Source Of Secondary Metabolites Research Articles

Evaluation of the Protoscolicidal Activity of Humulus lupulus Methanolic Extracts on Echinococcus granulosus Sensu Stricto.

The larval stage of the parasite Echinococcus granulosus sensu lato (s.l) is responsible for cystic echinococcosis (CE), a long-term infection affecting humans and animals worldwide, and constitutes a serious public health concern. If left untreated, CE can cause serious damage to multiple organs, especially the liver and lungs. Regarding the treatment, in the last few years, the use of pharmacological treatment has increased, suggesting that in the future, drug therapy may replace surgery for uncomplicated cysts. However, the only available anthelmintic drug to treat this infection is the albendazole, which has an efficacy that does not exceed 50%. On the basis of the above-mentioned evidence, new and improved alternative treatments are urgently needed. The use of natural products and their active fractions and components holds great promise as a valuable resource for the development of novel and effective therapies. Hop (Humulus lupulus L.) is a bittering agent in the brewing industry for which the sedative, digestive, anti-inflammatory, and antimicrobial effects have been reported. The purpose of this study was to assess the in vitro efficacy of methanolic extracts from the leaves of hop varieties against E. granulosus sensu stricto (s.s) protoscoleces. Varieties Mapuche and Victoria caused a stronger protoscolicidal effect compared to the Bullion, Cascade, and Traful varieties (P < 0.01), coinciding with their highest content of flavonoids, total polyphenols, and saponins. The viability of protoscoleces treated with the varieties Mapuche and Victoria decreased to approximately 50% at days 5 y 8, respectively, showing alterations such as soma contraction and impaired microtriches. After 18 days of treatment with both varieties, protoscoleces were completely altered both structurally and ultrastructurally. In conclusion, the methanolic extracts of the H. lupulus varieties Mapuche and Victoria demonstrated a marked in vitro effect against E. granulosus s.s. protoscoleces. The beer-making industry exclusively uses hop cones, leaving behind large amounts of hop leaves as an agricultural by-product that is not being utilized. On the basis of our study, we propose that hop leaves could also be used as a source of secondary metabolites with anthelmintic activity.

Secondary Metabolites from Symbiotic Bacteria of Seagrass and Molluscs as A Reference for Natural Food Preservatives

Symbiotic bacteria from seagrass and molluscs have the potential to be a source of secondary metabolites. Compounds from these secondary metabolites, such as natural food preservatives, can be used in the bioindustry sector. This research aims to identify the potential secondary metabolites from symbiotic bacteria in molluscs and seagrass that can support the Sustainable Development Goals (SDG) public health program. The samples used in this study were symbiotic bacteria of mollusc from seagrass environments, symbiotic bacteria from seagrass, and seagrass samples. The seagrass samples were analysed phytochemically, while the symbiotic bacteria samples from molluscs and seagrass were tested for their antibacterial activity against food spoilage pathogens such as Staphylococcus aureus and Escherichia coli using the disc diffusion method. Bacteria that showed potential antibacterial activity were identified using molecular methods, and the content of active compounds was analysed using gas chromatography-mass spectrometry. The phytochemical analysis revealed that seagrass contains flavones, tannins, steroids, and compounds with potential antibacterial properties. GC-MS analysis indicated that seagrass is predominantly composed of unsaturated fatty acids, which have antimicrobial effects by damaging bacterial cell membranes and disrupting the function of enzymes essential for growth and reproduction. Ten symbiotic bacteria isolates demonstrated proteolytic, cellulolytic, and lipolytic enzyme activity, suggesting their potential as antibacterial agents due to their ability to break down cell walls. Molecular identification of selected bacteria revealed the presence of mollusc symbionts, including Vibrio owensii, Bacillus paramycoides, and Pseudoalteromonas flavipulchra. The symbiotic bacteria found in seagrass in this study included Bacillus velezensis, Bacillus paramycoides, Nocardiopsis alba, Nocardiopsis alba, Bacillus tropicus, Lysinibacillus fusiformis, and Bacillus tropicus. GC-MS analysis of selected symbiotic bacteria from seagrass showed that the dominant compound components were phthalic acid, bis(7-methyl octyl) ester (25.18, 43.84, 35.55 %), and trimethoxy-3-piperidyl-2,2'-binaphthalene-1,1',4,4'-tetrone (36.36, 47.71, 64.48 %). In conclusion, seagrass and its symbiotic bacteria, as well as symbiotic bacteria from molluscs living in seagrass, have the potential to serve as antibacterial agents and can be used as references for food preservatives. HIGHLIGHTS Seagrass and mollusc symbiotic bacteria produce secondary metabolites that have antimicrobial properties, making them suitable for food preservation The component that acts as an antibacterial agent is found in seagrass: Essential fatty acids, which can have antibacterial properties Symbiotic bacteria are microorganisms that live in mutualistic symbiosis with other organisms. The enzymatic activities of symbiotic bacteria can involve the production of enzymes that break down complex molecules into simpler molecules In food preservation, symbiotic bacteria, with their enzymatic activity, can be used as natural preservatives Using natural food preservatives derived from seagrass and mollusc symbiotic bacteria can contribute to a more sustainable and environmentally friendly approach to food preservation GRAPHICAL ABSTRACT

