Deciphering the multi-scale mechanism of herbal phytoconstituents in targeting breast cancer: a computational pharmacological perspective.

Breast Cancer (BC) is the most common cause of cancer-associated deaths in females worldwide. Despite advancements in BC treatment driven by extensive characterization of its molecular hallmarks, challenges such as drug resistance, tumor relapse, and metastasis persist. Therefore, there is an urgent need for alternative treatment approaches with multi-modal efficacy to overcome these hurdles. In this context, natural bioactives are increasingly recognized for their pivotal role as anti-cancer compounds. This study focuses on predicting molecular targets for key herbal phytoconstituents-gallic acid, piperine, quercetin, resveratrol, and beta-sitosterol-present in the polyherbal formulation, Krishnadi Churna. Using an in-silico network pharmacology model, key genes were identified and docked against these marker compounds and controls. Mammary carcinoma emerged as the most significant phenotype of the putative targets. Analysis of an online database revealed that out of 135 predicted targets, 134 were mutated in breast cancer patients. Notably, ESR1, CYP19A1, and EGFR were identified as key genes which are known to regulate the BC progression. Docking studies demonstrated that the herbal phytoconstituents had similar or better docking scores than positive controls for these key genes, with convincing protein-ligand interactions confirmed by molecular dynamics simulations, MM/GBSA and free energy landscape (FEL) analysis. Overall, this study highlights the predictive potential of herbal phytoconstituents in targeting BC genes, suggesting their promise as a basis for developing new therapeutic formulations for BC.

Antibacterial, phytochemical and GC-MS analyses of argel (Solanum argel) leaves.

Finding novel, efficient antimicrobial drugs is crucial in this age of pressing global health challenges. The medicinal qualities of the leaves of the argel plant (Solanum argel, or S. argel) have been recognized in traditional medicine for quite some time. The medicinal potential of these leaves may be due to the presence of bioactive substances such as alkaloids, flavonoids, and phenolic acids. S. argel leaf antibacterial, phytochemical, and gas chromatography-mass spectrometry (GC-MS) characteristics are the focus of this investigation. To conduct the study, bioactive compounds would be extracted from the leaves and tested against a panel of bacterial pathogens. Then, the compounds would be identified using GC-MS analysis. Mean inhibition zones of 15.30±1.0 mm, 14.67±0.42 mm, 15.0±0.01 mm, and 15.56±0.22 mm for the bacteria E. coli, Staph. aureus, and Sal. typhimurium, respectively, were seen in the antibacterial results at a concentration of 3 µg/disc. Secondary metabolites such as alkaloids, flavonoids, phenolic substances, and tannins were identified using phytochemical investigation. Antimicrobial, antioxidant, and anti-inflammatory are just a few of the many bioactivities associated with these phytochemicals. Argel plant leaves contain bioactive chemicals that show they could be a source of new pharmaceuticals. Argel leaves were analyzed using GC-MS and 37 different chemicals were found. The most abundant compounds were 4H-Pyran-4-one and 2,3-dihydro-3.5-hydroxy, followed by 3-Pentanol, 2,2,4,4-tetramethyl, and 2,2-Dimethyl-3-[3-methyl-5-(phenylthio)-, with areas of 11.80%, 10.6%, and 9.47%, respectively. The analysis was performed within a time range of 5.070 to 34.464 minutes. According to the research, Argel leaf has powerful antioxidant and antibacterial capabilities, making it an excellent substance for medical and food preservation applications.

The synthetic chemistry of sarpagine-ajmaline-type alkaloids.

The sarpagine-ajmaline type monoterpenoid indole alkaloids are among the most important groups of natural alkaloids, and the complex polycyclic and cage-like architectures present significant synthetic challenges. Because of their characteristic indole-fused azabicyclo[3.3.1]nonane structures and prominent biological activities, sarpagine-ajmaline related alkaloids have captured the attention of organic synthetic chemists for decades. In this chapter, the strategies employed in the synthesis of sarpagine-ajmaline related alkaloids are outlined, and the synthetic progress during the period of 2019-2023 is provided in detail. To provide potential targets for future synthetic endeavors, some sarpagine/ajmaline type alkaloids isolated in recent years with novel structures and biological activities are also summarized.

Structure, biosynthesis and activity of indolactam alkaloids.

