A rapid spectrophotometric method for the quantitative estimation of octadecyl p-coumarates

The UV spectrum of octadecyl p-coumarates gives a peak at λmax(MeOH) = 308.6 nm (log e = 4.13). On addition of alkali, the peak undergoes a bathochromic shift to 358.2 nm with a hyperchromic effect. A linear relationship found between the concentration of octadecyl p-coumarates and the hyperchromic effect can be used to quantitatively estimate octadecyl p-coumarates in samples devoid of other compounds exhibiting the similar hyperchromic effect. The method may also be useful for quantitative comparison of total alkyl coumarates in plant samples.