The Precious Potential of the Sacred Tree Chamaecyparis obtusa (Siebold & Zucc.) Endl. as a Source of Secondary Metabolites with Broad Biological Applications.

Chamaecyparis obtusa (Siebold & Zucc.) Endl., which belongs to the Cupressaceae family, occurs naturally in North America and Asia, especially in Korea, Taiwan and Japan, where it is an evergreen, coniferous, sacred, ethnic tree. It has many useful varieties that are widespread throughout the world and grown for decorative purposes. It is most commonly used as an ornamental plant in homes, gardens or parks. It is also widely used in many areas of the economy; for example, its wood is used in architecture as well as furniture production. In addition, oil extracted from Chamaecyparis obtusa is increasingly used in cosmetology for skin care. Due to its wide economic demand, mainly in Japan, it represents the largest area of plantation forest. Despite this, it is on the red list of endangered species. Its use in ethnopharmacology has led to more and more research in recent years in an attempt to elucidate the potential mechanisms of its various biological activities, such as antimicrobial, antioxidant, anticancer, antidiabetic, antiasthmatic, anti-inflammatory, antiallergic, analgesic and central nervous system effects. It has also been shown that Chamaecyparis obtusa can be used as an insect repellent and an ingredient in plant disease treatment. This thesis provides a comprehensive review of the biological studies to date, looking at different areas of the economic fields of potential use of Chamaecyparis obtusa.

The difference in leaves production, protein and calcium of Moringa oleifera under modification planting media, application of PGR and nitrogen

Moringa has many ingredients of nutrients that are beneficial for food sources and nutrients that have not been widely cultivated. The nutritional content, benefits and high demand for Moringa abroad will open large opportunities for exporting Moringa flour. Foods full of nutrition will support the maintenance of good public health. For this reason, it is necessary to study and research cultivation techniques that produce high Moringa leaves and can be available sustainably. Production of Moringa leaves as a source of secondary metabolites can be increased by modifying the planting media and applying Plant Growth Regulator (PGR) and Nitrogen. The study used Split Split Plot Design with the main plot immersion by PGR, consisting of 3 types, namely: G1 (Fresh water), G2 (Coconut water), and G3 (GA3). The subplot was the treatment of planting media with two types: M₁ (soil: sand: manure = 1:1:2); M₂ (soil: sand: manure = 1:2:1). The sub subplots were N (urea) fertilizer, with four levels: N0 (0 g/plant); N1 (5 g/plant); N₂ (10 g/plant); and N₃ (15 g/plant). Each treatment combination goes over three times. The agronomic parameters observed were plant height, the number of leaves, fresh crop weight, and root volume, and the biochemical parameters observed were chlorophyll, protein, and calcium levels. The composition of the planting media caused significant differences in plant height at 4, 6, and 10 weeks after planting (WAP), the number of leaves at 4 WAP, and root length at 10 WAP. Growth Regulators significantly affected plant height at 4, 6, and 10 WAP, the number of leaves at 4 WAP, and root length at harvest. Nitrogen fertilization caused significant differences in plant height at 4, 6, and 10 WAP, volume, and root length at harvest (10 WAP). The combination of Planting media, PGR, and Nitrogen treatments caused significant differences in plant height at 4, 6, and 10 WAP and the number of leaves at 6 WAP. Laboratory analysis in this study showed high calcium and protein in Moringa leaves.

