Palytoxin spectrum

Figure 5.4. Ultraviolet spectrum of reference palytoxin from Palythoa tuberculosa at 25 pg/ml in water.

The infrared (IR) spectrum of purified palytoxin or its congener shows a band at 1670 cm due to the presence of an a, P-unsaturated amide carbonyl group (Moore and Scheuer 1971). Similar IR data have also been obtained for purified palytoxin both from P. caribaeorum (Beress et al. 1983) and from the xanthid crab Lophozozymuspictor (Tan and Lau 2000). 

Ostreocin-D is a colorless, amorphous solid, positive to ninlydrin. It is an optically active compound, having a specific rotation of+16.6 in water (c 0.12, T = 23°C). Its UV absorprion spectrum exhibits two maxima, at 234 (e 35000) and 263 nm ( 22000). The UV absorptions together with NMR spectra indicate that ostreocin-D has conjugated diene and ketone functionafity analogous with palytoxin (Usami etal. 1995). 

The UV spectrum of palytoxin, as discussed earlier, shows two characteristic absorption peaks at 233 and 263 nm, contributed by the respective chromophores (Figure 29.4). The ratio of their absorbance (233 versus 263 mn), which is approximately 1.7 [3], is characteristic and indicative of the toxin s presence. The absorptions at either wavelength have been reported to be linearly related to palytoxin concentration in the range of 5-20 pg/mL. However, the disadvantage of this method is its detection limit, as the minimum detectable concentration has been reported to be 5 pg/mL (palytoxin standard in water), while toxicological and physiological effects have been observed with concentrations as low as 0.05-0.1 pg/mL [103], which limits its suitability as a regulatory analysis method. 

Figure 1. A 600-MHz high resolution spectrum of palytoxin, a marine toxin isolated from a species of Palythoa. The gross structure deduced for the toxin also is...

Figure 2. Expanded view of a small region of the spectrum of palytoxin shown in...

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