Moringa oleifera Lam. is a fast-growing and drought-resistant tree of the Moringaceae family. The tree is known with some common names: miracle, ben oil, drumstick, horseradish or simply moringa. The plant grows in a variety of environments including harsh conditions. The plant has a high content of phytonutrients, being used as natural integrators to cure malnutrition. Phytochemical studies of plant organs showed the plant as a rich source of primary and secondary metabolites belonging to different classes of organic compounds. Pharmacological studies confirmed the use of the plant to cure several diseases and to possess nutraceutical properties. This review is aimed to contribute to the knowledge of M. oleifera by providing its plant description, phytochemistry and pharmacology.

Moringa oleifera is a traditional food crop widespread in Asiatic, African, and South American continents. The plant, able to grow in harsh conditions, shows a high nutritional value and medicinal potential evidencing cardioprotective, anti-inflammatory, antioxidant, and antimicrobial properties. The purpose of this study was the phytochemical analysis of M. oleifera and the identification of the antimicrobial compounds by combining a chemical approach with in vitro tests. The metabolite profile of M. oleifera polar and apolar extracts of leaves and seeds were investigated by using Nuclear Magnetic Resonance spectroscopy and Gas Chromatography-Mass Spectrometry. The antimicrobial activity of all of the obtained extract was evaluated against four bacterial pathogens (Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa and Salmonella enterica). The chemical analysis provided a wide set of metabolites that were identified and quantified. Moreover, apolar extracts from seeds showed a significant concentration-dependent antimicrobial activity against S. aureus and S. epidermidis, (4 mg/mL reduced the viability up to 50%) that was associated to the content of specific fatty acids. Our results remarked the advantages of an integrated approach for the identification of plant metabolites and its use in association with biological tests to recognize the compounds responsible for bioactivity without compounds purification.

Lettuce plants were grown in a greenhouse affected by the fungal pathogen Fusarium oxysporum to test the effects on plant metabolomics by different organic treatments. Three foliar application treatments were applied: a commercial compost tea made of aerobically fermented plant organic matter, a pure lyophilized microalga Artrospira platensis, commonly named spirulina, and the same microalga previously exposed during its culture to a natural uptake from medium enriched with F. oxysporum fragmented DNA (NAT). The experiment is the first attempt to observe in field conditions, the use and effects of a natural microbial library as a carrier of pathogenic fungal DNA for disease control. Untargeted NMR metabolomics and chemometrics showed that foliar organic application significantly reduced fumaric and formic acids, aromatic amino acids, and nucleosides, while increasing ethanolamine. A strong decrease in phenolic acids and an increase in citric acid and glutamine were specifically observed in the NAT treatment. It is noteworthy that the exposure of a known biostimulant microalga to fungal DNA in its culture medium was sufficient to induce detectable changes in the metabolomic profiles of the fertilized plants. These findings deserve further investigation to assess the potential relevance of the presented approach in the field of crop biostimulation and biocontrol of plant pathogens.

Ecballium elaterium, also known as squirting cucumber, is a plant which is widespread in temperate regions of Europe, Africa and Asia. The plant is considered to be one of the oldest used drugs. In the last decades, E. elaterium has been widely studied as a source of triterpene metabolites named cucurbitacins, often found as glycosylated derivatives, used by the plant as defensive agents. Such metabolites exhibit several biological activities, including cytotoxic, anti-inflammatory, and anti-cancer. Interestingly, the bioactive properties of E. elaterium extracts have been investigated in dozens of studies, especially by testing the apolar fractions, including the essential oils, extracted from leaves and fruits. The purpose of this review is to provide an overview of the chemical profile of different parts of the plants (leaves, flowers, and seeds) analyzing the methods used for structure elucidation and identification of single metabolites. The pharmacological studies on the isolated compounds are also reported, to highlight their potential as good candidates for drug discovery.

The chemical composition of Aloe vera leaves was investigated by using liquid chromatography–high-resolution tandem mass spectrometry (LC-HRMS/MS). Five A. vera samples were collected across diverse geographical origins and cultivation practices: PO (Botanical Garden of Portici, Italy), CAN (Gran Canaria, Canary Islands), CA, E, and MM (Marine Reserve of Torre Guaceto, Brindisi, Italy). Analysis of hydroalcoholic organic extracts revealed 77 organic compounds, including ubiquitous primary metabolites (i.e., sugars, amino acids, and fatty acids) and natural products (i.e., phenols and aromatics, terpenes, and anthraquinones). Principal component analysis (PCA) on the raw dataset indicated a clear separation of samples depending on their geographical origins. PO samples showed high amounts of citric acid, the anthraquinone aloe-emodin, and the alkaloids tropine and tropinone. CAN samples showed high content of malic, citramalic, citraconic, erucic, and 3-dehydroquinic acids. CAN and PO samples contained high amounts of jasmonic, quinic, and 4-methoxycinnamic acids along with aloesin, tyramine, coumarin, and saponarin. Among the Brindisi samples, MM contained high amounts of limonene and α-linolenic acid. CA, E, and MM samples presented high amounts of eritrose-4-phosphate, glucose-1-phosphate, and fructosyl valine along with ginsenoside, proline, and ascorbic acid. These findings indicate that geographical origins and cultivation practices affect to different extents the metabolite profile of A. vera plants.