Paralemnalia thyrsoides-associated fungi: phylogenetic diversity, cytotoxic potential, metabolomic profiling and docking analysis.

BACKGROUND: Cancer continues to be one of the biggest causes of death that affects human health. Chemical resistance is still a problem in conventional cancer treatments. Fortunately, numerous natural compounds originating from different microbes, including fungi, possess cytotoxic characteristics that are now well known. This study aims to investigate the anticancer prospects of five fungal strains that were cultivated and isolated from the Red Sea soft coral Paralemnalia thyrsoides. The in vitro cytotoxic potential of the ethyl acetate extracts of the different five isolates were evaluated using MTS assay against four cancer cell lines; A549, CT-26, MDA-MB-231, and U87. Metabolomics profiling of the different extracts using LC-HR-ESI-MS, besides molecular docking studies for the dereplicated compounds were performed to unveil the chemical profile and the cytotoxic mechanism of the soft coral associated fungi. RESULTS: The five isolated fungal strains were identified as Penicillium griseofulvum (RD1), Cladosporium sphaerospermum (RD2), Cladosporium liminiforme (RD3), Penicillium chrysogenum (RD4), and Epicoccum nigrum (RD5). The in vitro study showed that the ethyl acetate extract of RD4 exhibited the strongest cytotoxic potency against three cancer cell lines A549, CT-26 and MDA-MB-231 with IC50 values of 1.45 ± 8.54, 1.58 ± 6.55 and 1.39 ± 2.0 µg/mL, respectively, also, RD3 revealed selective cytotoxic potency against A549 with IC50 value of 6.99 ± 3.47 µg/mL. Docking study of 32 compounds dereplicated from the metabolomics profiling demonstrated a promising binding conformation with EGFR tyrosine kinase that resembled its co-crystallized ligand albeit with better binding energy score. CONCLUSION: Our results highlight the importance of soft coral-associated fungi as a promising source for anticancer metabolites for future drug discovery.

Targeting 3CLpro and SARS-CoV-2 RdRp by Amphimedon sp. Metabolites: A Computational Study.

Since December 2019, novel coronavirus disease 2019 (COVID-19) pandemic has caused tremendous economic loss and serious health problems worldwide. In this study, we investigated 14 natural compounds isolated from Amphimedon sp. via a molecular docking study, to examine their ability to act as anti-COVID-19 agents. Moreover, the pharmacokinetic properties of the most promising compounds were studied. The docking study showed that virtually screened compounds were effective against the new coronavirus via dual inhibition of SARS-CoV-2 RdRp and the 3CL main protease. In particular, nakinadine B (1), 20-hepacosenoic acid (11) and amphimedoside C (12) were the most promising compounds, as they demonstrated good interactions with the pockets of both enzymes. Based on the analysis of the molecular docking results, compounds 1 and 12 were selected for molecular dynamics simulation studies. Our results showed Amphimedon sp. to be a rich source for anti-COVID-19 metabolites.

Mitochondrial Targeting in an Anti-Austerity Approach Involving Bioactive Metabolites Isolated from the Marine-Derived Fungus Aspergillus sp.

The tumor microenvironment is a nutrient-deficient region that alters the cancer cell phenotype to aggravate cancer pathology. The ability of cancer cells to tolerate nutrient starvation is referred to as austerity. Compounds that preferentially target cancer cells growing under nutrient-deficient conditions are being employed in anti-austerity approaches in anticancer drug discovery. Therefore, in this study, we investigated physcion (1) and 2-(2',3-epoxy-1',3',5'-heptatrienyl)-6-hydroxy-5-(3-methyl-2-butenyl) benzaldehyde (2) obtained from a culture extract of the marine-derived fungus Aspergillus species (sp.), which were isolated from an unidentified marine sponge, as anti-austerity agents. The chemical structures of 1 and 2 were determined via spectroscopic analysis and comparison with authentic spectral data. Compounds 1 and 2 exhibited selective cytotoxicity against human pancreatic carcinoma PANC-1 cells cultured under glucose-deficient conditions, with IC50 values of 6.0 and 1.7 µM, respectively. Compound 2 showed higher selective growth-inhibitory activity (505-fold higher) under glucose-deficient conditions than under general culture conditions. Further analysis of the mechanism underlying the anti-austerity activity of compounds 1 and 2 against glucose-starved PANC-1 cells suggested that they inhibited the mitochondrial electron transport chain.