Antibacterial activity of faloak (Sterculia quadrifida) leaves extract

Abstract. Purwantiningsih TI, Widyobroto BP, Suranindyah YY, Artama WT. 2023. Antibacterial activity of faloak (Sterculia quadrifida) leaves extract. Biodiversitas 24: 6613-6620. Restrictions on the use of antibiotics have made people start looking for alternatives to antibiotics, one of which is ingredients that come from nature. Faloak (Sterculia quadrifida R. Br) leaves are a source of secondary metabolites that have not been widely utilized. The aim of this study was to assess the antibacterial activity of faloak leaves extract in inhibiting Staphylococcus aureus (gram-positive bacteria) and Escherichia coli (gram-negative bacteria). Powdered faloak leaves were macerated with 96% ethanol solvent. After obtaining the crude extract, it was fractionated using the liquid-liquid method using methanol, hexane, distilled water and ethyl acetate as solvents. The crude extract of faloak leaves was then dissolved into several concentrations. The crude extract of faloak leaves and the fractions obtained were tested for antibacterial activity in vitro using the Kirby Bauer method against Staphylococcus aureus and Escherichia coli. The most active fraction in inhibiting the tested bacteria was then screened for bioactive compounds using instrument LC-HRMS. The results showed that faloak leaves extract and its fractions were able to inhibit Staphylococcus aureus and Escherichia coli bacteria. The ethyl acetate fraction was the most active fraction in inhibiting bacteria and the most occurring bioactive compounds appeared in LC-HRMS testing were luteolin, rutin and corchorifatty acid. The total flavonoid compound in the crude extract was 227.281 QE µg/mL and the highest i.e. 351.456 QE µg/mL total flavonoid compound was in methanol fraction.

In vitro cultivation of Vismia japurensis: Isolation of the new anthrone 1,8,10-trihydroxy-3,10-dimethyl-9(10H)-anthracenone.

Vismia japurensis Reichardt is a plant of ecological and chemical importance from which a variety of bioactive substances have been isolated. The current study aimed to establish in vitro cultures of this species as a source of secondary metabolites. Appropriate decontamination treatments and germination tests were performed and, after in vitro culture establishment, the propagated plants were multiplied in a sterile environment to increase the biomass of available experimental material. Seeds showed low contamination and a high germination percentage on Woody Plant Medium (WPM) supplemented with gibberellic acid (both at concentrations of 5 and 10 mg/L). V. japurensis nodal segments rapidly regenerated when first grown in WPM and then transplanted to Murashige and Skoog medium (MS). After 60 days in MS medium, the propagated plants were removed, lyophilized, and extracted with hexane and methanol. The hexane extract was fractionated via open column chromatography, and the substance isolated was purified by high performance liquid chromatography. Structural determination of the isolated substance was carried out using one and two-dimensional nuclear magnetic resonance and mass spectrometry. The isolated substance was identified as 1,8,10-trihydroxy-3,10-dimethyl-9(10H)-anthracenone, which, based on the conducted literature search, is reported for the first time.

