Dried plant materials

Gregory, G.K. et ah. Quantitative analysis of lutein esters in marigold flowers (Tagetes erecta) by high performance liquid chromatography, J. Food ScL, 51, 1093, 1986. Livingston, A.L., Rapid analysis of xanthophyll and carotene in dried plant materials, J. AOAC, 69, 1017, 1986. 

Livingston, A.L., Rapid analysis of xanthophyll and carotene in dried plant materials, J. AOAC, 69, 1017, 1986. 

Materials required Dry plant material, methanol, diethyl ether, anhydrous Na2C03 and 2N HC1 (HPLC grade), N2, distilled water, Amberlite IR-45 (OH) ion-exchange resin (Rohm and Haas Company, Philadelphia, USA), graduated tube, Erlenmeyer flask (100 ml), filter paper, funnels, separatory funnels, rotary evaporator, mill, water bath, shaker, sieve of 0.5 mm in diameter, pipette of 1,2 and 10 ml, test tube of 20 ml. 

Studies of the transfer of radiocerium into various plant parts via the soil-root pathway are summarized in Table 6. Other laboratory and field studies employing tracer radiocerium or nuclear weapons fallout simulants are summarized in Tables 7 and 8. In general, the cereal grains and vegetable pulp showed plant-to-soil concentration factors (radioactivity per gram of dry plant material/radioactivity per gram of... 

Activity per gram dry plant material/activity per gram dry soil. 

As a plant tissue ages, the solubility of the polysaccharides decreases to some extent. Decreased solubility is most pronounced when the tissue material is dried. Insolubilization is not inherent in the drying process itself because it is possible to dry plant material in such a way as to prevent loss of solubility or chemical reactivity. Optimum drying... 

Effects of extracts with dry material and with fresh material were not correlated. This may be because drying plant material causes hydrolysis of glucosinolates to isothiocyanates, while autolysis of fresh crucifers yields predominantly nitriles (28). 

Details of the extraction methods for ficine (4) and isoficine (5) were not given. Phyllospadine (6) was isolated from the flavonoid-containing n-butanol-soluble extract from dried plant material (4). The alkaloids from Vochysia and Buchenavia were isolated by conventional procedures, utilizing acid-base extraction and subsequent column or thin-layer chromatography using silica gel or alumina (5,6). 

Toxicity. Atractyloside, a diterpenoid glycoside that occurs naturally in plants, may be present at levels as high as 600 mg/kg of dried plant material. Gonsumption of plants containing atractyloside or carboxyatractyl-oside has caused fatal renal proximal tubule necrosis and/or centrilobular hepatic necrosis in man and farm animals. Although pure atractyloside and crude plant extracts disrupt carbohydrate homeostasis and induce similar pathophysiological lesions in the kidney and liver, it is also possible that the toxicity of atractyloside may be confounded by the presence of other natural constituents in plants. Atractyloside competitively inhibits the adenine nucleoside... 

Coenegracht et al. [3] have introduced a four solvent system to compose mobile phases for the separation of the parent alkaloids in different medicinal dry plant materials, like Cinchona bark and Opium. Through the use of mixture designs and response surface modeling an optimal mobile phase was found for each type of plant material. These new mobile phases resulted in equally good or better separations than obtained by the procedures of the Pharmacopeias. Although separations were as predicted, the accuracy of the quantitative predictions needed to be improved. 

Our standard procedure consisted of first defatting the air-dried plant material with n-hexane followed by extraction with solvents of increasing polarity starting from chloroform, chloroform-methanol 9 1, methanol, and water in a Soxhlet apparatus or at room temperature. Only in a few... 

Element Form Available to Plants Relative Number of Ions in Dry Plant Material ... 

AOAC (Association of Official Analytical Chemists). 1990. Carotenes and Xanthophylls in Dried Plant Materials and Mixed Feeds. AOAC Method 970.64. In AOAC Official Methods of Analysis, 15th ed. (K. Helrich, ed.) pp. 1048-1049. AOAC, Arlington, Va. 

