Antibacterial activity of mycelial extract from a local fungus, Sclerotium rolfsii

The search for bioactive natural compounds, traditionally focused on terrestrial environments, has increasingly expanded to the seas and oceans, opening new frontiers for exploration. Among the diverse organisms inhabiting these ecosystems, marine phanerogams have emerged as a promising source of health-promoting bioactive compounds. This review highlights the distinctive chemical diversity of seagrasses including species such as Posidonia oceanica, Zostera marina, and Cymodocea nodosa, among others, and focusses on the growing interest in natural therapies as alternatives to conventional pharmaceuticals. Compounds such as polysaccharides or secondary metabolites such as polyphenol and flavonoids produced by marine plants exhibit a broad range of beneficial properties, including anti-inflammatory, antibacterial, antioxidant, and antidiabetic qualities. This review describes how these compounds can mitigate inflammation, promote skin health, and combat oxidative stress. Moreover, certain marine extracts have demonstrated potential to inhibit cancer cell growth and improve metabolic disorders like obesity and diabetes. The manuscript also discusses the potential of marine plant extracts in the development of novel therapeutic agents to address various illnesses, including infections, chronic diseases, and metabolic disorders. It emphasizes the need for further research to fully elucidate the mechanisms underlying the activity of these bioactive compounds and their potential therapeutic applications. In summary, this study highlights marine plants as a valuable reservoir for identifying organic molecules, paving the way for innovative advancements in medical and healthcare interventions.

Curcuma soloensis is one of the medicinal plants that has the potential to be a source of bioactive compounds. The antimicrobial study of the bioactive compounds from C. soloensis was still limited. This study aimed to isolate the bioactive compounds from C. soloensis rhizomes and to evaluate their potential as antimicrobial agents. C. soloensis rhizome extraction was done using the maceration method with acetone and then fractionated with n-hexane: methanol (1:1). The compounds were separated and purified using vacuum liquid chromatography and radial chromatography. The structure of the isolated compounds was determined using the nuclear magnetic resonance (1H and 13C NMR) spectroscopy analysis and comparison with literature data. Antimicrobial activity assays of the extract, n-hexane fraction, and isolated compounds were carried out by microdilution methods against Escherichia coli, Staphylococcus aureus, Candida albicans, and Malaszezia furfur. Two bioactive compounds from the n-hexane extract of C. soloensis rhizome have been isolated: ar-curcumene and ar-turmerone. Antimicrobial test results on acetone extract, n-hexane fraction, and isolated compounds showed that ar-turmerone had the highest activity against S. aureus with a MIC value of 15.6 μg / mL. In comparison, ar-curcumene showed the same activity against all test microbes with a MIC value of 62.5 μg / mL. This study showed that secondary metabolite compounds of C. soloensis rhizomes have the potential to be developed as antimicrobial agents.

Potatoes are a valuable source of diverse bioactive compounds, including phenolics. In recent years, red- and purple-fleshed cultivars have garnered increasing scientific interest due to their higher content of phenolic compounds. The aim of this study was to evaluate the impact of 60%, 80%, and 100% methanol concentrations on the extraction of bioactive phenolic compounds from three red- and purple-fleshed potato cultivars. The qualitative and quantitative composition of phenolic compounds, the total anthocyanin content, as well as antioxidant activity in the prepared potato extracts were investigated. The results showed that the contents of the tested compounds and antioxidant activity in potato tuber methanolic extracts varied depending on the cultivar and methanol concentration. The potato extract obtained by 60% and 80% methanol showed the significantly highest contents of total phenolics (TPs) and total phenolic acids (TPAs). ‘Violet Queen’ extracts with 60% and 80% methanol had the significantly highest contents of TP, TPA, and caffeic acid. The significantly highest contents of p-coumaric acid were observed in ‘Mulberry Beauty’ extracts using 60% and 80% methanol. The significantly highest contents of epicatechin and quercetin were found in ‘Violet Queen’ extracts with 80% methanol, while the highest contents of myricetin, m-coumaric, and o-coumaric acids as well as the highest antioxidant activity were recorded in ‘Violet Queen’ extracts with 60% methanol.

