Extraction and Isolation

500 g of Semecarpus anacardium seeds were crushed and soaked in a liter of methanol and kept in refrigerator for 3 days. Then, the filtrate was filtered through Whatman filter paper No 1 and this was repeated three to four times until the filtrate gave no coloration and concentrate using vacuum rotary evaporator at 40 °C. The methanolic concentrate was fractionated sequentially with petroleum, diethyl ether, chloroform and n-butanol. The n-butanolic fraction was evaporated to dryness and then checked it on thin layer chromatography with hexane and ethyl acetate (8:2 ratios) in which four spots were appeared. The n-butanolic concentrate was chromatographed on silica gel column (Merk 60-120 mesh size) and eluted successively with hexane and ethyl acetate in the ratio of 8:2. A total of 50 fractions were collected at an interval of 5 ml each and monitored by thin layer chromatography (precoated silica gel merk-60 F₂₅₄ 0.25 mm thick plate). Fraction from 1 to 5 formed as a pale green coloured and showed single spot on TLC and pooled together in a cleaned vial and evaporated to dryness. This process was repeated until getting satisfactory yield of the compound. The structure of the compound was confirmed as acyclic isoprenoid derivatives on the basis of IR, ¹H NMR, ¹³C NMR and high-resolution mass spectrometry (HRMS). Molecular formula of the compound is C₂₁H₃₂O. Yield of the compound was 300 mg/500 g of methanolic crude extract. The chemical structure of the acyclic isoprenoid was given in Fig. 1.