Stages of Development and Solvents Determine the Anticancer Potential of Mountain Arnica (Arnica montana L.) Inflorescence Extracts

In recent years, new sources of secondary metabolites (SMs) in medicinal plants have been identified, and the introduction of these plants into field conditions has been carried out to obtain chemically diverse standardized raw material (RM). An example is mountain arnica Arnica montana L., one of Europe’s endemic endangered medicinal plant species, commonly used in pharmacy, cosmetics, and medicine. Its inflorescences (Arnicae flos) are characterized by anti-inflammatory, antiradical, antioxidant, antibacterial, antifungal, and antitumor properties. The main goals of the present research included: (i) characterization of the chemical composition of the inflorescences of A. montana harvested in different development stages; and (ii) presentation of the role of the development stage and different extraction methods in the antitumor activity of extracts through analyses of apoptosis, autophagy, and necrosis induction in human cervical carcinoma HeLa, human colon carcinoma HT29, and human colon metastatic carcinoma SW620 cell lines. The development stage was found to modify the composition of pharmacologically active substances, e.g., sesquiterpene lactones (SLs), flavonoids (Fs), and essential oil (EO), in arnica inflorescences. The content of Fs and EO increased during flowering to the full flowering phase; however, the highest content of SLs was noted in the full flowering phase and at the end of flowering. More promising results, i.e., a relatively high level of apoptosis and a low level of necrosis induced by the arnica extracts, were demonstrated in the HeLa cell line (full flowering; concentration: 0.5 µL/mL), the HT29 cell line (beginning of flowering; concentration: 0.5 µL/mL), and the SW620 cell line (stage of yellow buds; concentration: 1 µL/mL). This extremely valuable medicinal plant species provides a very broad range of RMs (e.g., inflorescences, rhizomes, roots, achenes, and all plant); therefore, attention should be paid to the more frequent use of water as a solvent in studies on the biological activity of mountain arnica extracts.

Antioxidant, α-glucosidase inhibitory, and cytotoxic activities of Mangifera rufocostata extract and identification of its compounds by LC-MS/MS analysis

Mangifera rufocostata, a member of the Mangifera genus, is a source of secondary metabolites and has been used traditionally as antidiabetic agent. Therefore, this study aims to determine the total flavonoid contens (TFC), total phenolic contents (TPC), antioxidant, α-glucosidase inhibitory, and cytotoxic activities of M. rufocostata stem bark extract. Antioxidant activity were evaluated by 2-2″-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH), and ferric reducing-antioxidant power (FRAP) tests. α-glucosidase inhibitory to prediction antidiabetic activity, and cytotoxic activity were studied against HT-29, HeLa, and MCF-7 cancer cell lines. The results showed that the methanol extract have the highest TFC, TPC, antioxidant, and α-glucosidase inhibitory activity. Furthermore, the methanol extract has strong cytotoxicity againts HT-29 cancer cells. Based on LC-MS/MS, the methanol extract contain several major compounds such as mangiferin, quinic acid, gallic acid, and 3-methoxy-4-hydroxy-phenyl glycol.

Total phenols and flavonoids in germinated barley using different solvents.

Sprouts are a source of secondary metabolites as phenolic compounds. Germination and the use of solvents can affect their content. The aim of this work was to identify the total content of phenols and flavonoids in ungerminated and germinated (3, 5, and 7 days) Esmeralda and Perla barley. Different solvents (water, 50% acetone, 80% methanol, 80% ethanol) were used to recover total phenols and flavonoids. The 7-day germination proved to be ideal for total phenol and flavonoid obtention from Esmeralda barley and the highest total phenol and flavonoid content in Perla variety was observed at 5 and 7 days of germination, respectively. Methanol and ethanol (80%) yielded the highest extraction percentage of total phenols; 50% acetone recovered the highest flavonoid concentrations in Esmeralda barley and 80% methanol in Perla barley. The highest total phenol concentration was obtained from Perla samples at 13.60 mg GAE/g, and the highest total flavonoids were observed in Esmeralda barley at 1.73 mg QE/g. A high correlation was found between the concentration of phenols (0.995) and total flavonoids (0.780) with the radicle size in the Esmeralda samples.