Recent Updates on Corals from Nephtheidae.

Marine natural products display a wide range of biological activities, which play a vital role in the innovation of lead compounds for the drug development. Soft corals have been ranked at the top in regard to the discovery of bioactive metabolites with potential pharmaceutical applications. Many of the isolated cembranoids revealed diverse biological activities, such as anticancer, antidiabetic and anti-osteoporosis. Likewise, sterols from soft corals exhibited interesting biological potential as anti-inflammatory, antituberculosis and anticancer. Consequently, investigating marine soft corals will definitely lead to the discovery of a large number of chemically varied secondary metabolites with countless bioactivities for possible applications in medicine and pharmaceutical industry. This review provides a complete survey of all metabolites isolated from the family Nephtheidae, from 2011 until November 2018, along with their natural sources and biological potential whenever possible.

Natural Product Potential of the Genus Nocardiopsis.

Actinomycetes are a relevant source of novel bioactive compounds. One of the pharmaceutically and biotechnologically important genera that attract natural products research is the genus Nocardiopsis, mainly for its ability to produce a wide variety of secondary metabolites accounting for its wide range of biological activities. This review covers the literature from January 2015 until February 2018 making a complete survey of all the compounds that were isolated from the genus Nocardiopsis, their biological activities, and natural sources, whenever applicable.

New Cytotoxic Cyclic Peptide from the Marine Sponge-Associated Nocardiopsis sp. UR67.

A new cyclic hexapeptide, nocardiotide A (1), together with three known compounds-tryptophan (2), kynurenic acid (3), and 4-amino-3-methoxy benzoic acid (4)-were isolated and identified from the broth culture of Nocardiopsis sp. UR67 strain associated with the marine sponge Callyspongia sp. from the Red Sea. The structure elucidation of the isolated compounds were determined based on detailed spectroscopic data including ¹D and ²D nuclear magnetic resonance (NMR) experimental analyses in combination with high resolution electrospray ionization mass spectrometry (HR-ESI-MS), while the absolute stereochemistry of all amino acids components of nocardiotide A (1) was deduced using Marfey's method. Additionally, ten known metabolites were dereplicated using HR-ESI-MS analysis. Nocardiotide A (1) displayed significant cytotoxic effects towards the murine CT26 colon carcinoma, human HeLa cervix carcinoma, and human MM.1S multiple myeloma cell lines. The results obtained revealed sponge-associated Nocardiopsis as a substantial source of lead natural products with pronounced pharmacological activities.

Bioactive Natural Products of Marine Sponges from the Genus Hyrtios.

Marine sponges are known as a rich source for novel bioactive compounds with valuable pharmacological potential. One of the most predominant sponge genera is Hyrtios, reported to have various species such as Hyrtios erectus, Hyrtios reticulatus, Hyrtios gumminae, Hyrtios communis, and Hyrtios tubulatus and a number of undescribed species. Members of the genus Hyrtios are a rich source of natural products with diverse and valuable biological activities, represented by different chemical classes including alkaloids, sesterterpenes and sesquiterpenes. This review covers the literature until June 2016, providing a complete survey of all compounds isolated from the genus Hyrtios with their corresponding biological activities whenever applicable.

Taxiphyllin 6'-O-gallate, actinidioionoside 6'-O-gallate and myricetrin 2″-O-sulfate from the leaves of Syzygium samarangense and their biological activities.