The production of bioactive compounds/secondary metabolites by endophytes is believed to be directly linked to the evolution of the host plant. Conventionally, plants were considered to be the only source of bioactive compounds, but now, the endophytic microbes associated with plants are also reported to produce a variety of bioactive metabolites. Once these endophytes are isolated from the plant and characterized, they can serve as an admirable source of novel bioactive compounds. In addition to these applications, endophytes are useful in developing a sustainable environment, improving crop productivity, enhancing plant growth, and increasing biotic and abiotic stress tolerance in host plants. Endophytes synthesize bioactive compounds that are of biotechnological interest, including the production of pharmaceutical drugs and enzymes. Endophytes are a less investigated group of microorganisms that have the ability to synthesize bioactive compounds and have a variety of applications.

Juncaceae species as sources of innovative bioactive compounds for the food industry: In vitro antioxidant activity, neuroprotective properties and in silico studies

Fruit peels are agroindustrial co-products that can be employed as a source of dietary fiber and bioactive compounds with an effect on the physicochemical and structural characteristics of cooked meat products. The potential of these fruit peels as a functional ingredient in cooked meat products was evaluated. Yield, moisture, expressible moisture, oxidative rancidity and textural profile analysis, besides electron scanning microscopy, were determined in cooked sausages inoculated with thermotolerant lactic acid bacteria. Cactus pear peen flour increased the moisture in the sausages, but in inoculated sausages, lower expressible moisture was observed, resulting in harder but less cohesive and less resilient structure. Cactus pear peel flour decreased the oxidative rancidity during storage. Microstructure analysis showed that the production of exopolysaccharides by the employed strain could explain the differences in the texture results. The use of fruit peels as a source of bioactive compounds (fiber, antioxidants and prebiotic) enhanced the development of thermotolerant lactic acid bacteria in cooked sausages during storage. Practical Applications Fruit peels become an environmental issue due first to the large volume that is generated during their process, generating large amount of organic matter. These co-products are a cheap source of bioactive compounds, such as fiber, prebiotics and antioxidants. In this research, cactus pear peel flour and pineapple peel flour were employed as a functional extensor in cooked meat sausages, inoculated with thermotolerant lactic acid bacteria, in order to promote the development of a symbiotic cooked meat product. Fiber content in both types of flour increased water retention, decreasing oxidative rancidity as well. The use of these types of flour in the inoculated sausages led to changes in textural properties, which could be due to the growth of thermotolerant lactic acid bacteria during storage. In this view, fruit peels could be employed as a source of bioactive compounds (fiber and antioxidants) that can enhance the development of beneficial bacteria after and before processing, such as thermotolerant lactic acid bacteria.

Evaluation of broccoli (Brassica oleracea var. italica) crop by-products as sources of bioactive compounds

This study presents the first report on phenolic composition and bioactivity of ethanolic extracts of three plant species that grow in the western Balkan mountains and are used in traditional folk medicine: Valeriana montana, Salix retusa, and Campanula hercegovina. Phenolics were extracted from different aerial plant parts using 80% ethanol to assess the possibility of sustainable use of these plants as a source of bioactive compounds without disruption to the roots (for V. montana) or destruction of whole habitats (for S. retusa and C. hercegovina). The ethanolic extract of V. montana flower contained noticeable levels of apigenin and quercetin. The branches and bark of S. retusa were significantly rich in catechin, while rutin was the major phenolic found in the leaf extract of C. hercegovina. Furthermore, the flower extract of V. montana revealed the best antioxidant activity, which was comparable to 4-hydroxybenzoic acid and quercetin. Considering antimicrobial activity, the leaf extracts of V. montana and C. hercegovina demonstrated potent activity against all microbes tested, while the extracts of S. retusa were moderately effective. The presented results emphasize the potential of these plants as novel sources of bioactive compounds.