Antioxidant and Antiproliferative Activities of Phenolic Extracts of Eriobotrya japonica (Thunb.) Lindl. Fruits and Leaves.

Increasing interest in new sources of secondary metabolites as biologically active substances has resulted in an advanced study of many plant species. Loquat (Eriobotrya japonica (Thunb.) Lindl. = Rhaphiolepis bibas (Lour.) Galasso & Banfi, Rosaceae family), an evergreen, subtropical fruit tree, native to China and Japan, but cultivated in southern countries of Europe, is a species commonly used in folk medicine and may be an excellent source of bioactive compounds. Therefore, the aim of the present study was to evaluate the profile of the phenolic constituents of E. japonica fruits and leaves originating from Tuscany (Italy), as well as their in vitro antioxidant and chemopreventive activities on human cancer cell lines breast adenocarcinoma (MCF-7), colon adenocarcinoma (Caco-2 and HT-29), and glioblastoma (U87MG). Results revealed that the extract of leaves displayed higher antioxidant and anticancer potential than the fruit extract and contained 25 individual phenolic compounds that have been characterized and quantified by the UPLC-PDA-MS method. The antiproliferative activity was correlated with the content of polyphenolic compounds indicating that both fruits and leaves are a good source of antioxidants and may be exploited as nutraceuticals enriching food or as components for the cosmetic/pharmaceutical industry.

Biological Potential of Carnivorous Plants from Nepenthales.

Since Charles Darwin and his book carnivorous plants have aroused interest and heated debate. In addition, there is growing interest in this group of plants as a source of secondary metabolites and in the application of their biological activity. The aim of this study was to trace the recent literature in search of the application of extracts obtained from families Droseraceae, Nepenthaceae, and Drosophyllaceae to show their biological potential. The data collected in the review clearly indicate that the studied Nepenthales species have great biological potential in terms of antibacterial, antifungal, antioxidant, anti-inflammatory, and anticancer use. We proposed that further investigations should include: (i) bioactivity-guided investigations of crude plant extract to connect a particular type of action with a specific compound or a group of metabolites; (ii) a search for new bioactive properties of carnivorous plants; (iii) establishment of molecular mechanisms associated with specific activity. Furthermore, further research should be extended to include less explored species, i.e., Drosophyllum lusitanicum and especially Aldrovanda vesiculosa.

Dulxanthone A from Ethyl Acetate Extract of Garcinia nigrolineata Stem Bark

The genus Garcinia is the largest genus of the Guttiferae family which is widely distributed in tropical and subtropical regions. There are 64 species of Garcinia in Indonesia, one of which is Garcinia nigrolineata known as “Kandis keling". This plant is reported as a source of secondary metabolites like xanthones. Xanthones are known to have interesting activities, such as anti-oxidant, anti-inflammatory, cytotoxic and antibacterial. This study aims to isolate xanthone compounds from stem bark of G. nigrolineata and determine their structures by using various spectroscopic methods. Samples were macerated with ethyl acetate. The ethyl acetate extract was then separated and purified by chromatographic method to obtain pure C6e isolates. The C6e isolates were characterized using UV, IR, 1HNMR, 13C-NMR, HMQC, 1H-1H COSY, HMBC and mass spectroscopy methods. The C6e isolates obtained were in the form of yellow oil as much as 5.6 mg. Based on the results of structural elucidation, the C6e isolates were xanthone compounds with the molecular formula of C19H18O6, namely dulxanthone A.