Indolactam alkaloids are a family of aromatic toxins produced by various actinobacteria and the cyanobacterium, Moorena producens. The best characterized examples include the teleocidins, lyngbyatoxins, olivoretins, blastmycetins, and pendolmycins, which share a nine-membered lactam core, comprised from l-tryptophanol and l-valine. Contact with indolactam alkaloids has been linked to severe dermatitis (swimmers itch), while accidental ingestion may lead to illness and fatalities. Indolactam alkaloids are also potent tumor promotors, due to their activation of protein kinase C isozymes. This chapter reviews the current literature on indolactam alkaloids, from their discovery in the early 1960s up to 2024. Topics covered include the isolation, structural elucidation, biosynthesis, bioactivity, and total synthesis of the indolactam alkaloid core.

Recent advancement of novel marine fungi derived secondary metabolite fibrinolytic compound FGFC in biomedical applications: a review.

For several decades, products derived from marine natural sources (PMN) have been widely identified for several therapeutic applications due to their rich sources of bioactive sub-stances, unique chemical diversity, biocompatibility and excellent biological activity. For the past 15 years, our research team explored several PMNs, especially fungi fibrinolytic compounds (FGFCs). FGFC is an isoindolone alkaloid derived from marine fungi, also known as staplabin analogs or Stachybotrys microspora triprenyl phenol (SMTP). For instance, our previous studies explored different types of FGFCs such as FGFC 1, 2, 3 and 4 from the marine fungi Stachybotrys longispora FG216 derived metabolites. The derivatives of FGFC are potentially employed in several disease treatments, mainly for stroke, cancer, ischemia, acute kidney injury, inflammation, cerebral infarction, thrombolysis and hemorrhagic activities, etc. Due to the increasing use of FGFCs in pharmaceutical and biomedical applications, it is important to understand the fundamental signaling concept of FGFCs. Hence, for the first time, this review collectively summarizes the background, types, mode of action and biological applications of FGFCs and their current endeavors for future therapies.

Review of the Structural Characteristics and Biological Activities of Tricholoma Secondary Metabolites (2018-2023).

Tricholoma are significant medicinal and edible mushrooms within Basidiomycota. Known for their various medicinal properties such as anti-tumor, immune regulation, and antioxidant effects, they are regarded worldwide as health foods of the 21st century. Tricholoma species produce various types of secondary metabolites, which have been extensively studied by the scientific community. In 2018, Clericuzio et al. summarized the structures, biosynthesis, and biological activities of over one hundred different secondary metabolites isolated from the fruiting bodies of 25 Tricholoma species. Building on this, the present article reviews the research progress on Tricholoma secondary metabolites from 2018 to 2023, identifying a total of 101 compounds, 46 of which were newly discovered. These secondary metabolites include a wide range of chemical categories such as terpenoids, steroids, and alkaloids, demonstrating broad biological activities. This article aims to provide in-depth scientific insights and guidance for researchers in this field by summarizing the chemical and biological properties of these secondary metabolites, promoting further applications and development of Tricholoma fungi in the pharmaceutical and food industries.

A Comprehensive Review on Deep Eutectic Solvents: Their Current Status and Potential for Extracting Active Compounds from Adaptogenic Plants.

Deep eutectic solvents (DESs) have attracted attention from researchers as novel compounds for extracting active substances because of their negligible toxicity, polarity, and ability to be tailored depending on the experiment. In this review, we discuss deep eutectic solvents as a promising medium for the extraction of adaptogenic compounds. In comparison to traditional methods, extraction with the use of DESs is a great alternative to the excessive usage of harmful organic solvents. It can be conducted in mild conditions, and DESs can be designed with different precursors, enhancing their versatility. Adaptogenic herbs have a long medicinal history, especially in Eastern Asia. They exhibit unique properties through the active compounds in their structures, including saponins, flavonoids, polysaccharides, and alkaloids. Therefore, they demonstrate a wide range of pharmaceutical effects, such as anti-inflammatory, antibacterial, and anticancer abilities. Since ancient times, many different adaptogenic herbs have been discovered and are well known, including Panax ginseng, Scutellaria baicalensis, and Schisandra chinensis. Active compounds can be extracted using standard methods, such as hydrolyzation, maceration, and conventional reflux extraction. However, due to the limitations of classical processing technologies, there has been a need to develop new and eco-friendly methods. We focus on the types of solvents, extraction efficiency, properties, and applications of the obtained active compounds. This review highlights the potential of DESs as eco-friendly alternatives for extracting bioactive compounds.