Chapter 11 - Edible flowers as a source of bioactive compounds

Brewer's spent grain (BSG) is one of the main by-products of beer industry, little used because of its high moisture making it difficult to transport and store. Mainly used as animal feed and for energy production, the agro-industrial waste have recently attracted attention as source of bioactive compounds, with potential applications in many sectors as food, nutraceutical, pharmaceutical, cosmetic, food packaging. The present work focuses on BSG as potential source of valuable small-size bioactive compounds. Laboratory-made BSG was obtained by using four base malts for mashing. After drying, BSG was eco-friendly extracted with water and the extracts analyzed by untargeted ElectroSpray Ionization (ESI)-Mass Spectrometry (MS)/Mass Spectrometry (MS) (ESI-MS/MS) infusion experiments and by targeted High Performance Liquid Chromatography-PhotoDiodeArray-ElectroSpray Ionization-Mass Spectrometry (HPLC-PDA-ESI-MS) in Selected Ion Recording (SIR) mode analysis, to investigate the metabolic profile, the phenolic profile, the individual phenolic content, and tryptophan content. Aqueous extracts of malts and wort samples were also analyzed for a comparison. Data were statistically analyzed by ANOVA test. An explorative analysis based on Principal Component Analysis (PCA) was also carried out on malts, wort and threshes, in order to study correlation among samples and between samples and variables. The untargeted ESI-MS/MS infusion experiments provided the mass spectral fingerprint of BSG, evidencing amino acids (γ-aminobutyric acid, proline, valine, threonine, leucine/isoleucine, lysine, histidine, phenylalanine and arginine) and organic and inorganic acids (pyruvic, lactic, phosphoric, valerianic, malonic, 2-furoic, malic, citric and gluconic acids), besides sugars. γ-Aminobutyric acid and lactic acid resulted predominant among the others. The targeted HPLC-PDA-ESI-MS in SIR mode analysis provided the phenolic profile of the polar fraction of BSG, evidenced tryptophan as the main residual metabolite in BSG (62.33-75.35 μg/g dry BSG), and catechin (1.13-4.24 μg/g dry BSG) as the representative phenolic antioxidant of not pre-treated BSG samples. The chemometric analysis of the individual compounds content in BSG, malt and wort evidenced similarities and differences among the samples. As main goal, the phytochemical characterization of BSG from base malts highlighted BSG as a potential source of small biomolecules, as tryptophan and catechin, besides γ-aminobutyric acid and lactic acid, opening to new perspectives of application for BSG. Strategies for their recovery are a future challenge. Moreover, ESI-MS/MS analysis was confirmed as a powerful tool for fast characterization of complex matrix. Last, results obtained by chemometric elaboration of data demonstrated the possibility to monitor a small number of molecules to ensure the quality of a final product.

Every year, the viticulture activity generates considerable amounts of underused lignocellulosic residues as grape cane, which are generally composted or burned despite their potential value as a source of bioactive compounds. Determination of their phytochemical composition and total antioxidant capacity (TAC) may be a useful way of exploiting different high-added value applications. Twenty-one phenolic compounds (PC) and two carotenoids (Car) were quantified by high performance-liquid chromatography-diode array detection in eight grape varieties from different locations in Mendoza, Argentina. The maximum concentrations corresponded to the stilbene ϵ-viniferin [10 552 μg g-1 dry weight (DW)], followed by the flavanols (+)-catechin (3718 μg g-1 DW) and (-)-epicatechin (2486 μg g-1 DW). In addition, lutein and β-carotene were quantified at levels ranging between 350 and 2400 ng g-1 DW. The TAC of the extracts was assessed by oxygen radical absorbance capacity, 2,20-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid and 1,1-diphenyl-2-picrylhydrazyl assays, with a good correlation between TAC and total PC for each sample (r ≥ 0.82). Samples of cv. Malbec, the most representative variety of Argentina's winemaking industry, presented high contents of PC, particularly ϵ-viniferin, (+)-catechin and (-)-epicatechin. Quercetin-3-galactoside, OH-tyrosol and Car were reported for the first time in grape canes of the eight varieties. The results add to the existing knowledge related to this inexpensive source of high-value bioactive compounds, which could be used as functional ingredients. © 2019 Society of Chemical Industry.

Turbinaria sp. is one of the species of the brown algae class that has extraordinary prospects for human health. The potential of the brown algae makes it a target for the search for sources of beneficial bioactive compounds in the pharmaceutical world. However, a serious problem in the development of bioactive compounds from these biotas is the problem of supply, because to obtain a relatively small number of active compounds requires a large number of marine organisms. It was reported that there are associations of microorganisms with brown algae which are thought to synthesize secondary metabolites such as the host organism. The presence of bacteria that is symbiotic with brown algae has made it possible to use these organisms as the main source of bioactive compounds from the marine. KRT-7 isolate is a pink bacterial isolate from the Turbinaria sp. collected from Menjangan Kecil, Karimunjawa Island, Indonesia. This isolate has been known to produce bio pigment and genes coding for its bioactive compounds. However, the physiological morpho character and its molecular identity are unknown. The study aims to determine the morphophysiological character and molecular identification of the prospective isolates. The research results obtained will contribute a scientific finding of the prospect of genetic diversity of Indonesian marine bacterial isolates and their corridor utilization as a source of bioactive compounds.