Three new compounds were isolated from a MeOH extract of the leaves of Syzygium samarangense, one new cyanogenic glucoside, taxiphyllin 6'-O-gallate (1), one new megastigmane glucoside, actinidioionoside 6'-O-gallate (2), and one new sulfated flavonoid rhamnoside, myricetrin 2″-O-sulfate (3), together with 14 known compounds, lupeol (4), demethoxymatteucinol (5), cryptostrobin (6), betulinic acid (7), ß-sitosterol glucoside (8), 2R-prunasin (9), myrciaphenone A (10), 1-feruloyl-ß-D-glucopyranoside (11), (3S,5R,6R,7E,9S)-3,5,6,9-tetrahydroxymegastigman-7-ene (12), guaijaverin (13), myricetin 4'-methyl ether 3-O-α-L-rhamnopyranoside (14), myricetrin (15), gallic acid (16) and actinidioionoside (17). The structures of the new compounds were determined through a combination of spectroscopic, HPLC and chemical analyses.

Isolation and structural characterization of phytoconstituents from leaves of Bignonia binata.

Phytochemical investigation of Bignonia binata leaves led to the isolation of three new compounds: including a glycoside of simple alcohol, namely binatoside (2), 3,4-dihydroxy-N-methyl piperidin-2-one (7), and a phenyl ethanoid glycoside, namely bignanoside C (8), alongside with five known compounds; including a glycoside of simple alcohol; (2S) propane-1,2-diol 1-O-(6-O-caffeoy1)-ß-D-glucopyranoside (1), phenyl ethanoids; leucosceptoside A (3) and plantainoside C (4), and iridoids; ipolamiide (5) and strictoloside (6). The structure of the isolated compounds was elucidated by various spectroscopic methods, including 1 D and 2 D NMR experiments, HR-ESI-MS as well as by comparison with the literature.

Ursolic acid inhibits NF-κB signaling and attenuates MMP-9/TIMP-1 in progressive osteoarthritis: a network pharmacology-based analysis.

Osteoarthritis (OA) is a degenerative joint disease, characterized by infiltration of monocytes into the synovial joint which promotes inflammation, stiffness, joint swelling, cartilage degradation and further bone destruction. The leaves of Ocimum forskolei have been used for inflammation-related disease management in traditional medicine. Additionally, the downregulation of NF-κB and the MMP/TIMP-1 ratio has been shown to protect against OA. The LC-HR-MS metabolic analysis of Ocimum yielded 19 putative compounds, among which ursolic acid (UA) was detected. Ursolic acid possesses significant anti-inflammatory effects and has been reported to downregulate oxidative stress and inflammatory biomarkers. It was tested on rats in a model of intra-articular carrageenan injection to investigate its efficacy on osteoarthritis progression. The UA emulgel exerted chondroprotective, analgesic and local anaesthetic efficacies confirmed via histopathological investigation and radiographical imaging. A network pharmacology followed by molecular docking highlighted TNF-α, TGF-ß and NF-κB as the top filtered genes. Quantitative real-time PCR analysis showed that UA significantly attenuated serum levels of TNF-α, IL-1ß, NF-κB, MMP-9/TIMP-1 and elevated levels of TGF-ß. Taken together, these results suggest that UA could serve as a functional food-derived phytochemical with a multi-targeted efficacy on progression of OA, regulating the immune and inflammatory responses, particularly, attenuating chondrocytes degeneration via suppression of NF-κB and MMP-9/TIMP-1. Accordingly, UA might be a promising alternative to conventional therapy for safe, easily applicable and effective management of OA.

Studies on the Nonalkaloidal Secondary Metabolites of Hippeastrum vittatum (L'Her.) Herb. Bulbs.