For freeze-dried samples, extract the dry sample ( 0.3 to 1 g dry weight starting from 2 to 3 g fresh weight) with diethyl ether and apply the equations given for diethyl ether (UNIT F4.3). Extraction of freeze-dried plant material with diethyl ether is performed by grinding in a mortar. It is also possible to use 80% acetone or 100% methanol, but diethyl ether has proved to be an excellent solvent for quantitative extraction of chlorophylls and carotenoids from freeze-dried plant material. 

Water-containing plant materials need to be extracted with polar solvents such as acetone, methanol, or ethanol that can take up water. Freeze-dried plant tissues and freeze-dried juices can be directly extracted with diethyl ether, which contains traces of water and is more polar than light petrol or hexane. Pure light petrol or hexane are less suitable, because more polar pigments, such as Chi b or xantho-phylls, are only partially extracted from freeze-dried plant samples. A few drops of acetone or ethanol added to light petrol or hexane will, however, guarantee a complete extraction. This mixture will extract Chi a, Chi b, and all carotenoids—including xanthophyll esters and secondary carotenoids that are present in many fruits and juices—from the freeze-dried plant material. 

Steeping the raw material in the chosen solvent, preferably in a closed container, which is usually made of stainless steel or a plastic capable of resisting attack by the solvent and the plant components. The quantity of solvent used needs to take into account the amount that is absorbed by the dry plant material in order to ensure the desired final yield of extract. 

Aconites, commonly called wolfsbane or monkshood, are species of Aconitum (Ranunculaceae), valued ornamental herbaceous plants, grown for their showy blue or purple flowers, which are shaped like a monk s cowl. Their alkaloid content, mainly in the roots, makes them some of the most toxic plants commonly encountered. The dried roots of Aconitum napellus were once used, mainly externally for relief of pain, e.g. in rheumatism. The toxic alkaloids (0.3-1.5%) are complex diterpene-derived esters. Aconitine (Figure 6.124) is the principal component (about 30%) and is a diester of aconine with acetic and benzoic acids. Hydrolysis products benzoylaconine and aconine are also present in dried plant material. These alkaloids appear to behave as neurotoxins by acting on sodium channels. All species of Aconitum and Delphinium are potentially toxic to man and animals and must be treated with caution. 

Cahill et al. [241] have developed a simple and sensitive analytical procedure for determining the concentration of trifluoroacetic acid in plant, soil, and water samples. The analysis involves extraction of trifluoroacetic acid by sulfuric acid and methanol followed by derivatisation to the methyl ester of trifluoroacetic acid. This is accomplished within a single vial without complex extraction procedures. The highly volatile methyl ester is then analysed using headspace gas chromatography. The spike recovery trials from all media ranged from a low of 86.7% to a high of 121.4%. The relative standard deviations were typically below 10%. The minimum detectable limit for the method was 34 ng/g for dry plant material, 0.20 ng/g for soil and 6.5 ng/1 for water. 

In the digestion procedure, 6 ml of acidified 12.5% m/v potassium hydrogen sulfate is placed in a PTFE lined screw-cap bottle together with four grams of oven-dried plant material. The uncapped bottle is subjected to the following regime. 

Extraction of dried plant materials from Colchicum species with methanol afforded, after separation into neutral and basic fractions and chromatography on silica, several tropolonic and alio congener alkaloids (listed in Table I and II). 

A further simplification has been reported (27) in which the dried plant material is extracted with three times its volume of a mixture of benzene, concentrated aqueous ammonia, and methanol in the ratio 100 1 1, respectively. Some five successive extractions appear to be adequate. The bases are separated from the combined benzene extract by shaking with 6% aqueous citric acid. The troublesome emulsions that are encountered in other procedures are largely avoided by this method. 

The alkaloids have been isolated either by alcohol extraction of the dried plant material (82, 90) or by ether extraction of the basified plant material (87). The crude mixture is then fractionated by countercurrent distribution, followed by chromatographic purification and recrystallization. 

---