Ultraviolet spectrophotometric method: Not possible for the simultaneous estimation of active constituents in Phyllanthus amarus

Abstract

Objective: Our objective was to develop and validate UV spectrophotometric method
for simultaneous estimation of phyllanthin, hypophyllanthin, and niranthin in Phyllanthus
amarus. P. amarus is highly valued in the treatment of liver ailments and has been shown to
posses antihepatitis B virus surface antigen activity. Several analytical methods including
high-performance thin layer chromatography (HPTLC) and high-performance liquid
chromatography (HPLC) are reported for respective phytoconstituents. However,
there is no simultaneous estimation of phyllanthin, hypophyllanthin, and niranthin,
active constituent of P. amarus. Hence, attempts have been made to develop UV
spectrophotometric method because of the simplicity and economical advantage of
this technique over other analytical techniques as HPTLC, HPLC, etc. Materials
and Methods: Standard solution of phyllanthin, hypophyllanthin, and niranthin were
prepared in methanol and scanned under a Shimadzu UV spectrophotomer, under
full UV (ultraviolet) range (200-400 nm) to get the spectra. Result: After some
experiments, it was found that it is impossible to quantify phyllanthin, hypophyllanthin,
and niranthin simultaneously by UV spectrophotometric method. This was evident from
the UV spectra as they were overlapping with each other. Conclusion: Same class of
drugs may have almost the same functional groups, and gradient reverse-phase liquid
chromatography and HPTLC will be more useful to separate such complicated mixtures.
Therefore, we propose to develop either HPLC or HPTLC method for simultaneous
estimation of these compounds.