Chemical Profile of Ocotea delicata (Lauraceae) Using Ultra High-Performance Liquid Chromatography-High-Resolution Mass Spectrometry-Global Natural Products Social Molecular Networking Workflow.

Ocotea, the largest genus in the Lauraceae family, encompasses numerous species of scientific interest. However, most Ocotea species have only been described morphologically. This study used an untargeted metabolomics workflow with UHPLC-HRMS and GNPS-FBMN to provide the first chemical evaluation of the polar specialized metabolites of O. delicata leaves. Leaves from three O. delicata specimens were extracted using ultrasound-assisted extraction with 70% ethanol. Among the examined samples, 44 metabolites, including alkaloids and flavonoids, were identified. In contrast to other Ocotea species, O. delicata has a wider diversity of kaempferol derivatives than quercetin. The biomass of the specimens showed a significant correlation with the chemical profile. The similarity among specimens was mostly determined by the concentrations of quinic acid, kaempferol glycosides, and boldine. The evaluated specimens exhibited chemical features similar to those of species classified as New World Ocotea, with the coexistence of aporphine and benzylisoquinoline alkaloids.

Chemophenetic study of Ocotea canaliculata (Lauraceae) by UHPLC-HRMS and GNPS.

The metabolic fingerprint of a non-volatile fraction of Ocotea canaliculata (Rich.) Mez (Lauraceae) leaves was determined by UHPLC-HRMS analysis. Twenty-four compounds were suggestively identified by GNPS-FBMN. The results revealed a large production of flavonoids, mainly flavones and flavanones, a chemical class poorly described in the Ocotea genus. Within the identified compounds, four are being described for the first time in this genus. The major metabolite detected was astilbin, with a concentration corresponding to 23.2 ± 1.58% of the extracts. The expressive content of astilbin also highlights it as a chemical marker for the species. As a species that is classified as a complex, qualitative and semi-quantitative features obtained through the O. canaliculata flavonoid fingerprint can be further used for a more precise circumscription and species-specific characterization.

Chemosystematic evaluation of Amazonian freshwater sponges.

Freshwater sponges can be considered a promising new source of bioactive compounds for the pharmaceutical industry; however, the research on their chemical composition is still in the incipient stage. We evaluated the most endemic Amazonian freshwater sponge species from the Drulia and Metania genera by untargeted metabolomic approaches, based on UHPCL-HRMS, in order to identify chemical markers and explore the diversity of specialized metabolites. The use of untargeted approaches allowed us to observe subsets of metabolites that enabled the characterization of, not only each genus, but also, of each species. Freshwater sponge species presented themselves as rich sources of fatty acids and sterols, which were putatively identified. These metabolites were suggested as chemical markers for further targeted metabolomic studies.

UHPLC-HRMS/MS on untargeted metabolomics: a case study with Copaifera (Fabaceae).

Untargeted metabolomics is a powerful tool in chemical fingerprinting. It can be applied in phytochemistry to aid species identification, systematic studies and quality control of bioproducts. This approach aims to produce as much chemical information as possible, without focusing on any specific chemical class, thus, requiring extensive chemometric effort. This study aimed to evaluate the feasibly of an untargeted metabolomics method in phytochemistry by a study case of the Copaifera genus (Fabaceae). This genus contains significant medicinal species used worldwidely. Copaifera exploitation issues include a lack of chemical data, ambiguous species identification methods and absence of quality control for its bioproducts. Different organs of five Copaifera species were analysed by UHPLC-HRMS/MS, GNPS platform and chemometric tools. Untargeted metabolomics enabled the identification of 19 chemical markers and 29 metabolites, distinguishing each sample by species, plant organs, and biome type. Chemical markers were classified as flavonoids, terpenoids and condensed tannins. The applied method provided reliable information about species chemodiversity using fast workflow with little sampling size. The untargeted approach by UHPLC-HRMS/MS proved to be a promising tool for species identification, pharmacological prospecting and in the future for the quality control of extracts used in the manufacture of bioproducts.