Reconstruction of quality marker system for Ginkgo Folium tablet using UHPLC-Q-Orbitrap MS, quantum chemical calculation, network pharmacology, and molecular simulation.

INTRODUCTION: Ginkgo Folium tablet (GFT) is a patented traditional Chinese medicine prepared from Ginkgo biloba leaves extract (GBE). However, the current quality indicators for GFT or GBE as designated by the Chinese Pharmacopoeia are insufficient in preventing counterfeit events. OBJECTIVE: This study aimed to putatively identify compounds in GFT and to further develop a quality marker (Q-marker) system for GFT. METHODS: A novel strategy utilizing database-aided ultrahigh-performance liquid chromatography-quadrupole-orbitrap mass spectrometry was employed to analyze the lyophilized aqueous powder of GFT. Subsequently, the identified compounds underwent quantum chemical calculations, network pharmacology, and molecular simulations through in silico approaches to evaluate the Q-marker principles of traceability, specificity, and efficiency-relevance. RESULTS: The results revealed the putative identification of a total of 66 compounds, including 36 flavonoids, 7 phenolic acids and derivatives, 5 terpene lactones, 4 fatty acids and derivatives, 3 alkaloids, 1 amino acid, and 10 other compounds. Particularly, 16 compounds were unexpectedly observed, and seven compounds met the Q-marker principles. CONCLUSION: This study recommends the seven compounds, namely, (-)-gallocatechin, matrine, (-)-epicatechin, ginkgolide C, ginkgolide A, ginkgolide B, and curdione, as the anti-counterfeiting pharmacopoeia Q-markers for GFT. The reconstruction of the Q-marker system for GFT not only enhances the understanding of the compounds in GFT and other GBE-based preparations but also provides valuable recommendations for the Pharmacopoeia Commission.

Discovery of Anti-Inflammatory Alkaloids from Sponge Stylissa massa Suggests New Biosynthetic Pathways for Pyrrole-Imidazole Alkaloids.

Pyrrole-imidazole alkaloids (PIAs) are a class of marine sponge derived natural products which have complex carbon frameworks and broad bioactivities. In this study, four new alkaloids, stylimassalins A-B (1-2), 3, and 5, together with two known compounds (4 and 6), were isolated from Stylissa massa. Compounds 2, 4, and 6 are the C-2 brominated analogues of 1, 3, and 5, respectively. Their structures display three different scaffolds, of which scaffold 1 (compounds 1,2) is new. A new biosynthetic pathway from oroidin, through spongiacidin, to latonduine and scaffold 1 was proposed by our group, in which the C12-N13-cleavaged compounds of spongiacidin (scaffold 2), dubbed seco-spongiacidins (3 and 4), are recognized as a key bridged scaffold, to afford PIA analogues (1,2 and 5,6). An anti-inflammatory evaluation in a zebrafish inflammation model induced by copper sulphate (CuSO4) demonstrated that stylimassalins A and B (1 and 2) could serve as a promising lead scaffold for treating inflammation.

Total Synthesis and Structural Reassignment of the Molt-Inhibiting Marine Alkaloid Erebusinone.

The marine alkaloid erebusinone is a secondary metabolite isolated from the Antarctic sponge Isodictya erinacea. Initial biological assays have shown that erebusinone increases amphipod mortality, probably by inhibition of the biosynthesis of molting hormone (ecdysone). Herein, we report the first total synthesis of the proposed structure of erebusinone and a structural revision.

Portable alkaloid discrimination via nanozyme-mediated colorimetric paper-based sensor array integrated with smartphone detection.

A paper-based colorimetric sensor array mediated by a novel nanozyme (CuCo2O4) was developed using a screen-printing technology. The aim was to facilitate the identification of different kinds of alkaloids. Typically, three chromogenic substrates (3,3',5,5'-tetramethylbenzidine, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), and o-phenylenediamine) were selected as sensing elements, which can be catalyzed by a CuCo2O4 nanozyme with peroxidase-like activity to yield corresponding oxidized products, thereby inducing color changes. Owing to the varying inhibitory ability of different alkaloids on acetylcholinesterase (AChE), a decrease in choline (Ch) concentration occurs and subsequently results in the restoration of color within the units of sensor array. Color data can be transformed into hue information with a smartphone. The above color variations generated a unique "fingerprint" pattern on five alkaloids (berberine, palmatine, jatrorrhizine, eserine, and harmane), which can be successfully discriminated through linear discriminant analysis in the range 0.2 to 20 µM. Furthermore, the sensor arrays allowed successful discrimination of the above five alkaloids in Chinese herbal medicine samples and recognition of 22 blind samples. This work presents a novel nanozyme-based paper sensor array, which is a user-friendly and reliable platform for probing different alkaloids. In addition, the developed sensing strategy enables the identification of AChE-related diseases, positively contributing to the screening available of AD-associated drugs.