Quinoa (Chenopodium quinoa Willd) is a source of nutrients and bioactive compounds with potential to promote intestinal health. Nine quinoa cultivars produced in the State of Washington and one produced in Peru were assessed for their content of non‐digestible bioactive compounds and their stability to cooking using standard analytical methods. We further investigated the prebiotic activity of a cherry vanilla (CV) cultivar with probiotic pills containing Lactobacillus gasseri, Bifidobacterium bifidum and Bifidobacterium longum. Results of extractable phenolics ranged from 1.48 to 2.42 mg/g for the Temuko and CV cultivars and the non‐extractable phenolics ranged from 1.37 to 3.23 mg/g for the Peru and Black cultivars, respectively. A principal component analysis (PCA) showed that the content of bioactive compounds was similar among quinoa cultivars with the exception of Blanca due to its high phytate content. Phenolics and antioxidant activities were more stable in CV and Faro cultivars after cooking, while non‐digestible compounds remained constant only in the CV cultivar. Growth of probiotics was observed in the CV cultivar (1.2‐fold of starch control) and this was accompanied by a decrease in extractable and non‐extractable phenolics by 44.6% and 21.4%, respectively. Overall, these results suggest the potential of quinoa cultivars for intestinal health. We are currently investigating the modulation of gut microflora by CV quinoa consumption using a murine in vivo model for obesity.

Umbu, a common fruit from the northeastern region of Brazil, contains many bioactive compounds not yet exploited. Thus, this study evaluated the potential of pulps and peels of mature and semi-mature umbu as a source of bioactive compounds. Trigonelline contents ranged from 1.75 to 6.14 mg/100 g, values higher than those of many vegetables described in the literature, such as corn and barley. The contents of extractable and non-extractable phenolic compounds were also higher than those of other vegetables. Bioaccessibility of total extractable phenolics, flavonoids, and tannins was determined (15.67–37.73%, 31.87–39.10% and 18.81–114.27%, respectively). The constituent polysaccharides of the pulp and peel were tentatively chemically characterized as arabinoxylans, arabinogalactans, rhamnoarabinogalactans, xyloglucans, and pectin of the rhamnogalacturonan type. The technological potential of peel flours was evaluated. The maturation advancement showed no significant changes in the technological properties of the flours, except for color and water solubility index. Results indicated excellent prospects for future research on umbu pulps and peels as potential sources of natural bioactive compounds.

Microbial natural products are specialized metabolites that are sources of many bioactive compounds including antibiotics, antifungals, antiparasitics, anticancer agents, and probes of biology. The assembly of libraries of producers of natural products has traditionally been the province of the pharmaceutical industry. This sector has gathered significant historical collections of bacteria and fungi to identify new drug leads with outstanding outcomes-upwards of 60% of drug scaffolds originate from such libraries. Despite this success, the repeated rediscovery of known compounds and the resultant diminishing chemical novelty contributed to a pivot from this source of bioactive compounds toward more tractable synthetic compounds in the drug industry. The advent of advanced mass spectrometry tools, along with rapid whole genome sequencing and in silico identification of biosynthetic gene clusters that encode the machinery necessary for the synthesis of specialized metabolites, offers the opportunity to revisit microbial natural product libraries with renewed vigor. Assembling a suitable library of microbes and extracts for screening requires the investment of resources and the development of methods that have customarily been the proprietary purview of large pharmaceutical companies. Here, we report a perspective on our efforts to assemble a library of natural product-producing microbes and the establishment of methods to extract and fractionate bioactive compounds using resources available to most academic labs. We validate the library and approach through a series of screens for antimicrobial and cytotoxic agents. This work serves as a blueprint for establishing libraries of microbial natural product producers and bioactive extract fractions suitable for screens of bioactive compounds.