Bacterial Carotenoids: Extraction, Characterization, and Applications.

Natural carotenoids are secondary metabolites that exhibit antioxidant, anti-inflammatory, and anti-cancer properties. These types of compounds are highly demanded by pharmaceutical, cosmetic, nutraceutical, and food industries, leading to the search for new natural sources of carotenoids. In recent years, the production of carotenoids from bacteria has become of great interest for industrial applications. In addition to carotenoids with C40-skeletons, some bacteria have the ability to synthesize characteristic carotenoids with C30-skeletons. In this regard, a great variety of methodologies for the extraction and identification of bacterial carotenoids has been reported and this is the first review that condenses most of this information. To understand the diversity of carotenoids from bacteria, we present their biosynthetic origin in order to focus on the methodologies employed in their extraction and characterization. Special emphasis has been made on high-performance liquid chromatography-mass spectrometry (HPLC-MS) for the analysis and identification of bacterial carotenoids. We end up this review showing their potential commercial use. This review is proposed as a guide for the identification of these metabolites, which are frequently reported in new bacteria strains.

Metabolite Profiling of Soy By-Products: A Comprehensive Approach.

Soy is the major oilseed crop as soybeans are widely used to produce biofuel, food, and feed. Other parts of the plant are left on the ground after harvest. The accumulation of such by-products on the soil can cause environmental problems. This work presents for the first time a comprehensive metabolite profiling of soy by-products collected directly from the ground just after mechanical harvesting. A two-liquid-phase extraction using n-heptane and EtOH-H2O 7:3 (v/v) provided extracts with complete characterization by gas chromatography and ultra-high-performance liquid chromatography both coupled to time-of-flight mass spectrometry. A total of 146 metabolites, including flavones, flavonols, isoflavonoids, fatty acids, steroids, mono-, sesqui-, di-, and triterpenoids, were tentatively identified in soy by-products and soybeans. These proved to be sources of a wide range of bioactive metabolites, thus suggesting that they could be valorized while reducing potential environmental damage in line with a circular economy model.

Comparison of different extraction methods of Brazilian "pacová" (Renealmia petasites Gagnep.) oilseeds for the determination of lipid and terpene composition, antioxidant capacity, and inhibitory effect on neurodegenerative enzymes.

Pacová (Renealmia petasites Gagnep.) is a Brazilian native plant, usually cultivated in south regions of the country. Pacová was previously reported concerning their possible health benefits, mostly from folk medicine. However, only few works relates the health benefits with the composition of the fruit parts. In this context, this work aimed to bring, for the first time in literature, the chemical characterization in respect to lipid and terpene composition of R. petasites oilseed, performed by three different extraction methods (supercritical fluid extraction (SFE) with CO2, Soxhlet with petroleum ether (SOX), and maceration with hexane (MAC)). SFE was most selective for MUFAs, PUFAs, sesqui- and diterpenes. The main terpene identified in all extracts was 2-carene. The extracts presented poor AChE inhibition, and SOX presented potential inhibitory effect against lipoxygenase activity. Overall, R. petasites oilseed is a natural source of terpenes and their potential health benefits are highly encouraged to be investigated.

Selective Extraction of Piceatannol from Passiflora edulis by-Products: Application of HSPs Strategy and Inhibition of Neurodegenerative Enzymes.

Passiflora edulis by-products (PFBP) are a rich source of polyphenols, of which piceatannol has gained special attention recently. However, there are few studies involving environmentally safe methods for obtaining extracts rich in piceatannol. This work aimed to concentrate piceatannol from defatted PFBP (d-PFBP) by means of pressurized liquid extraction (PLE) and conventional extraction, using the bio-based solvents selected with the Hansen solubility parameters approach. The relative energy distance (Ra) between solvent and solute was: Benzyl Alcohol (BnOH) < Ethyl Acetate (EtOAc) < Ethanol (EtOH) < EtOH:H2O. Nonetheless, EtOH presented the best selectivity for piceatannol. Multi-cycle PLE at 110 °C was able to concentrate piceatannol 2.4 times more than conventional extraction. PLE exhibited a dependence on kinetic parameters and temperature, which could be associated with hydrogen bonding forces and the dielectric constant of the solvents. The acetylcholinesterase (AChE) and lipoxygenase (LOX) IC50 were 29.420 µg/mL and 27.682 µg/mL, respectively. The results reinforce the demand for processes to concentrate natural extracts from food by-products.

Metabolite Profiling of Rosemary Cell Lines with Antiproliferative Potential against Human HT-29 Colon Cancer Cells.

Rosemary (Rosmarinus officinalis) is a culinary and medicinal plant used in food and pharmaceutical industry. The wide range of biological activities is mainly related to phenolic and terpenic compounds; like carnosic acid (CA), carnosol (CS) and rosmarinic acid (RA), mainly reported in rosemary leaf extracts, and recently described in rosemary callus extracts. The aim of this work was to investigate the chemical profile of rosemary cell lines and evaluate their antiproliferative potential against human HT-29 colorectal cancer cell lines. For this purpose, rosemary leaf explants were dedifferentiated on MS medium and added with 2, 4-D (2, 4-dichlorophenoxyacetic acid; 2 mg/L) and BAP (6-benzylaminopurine; 2 mg/L). Cell aggregates were separated according to colour and three rosemary cell lines cultures were established: green (RoG), yellow (RoY) and white (RoW). The chemical profile of rosemary cell lines extracts was characterized by combining HPLC and GC platforms coupled to HR-MS/MS. The antiproliferative activity against HT-29 cell line was analyzed with MTT assay. A total of 71 compounds, including hydroxycinnamic acid and hydroxybenzoic acid derivatives, flavonoids, phenolic di- and triterpenes, as well as relevant unsaturated fatty acids and their esters, phytosterols, and carotenoids were tentatively identified in the extract of the target cell lines. The antiproliferative activity test against HT-29 cell using the MTT assay revealed that the viability of HT-29 colon cancer cells was affected after treatment with the RoW extract (IC50 of 49.63 µg/mL) at 48 h. These results showed that rosemary cell lines can also accumulate other bioactive phytochemicals with demonstrated antiproliferative potential.