ISOLATION, CHARACTERIZATION, AND ANTIHYPERTENSIVE ACTIVITY ALKALOIDS EXTRACTED FROM THE LEAVES OF THE ALSTONIA SCHOLARIS PLANT.

The study aims to investigate the Isolation, Characterization & Antihypertensive Life of Natural Alkaloids out of certain Selected Plants. The Alstonia scholaris papers used in this study are generally available in the tropics and can be obtained in Asia. The plant sample was verified by the pharmacognosy and pharmacology department. The powdered leaves of Alstonia scholaris (500 gm) are macerated using 1% HCl (pH 2) at space temperature overnight. After that, the combination was produced alkaline by putting 25% NH4OH solution (pH 9). The combination's color changed from the red wine to the black. The alkaline mixture was then bounced satisfactorily and purified using Whatman filter paper. Four fractions (15-19) were collected from column chromatography. All the fractions have shown the same Rf value in the TLC fingerprint, therefore they are incorporated established on TLC analysis generated in Hexane: Ethyl acetate (14:6). Nitric oxide synthase inhibitor, i.e. N-nitro-L-arginine methyl ester was used to produce hypertension in rats in (40 mg/ml/kg, i.p.). Every day, it is solubilized in 0.9 per cent NaCl solution. Colourless powder compound was obtained (yield 0.4%) and having MP 132-1340 C. Rf value in (Hexane: Ethyl acetate,65:35) at 0.55, UV-Vis λmax in methanol: (nm) 297, IR (KBr), m 913 (N-H bending), 1260 (C-N Stretching), 1396 (C-N), 1165, 1259 (-C-O- stretching) 1396, 1464 (C=C, Ar.), 2831, 2928 (C-H, Aliphatic) and 3564, 3315 (N-H Stretching). The 1H NMR spectrum also portrayed the distinctive peaks for various chemical compounds. The peak of 7.28-8.85 ppm was due to multiple aromatic protons. The 6.94-7.04 ppm peaks were characteristic of ethylene amino protons, and the 1.57-2 ppm peaks were allocated to alcohol protons. L-NAME significantly elevated MABP, SBP, and DBP in pentobarbital-anesthetized rats but not HR. The mean arterial blood pressure, systolic blood pressure and diastolic blood pressure of pentobarbital-anaesthetized L-NAME caused hypertensive rats do not alter after a single intragastric injection of the isolated alkaloid. Finally, isolated alkaloids from Alstonia scholaris supplement had antihypertensive properties in hypertensive rats.

Streptomyces sp. from desert soil as a biofactory for antioxidants with radical scavenging and iron chelating potential.

Iron homeostasis is vital for normal physiology, but in the majority of circumstances, like iron overload, this equilibrium is upset leading to free iron in the plasma. This condition with excess iron is known as hemochromatosis, which has been linked to many side effects, including cancer and liver cirrhosis. The current research aimed to investigate active molecules from Streptomyces sp. isolated from the extreme environment of Bahawalpur deserts. The strain was characterized using 16 S rRNA sequencing. Chemical analysis of the ethyl acetate cure extract revealed the presence of phenols, flavonoids, alkaloids, and tannins. Multiple ultraviolet (UV) active metabolites that were essential for the stated pharmacological activities were also demonstrated by thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Additionally, Gas chromatography/mass spectrometry (GC-MS) analysis revealed the primary constituents of the extract to compose of phenol and ester compounds. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was used to assess the extract's antioxidant capacity, and the results showed a good half-maximal inhibitory concentration (IC50) value of 0.034 µg/mL in comparison to the positive control ascorbic acid's 0.12 µg/mL. In addition, iron chelation activity of extract showed significant chelation potential at 250 and 125 µg/mL, while 62.5 µg/mL showed only mild chelation of the ferrous ion using ethylene diamine tetra acetic acid (EDTA) as a positive control. Likewise, the extract's cytotoxicity was analyzed through 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay using varying concentrations of the extract and showed 51% cytotoxicity at 350 µg/mL and 65% inhibition of cell growth at 700 µg/mL, respectively. The bioactive compounds from Streptomyces sp. demonstrated strong antioxidant and iron chelating potentials and can prolong the cell survival in extreme environment.

