Plant-derived chromatography

Anon (n.d.b) Dionex application note number 67 The determinadon of plant-derived neutral oligo- and polysaccharides. Available as a downloadable file from the Dionex website(http //www.Dionex.com). Anon (n.d.c) Dionex application note number 54 The determination of sulfite in food and beverages by ion exclusion chromatography with pulsed amperometric detection. Available as a downloadable file from the Dionex website (http //www.Dionex.com). 

Most common furanocoumarins have characteristic retention properties on HPLC (High Performance Liquid Chromatography) with both reversed-phase and conventional-phase columns (Spencer et al., 1987). The assignment of ring-substitution patterns of plant-derived furanocoumarins can be made by negative-ion mass spectrometry (Plattner and Spencer, 1988). 

With the increasing interest in medicinal plants and plant-derived substances, the use of planar chromatography is necessary for the identification, quantitative determination, and isolation of naturally occurring compounds. The identification of compounds in complex samples, e.g., medicinal plant extracts, are often very difficult due to the similarity of the chemical structures. A schematic of identification with and without the isolation procedure is given in Figure 9. 

Diets rich in plant-derived foods can provide more than 1 g of phenolic compounds per day, although there are major international and interindividual differences in exposure. Flavonols, flavones, and fla-van-3-ols constitute the three major subclasses of flavonoids, and a significant amount of information on the content of selected flavonoids from these subclasses in fruits and vegetables has been obtained using high-performance liquid chromatography techniques. The other subclasses are flavanones, anthocyanidins, and isoflavones. 

Extraction of Sodium Channel Blockers. A review of published reports shows that methods for purification of sodium channel blockers from bacterial cultures are similar to techniques for isolation of TTX and STX from pufferfish and dinoflagellates (30, 31, 38, 39). Typically, cell pellets of bacterial cultures are extracted with hot 0.1% acetic acid, the resulting supernatant ultra-filtered, lyo-philized, and reconstituted in a minimal volume of 0.1% acetic acid. Culture media can also be extracted for TTX by a similar procedure (Ji). Both cell and supernatant extracts are analyzed further by gel filtration chromatography and other biological, chemical, and immunological methods. Few reports describe purification schemes that include extraction of control samples of bacteriological media (e.g., broths and agars) which may be derived from marine plant and animal tissues. 

The current methodology to determine residues of alachlor, acetochlor, propachlor, and butachlor in crops and animal products was developed over the last two decades by researchers at the Monsanto Company. These herbicides degrade rapidly in plants and animals to numerous metabolites that can be hydrolyzed to common aniline moieties. Little to no parent herbicide is found as intact residue in crops and animal products therefore, the residue methodology focuses on the determination of the common moieties that are derived from the parent herbicides and their metabolites. Initially, gas chromatography (GC) with flame ionization detection, nitrogen-phosphorus... 

A Multi-residue analytical method (for plants) is used for rice, citrus and tomato. Buprofezin and p-OH-buprofezin (as the acetylated derivative, p-AcO-buprofezin) are analyzed simultaneously using gas chromatography/nitrogen-phosphorus detection (GC/NPD). 

Milbemectin consists of two active ingredients, M.A3 and M.A4. Milbemectin is extracted from plant materials and soils with methanol-water (7 3, v/v). After centrifugation, the extracts obtained are diluted to volume with the extraction solvent in a volumetric flask. Aliquots of the extracts are transferred on to a previously conditioned Cl8 solid-phase extraction (SPE) column. Milbemectin is eluted with methanol after washing the column with aqueous methanol. The eluate is evaporated to dryness and the residual milbemectin is converted to fluorescent anhydride derivatives after treatment with trifluoroacetic anhydride in 0.5 M triethylamine in benzene solution. The anhydride derivatives of M.A3 and M.A4 possess fluorescent sensitivity. The derivatized samples are dissolved in methanol and injected into a high-performance liquid chromatography (HPLC) system equipped with a fluorescence detector for quantitative determination. 

ADAMS, M.A., CHEN, Z., LANDMAN, P., COLMER, T., Simultaneous determination by capillary gas chromatography of organic acids, sugars, and sugar alcohols in plant tissue extracts as their trimethylsilyl derivatives, Anal. Biochem., 1999, 266, 77-84. 

A few groups have made substantial progress toward the identification of Gossypium secondary metabolites. Stlpanovic, in collaboration with Wakelyn, Bell, and others, has identified several compounds, primarily cadlnane sesquiterpenolds (17, 21 - 28, 31). Hedin s group has used gas chromatography-mass spectrometry to identify a wide variety of substances which may be derived from the cotton plant (8 - 1, 20). Brzozowska, Hanower,... 

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