Sixteen chemically varied metabolites were isolated from the bulbs of Hippeastrum vittatum (L'Her.) Herb., including eight flavonoids [3'-methyl isoliquiritigenin (2), 7-hydroxyflavan (8), 7-hydroxyflavanone (9), 7-hydroxyflavan-3-ol (10), 7-methoxy-3',4'-methylenedioxyflavan-3-ol (11), 7-hydroxy-3',4'-methylenedioxy flavan (12), 2',4'-dihydroxy-3'-methyl-3,4-methylenedioxychalcone (13), and isoliquiritigenin (14)], four acetophenones [2,6-dimethoxy-4-hydroxyacetophenone (3), 2,4-dihydroxyacetophenone (4), 2,4-dihydroxy-6-methoxy-3-methylacetophenone (6), and 2,4,6-trimethoxyacetophenone (7)], two alkaloids [lycorine (1) and narciprimine (15)], one phenol derivative [p-nitrophenol (5)], and one steroid [ß-sitosterol 3-O-ß-glucopyranoside (16)]. Their structures were elucidated by combining one- and two-dimensional NMR and ESI-MS techniques and by comparison with the reported literature data and some authentic samples. Except for lycorine (1), the isolated metabolites were obtained herein for the first time from Hippeastrum plants, among which compound 13 was identified as a new chalcone derivative. Additionally, the total phenolic and flavonoid contents of the total ethanol extract and different fractions of the bulbs were determined by the Folin-Ciocalteu and aluminum chloride colorimetric methods, respectively, whereas their antioxidant potential was compared using the phosphomolybdenum and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assays. Finally, the binding affinities of compounds 1-16 to some key target proteins of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), namely, main protease (Mpro), papain-like protease (PLpro), and RNA-dependent RNA polymerase (RdRp), were screened and compared using molecular docking analysis. The possible chemotaxonomic significance of the identified metabolites was also discussed.

Metabolic profiling and biological potential of the marine sponge associated Nocardiopsis sp. UR67 along with docking studies.

This work was performed to dig into the phytochemical composition and bioactivities of Nocardiopsis sp. UR67 associated with the marine sponge Callyspongia sp. It was fermented in suspension and immobilised in calcium alginate bead cultures. The ethyl acetate extracts, afforded from the broth in each case named EG-49 and J-48g, respectively, revealed 16 chemical principles mostly belonging to polyketides, macrolides, and peptides. EG-49 and J-48g displayed anti-Candida albicans activity with IC50 values of 8.1 and 8.3 µg/mL, and a substantial cytotoxic effect against lung adenocarcinoma H1650 at IC50 12.6 and 13.7 µg/mL, respectively. However, only EG-49 exhibited a noteworthy anti-trypanosomal activity at 7.5 µg/mL. Molecular docking of the characterised compounds against Trypanosoma brucei trypanothione reductase demonstrated the highest binding models of griseochelin-methyl ester (9) and filipin-II (11), which drew considerable significance of the metabolites derived from Nocardiopsis sp. UR67 developing potential T. brucei trypanothione reductase inhibitors.

Cytotoxicity and chemical profiling of the Red Sea soft corals Litophyton arboreum.

The objective of this research was to evaluate the cytotoxic activities of the fractions and isolated compounds of the soft corals Litophyton arboreum against A549, MCF-7 and HepG2 cell lines by MTT assay method, and to chemically investigate the various metabolites of its total extract using LC-HR-ESI-MS metabolomic profiling. The metabolomic profiling revealed the presence of various metabolites, mainly sesquiterpenes and steroids reported for the first time in L. arboreum. Additionally, eight compounds (1-8) have been isolated from the n-hexane-chloroform (1:1) fraction that exhibited noticeable activity towards A549, MCF-7 and HepG2 cell lines. The steroids (5 and 6), and the sesquiterpene (1) exerted noticeable activity against A549 cell line (IC50 28.5 ± 4.4, 36.9 ± 2.9 and 67.3 ± 9.9 µM/mL, respectively) compared to etoposide as standard cytotoxic agent (IC50 48.3 ± 7.6 µM/mL). Compound 6 also exhibited cytotoxicity against MCF-7 cell line (IC50 55.3 ± 4.9 µM/mL).

Aureanin: a new iridoid from the leaves of Tabebuia aurea (Silva Manso) Benth. & Hook.f. ex S.Moore.

