Exploring The Phytochemical Composition Of An Aqueous Extract Of Neltuma Caldenia Leaves

Abstract

Neltuma caldenia, commonly known as “caldén”, is an endemic tree from Espinal region of Argentina. Previously, we evaluated the antitumor activity of an Aqueous Extract from Neltuma caldenia (AENc) leaves in Triple-Negative Breast Cancer (TNBC) cells studying its effects on cell viability, cell cycle, apoptosis and cell migration. In this work, phytochemical components of the AENc were screened by HPLC and GC-MS analysis. In addition, the content of proteins, carbohydrates, total phenolic acids and flavonoids were determined by colorimetric assays. The separation and identification of secondary metabolites from AENc were carried out on an UHPLC-ESI-QTOF-MS system and the analysis of the chromatographic peaks showed the presence of phenolic compounds; mainly flavonoids as quercetin, isorhamnetin, isovitexin, kaempferol, rutin, isorhoifolin, tricin, luteonin and catechin. Regarding GC-MS, interpretation of mass spectrum was conducted using the NIST database and the analysis showed the presence of volatile compounds: L-gala-L-ido-octose, 2-butyl-2,7-octadien- 1-ol, 7-methyl-tetradecen-1-olacetate, 12-methyl-(E,E)-2,13-octadienol, 2- butenal-2-methyl-4-(2,6,6-trimethyl-1-cyclohexen-1-yl), dihydroactinidiolide and (E,E,Z)-1,3,12-nonadecatriene-5,14-diol. Additionally, the protein content of the AENc was 8.71 ± 1.26 mg/g (Bradford method; R2 albumin calibration curve: 0.9883); the carbohydrates content was 0.29 ± 0.02 mg/g (phenol-sulfuric acid method; R2 glucose calibration curve: 0.9938); the total phenolic acids content was 152 ± 0.3 mg/g (Folin-Ciocalteu method; R2 gallic acid calibration curve: 0.9984) and the flavonoids content was 13.6 ± 0.023 mg/g (aluminium chloride method; R2 quercetin calibration curve: 0.9980). In conclusion, the AENc is mainly composed of phenolic compounds which could be, at least in part, responsible for its antitumor properties in TNBC cells. Further studies are necessary in order to quantify the metabolites found in the AENc accurately.