Revisiting Previously Investigated Plants: A Molecular Networking-Based Study of Geissospermum laeve

Abstract

Three new monoterpene indole alkaloids (1-3) have been isolated from the bark of Geissospermum laeve, together with the known alkaloids (-)-leuconolam (4), geissolosimine (5), and geissospermine (6). The structures of 1-3 were elucidated by analysis of their HRMS and NMR spectroscopic data. The absolute configuration of geissolaevine (1) was deduced from the comparison of experimental and theoretically calculated ECD spectra. The isolation workflow was guided by a molecular networking-based dereplication strategy using an in-house database of monoterpene indole alkaloids. In addition, five known compounds previously undescribed in the Geissospermum genus were dereplicated from the G. laeve alkaloid extract network and were assigned with various levels of identification confidence. The antiparasitic activities against Plasmodium falciparum and Leishmania donovani as well as the cytotoxic activity against the MRC-5 cell line were determined for compounds 1-5.

Current status and contemporary approaches to the discovery of antitumor agents from higher plants

“…The use of molecular networking as a dereplication strategy has been successfully articulated effectively earlier, and successful dereplication using molecular networking involves three main steps: (i) acquisition of tandem mass spectra, (ii) the generation of molecular networks (iii) and analyses using various mechanisms (Yang et al, 2013). In particular, it has been emphasized that reference LC-MS/MS spectra of known compounds and/or previously isolated and well-characterized compounds can be generated in the same manner as the sample to aid in the dereplication process by serving as a "seed" (Fox Ramos et al, 2017;Yang et al, 2013). However, it should be noted that application of molecular networking is not strictly dependent on databases or reference compounds (Yang et al, 2013).…”

Clerodane furanoditerpenoids as the probable cause of toxic hepatitis induced by Tinospora crispa

“…A targeted analysis of MS/MS data was facilitated by introducing a molecular networking approach in the data analysis workflow. MN is becoming one of the most efficient tools for the analysis of untargeted MS/MS data, allowing dereplication of complex extracts and exploration of molecular diversity 21 . We have showed here that MN is also valuable for targeted metabolite fingerprinting.…”

Innovative omics-based approaches for prioritisation and targeted isolation of natural products – new strategies for drug discovery

“…As an example, the efficiency of MNs combined with MS/MS searches through a restricted spectral library of monoterpene indole alkaloids for novel NP prioritisation has been demonstrated in the investigation of Apocynaceae species Geissospermum laeve. 34 The quality and completeness of public or commercial MS/ MS DBs are however still lacking with regard to the total number of NPs described to date. This is why in silico fragmentation tools that allow for a match between experimental and predicted spectra are increasingly used.…”