Short Communication: Analysis of rhizome color and phytochemical content of 10 accessions of Curcuma zanthorrhiza Roxb. in Jambi, Indonesia

Abstract. Minarni M, Asyhar R, Juliana D, Yudha YS, Nurcholis W. 2023. Short Communication: Analysis of rhizome color and phytochemical content of 10 accessions of Curcuma zanthorrhiza Roxb. in Jambi, Indonesia. Biodiversitas 24: 149-155. Plants are a source of secondary metabolites that have various biological functions and are beneficial for humans, particularly in the health sector. One such beneficial herbal plant, temulawak (Curcuma zanthorrhiza Roxb.), a member of the genus Curcuma L. in the Zingiberaceae family, is widely known as Javanese turmeric. C. zanthorrhiza is a potential source of drugs in the field of pharmacology. One part of temulawak that has an important role is the rhizome, commonly used in the formulation of traditional herbal medicines. There are many pharmacologically active components contained in the C. zanthorrhiza rhizome. Thus, this plant, found in many parts of Indonesia, such as Jambi and Sumatra, is worthy of detailed pharmacological investigation. The study reported in this paper aimed to determine the potential content of secondary metabolites of alkaloids, flavonoids, saponins, tannins/phenolics, and triterpenoids/steroids in 10 accessions of temulawak rhizomes in Jambi. The phytochemical content analysis in temulawak was carried out by qualitative phytochemical screening using dye reagents. Multivariate cluster analysis was carried out to determine the relationships between the 10 accessions based on similarities in the color and phytochemical content of their rhizomes. Generally, the screening results showed that the rhizomes of the 10 C. zanthorrhiza accessions contained the same intensities of alkaloids (dragendof, mayer and wagner), flavonoids, tannins/phenolics (+++) and steroid compounds (++). On the other hand, saponin and triterpenoid were not detected in the tests of rhizomes of the 10 accessions (-). The clustering analysis of the results divided the 10 local temulawak accessions into three clusters. Cluster-1 consisted of two accessions (JM and JBB), cluster-2 consisted of three accessions (JT, JPB, and JBS), and cluster-3 consisted of five accessions (JSS, JJ, JB, JBE, and JG).

The endophytic Fusarium strains: a treasure trove of natural products.

The complexity and structural diversity of the secondary metabolites produced by endophytes make them an attractive source of natural products with novel structures that can help in treating life-changing diseases. The genus Fusarium is one of the most abundant endophytic fungal genera, comprising about 70 species characterized by extraordinary discrepancy in terms of genetics and ability to grow on a wide range of substrates, affecting not only their biology and interaction with their surrounding organisms, but also their secondary metabolism. Members of the genus Fusarium are a source of secondary metabolites with structural and chemical diversity and reported to exhibit diverse pharmacological activities. This comprehensive review focuses on the secondary metabolites isolated from different endophytic Fusarium species along with their various biological activities, reported in the period from April 1999 to April 2022.

Assessment of metabolic, mineral, and cytotoxic profile in pineapple leaves of different commercial varieties: A new eco-friendly and inexpensive source of bioactive compounds

Pineapple is among the most produced and consumed fruits worldwide, and consequently, its agroindustrial production/processing generates high amounts of agricultural waste, which are routinely discarded. Thus, it is crucial to seek alternatives to reuse this agricultural waste that are in high availability. Therefore, this work aims to evaluate the chemical composition of a specific residue (leaves) of seven commercial varieties of pineapples, to attribute high added value uses, and to evaluate its potential as a source of secondary metabolites and minerals. Thereby, twenty-eight metabolites were annotated by UPLC-QTOF-MSE, including amino acids, organic acids, and phenolic compounds. The following minerals were quantitatively assessed by ICP-OES: Zn (5.30–19.77 mg kg−1), Cr, Cd, Mn (50.80–113.98 mg kg−1), Cu (1.05–4.01 mg kg−1), P (1030.77–6163.63 mg kg−1) and Fe (9.06–70.17 mg kg−1). In addition, Cr and Cd (toxic materials) present concentration levels below the limit of quantification of the analytical method (LOQCr and LOQCd = 0.02 mg kg−1) for all samples. The multivariate analysis was conceived from the chemical profile, through the tools of PCA (principal component analysis) and HCA (hierarchical cluster analysis). The results show that pineapple leaves have similarities and differences concerning their chemical composition. In addition, the cytotoxicity assays of the extracts against tumor and non-tumor strains shows that the extracts were non-toxic. This fact can corroborate and enhance the prospection of new uses and applications of agroindustrial co-products from pineapple, enabling the evaluation and use in different types of industries, such as pharmacological, cosmetic, and food, in addition to the possibility of being a potential source of bioactive compounds.

