A Natural Triglyceride from the Methanol Root Extract of Cyphostemma Adenocaule (Steud. Ex A. Rich.) Wild & R.B.Drumm
Cyphostemma adenocaule (Steud. ex A. Rich.) is one of the specie plant that belongs to the family vitacea. In this study, Trilinolein was isolated and characterized from the methanol root extract of the plant. Column chromatography over silica gel granules as the stationary phase and eluted with a mobile phase mixture of n-Hex-EtA; EtA-CHCL3 and CHCL3-MeOH with gradient increasing polarity, followed by a second column using saphadex-LH20 and 100% MeOH as stationary and mobile phase vehicle respectively. TLC was developed with EtA 15: CHCL3 8: MeOH 4: H2O 1 as solvent system; sprayed with 10% H2SO4 ,Vanillin-sulphuric acid, and/ or Polyethylene glycol PEG and heat for spot detection and confirmation of bioactive principles. Compound CA1 was obtained and purified with CHCL3 to give a yellow semi-solid compound (0.23g). The 1H-NMR spectra showed 9 different signals; a signal peak of a glycerol (-CH2OCOR-) moiety on the first α-C chain and on the third αʹ-C at 4.143-4.187ppm and 4.296-4.325ppm respectively, while that of a β glycerol (-CHCOR-) at 5.286ppm. Signals of an allylic methylene group at 2.023-2.035ppm, Olefenic hydrogen group at signal peak of 5.362ppm and a diallylic methylene group at signal 2.790ppm were also observed. In the 13C NMR spectra of compound CA1, 57 carbon atoms where observed, multiple signals overlapping at a range of 14.13-34.21ppm corresponding to the aliphatic CH3 (C18), CH2 (C2, C3, C4, C5, C6, C7, C15, C16, and C17) and allylic (C8, C14) carbon atoms. Signals at 127.90-130.24ppm were assigned to the olefienic C atoms (C9, C10, C12, and C13) while signal of 172.87ppm and 173.32ppm were assigned to the carbonyl (C=O) carbon atoms (C1 and C2) respectively (Table 2).
Analysis with DEPT-135, H-H COSY, HMBC and HSQC assignments of CA1 augments assignment of signals made for CA1 from 1H-NMR and 13C-NMR and corresponded to that of Trilinolein (C57H98O6, MW 879.4 g/mol). The isolated compound was positive for the acrolein test for triglycerides; fat & oil and had an IC50 of 46.08µg/ml radical scavenging activity.