Reagent Dragendorff

Analyses in the pg range, e.g., in water and oil, can be carried out with thin-layer chromatography [244]. After separation on the thin-layer plates, then by Dragendorff reagent, colored spots are measured with the help of a spectral photometer at 525 nm. 

Note The colors obtained are characteristic for the various substance classes (Table 1). Thus color tones obtained for phenothiazine derivatives are mainly reddish [1], If the j chromatogram zone contains more than 10 pg substance per spot there is only a colored 1 outer ring surrounding an uncolored center (Fig. 1) [1, 4]. The Forrest reagent does not interfere with subsequent detection with the Dragendorff reagent [1, 4], 1... 

Choline-containing phospholipids Potassium iodide-bismuth subnitrate (phosphatidylcholine and Dragendorff reagent... 

Muscarine is detected by high-performance thin-layer chromatography (HPTLC), with a limit of detection of 50 ng (Stijve, 1981). Using Dragendorff reagent, muscarine appears as an orange spot. 

D development with acetone-CH2Cl2-aq. 25%NH3 (40 60 1) followed by acetone. Dragendorff reagent 50... 

Positive alkaloid tests are apt to be due to the fonnation of complexes of nonalkaloidal constituents with the Dragendorff reagent alkaloids are not known in the family. 

Dragendorff Reagent (test), 133 Dragendorff spray, 1169 Dralzine, 662 Dramamine, 549 Dramion, 640 Dramocen, 549 Drauxin, 403 Drazoxolon, 83... 

Solamargine and solasonine were isolated from fresh fruits of S. khasianum as previously described [10]. Solasodine was obtained from solamargine by add hydrolysis as previously described [10]. Solamargine (1 mg) was dissolved in MeOH containing IM HCl (1 mL). The mixture was heated at 70°C for 10,20, 30, 60, and 90 min, respectively. Individual hydrolysates were evaporated in vacuo and applied to TLC. Spots developed on TLC were determined by H2SO4 and Dragendorff reagent. 

Fig. 1 Hydrolyzed products of solamargine by HCI. (a), (b), and (c) show TLC-immunostaining and the stainings with sulfuric acid and with Dragendorff reagent, respectively. Solamargine was hydrolyzed by IM HCI for 10, 20, 30, 60, and 90 min, respectively. Spots 1-4 were identified with solasodine, 3-0-/3-D-glucopyranosyl solasodine, L-rhamnosyl-(l—>4)-0-3-/3-D-glucopyranosyl solasodine, L-rhamnosyl-(l—>2)-3-/3-0-D-gluco-pyranosyl solasodine, respectively.

The mesembrine alkaloids can be separated chromatographically by the ascending method on paper (Schleicher and Schuell 2042 b mgl), impregnated with a solution of formamide in acetone (1 4), with the solvent systems A (methyl ethyl ketone heptane = 2 3) and B (methyl ethyl ketone xylene = 1 1), in an atmosphere saturated with ammonia (12). After spraying with Dragendorff reagent an extract from /S. nama-quense showed at least nine alkaloids. The Rf values of the mesembrine alkaloids are given in Table II. 

UV light is used for general visualization. For specific visualization, use dragendorff reagent, molybdenum reagent and ninhydrin reagent are used for PEG spots, PE spots (phosphorus detection) and primary amine spots, respectively. 

Table 1 summarizes the alkaloid producing species found in Malaysia. The plants are listed systematically under family, genus and species. The alkaloids were detected by the Mayer or Dragendorff reagents or by TLC of an alkaloidal extract followed by detection with the Dragendorff reagent. The test results are cited as strong (s), medium (m), weak (w) or just (+) in cases where a positive result was obtained but no attempt was made to estimate the relative amount. The plant parts examined are abbreviated as follows L (leaves), B (bark), S (stem), Wd (wood), Sd (seed), F (fruit), FI (flowers), R (root) and W (whole plant). It is evident from examination of these results as well as from the subsequent chemical studies that have followed that alkaloid rich species predominate in the Families Annonaceae, Apocynaceae and Rubiaceae and to a lesser extent in Lauraceae, Menispermaceae, Verbanaceae, Euphorbiaceae and Rutaceae. 

Polydocanol is a mixture of monoethers from dodecyl alcohol and Macrogols, which contains an average of 9 oxyethylene units and is used as a local anesthetic. As this mixture of substances is not UV active, visualization by derivatization is performed with a modified Dragendorff reagent ... 

Figure 87. Identification of metoclopramide base and polidocanol in a suppository mass after dipping in a modified Dragendorff reagent...

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