). Judicious use of the assay—with consideration of potential interferences in particular samples and prior study if necessary—can lead to very informative results. Aggregate analysis of this type is an important supplement to and often more informative than reems of data difficult to summarize from various techniques, such as high-performance liquid chromatography (HPLC) that separate a large number of individual compounds .The predictable reaction of components in a mixture makes it possible to determine a single reactant by other means and to calculate its contribution to the total FC phenol content. Relative insensitivity of the FC analysis to many adsorbents and precipitants makes differential assay—before and after several different treatments—informative.

Analysis of total phenols and other oxidation substrates and antioxidants by means of folin-ciocalteu reagent

Structure-antioxidant activity relationships of flavonoids and phenolic acids

typically written from a biophysicist’s or a molecular plant physiologist’s point of view (Horton and Bowyer, Chlorophyll fluorescence analysis has become one of 1990; Krause and Weis, 1991; Govindjee, 1995). The aim the most powerful and widely used techniques avail- of this review is to provide a simple, practical guide to able to plant physiologists and ecophysiologists. This chlorophyll fluorescence for those beginners who are review aims to provide an introduction for the novice interested in applying the technique in both field and into the methodology and applications of chlorophyll laboratory situations. Whilst the principles behind the fluorescence. After a brief introduction into the theor- measurements will be discussed briefly, the emphasis will etical background of the technique, the methodology be on the applications and limitations of this technique and some of the technical pitfalls that can be encoun- in plant ecophysiology. tered are explained. A selection of examples is then used to illustrate the types of information that fluorescence can provide. The basis of chlorophyll fluorescence measurements

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Chlorophyll fluorescence—a practical guide

The use of and search for drugs and dietary supplements derived from plants have accelerated in recent years. Ethnopharmacologists, botanists, microbiologists, and natural-products chemists are combing the Earth for phytochemicals and “leads” which could be developed for treatment of infectious diseases. While 25 to 50% of current pharmaceuticals are derived from plants, none are used as antimicrobials. Traditional healers have long used plants to prevent or cure infectious conditions; Western medicine is trying to duplicate their successes. Plants are rich in a wide variety of secondary metabolites, such as tannins, terpenoids, alkaloids, and flavonoids, which have been found in vitro to have antimicrobial properties. This review attempts to summarize the current status of botanical screening efforts, as well as in vivo studies of their effectiveness and toxicity. The structure and antimicrobial properties of phytochemicals are also addressed. Since many of these compounds are currently available as unregulated botanical preparations and their use by the public is increasing rapidly, clinicians need to consider the consequences of patients self-medicating with these preparations.

Plant Products as Antimicrobial Agents

Plant responses to salt and water stress have much in common. Salinity reduces the ability of plants to take up water, and this quickly causes reductions in growth rate, along with a suite of metabolic changes identical to those caused by water stress. The initial reduction in shoot growth is probably due to hormonal signals generated by the roots. There may be salt-specific effects that later have an impact on growth; if excessive amounts of salt enter the plant, salt will eventually rise to toxic levels in the older transpiring leaves, causing premature senescence, and reduce the photosynthetic leaf area of the plant to a level that cannot sustain growth. These effects take time to develop. Salttolerant plants differ from salt-sensitive ones in having a low rate of Na + and Cl ‐ transport to leaves, and the ability to compartmentalize these ions in vacuoles to prevent their build-up in cytoplasm or cell walls and thus avoid salt toxicity. In order to understand the processes that give rise to tolerance of salt, as distinct from tolerance of osmotic stress, and to identify genes that control the transport of salt across membranes, it is important to avoid treatments that induce cell plasmolysis, and to design experiments that distinguish between tolerance of salt and tolerance of water stress.

https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.0016-8025.2001.00808.x

Comparative physiology of salt and water stress

1 Methods of Plant Analysis.- 1.1 Introduction.- 1.2 Methods of extraction and isolation.- 1.3 Methods of separation.- 1.4 Methods of identification.- 1.5 Analysis of results.- 1.6 Applications.- 2 Phenolic Compounds.- 2.1 Introduction.- 2.2 Phenols and phenolic acids.- 2.3 Phenylpropanoids.- 2.4 Flavonoid pigments.- 2.5 Anthocyanins.- 2.6 Flavonols and flavones.- 2.7 Minor flavonoids, xanthones and stilbenes.- 2.8 Tannins.- 2.9 Quinone pigments.- 3 The Terpenoids.- 3.1 Introduction.- 3.2 Essential oils.- 3.3 Diterpenoids and gibberellins.- 3.4 Triterpenoids and steroids.- 3.5 Carotenoids.- 4 Organic Acids, Lipids and Related Compounds.- 4.1 Plant acids.- 4.2 Fatty acids and lipids.- 4.3 Alkanes and related hydrocarbons.- 4.4 Polyacetylenes.- 4.5 Sulphur compounds.- 5 Nitrogen Compounds.- 5.1 Introduction.- 5.2 Amino acids.- 5.3 Amines.- 5.4 Alkaloids.- 5.5 Cyanogenic glycosides.- 5.6 Indoles.- 5.7 Purines, pyrimidines and cytokinins.- 5.8 Chlorophylls.- 6 Sugars and their Derivatives.- 6.1 Introduction.- 6.2 Monosaccharides.- 6.3 Oligosaccharides.- 6.4 Sugar alcohols and cyclitols.- 7 Macromolecules.- 7.1 Introduction.- 7.2 Nucleic acids.- 7.3 Proteins.- 7.4 Polysaccharides.

https://www.springer.com/cda/content/document/productFlyer/productFlyer_978-0-412-57260-9.pdf?SGWID=0-0-1297-33550746-0

Phytochemical Methods: A Guide to Modern Techniques of Plant Analysis

Advances in flavonoid research since 1992.

1 The Anthocyanins.- 2 Flavans and Proanthocyanidins.- 3 C-Glycosylflavonoids.- 4 Biflavonoids.- 5 Isoflavonoids.- 6 Neoflavonoids.- 7 Flavones and Flavonols.- 8 Flavone and Flavonol Glycosides.- 9 The Minor Flavonoids.- 10 Miscellaneous Flavonoids.- 11 Biosynthesis.- 12 Distribution of Flavonoids in the Lower Plants and Its Evolutionary Significance.- 13 Distribution and Evolution of the Flavonoids in Gymnosperms.- 14 Flavonoids and Evolution in the Dicotyledons.- 15 Distribution and Evolution of Flavonoids in the Monocotyledons.- 16 Flavonoids and Flower Colour.- Plant Species Index.

The Flavonoids: Advances in Research since 1980

Encyclopedia of plant physiology, New series

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Jeffrey B. Harborne

Papers

Phytochemical Methods: A Guide to Modern Techniques of Plant Analysis

Advances in flavonoid research since 1992.

The Flavonoids: Advances in Research since 1980

Encyclopedia of plant physiology, New series

Methods in plant biochemistry