Nutraceutical Valorization of Exhausted Olive Pomace from L. Using Advanced Extraction Techniques.

Exhausted olive pomace (EOP) represents the principal residue of olive pomace. Several studies have optimized the extraction of specialized metabolites from the EOP of L., but a comparison between different extractive methods has not been made.

When Synthesis Gets It Wrong: Unexpected Epimerization Using PyBOP in the Synthesis of the Cyclic Peptide Thermoactinoamide A.

Chemical synthesis is commonly seen as the final proof of the structure of complex natural products, but even a seemingly easy and well-established synthetic procedure may lead to an unexpected result. This is what happened with the synthesis of thermoactinoamide A (), an antimicrobial and antitumor nonribosomal cyclic hexapeptide produced by the thermophilic bacterium . The synthetic thermoactinoamide A outsourced to a company and the one described in a synthetic paper showed spectroscopic data identical to each other but different from those of the natural product.

Harnessing Cyanobacteria's Bioactive Potential: A Sustainable Strategy for Antioxidant Production.

Unsaturated diacylglycerols are a class of antioxidant compounds with the potential to positively impact human health. Their ability to combat oxidative stress through radical scavenger activity underscores their significance in the context of preventive and therapeutic strategies. In this paper we highlight the role of as a producer of unsaturated mono and diacylglycerols, and then demonstrate the antioxidant activity of its methanolic extract, which has as its main components a variety of acylglycerol analogues.

Lake Avernus Has Turned Red: Bioindicator Monitoring Unveils the Secrets of "Gates of Hades".

Lake Avernus is a volcanic lake located in southern Italy. Since ancient times, it has inspired numerous myths and legends due to the occurrence of singular phenomena, such as coloring events. Only recently has an explanation been found for them, i.

Novel Insights in the Potential of Halogenated Polyketide-Peptide Molecules as Lead Compounds in Cancer Drug Discovery.

In this interdisciplinary study, we selected two compounds, namely, smenamide A, a peptide-polyketide, and smenolactone D, a polyketide, as models because they are representative of two different classes of molecules isolated from the marine sponge . The organic extract of was analyzed using a combination of high-resolution LC-MS/MS and molecular networking, a recently developed method for automated LC-MS data analysis. The analyses were targeted to highlight clusters made by chlorinated compounds present in the extracts.

A Four-Step Platform to Optimize Growth Conditions for High-Yield Production of Siderophores in Cyanobacteria.

In response to Iron deprivation and in specific environmental conditions, the cyanobacteria produce siderophores, iron-chelating molecules that in virtue of their interesting environmental and clinical applications, are recently gaining the interest of the pharmaceutical industry. Yields of siderophore recovery from in vitro producing cyanobacterial cultures are, unfortunately, very low and reach most of the times only analytical quantities. We here propose a four-step experimental pipeline for a rapid and inexpensive identification and optimization of growth parameters influencing, at the transcriptional level, siderophore production in .

Computational Metabolomics Tools Reveal Subarmigerides, Unprecedented Linear Peptides from the Marine Sponge Holobiont .

A detailed examination of a unique molecular family, restricted to the genus, in a molecular network obtained from an in-house Haplosclerida marine sponge collection (including , , , and species) led to the discovery of subarmigerides, a series of rare linear peptides from , a genus mainly known for polyacetylenes and lipids. The structure of the sole isolated peptide, subarmigeride A () was elucidated through extensive 1D and 2D NMR spectroscopy, HRMS/MS, and Marfey's method to assign its absolute configuration. The putative structures of seven additional linear peptides were proposed by an analysis of their respective MS/MS spectra and a comparison of their fragmentation patterns with the heptapeptide .

Fatty Acid Substitutions Modulate the Cytotoxicity of Puwainaphycins/Minutissamides Isolated from the Baltic Sea Cyanobacterium UHCC-0300.

Puwainaphycins (PUW) and minutissamides (MIN) are structurally homologous cyclic lipopeptides that exhibit high structural variability and possess antifungal and cytotoxic activities. While only a minor variation can be found in the amino acid composition of the peptide cycle, the fatty acid (FA) moiety varies largely. The effect of FA functionalization on the bioactivity of PUW/MIN chemical variants is poorly understood.

