Development of a High-Performance Thin-Layer Chromatographic Method for Quantification of Cucurbitacin B in Bottle Gourd (Lagenaria siceraria) for Quality Control

Bottle gourd (Lagenaria siceraria (Molina) Standl.) is an important vegetable cucurbit cultivated in the warmer parts of the world. Forms bearing nonbitter fruits are used as vegetables, while those with bitter fruits are used in the Indian Traditional System of Medicine. The presence of cucurbitacins is probably the only distinguishing feature between the two forms. The present communication describes the development and validation of a high-performance thin-layer chromatographic (HPTLC)-densitometric method for the estimation of cucurbitacin B in bottle gourd using the International Conference on Harmonization (ICH) guidelines. The complete methanol extracts obtained by accelerated solvent extraction (ASE) were resolved in the mobile phase chloroform-methanol (9.5: 0.5, v/v), wherein cucurbitacin B was resolved at R-F 0.67 +/- 0.02. Linear relationship was obtained between the values 200 and 1200 ng per spot (r = 0.9909). The limit of detection and limit of quantification were 40 and 200 ng per spot, respectively. The recovery of compound varied between 94 and 96%. Using the developed HPTLC method, the cucurbitacin B content in the vegetative parts (VP) and fruits (F) of the bitter form was found to be 0.017% and 0.062%, respectively, while it was not detected in the nonbitter form. The application of the method to study the accumulation of cucurbitacin B during progressive developmental stages of fruits of both forms revealed an increasing content of cucurbitacin B from 0.001 to 0.085% during the fruit development in the bitter form. In investigations of market samples, cucurbitacin B was detected in two out of six samples indicating admixture of bitter and nonbitter forms. To the best of our knowledge, this study is the first report of the evaluation of bitter and nonbitter forms of bottle gourd for cucurbitacin B using HPTLC. The developed method may be applicable in the routine quality control of marketed products and formulations of bottle gourd.