Filix-Phloroglucinol Butanones

TLC-separation is carried out mostly on acid or basic impregnated silica gel GF254 layers. The reversed phase technique has also been used, for which normal silica gel G layers were impregnated with paraffin-petrol ether (5 + 95) (p. 48) and methanol-formic acid-water (75 + 10 + 15) was used as solvent. The results are in Table 172. 

The relation between the number of phloroglucinol rings and the hR/-value, observed in reversed phase procedures, is of some interest. The hR/-value falls as the molecular weight rises for one ring it lies between 78 and 100 and for two rings, either ca. 70 (24 carbon atoms) or ca. 10 (with one methyl group more). 

Visualisation Phloroglucinol derivatives may be detected through their quenching on fluorescence layers in short-wave UV light. Coupling with the stable Past Blue B salt (Bgt. No. 100) yields the colours quoted in Table 172. VoN Schantz [191] gives data about the reaction products 

I = Silica gel G, acid-buffered with Mcllvaine buffer, pH 6 solvent petrol ether-chloroform-ethanol (47. 5 -f 47.5 + 5) [191] II = Silica gel G, acid-buffered with 0.5N oxalic acid solvent benzene-chloroform (50 + 50), chamber saturation [199] III = Silica gel GP254, alkali-buffered (0.3M sodium acetate) solvent ethyl acetate, double development at chamber saturation [205] IV = Silica gel GF254 impregnated with paraffin solvent methanol-formic acid-water (75 -t 10 -h 15), chamber saturation [205]. 

Applications With the help of TLC, Pentilla and Sundman [168] in particular have been able, in a comparatively brief period, to discover and identify new fihx phloro-glucides [22, 46, 47, 48]. The quantitative evaluations after TLC-sepa-ration furnished the first useful data about the composition of the crude filicins obtained in different ways [192,199]. 

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