Endophytic Fungi as a Source of Antibacterial Compounds-A Focus on Gram-Negative Bacteria.

Bacterial resistance has become one of the main motives in the worldwide race for undescribed antibacterial agents. The difficulties in the treatment of bacterial infections are a public health issue that increasingly highlights the need for antimicrobial agents. Endophytic microorganisms are a promising alternative in the search for drugs, due to the vast number of metabolites produced with unique characteristics and bioactive potential. This review highlights the importance of endophytic microorganisms as a source of secondary metabolites in the search for active molecules against bacteria of medical importance, with a special focus on gram-negative species. This fact is supported by the findings raised in this review, which brings an arsenal of 166 molecules with characterized chemical structures and their antibacterial activities. In addition, the low cost, ease of maintenance, and optimization-controlled fermentation conditions favor reproducibility in commercial scale. Given their importance, it is necessary to intensify the search for new molecules from endophytic microorganisms, and to increasingly invest in this very promising font.

Marine-Derived Compounds Targeting Topoisomerase II in Cancer Cells: A Review.

Cancer affects more than 19 million people and is the second leading cause of death in the world. One of the principal strategies used in cancer therapy is the inhibition of topoisomerase II, involved in the survival of cells. Side effects and adverse reactions limit the use of topoisomerase II inhibitors; hence, research is focused on discovering novel compounds that can inhibit topoisomerase II and have a safer toxicological profile. Marine organisms are a source of secondary metabolites with different pharmacological properties including anticancer activity. The objective of this review is to present and discuss the pharmacological potential of marine-derived compounds whose antitumor activity is mediated by topoisomerase II inhibition. Several compounds derived from sponges, fungi, bacteria, ascidians, and other marine sources have been demonstrated to inhibit topoisomerase II. However, some studies only report docking interactions, whereas others do not fully explain the mechanisms of topoisomerase II inhibition. Further in vitro and in vivo studies are needed, as well as a careful toxicological profile evaluation with a focus on cancer cell selectivity.

Antibiofilm activity of secondary metabolites of sponge-associated bacterium Alcanivorax sp. from the Red Sea

Sponge-associated bacteria are a well-known source of unique and diverse natural products with potential biological activities. In this study, a rarely occurring sponge-associated bacterium from the genus Alcanivorax was isolated from the sponge Siphonochalina siphonella and subjected to extraction of metabolites. Metabolites were extracted from the culture supernatant and biomass of the bacterium using the solvent extraction method. Extracts were evaluated for antibacterial and antibiofilm activities against five different biofilm-forming bacteria isolated from the microfouling assemblage. The crude extracts were subjected to chemical profiling to identify their composition using gas chromatography-coupled mass spectrometry (GC-MS). The results obtained show mild to strong antibacterial activity of the extracts against the biofilm-forming bacteria with the minimum inhibitory concentration (MIC) of 3.125 mg ml-1. The percentage inhibition of biofilm formation ranged from 46% to 71%. Compounds detected in GC-MS analysis are mostly fatty acids and their derivatives that include compounds with known antibiofilm activity such as tetradecanoic acid, dodecanoic acid, and hexadecanol from the culture supernatant extract. Eicosane; hexadecanoic acid, methyl ester; and hexadecanoic acid, ethyl ester were detected from the biomass extract. Molecular docking analysis of the compounds from the bacterial extracts confirms their potential antibiofilm properties. The result indicated that Alcanivorax sp. associated with the sponge possess relevant antibiofilm activity and may serve as a novel source of secondary metabolites with the application as antibiofilm agents.

