The compound isolated as white amorphous powder (50 mg) was identified as pulchranin A with ESI-MS in positive ion mode [M+H]+ ion of m/z 256.19 and a molecular formula of C14H29N3O(Guzii et al., 2013). 1H and HSQC NMR data (DMSO-d6) revealed the presence of nine methylene groups, an N-substituted methylene at C-3 (δC 53.2; δH 3.73), a guanidine group showing two singlets and one triplet proton signals ( δH 8.52, 7.46, and 7.49), an OH group at C-6 (δH 3.95), one terminal methyl group at C-15 (δH 0.86; δC 14.0), a double bond between C-5 and C-6 (δH 5.39 and 5.55; δC 129.20 and 131.27) and an oxygenated methine at C-6 (δH 3.51; δC 69.37).The COSY spectra revealed an open-chain guanidine derivative with a double bond at C5–C6. The COSY correlations, marked as bold in the structure, showed cross peaks between the signals of the hydroxy group proton and the methine proton at C-8 as well as between protons from C-5 to C-9 and from the proton attached to N-2 to that of …show more content…
Cytotoxicity assay:
Cytotoxic and viability assay of pulchranin A on human cancer cell lines:
The isolated compound exhibited a moderate cytotoxic effect on the three tested cell lines: HCT, HepG2 and MCF-7 where the cell viability, measured by SRB assay, and the IC50 was found to be 91, 80, 63 µg/ml respectively (Figure 3). The standard used was doxorubicin, which gave an IC50 value of 5.87, 4.19 and 3.83 µg/ml on each cell line respectively. Figure 3. Cytotoxic effect of pulchranin A (1) and doxorubicin (2) on HEPG2 (a), HCT (b) and MCF-7 (c) cell lines.
The ability of pulchranin A to inhibit CDKs enzymes (Figure 4) was assessed on human breast cancer cell lines MCF-7 cells, as they were the most sensitive to our compound and showed the least cell