Mapping metabolome changes in Luffa aegyptiaca Mill fruits at different maturation stages via MS-based metabolomics and chemometrics

Amal A Maamoun; Radwa H El-Akkad; Mohamed A Farag

doi:10.1016/j.jare.2019.10.009

Mapping metabolome changes in Luffa aegyptiaca Mill fruits at different maturation stages via MS-based metabolomics and chemometrics

J Adv Res. 2019 Oct 24:29:179-189. doi: 10.1016/j.jare.2019.10.009. eCollection 2021 Mar.

Authors

Amal A Maamoun¹, Radwa H El-Akkad¹, Mohamed A Farag^{2

3}

Affiliations

¹ Department of Pharmacognosy, National Research Centre, 33 El Buhouth St., P.O. 12622 (ID:60014618), Cairo, Egypt.
² Pharmacognosy Department, College of Pharmacy, Cairo University, Kasr el Aini St., P.B. 11562, Cairo, Egypt.
³ Chemistry Department, School of Sciences & Engineering, The American University in Cairo, New Cairo 11835, Egypt.

Abstract

Introduction: Luffa aegyptiaca Mill, sponge gourd or Egyptian cucumber, is grown worldwide for its edible fruit consumed as a vegetable like cucumber. Unlike young fruit (YF), the fully mature ripened fruit (MF) is strongly fibrous and is used as a cleanser to make scrubbing bath sponges. YF undergoes a complex series of physiological and biochemical changes during fruit ripening. However, the chemical compositional differences between YF and MF in Luffa aegyptiaca have not been distinguished to date.

Objectives: Comprehensively compare the metabolites profile of YF and MF to give insight on how maturation stage affects chemical composition.

Methods: Mass-based metabolomics comprising GC/MS and UHPLC/MS were adopted in this study targeting its volatile and non-volatile metabolites coupled with chemometrics to rationalize for the differences.

Results: A total of 53 volatile metabolites were identified via headspace solid phase microextraction (SPME) comprising 66.2% aldehydes/furans, 51.6% alcohols, 38.2% ketones, 15.1% acids and 10.1% aromatics of which aldehydes/ furans were dominant at both fruit stages. Young fruit was in general more erniched in metabolites as revealed from UHPLC/MS and GC/MS analyses. The YF group encompassed higher levels of short chain alcohols (1-octen-3-ol) and aldehydes ((E)-2-hexenal and cucumber aldehyde) in addition to terpenoids (linalool). In contrast, fatty acids (octanoic acid) predominated MF specimens. UHPLC/MS analysis revealed for several oleanene triterpene glycosides as major secondary bioactive compounds, dihydroxy-oxo-oleanenoic acid glycoside found more abundant in YF versus MF as revealed from multivariate data analyses.

Conclusions: Our results reveal for the distinct metabolite changes in L. aegyptiaca fruit in its different stages and to rationalize for its different usage.

Keywords: GC/MS; Luffa aegyptiaca; Metabolomics; SPME; UHPLC/MS.

Publication types

Review