One new iridoid named aureanin (1) was isolated from the leaves of Tabebuia aurea (Silva Manso) Benth. & Hook.f. ex S.Moore, together with eight known compounds, isoquercetin (2), astragalin (3), callicoside B (4), amphipaniculoside E (5), rehmaglutin D (6), quercetin-3-sambubioside (7), rutin (8), kaempferol-3-O-rutinoside (9). The structures of the isolated compounds were elucidated and confirmed by spectroscopic methods, including 1 D and 2 D NMR experiments, as well as HR-ESI-MS. Compounds 1-9 were evaluated for their in vitro cytotoxic activity against three human cancer cell lines (A549, HepG2, and MCF-7) and Leishmania major. Compound 4 showed activity against A549 (IC50: 36.8 ± 1.5 µg/mL, etoposide (positive control): 28.1 ± 4.2 µg/mL), however, none of the compounds were active against L. major.

Cytotoxic and antileishmanial triterpenes of Tabebuia aurea (Silva Manso) leaves.

The bioactivity-guided fractionation of the total ethanolic extract of the leaves of Tabebuia aurea revealed the cytotoxic and antileishmanial potency of the ethyl acetate fraction, in which its phytochemical investigation resulted in the isolation of five triterpenes; identified as oleanolic acid (1), ursolic acid (2), pomolic acid (3), tormentic acid (4), 3ß,6ß,19α-trihydroxy-urs-12-en-28-oic acid (5) in addition to one triterpenoid glucoside, spathodic acid 28-O-ß-D-glucopyranoside (6). Whereas compound 1 showed cytotoxic activity against three different cell lines; A549, MCF-7 and HepG2 with IC50 values of 31.7 ± 1.2, 27.4 ± 1.8 and 28.8 ± 1.1 µg/mL, respectively (etoposide as a positive control: 28.1 ± 4.2, 22.5 ± 4.5, and 20.4 ± 0.8 µg/mL, respectively), while compounds 1 and 2 showed antileishmanial activity with IC50 values of 10.2 ± 0.9 µg/mL and 5.1 ± 0.4 µg/mL, respectively (miltefosine: 7.7 ± 2.1 µg/mL).

Natural metabolites from the soft coral Nephthea sp. as potential SARS-CoV-2 main protease inhibitors.

The ongoing spread of SARS-CoV-2 has created a growing need to develop effective antiviral treatments; therefore, this work was undertaken to delve into the natural metabolites of the Red Sea soft coral Nephthea sp. (family Nephtheidae) as a source of potential anti-COVID-19 agents. Overall, a total of 14 structurally diverse minor constituents were isolated and identified from the petroleum ether fraction of Nephthea sp. The characterised compounds were screened and compared for their inhibitory potential against SARS-CoV-2 main protease (Mpro) using Autodock Vina and MOE software. Interestingly, most compounds were able to bind effectively to the active site of Mpro, of which nephthoside monoacetate (1); an acylated tetraprenyltoluquinol glycoside, exhibited the highest binding capacity in both software with comparable interaction energies to the ligand N3 and moderately acceptable drug-likeness properties, which drew attention to the relevance of marine-derived metabolites from Nephthea sp., particularly compound (1), to develop potential SARS-CoV-2 protease inhibitors.

Cytotoxic activity of actinomycetes Nocardia sp. and Nocardiopsis sp. associated with marine sponge Amphimedon sp.

Cancer is a hazard life-threatening disease, which affect huge population worldwide. Marine actinomycetes are considered as promising source for potential chemotherapeutic agents. In our study, we carried out metabolic profiling for Nocardia sp. UR 86 and Nocardiopsis sp. UR 92 that were cultivated from the Red Sea sponge Amphimedon sp. to investigate their chemical diversity using different media conditions. The crude culture extracts were subjected to high-resolution mass spectrometry (HRMS) analysis. The chemical profiles of the different extracts of Nocardia sp. UR 86 and Nocardiopsis sp. UR 92 revealed their richness in diverse metabolites and consequently twenty compounds (1-20) were annotated. Moreover, the obtained extracts of the differently cultivated Nocardia sp. UR 86 and Nocardiopsis sp. UR 92 were investigated against three cell lines HepG2, MCF-7 and CACO2 and revealed the targeted cytotoxicity of Nocardia sp. and Nocardiopsis sp. metabolites against the three cell lines.

