Non-Polar Natural Products from Bromelia laciniosa, Neoglaziovia variegata and Encholirium spectabile (Bromeliaceae)

Biodiverse food plants in the semiarid region of Brazil have unknown potential: A systematic review

Food biodiversity presents one of the most significant opportunities to enhance food and nutrition security today. The lack of data on many plants, however, limits our understanding of their potential and the possibility of building a research agenda focused on them. Our objective with this systematic review was to identify biodiverse food plants occurring in the Caatinga biome, Brazil, strategic for the promotion of food and nutrition security. We selected studies from the following databases: Web of Science, Medline/PubMed (via the National Library of Medicine), Scopus and Embrapa Agricultural Research Databases (BDPA). Eligible were original articles, published since 2008, studying food plants occurring in the Caatinga. We assessed the methodological quality of the studies we selected. We reviewed a total of fifteen studies in which 65 plants that met our inclusion criteria were mentioned. Of this amount, 17 species, including varieties, subspecies, and different parts of plants, had data on chemical composition, in addition to being mentioned as food consumed by rural communities in observational ethnobotanical studies. From the energy and protein data associated with these plants, we produced a ranking of strategic species. The plants with values higher than the average of the set were: Dioclea grandiflora Mart. ex Benth (mucunã), Hymenaea courbaril L. (jatobá), Syagrus cearensis Noblick (coco-catolé), Libidibia ferrea (Mart. ex Tul.) L.P.Queiroz (jucá), Sideroxylon obtusifolium (Roem. & Schult.) T.D.Penn. (quixabeira). We suggest that the scientific community concentrates research efforts on tree legumes, due to their resilience and physiological, nutritional, and culinary qualities.

Phytochemical analysis and biological activities of in vitro cultured Nidularium procerum, a bromeliad vulnerable to extinction

This study reports the first phytochemical and biological characterization in treatment of adrenocortical carcinoma cells (H295R) of extracts from Nidularium procerum, an endemic bromeliad of Atlantic Forest vulnerable to extinction. Extracts of dry leaves obtained from in vitro-grown plants were recovered by different extraction methods, viz., hexanoic, ethanolic, and hot and cold aqueous. Chromatography-based metabolite profiling and chemical reaction methods revealed the presence of flavonoids, steroids, lipids, vitamins, among other antioxidant and antitumor biomolecules. Eicosanoic and tricosanoic acids, α-Tocopherol (vitamin E) and scutellarein were, for the first time, described in the Nidularium group. Ethanolic and aqueous extracts contained the highest phenolic content (107.3 mg of GAE.100 g-1) and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging activity, respectively. The immunomodulatory and antitumoral activities of aqueous extracts were assessed using specific tests of murine macrophages modulation (RAW 264.7) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay against adrenocortical carcinoma cell line, respectively. The aqueous extract improved cell adhesion and phagocytic activities and phagolysossomal formation of murine macrophages. This constitutes new data on the Bromeliaceae family, which should be better exploited to the production of new phytomedicines for pharmacological uses.

Hechtia glomerata Zucc: Phytochemistry and Activity of Its Extracts and Major Constituents Against Resistant Bacteria