Ultra-high-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flightmass spectrometryand molecular networking analysis to investigate the chemodiversity of bioactive extracts of Annona jahnii Saff. fungi from the Brazilian Amazon.

Annona species are of interest for the isolation of bioactive molecules; however, studies of Annona jahnii Saff. are limited. The exploration of bioactive metabolites of endophytes isolated from this species is unprecedented and allows the preservation of the host plant, in addition to enabling the discovery of compounds with promising biological activities. Ethyl acetate extracts from the cultured media of five fungi were obtained. The antioxidant capacity of the extracts was measured using the 1,1-diphenyl-2-picrylhydrazyl free radical method. Antimicrobial activity was determined using the microdilution method in broth in 96-well plates. The exploration of the metabolic profile of the extracts and dereplication of the compounds were performed using ultra-high-performance liquid chromatography/electrospray ionization/tandem mass spectrometry (UHPLC/ESI-MS/MS) combined with analysis using molecular networking (MN). A total of 1818 MS features were detected in the five selected extracts, of which 39 compounds were putatively identified. The secondary metabolites with the highest abundance were alkaloids, naphthopyrons, and cytochalasins. Other secondary metabolites include fumonisins, coumarin, and a meroterpenoid. Most of these compounds are related to specific biological properties such as antioxidant, anti-inflammatory, antimicrobial, antiviral, and antitumor activities. Extracts F398 and F403 showed inhibitory activity of the four pathogens tested. Extracts F475 and F506 did not inhibit the growth of Staphylococcus aureus, and F407 did not inhibit the growth of Escherichia coli in addition to having potent antioxidant activity, with IC50 values of 10μg/mL or less. The use of UHPLC/ESI-MS/MS data combined with MN proved useful in the dereplication of bioactive molecules of complex extracts that are still unexplored. These initial investigations should significantly assist in further research and increase the efficiency and speed in the discovery of new sources of secondary metabolites and new natural products.

Hydroponics and elicitation, a combined approach to enhance the production of designer secondary medicinal metabolites in Silybum marianum.

Medicinal plants have been used to cure human diseases since decades. Silybum marianum, a medicinal plant, is regarded as a source of secondary metabolites with therapeutic value against liver diseases and diabetes. The present study was conducted to enrich the production of secondary metabolites in the vegetative parts of Silybum marianum using elicitation strategy in hydroponic system with different elicitors. The elicitors of fungus Aspergillus niger (0.2 g/L), methyl jasmonate (MeJA) (100 μM) and silver nanoparticles (AgNPs) (1 ppm) were added in hydroponic medium, individually and in combination form to the 15 days old plant. The elicitor-treated plants were harvested at different time points (24–144 h; increment 24 h) and their biochemical parameters like phenolics, flavonoids, nitric oxide (NO), and superoxide dismutase (SOD) were analyzed. The results showed hyper-accumulation of these biochemical contents, especially in response to MeJA (100 μM), followed by AgNPs (1 ppm) and co-treatment of AgNPs (1 ppm) with other elicitors. The results revealed that the treatment with MeJA (100 μM) exhibited the highest flavonoid (304 μg g–1), phenolic (372 μg g–1), and SOD (16.2 U g–1) contents. For NO levels, the maximum value of 198.6 nmole g–1 was achieved in response to the treatment with MeJA + Green synthesized AgNPs (100 μM + 1 ppm). Our findings depicted an enhanced production of medicinally important plant secondary metabolites and antioxidants; hence, the method applied in this study can play a significant role to improve therapeutic values of the plants.