Antiangiogenic Effects and Therapeutic Targets of Azadirachta indica Leaf Extract in Endothelial Cells

Figure 6

Mass spectrometric analysis of the standards nimbolide and 2′,3′-dehydrosalannol and ethanol extract of neem leaves (EENLs). (a) The mass spectrum of the nimbolide standard depicts the monoisotopic [M + Na]⁺ ion 489.204 𝑚/𝑧 and the [M + H]⁺ ion 467.221 m/z. (b) The mass spectrum of the 2′,3′-dehydrosalannol depicts the monoisotopic [M+Na]⁺ ion 577.2780 𝑚/𝑧. (c) The total ion chromatogram of EENL. (c1) The mass spectrum of the peak 1 depicts the dominant monoisotopic ion 475.2105 𝑚/𝑧, at a retention time of 11.68 minutes. Subtracting the mass of sodium (22.9898) from the observed mass results in a mass is suggestive by mass alone as nimolinone. (c2) The mass spectrum of the peak 2 depicts the dominant monoisotopic ion 489.1891 𝑚/𝑧, at a retention time of 11.91 minutes. After subtracting the sodium mass, this is suggestive by mass and retention time as nimbolide (c3) The mass spectrum of the peak 3 depicts the dominant monoisotopic ion 463.2094 𝑚/𝑧, at a retention time of 12.12 minutes. Subtracting the mass of sodium from the observed mass results in a mass is suggestive by mass alone as 6-desacetyl nimbinene. (c4) The mass spectrum of the peak 4 depicts the dominant monoisotopic ion 577.2775 𝑚/𝑧, at a retention time of 12.35 minutes. After subtracting the sodium mass, this is suggestive by mass and retention time as 2′,3′-dehydrosalannol. A comparison of the spectra of the nimbolide and 2′,3′-dehydrosalannol standards to the spectra from the EENL peaks suggests that peaks 2 and 4 are nimbolide and 2′,3′-dehydrosalannol, respectively.