Agar blocks of the stem TR-S1 endophyte were cut from the pure strain actively growing on PDA Petri dishes and transferred to 1 L Erlenmeyer flasks containing a 200 g sized recipe of Corn Grit Agar(CGA). TR-S1 endophyte was incubated at room temperature at 26-28C for 21 days. Fungal metabolites were then extracted by acetone which was then partitioned with ethyl acetate and methanol respectively. TLC analysis of the ethyl acetate fraction revealed the characteristic blue spots of polyketides with vanillin/sulfuric spraying reagent as well as the positive results with Dragendorff’s reagent. Using silica gel column chromatography run with dichloromethane and methanol, pulchranin A was detected in the first few fractions F5 to F10 with Rf value
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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
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