PeerJ Award Winners: PSE Young Scientists Meeting 2023

Organised by the ​Phytochemical Society of Europe (PSE) and the Université Paris Cité, the PSE Young Scientists Meeting 2023 was held from June 28th to 30th at the university campus of the Faculty of Pharmacy in Paris, near the famous Jardin de Luxembourg. This international congress hosted nearly 200 experienced and young international researchers working on chemistry of natural substances with applications in several fields (Health, Agro-food and Cosmetics). The scientific program included plenary lectures, oral communications by young researchers, poster contributions and a workshop. During the three days, participants met around different innovative scientific themes related to natural products, metabolomics, genetics, biotechnology and more.

PeerJ sponsored three awards at PSE Young Scientists Meeting 2023 – two for the best poster presentations and one for the best oral presentation. We recently talked to the winners to discuss their research.

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Francesca Guzzo PhD candidate at Università degli Studi della Campania “Luigi Vanvitelli”, Italy.

Can you tell us a bit about yourself and your research interests?

I am a PhD student enrolled in a course on Biomolecular Sciences. I am in my third and final year of what I consider one of the toughest but most stimulating paths. My main objective is the isolation, spectroscopic characterization and study of new natural organic compounds from plant organisms, which may also have biological activity. In particular, my research group and I try to expand the knowledge on the bio- and chemo-diversity of plants, food and officinal; to investigate the metabolic profile and to contribute to the rational chemical design of new drugs by providing lead compounds.

What first interested you in this field of research?

The first thing that has always “animated” me in this field of research is the idea of how from an apparently harmless organism like a plant, you can actually hide a vast metabolic content, made up of compounds with particular chemical structures, which can also have biological activities. Plants are invincible organisms!

Can you briefly explain the research you presented at PSE Young Scientists Meeting 2023?

At the PSE Young Scientists Meeting, I presented part of my PhD project, namely “Terpenoid from bioactive extracts of Myrcianthes cisplatensis: Bio-guided approach as a valuable strategy in the search of antibacterial compounds”. M. cisplatensis O. Berg is a native plant to northern Argentina, southern Brazil, and Uruguay, belonged to the large family of Myrtaceae. This plant is reported to be used in traditional medicine but it is less explored from a phytochemical point of view. My work aims to study the methanolic extracts of M. cisplatensis, grown and collected in Arizona, combining antimicrobial assays and NMR analysis, trying to discover potential antimicrobial compounds. The methanolic extract was evaluated for its antimicrobial potential against two strains of Staphylococcus aureus: ATCC 29213 and 43300 (a methicillin-resistant S. aureus strain, MRSA), exhibiting a minimal inhibitory concentration (MIC) of 64 μg/mL against both the strains. To understand the molecules responsible for antimicrobial activity, the extract was subjected to liquid-liquid separation with dichloromethane and ethyl acetate, obtaining two fractions tested for the same activity. The increasing potential antimicrobial effect showed by the dichloromethane extract (MIC of 16 μg/mL against both strains) led us to a fractionation using different chromatographic techniques in order to identify the potential component responsible of the highlighted antimicrobial properties. Tricyclic sesquiterpene, pentacyclic triterpenes, along with phologlucinol derivatives were isolated from bioactive fractions and characterize by 2D NMR analysis.

What are you next steps?

Next step is to continue investigating the other active fractions, looking for the specialized metabolite responsible for antimicrobial activity. It would also be nice to be able to schedule synergy antimicrobial tests with commonly used drugs, molecular docking analysis or chemical modifications to increase antimicrobial activity… But let’s see what time will allow me to do.

Do you have any advice for those who want to start in your field of research?

My advice is to always remain “enthusiastically curious and creative”. Scientific research is a complex world, made up of continuous study, of experiments that succeed, and others that fail. It is made of discoveries, big or small, that fill your heart first and then your mind with an invincible motivation. So, never give up, but always persevere. Be curious and if your intuition is right, it will perhaps lead you to a great discovery.

David Hozain PhD candidate at Université Paris Cité, France.

Can you tell us a bit about yourself and your research interests?

My name is David Hozain, I’m 23 and I’m currently in my first year of a PhD in pharmacognosy at the Faculty of Pharmacy in Paris. Before this doctorate, I did a bachelor’s degree in Chemistry and then a Masters’s degree in Drug Sciences, Medicinal Chemistry and Molecular Pharmacology at the Paris Cité University. Outside my research work, I play volleyball and do bodybuilding.

My research is focused on the discovery of new active molecules against diseases of global concern such as cancer or parasitic disorders (malaria, trypanosomiasis, and leishmaniasis).

What first interested you in this field of research?

I’ve always wanted to work in the health sector, with the aim of helping people. The idea of discovering new compounds that are active against diseases affecting the whole world is particularly close to my heart, as this would help to improve people’s lives. What’s more, I discovered pharmacognosy during my Master’s training thanks to my thesis supervisor, Professor Marie-Christine Lallemand, whom I’d like to thank warmly. She opened my eyes to the great potential of living organisms to discover new active compounds, given that only a small percentage of fauna and flora has been studied to date.