Alkaloids solenopsins from fire ants display in vitro and in vivo activity against the yeast Candida auris.

The urgency surrounding Candida auris as a public health threat is highlighted by both the Center for Disease Control (CDC) and World Health Organization (WHO) that categorized this species as a priority fungal pathogen. Given the current limitations of antifungal therapy for C. auris, particularly due to its multiple resistance to the current antifungals, the identification of new drugs is of paramount importance. Some alkaloids abundant in the venom of the red invasive fire ant (Solenopsis invicta), known as solenopsins, have garnered attention as potent inhibitors of bacterial biofilms, and there are no studies demonstrating such effects against fungal pathogens. Thus, we herein investigated the antibiotic efficacy of solenopsin alkaloids against C. auris biofilms and planktonic cells. Both natural and synthetic solenopsins inhibited the growth of C. auris strains from different clades, including fluconazole and amphotericin B-resistant isolates. Such alkaloids also inhibited matrix deposition and altered cellular metabolic activity of C. auris in biofilm conditions. Mechanistically, the alkaloids compromised membrane integrity as measured by propidium iodide uptake in exposed planktonic cells. Additionally, combining the alkaloids with AMB yielded an additive antifungal effect, even against AMB-resistant strains. Finally, both extracted solenopsins and the synthetic analogues demonstrated protective effect in vivo against C. auris infection in the invertebrate model Galleria mellonella. These findings underscore the potent antifungal activities of solenopsins against C. auris and suggest their inclusion in future drug development. Furthermore, exploring derivatives of solenopsins could reveal novel compounds with therapeutic promise.

The interdisciplinary approach to investigate bona fide agent(s) in flavonoids or alkaloids in treating HCC.

Currently, the treatment of hepatocellular carcinoma (HCC) is yet to be determined, alternatively, flavonoids or alkaloids from nature have been considered as significant mediators against HCC. In the scenario, we pioneered the most significant agent(s) in either flavonoid(s) or alkaloid(s) against HCC with cheminformatics, bioinformatics, computer screening tools and quantum chemistry concept. In prospect, the intent was to provide the theoretical scaffold in the myriad natural organic molecules. The cheminformatics (natural product activity & species source database (NPASS), SwissADME, PubChem, Similarity Ensemble Approach (SEA) and SwissTargetPrediction (STP)), bioinformatics (DisGeNET, OMIM and STRING) were employed to underpin promising therapeutic components. The protein-protein interaction (PPI) network to identify the relationships between each target and a bubble chart to elucidate key signalling pathway(s) was constructed via STRING database. Ultimately, computer screening tools (PyMOL and AutoDockTools 1.5.6) and quantum chemistry (GaussView 6 and Gaussian) concept were adopted to decrypt the key molecule(s), target(s) and key mechanism(s). The most significant target was AKT1 in PPI network, AKT1 - isorhamnetin, MCL1 - ochrindole D and PIM1 - heyneanine hydroxyindolenine were the most stable conformers to antagonize JAK-STAT signalling pathway. This study provides scientific manifestation to facilitate the clinical test despite the enormous complexity of herbal medicine, and the devised platform for further clarifying the bioactive(s) and mechanism(s) against HCC.

[Research progress on C_(20)-diterpenoid alkaloids and their bioactivities in Ranunculaceae].

C_(20)-diterpenoid alkaloids are mainly distributed in plants of genus Aconitum, Delphinium, and Consolida in the Ranunculaceae. Their chemical structures are mainly categorized into nine types such as atisines, denudatines, hetidines, and hetisines. Bioactivity studies have shown that C_(20)-diterpenoid alkaloids have exhibited superior anti-tumor, analgesic, antiarrhythmic, and anti-inflammatory effects. In this review, the chemical structures and biological activities of 190 C_(20)-diterpenoid alkaloids reported in the Ranunculaceae from 2002 to the present were summarized, so as to provide a reference for the subsequent research on C_(20)-diterpenoid alkaloids in plants of Ranunculaceae.