Hechtia glomerata Zucc. is used both as a source of food and in ethnomedicine to treat various diseases derived from bacterial infections such as bronchitis, laryngitis, nephritis, whooping cough, urethritis, and sepsis. There are no previous reports about its chemistry and biological activities. Therefore, the aims of this study were to identify components from organic and aqueous extracts of H. glomerata and test the extracts and major isolate compounds against resistant bacteria. Hexane, CHCl₃/MeOH, and aqueous extracts were prepared and analyzed by different chromatographic techniques. Structural elucidation was carried out by NMR spectroscopy and X-ray diffraction. The antibacterial activities of extracts, phytochemicals, and semisynthetic derivatives against resistant bacteria were determined by the broth micro-dilution method. From the hexane extract nonacosane (1), hexatriacontanyl stearate (2), hexacosanol (3), oleic acid (4), and β-sitosterol (5) were isolated and characterized. From the CHCl₃/MeOH extract, p-coumaric acid (6), margaric acid (7), caffeic acid (8), daucosterol (9), and potassium chloride (10) were isolated and characterized. A total of 58 volatile compounds were identified by GC-MS from the hexane extract and two solids were isolated from the CHCl₃/MeOH extract. The UPLC-QTOF-MS analysis of the aqueous extract allowed the identification of 55 polar compounds. Hexane and aqueous extracts showed antibacterial activity against ESBL Escherichia coli, and three strains of Klebsiella pneumoniae ESBL, NDM-1 +, and OXA-48 with MIC values of 500 µg/mL. The CHCl₃/MeOH extract was devoid of activity. The activity of phytocompounds and their semisynthetic derivatives toward resistant bacteria was weak. The most active compound was β-sitosterol acetate, with a MIC value of 100 µg/mL against carbapenem-resistant A. baumannii. This is the first report of the secondary metabolites of H. glomerata Zucc. and the activity of its extracts and major pure compounds against resistant bacterial strains.

Ecosystem services provided by bromeliad plants: A systematic review

The unprecedented loss of biological diversity has negative impacts on ecosystems and the associated benefits which they provide to humans. Bromeliads have high diversity throughout the Neotropics, but they have been negatively affected by habitat loss and fragmentation, climate change, invasive species, and commercialization for ornamental purpose. These plants provide direct benefits to the human society, and they also form microecosystems in which accumulated water and nutrients support the communities of aquatic and terrestrial species, thus maintaining local diversity. We performed a systematic review of the contribution of bromeliads to ecosystem services across their native geographical distribution. We showed that bromeliads provide a range of ecosystem services such as maintenance of biodiversity, community structure, nutrient cycling, and the provisioning of food and water. Moreover, bromeliads can regulate the spread of diseases, and water and carbon cycling, and they have the potential to become important sources of chemical and pharmaceutical products. The majority of this research was performed in Brazil, but future research from other Neotropical countries with a high diversity of bromeliads would fill the current knowledge gaps and increase the generality of these findings. This systematic review identified that future research should focus on provisioning, regulating, and cultural services that have been currently overlooked. This would enhance our understanding of how bromeliad diversity contributes to human welfare, and the negative consequences that loss of bromeliad plants can have on communities of other species and the healthy functioning of the entire ecosystems.

A novel poly-oxygenated flavone glucoside from aerial parts of the Brazilian plant Neoglaziovia variegata (Bromeliaceae)

Neoglaziovia variegata is endemic to northeastern Brazil. The drought resistant plant produces edible fruits and is used as a fibre plant by rural communities in the Caatinga region where a variety of products are made from the white, soft and flexible fibres. Extracts of N. variegata have been reported to be of low toxicity and to exhibit antinociceptive effect, photoprotective potential, antioxidant effect, gastroprotective effects and antibacterial effect against both Gram-positive and Gram-negative bacteria, however, the chemical constituents of this species are mainly unknown. The novel poly-oxygenated flavone glucoside 5,6,7,4'-tetrahydroxy-3',5'-dimethoxy-flavone 7-O-β-glucopyranoside in addition to the rare poly-oxygenated flavone 5,4'-dihydroxy-6,7,3'-trimethoxyflavone 4'-O-β-glucopyranoside and the flavonol quercetin 3-O-(6''-rhamnopyranosyl-β-glucopyranoside) have been characterised from the leaves of N. variegata. 5,6,7,4'-tetrahydroxy-3',5'-dimethoxy-flavone, which comprises the core structure of the novel compound, is a new flavonoid aglycone in nature. The structure determinations were based on extensive use of 2D NMR spectroscopic techniques and high-resolution mass spectrometry. Both substances exhibited toxicity towards MOLM-13 acute myeloid leukaemia cells.