A Glimpse at Siderophores Production by UTEX 1444.

In this study, a strain of UTEX 1444 was cultivated in six different concentrations of iron (III). Cultures were extracted with organic solvents and analyzed using our dereplication strategy, based on the combined use of high-resolution tandem mass spectrometry and molecular networking. The analysis showed the presence of the siderophores' family, named synechobactins, only in the zero iron (III) treatment culture.

(L.) Greuter, a Rapidly Spreading Invasive Plant: Chemistry and Bioactivity.

L. Greuter belonging to the Asteraceae family, is an aromatic herbaceous plant native to the Mediterranean region. This plant species has been extensively studied for its biological activities, including antioxidant, antitumor, antimicrobial, antifungal, anti-inflammatory, anticholinesterase, and antityrosinase, and for its peculiar metabolic profile.

Exploring Chemical Diversity of Sponges as a Source of Novel Lead Compounds in Drug Discovery.

Porifera, commonly referred to as marine sponges, are acknowledged as major producers of marine natural products (MNPs). Sponges of the genus have attracted much attention over the years. They are widespread in all continents, and several structurally unique compounds have been identified from this species.

Monitoring Cyanobacterial Blooms during the COVID-19 Pandemic in Campania, Italy: The Case of Lake Avernus.

Cyanobacteria are ubiquitous photosynthetic microorganisms considered as important contributors to the formation of Earth's atmosphere and to the process of nitrogen fixation. However, they are also frequently associated with toxic blooms, named cyanobacterial harmful algal blooms (cyanoHABs). This paper reports on an unusual out-of-season cyanoHAB and its dynamics during the COVID-19 pandemic, in Lake Avernus, South Italy.

Cyanochelins, an Overlooked Class of Widely Distributed Cyanobacterial Siderophores, Discovered by Silent Gene Cluster Awakening.

Cyanobacteria require iron for growth and often inhabit iron-limited habitats, yet only a few siderophores are known to be produced by them. We report that cyanobacterial genomes frequently encode polyketide synthase (PKS)/nonribosomal peptide synthetase (NRPS) biosynthetic pathways for synthesis of lipopeptides featuring -hydroxyaspartate (-OH-Asp), a residue known to be involved in iron chelation. Iron starvation triggered the synthesis of -OH-Asp lipopeptides in the cyanobacteria sp.

Early Detection of Cyanobacterial Blooms and Associated Cyanotoxins using Fast Detection Strategy.

Fast detection of cyanobacteria and cyanotoxins is achieved using a Fast Detection Strategy (FDS). Only 24 h are needed to unravel the presence of cyanobacteria and related cyanotoxins in water samples and in an organic matrix, such as bivalve extracts. FDS combines remote/proximal sensing techniques with analytical/bioinformatics analyses.

Discovery of Unusual Cyanobacterial Tryptophan-Containing Anabaenopeptins by MS/MS-Based Molecular Networking.

Heterocytous cyanobacteria are among the most prolific sources of bioactive secondary metabolites, including anabaenopeptins (APTs). A terrestrial filamentous sp. CT11 collected in Costa Rica bamboo forest as a black mat, was studied using a multidisciplinary approach: genome mining and HPLC-HRMS/MS coupled with bioinformatic analyses.

Identification of Quorum Sensing Activators and Inhibitors in The Marine Sponge .

Marine sponges, a well-documented prolific source of natural products, harbor highly diverse microbial communities. Their extracts were previously shown to contain quorum sensing (QS) signal molecules of the -acyl homoserine lactone (AHL) type, known to orchestrate bacterial gene regulation. Some bacteria and eukaryotic organisms are known to produce molecules that can interfere with QS signaling, thus affecting microbial genetic regulation and function.

A joint molecular networking study of a sponge and a cyanobacterial bloom revealed new antiproliferative chlorinated polyketides.