Green microsaponification-based method for gas chromatography determination of sterol and squalene in cyanobacterial biomass.

Sterol analysis of complex matrices can be very laborious. To minimize the existing drawbacks, a new micro-method of sterols and squalene determination in cyanobacteria was developed and applied to monitor their production of Phormidium autumnale cultured heterotrophically. Sample extraction/saponification and GC analysis of the target compounds were optimized separately using Plackett-Burman design (PB) followed by a central composite rotational design (CCRD). The most influential variables were identified to maximize compound recovery. Chloroform presented the highest capability to extract all target compounds with a horizontal shaker table (HST) for homogenization in the saponification step. For the pretreatment, a small amount of chloroform was used for 90 min at 50 °C and 6 min for the saponification time. The sample introduction in the GC injector was studied by evaluating pressure and injector temperature. High response for sterols and squalene were obtained between 19 and 23 psi and at 310 °C of injection temperature. The new method was able to determine different sterol concentrations: 0.2-0.6 mg kg-1 of squalene, 5-18 mg kg-1 of stigmasterol, 6 mg kg-1 of cholesterol, and 3 mg kg-1 of ß-sitosterol, showing high analytical performance and fulfilling all steps, thus proving to be a promising technique.

Compressed fluids and phytochemical profiling tools to obtain and characterize antiviral and anti-inflammatory compounds from natural sources.

Many natural compounds, found mainly in plants, are associated with the treatment of various diseases. The search for natural therapeutic agents includes compounds with antiviral and anti-inflammatory activities. Among the many steps involved in bioprospection, extraction is the first and most critical step for obtaining bioactive compounds. One of the main advantages of using compressed fluids extraction is the high quality of the final product obtained due to the use of green solvents, while the selectivity towards target compounds can be tuned by adjusting the process parameters, especially pressure, temperature and solvent characteristics. In this review, a discussion is provided on the power of compressed fluids, such as supercritical fluid extraction (SFE), pressurized liquid extraction (PLE) and subcritical water extraction (SWE) to obtain antiviral and anti-inflammatory compounds from natural sources. In addition, an adequate knowledge about the identity and quantity of the compounds present in the extract is essential to correlate biological activity with chemical composition. Phytochemical profiling tools used for identification and quantification of these bioactive natural compound are also discussed. It can be anticipated that after the current SARS-COV-2 pandemic, the search of new natural compounds with antiviral and anti-inflammatory activity will be a hot research topic, so, this review provides an overview on the technologies currently used that could help this research.

Foodomics evaluation of the anti-proliferative potential of Passiflora mollissima seeds.

The anti-proliferative potential of Passiflora mollissima seeds, an underexplored agri-food waste, was investigated in this work by evaluating the molecular changes induced at transcript and metabolite expression levels on HT-29 human colon cancer cells. For this purpose, a pressurized-liquid extract from P. mollissima seeds obtained under optimized conditions was used for the treatment of HT-29 cells and a multi-omics strategy applied, integrating transcriptomics and metabolomics analysis, along with viability and cell cycle assays to study the molecular mechanisms that explain the anti-proliferative activity of this fruit by-product. After treatment for 48 and 72 h, the viability of HT-29 colon cancer cells was markedly affected, whereas minor effects were observed on normal human colon fibroblast cells. The bioactive extract was shown to arrest HT-29 cells in the S and G2/M phases of the cell cycle, which might be mediated by the inactivation of the FAT10 cancer signalling pathway among other genes identified as altered in the transcriptomic analysis. In addition, cellular redox homeostasis, as well as the polyamines pathway and methionine metabolism were found to be affected as suggested from the metabolomics data. Finally, the Foodomics integration enabled the identification of genes, such as MAD2L1, involved in the polyamine and glutathione metabolism, or the inactivation of the NUPR1 transcription factor, that might be related with the alteration of the intracellular ceramide levels in response to endoplasmic reticulum stress.

Insight of Stability of Procyanidins in Free and Liposomal Form under an in Vitro Digestion Model: Study of Bioaccessibility, Kinetic Release Profile, Degradation, and Antioxidant Activity.

Small unilamellar and multilayered liposomes loaded with polymeric (epi)catechins up to pentamers were produced. The bioaccessibility, kinetic release profile, and degradation under in vitro gastrointestinal conditions were monitored by UHPLC-DAD-QTOF-MS/MS. The results show that all of the procyanidins underwent depolymerization and epimerization into small molecular oligomers and mainly to (epi)catechin subunits. Moreover, all of the liposome formulations presented higher bioaccessibility and antioxidant activity in comparison to their respective counterparts in non-encapsulated form. Similar results were obtained with procyanidins from cocoa extract-loaded liposomes. Namely, the bioaccessibility of dimer, trimer, and tetramer fractions from cocoa-loaded liposomes were 4.5-, 2.1-, and 9.3-fold higher than those from the non-encapsulated cocoa extract. Overall, the procyanidin release profile was dependent on their chemical structure and physicochemical interaction with the lipid carrier. These results confirmed that liposomes are efficient carriers to stabilize and transport procyanidins with the aim of enhancing their bioaccessibility at a controlled release rate.