Can you briefly explain the research you presented at PSE Young Scientists Meeting 2023?

My results presented at the PSE Congress concern the anti-melanoma potential of guttiferones A and C isolated from Symphonia globulifera latex by centrifugal partition chromatography.

Latex of Symphonia globulifera

S. globulifera is a tropical tree mostly distributed on the American and African continents. Widely used in traditional medicine, this plant has been the subject of phytochemical studies leading to the identification of several polyprenylated polycyclic acylphloroglucinols (PPAPs). Guttiferones A and C represent more than a quarter of the secondary metabolite content of its latex. These compounds possess numerous pharmacological properties such as antiparasitic, antimicrobial, antiviral, and cytotoxic activities, conferring them a remarkable therapeutic potential. This study aimed to explore the anti-melanoma potential of the major guttiferones found in the S. globulifera latex from French Guiana. Initially, we employed centrifugal partition chromatography for the isolation of major gutiferones from a crude extract of latex. This technique allows rapid separation of large amounts of sample without using a solid stationary phase, which increases the product recovery rate and reduces the environmental impact of the purification process. Guttiferone A and C were purified with yields of 21/5 and 2.5%, respectively, in a single run. Both molecules exhibited significant cytotoxic activity against chemoresistant melanoma cells (A2058 cell line) after 72h of treatment, presenting IC50 values of 11.25 and 5.76 µM, respectively. As guttiferone C is predominant in the latex and showed a better cytotoxic activity on tumor cells than guttiferone A, semisynthesis reactions will be performed on this compound in order to improve its anti-melanoma activity.

What are you next steps?

We have used an interdisciplinary approach to valorize the secondary metabolites identified in the latex of the plant. A molecular docking study allowed us to identify analogs potentially more active than the starting molecules (Guttiferones A and C). Our aim now is to synthesize these compounds and evaluate their biological activity. For this, we will use two different strategies: 1) classical semisynthesis, using chemical catalysts; 2) biotransformation, using microorganisms capable of recognizing guttiferones and selectively transforming them into the desired products by enzymatic catalysis.

Shurooq Ismail Lecturer at An-Najah National University, Palestine.

Can you tell us a bit about yourself and your research interests?

I am a Palestinian young researcher as well as a member of the academic teaching staff at the department of Biotechnology at the Science Faculty of An-Najah National University. I accomplished my master degree studies in the plant sciences filed in Germany at Bonn University after winning one of the DAAD scholarships. Later I proceed with my PhD research activities at University of Naples Federico II in Italy. My research activity was mainly focused on the wild medicinal plants used in Palestinian folk medicine to analyze their putative chemical metabolites and reveal their bioactivity that could be applied in various biotechnological applications.

What first interested you in this field of research?

My interest in this field started from realizing the importance of analyzing natural metabolites that will enable us to understand their potential biological activates. It is a challenging field where several biotic and abiotic factors play various roles which influence the nature and the quantity of the produced metabolites, and based on that there would be several applications in medical and biotechnological fields.

Can you briefly explain the research you presented at PSE Young Scientists Meeting 2023?

I performed my research while I was A PhD Student at University of Naples Federico II and in collaboration with my home institute at An-Najah National University.

The development of multidrug resistant (MDR) microorganisms is a worrying phenomenon that requires the urgent development of effective strategies alternative to conventional antibiotics. Therefore, plants are considered as a wealthy resource of novel natural drugs considering that they had adapted and encountered diverse environmental challenges since their existence. Hence, they evolved sophisticated and effective defense mechanisms against predators, abiotic stress, and diseases. Due to these adaptive processes, plants are able to produce a massive chemical arsenal of specialized metabolites effective in combating even the most dangerous infections. Ephedra foeminea ethanolic extracts reveled potential antimicrobial activity. Thus, a bio-guided purification of its extracts was performed to isolate and identify the bioactive metabolites. The determination of antimicrobial properties was achieved by broth microdilution assays to evaluate minimal inhibitory concentration (MIC) values and by crystal violet staining and confocal laser scanning microscopy analyses (CLSM) to investigate the antibiofilm capacity of the isolated compounds. Assays were performed on a panel of three gram-positive and three gram-negative bacterial strains. Six active metabolites were identified by nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) analyses. The identification disclosed the presence of the well-known monoterpenoid phenols carvacrol and thymol as well as four acylated kaempferol glycosides. Interestingly, the compound kaempferol-3-O-α-L-(2”,4”-di-E-p-coumaroyl)-rhamnopyranoside showed strong antibacterial properties and significant antibiofilm activity against Staphylococcus aureus bacterial strains. Moreover, molecular docking analyses on this compound suggested that the antibacterial activity of the identified compound against S. aureus strains might be correlated to the inhibition of Sortase A and/or of tyrosyl tRNA synthase.

What are you next steps?

The results achieved open interesting perspectives to kaempferol-3-O-α-L-(2”,4”-di-E-p-coumaroyl)-rhamnopyranoside applicability in different areas, such as biomedical and food fields, since it could be employed in future therapeutic strategies to counteract the MDR microbes. Furthermore, it could be applied in biotechnological purposes such as food preservation and active packaging strategies.