Ocotea complex: A metabolomic analysis of a Lauraceae genus.

The genus Ocotea is one of the largest and most economically explored in the Lauraceae family. However, its current industrial use is limited by the difficult identification of Ocotea species. At present, the genus is botanically considered a complex since accurate classification is very difficult to achieve based on taxonomic characteristics. As chemophenetics can aid in Ocotea species identification processes, we propose to evaluate the chemical data in several studies of Lauraceae species published between 1906 and 2019 in order to provide insights of the identification issue of matrix which DNA material or full morphological characteristics may not be readily available. Several alkaloids and lignoids have been found to be specifically synthesized by Ocotea species, enabling their usage in species identification by targeted and untargeted metabolomic approaches. The multivariate analysis of alkaloid, lignoid and flavonoid profiles allowed the characterization of subsets of species, the differentiation of chemical profile based on plant parts (leaves and branches), and to elucidate specific biomarkers for species. The previous chemophenetic model was contradicted by our data using statistical tools, such as HCPC, which allowed clustering adjustments based not only in the presence or absence of two single chemical classes. Chemophenetic study has proved to be a reliable tool in the enhancement of the identification and comprehension of this genus and the family. Here, the current status, pitfalls and future perspectives in Ocotea species metabolomic characterization will be presented.

Phytochemistry by design: a case study of the chemical composition of Ocotea guianensis optimized extracts focused on untargeted metabolomics analysis.

Untargeted metabolomics aim to provide a global chemical fingerprint of biological matrices. This research field can be used in phytochemical screenings for bioactive species or in the identification of species. Despite its importance in providing a global chemical profile, little research has focused on the optimization of the extraction methods, as each type of matrix requires a specific procedure. Therefore, we propose to evaluate the effect of different extraction features in an ultrasound-assisted extraction for the untargeted metabolomic study of an Ocotea species, a genus of great economical interest but little chemical exploitation. Method optimization was performed in a full factorial 2232 design, evaluating the solvent composition, extraction temperature, sample particle size and sample : solvent ratio effects in the metabolomic response. The effect of these parameters on the quality of the untargeted metabolomic profiles was studied by analysis of the extraction yield as well as the chromatographic and spectrometric profiles. Most substances identified were glycosylated flavonoids and aporphinic alkaloids. The application of 70% ethanol enhanced the extraction of several specialized metabolites. Statistical analysis of extraction yield and chemical profiles indicates that high temperatures and low proportion between sample and extracting solvent reduce the quality and modify the chemical profile, both qualitatively and quantitatively. The use of 70% ethanol as the extracting solvent, 1 : 12 sample : solvent ratio, 40 °C as the extraction temperature and particle size of 0.595 mm were the optimized conditions to produce a comprehensive chemical profile for Ocotea guianensis.

Natural products' role against COVID-19.

COVID-19 is a viral disease caused by a new severe acute respiratory syndrome (SARS-CoV-2), which has quickly resulted in a pandemic. As a great threat to global public health, the development of a treatment has become vital, and a rush to find a cure has mobilized researchers from all areas across the world. Synthetic drugs, such as hydroxychloroquine, have gained attention. However, the efficacy of repositioned drugs is still under evaluation, and besides, some severe side effects are a cause for concern. This emphasizes the urgency for treatment options, which can be both safe and effective. With this in mind, natural products could be an important resource in the development of COVID-19 treatment, as they have already contributed in the past to treatments against other viruses, such as HIV, MERS-CoV, and influenza. Natural products are described long term as bioactive substances and some phytochemical classes such as flavonoids, alkaloids, and peptides are known antiviral bioproducts, and have been virtually tested with success against COVID-19. However, important issues still need to be addressed as to their bioavailability and true efficacy in vivo. This review intends to systematically evaluate the natural metabolites that could potentially be used against this new disease looking at their natural sources, mechanism of action and previous pharmacological usages. The aim is to provide a starting point for this research area in order to speed up the establishment of anti-SARS-CoV-2 bioproducts.