Cytotoxic potential of Nephthea sp.-derived actinomycetes supported by metabolomics analysis.

Soft corals and associated microorganisms are known to produce leads for anticancer drugs. Keeping this in mind, Nephthea sp.; a Red Sea soft coral was investigated for the first time using the OSMAC approach. Two isolates, Streptomyces sp. UR63 and Micrococcus sp. UR67 were identified. Their extracts revealed the presence of alkaloids, macrolides, quinones, fatty acids and terpenoids. Further comparison through a set of multivariate data analyses revealed their unique chemical profiles. The extracts displayed inhibitory potencies against HepG-2, Caco-2 and MCF-7 tumor cell lines with IC50 values ranging from 11.4 to 38.7 µg/mL when compared with the positive control, doxorubicin. The study not only highlights the cytotoxic potential of soft coral-associated actinomycetes but also shows the advantage of using the OSMAC approach in this regard.

LC-MS-based identification of bioactive compounds and hepatoprotective and nephroprotective activities of Bignonia binata leaves against carbon tetrachloride-induced injury in rats.

The chemical profiling of the main phytoconstituents of total ethanolic extract (TEE) and its different fractions of Bignonia binata leaves was dereplicated using liquid chromatography-high resolution-electrospray ionisation-mass spectrometry (LC-HR-ESI-MS), revealed the presence of various classes of secondary metabolites; eight phenylethanoids, two flavonoidal glycosides and two iridoids. Moreover, the hepatoprotective and nephroprotective activities of the TEE and its different fractions were investigated in carbon tetrachloride (CCl4)-intoxicated rats and were compared with those of silymarin-treated group, revealing the highest potency of the EtOAc group, followed by the aqueous one in improving the CCl4-induced alterations in several biochemical parameters. Besides, EtOAc and aqueous fractions exhibited the most inhibition of CCl4-induced inflammatory mediators and improving the changes in the histopathological structures of the liver and kidney. In addition, the EtOAc fraction demonstrated the highest total phenolic content, whereas TEE showed the highest amount of total flavonoid content.[Formula: see text].

Multitarget in silico studies of Ocimum menthiifolium, family Lamiaceae against SARS-CoV-2 supported by molecular dynamics simulation.

The novel strain of human coronavirus, emerged in December 2019, which has been designated as SARS-CoV-2, causes a severe acute respiratory syndrome. Since then, it has arisen as a serious threat to the world public health. Since no approved vaccines or drugs has been found to efficiently stop the virulent spread of the virus, progressive inquiries targeting these viruses are urgently needed, especially those from plant sources. Metabolic profiling using LC-HR-ESI-MS of the butanol extract of Ocimum menthiifolium (Lamiaceae) aerial parts yielded 10 compounds including flavonoids, iridoids and phenolics. As it has been previously reported that some flavonoids can be used as anti-SARS drugs by targeting SARS-CoV-1 3CLpro, we chose to examine 14 flavonoids (detected by metabolomics and other compounds isolated via several chromatographic techniques). We investigated their potential binding interactions with the 4 main SARS-CoV-2 targets: Mpro, nsp16/nsp10 complex, ACE2-PD and RBD-S-protein via molecular docking. Docking results indicated that the nsp16/nsp10 complex has the best binding affinities where the strongest binding was detected with apigenin-7-O-rutinoside, prunin and acaciin with -9.4, -9.3 and -9.3 kcal/mol binding energy, respectively, compared to the control (SAM) with -8.2 kcal/mol. Furthermore, the stability of these complexes was studied using molecular dynamics of 150 ns, which were then compared to their complexes in the other three targets. MM-PBSA calculations suggested the high stability of acaciin-nsp16 complex with binding energy of -110 kJ/mol. This study sheds light on the structure-based design of natural flavonoids as anti-SARS-CoV-2 drugs targeting the nsp16/10 complex.Communicated by Ramaswamy H. Sarma.