The bloom-forming cyanobacteria sp. have been recently shown to produce some of the chlorinated peptides/polyketides previously isolated from the marine sponge . A comparative analysis of extracts from and sp.

Fast Detection of Two Smenamide Family Members Using Molecular Networking.

Caribbean sponges of the genus are a prolific source of chlorinated secondary metabolites. The use of molecular networking as a powerful dereplication tool revealed in the metabolome of two new members of the smenamide family, namely smenamide F () and G (). The structure of smenamide F () and G () was determined by spectroscopic analysis (NMR, MS, ECD).

A Collection of Bioactive Nitrogen-Containing Molecules from the Marine Sponge .

Thirteen nitrogen-containing molecules (/ and -) were isolated from the Indonesian sponge , highlighting the richness of this organism as a source of alkaloids. Their structures were elucidated using one- and two-dimensional NMR spectroscopy and HR-ESI-MS, while the stereochemistry of the diketopiperazines was established using Marfey's method. All compounds were screened in our standard bioactivity assays, including antibacterial, antikinases, and amyloid β-42 assays.

Computational prediction of chiroptical properties in structure elucidation of natural products.

Covering: up to 2019This review covers the current status of the quantum mechanical prediction of chiroptical properties, such as electronic CD and optical rotation, as needed for stereochemical assignments in new natural products. The reliability of the prediction of chiroptical properties is steadily increasing, with a parallel decrease in the required computational resources. Now, quantum mechanical calculations for a medium-sized natural product can be reliably performed by natural product chemists on a mainstream PC.

A Fast Detection Strategy for Cyanobacterial blooms and associated cyanotoxins (FDSCC) reveals the occurrence of lyngbyatoxin A in campania (South Italy).

Fast Detection Strategy for Cyanobacterial blooms and associated Cyanotoxins (FDSCC) is a multidisciplinary strategy that allows early detection, in 24 man-hours, of cyanobacteria and related cyanotoxins in water and bivalve samples. This approach combines the advantages of remote/proximal sensing with those of analytical/bioinformatics analyses, namely, LC-HRMS-based molecular networking. The detection of Lyngbyatoxin A, a lipophilic cyanotoxin, in all analyzed water samples and in bivalves, commonly used as food, was the proof of the reliability of the new method.

Isolation of Smenopyrone, a Bis-γ-Pyrone Polypropionate from the Caribbean Sponge .

The organic extract of the Caribbean sponge has been shown to contain an array of novel chlorinated secondary metabolites derived from a mixed PKS-NRPS biogenetic route such as the smenamides. In this paper, we report the presence of a biogenetically different compound known as smenopyrone, which is a polypropionate containing two γ-pyrone rings. The structure of smenopyrone including its relative and absolute stereochemistry was determined by spectroscopic analysis (NMR, MS, ECD) and supported by a comparison with model compounds from research studies.

Smenamide A Analogues. Synthesis and Biological Activity on Multiple Myeloma Cells.

Smenamides are an intriguing class of peptide/polyketide molecules of marine origin showing antiproliferative activity against lung cancer Calu-1 cells at nanomolar concentrations through a clear pro-apoptotic mechanism. To probe the role of the activity-determining structural features, the 16--analogue of smenamide A and eight simplified analogues in the 16- series were prepared using a flexible synthetic route. The synthetic analogues were tested on multiple myeloma (MM) cell lines showing that the configuration at C-16 slightly affects the activity, since the 16--derivative is still active at nanomolar concentrations.

Zeamide, a Glycosylinositol Phosphorylceramide with the Novel Core Arap(1β→6)Ins Motif from the Marine Sponge Svenzea zeai.

Glycosylinositol phosphorylceramides (GIPCs) show a great structural diversity, but all share a small number of core structures, with a glucosamine, a mannose, or a glucuronic acid as the first sugar linked to the inositol. The Caribbean sponge was shown to consistently contain zeamide (), the first example of a new class of GIPCs, in which the inositol is glycosylated by a d-arabinose. The structure of zeamide was determined by spectroscopic analysis (NMR, MS, ECD) and microscale chemical degradation.