Stonikacidin A, an Antimicrobial 4-Bromopyrrole Alkaloid Containing L-Idonic Acid Core from the Northwestern Pacific Marine Sponge Lissodendoryx papillosa.

Stonikacidin A (1), the first representative of a new class of 4-bromopyrrole alkaloids containing an aldonic acid core, was isolated from the marine sponge Lissodendoryx papillosa. The compound is named in honor of Prof. Valentin A. Stonik, who is one of the outstanding investigators in the field of marine natural chemistry. The structure of 1 was determined using NMR, MS analysis, and chemical correlations. The L-idonic acid core was established by the comparison of GC, NMR, MS, and optical rotation data of methyl-pentaacetyl-aldonates obtained from the hydrolysis products of 1 and standard hexoses. The L-form of the idonic acid residue in 1 was confirmed by GC analysis of pentaacetate of (S)-2-butyl ester of the hydrolysis product from 1 and compared with corresponding derivatives of L- and D-idonic acids. The biosynthetic pathway for stonikacidin A (1) was proposed. The alkaloid 1 inhibited the growth of Staphylococcus aureus and Escherichia coli test strains, as well as affected the formation of S. aureus and E. coli biofilms. Compound 1 inhibited the activity of sortase A. Molecular docking data showed that stonikacidin A (1) can bind with sortase A due to the interactions between its bromine atoms and some amino acid residues of the enzyme.

Evaluation of the in vivo acute toxicity and in vitro genotoxicity and mutagenicity of synthetic ß-carboline alkaloids with selective cytotoxic activity against ovarian and breast cancer cell lines.

The aim of this study was to evaluate the in vitro cytotoxic, genotoxic, and mutagenic potential and to determine the in silico ADME parameters of two synthetic ß-carboline alkaloids developed as prototypes of antitumor agents (NQBio-06 and NQBio-21). Additionally, acute toxicity of the compounds was evaluated in mice. The results from the MTT assay showed that NQBio-06 presented higher cytotoxicity in the ovarian cancer cell line TOV-21 G (IC50 = 2.5 µM, selectivity index = 23.7). NQBio-21 presented an IC50 of 6.9 µM and a selectivity index of 14.5 against MDA-MB-231 breast cancer cells. Comet assay results showed that NQBio-06 did not induce chromosomal breaks in vitro, but NQBio-21 was genotoxic with and without metabolic activation (S9 fraction). Micronucleus assay showed that both compounds were mutagenic. In addition, metabolic activation enhanced this effect in vitro. The in silico predictions showed that the compounds met the criteria set by Lipinski's rules, had strong prediction for intestinal absorption, and were possible substrates for P-glycoprotein. The in vivo results demonstrated that both the compounds exhibited low acute toxicity. These results suggest that the mechanisms underlying the cytotoxicity of NQBio-06 and NQBio-21 are related to DNA damage induction and that the use of S9 enhanced these effects. In vivo analysis showed signs of toxicity after a single administration of the compounds in mice. These findings highlight the potential of ß-carboline compounds as sources for the development of new anticancer chemotherapeutic agents.

Antibacterial and cytotoxic metabolites produced by Streptomyces tanashiensis BYF-112 isolated from Odontotermes formosanus.

Chemical investigations of the termite-associated Streptomyces tanashiensis BYF-112 resulted in the discovery of four novel alkaloid derivatives: vegfrecines A and B (1 and 2), exfoliazone A (3), and venezueline H (7), in addition to nine known metabolites (4-6, 8-13). The structures of these compounds were elucidated through comprehensive spectroscopic analysis and comparison with existing literature data. Antibacterial assays revealed that viridomycin A (11) exhibited potent antibacterial activity against Staphylococcus aureus, with a zone of inhibition (ZOI) of 12.67 mm, in comparison to a ZOI of 17.67 mm for the positive control gentamicin sulfate. Viridomycin A (11) showed moderate activity against Micrococcus tetragenus and Pseudomonas syringae pv. actinidae, with ZOI values of 15.50 and 14.33 mm, respectively, which were inferior to those of gentamicin sulfate (34.67 and 24.00 mm). Viridomycin F (12) also exhibited moderate antibacterial effects against S. aureus, M. tetragenus, and P. syringae pv. actinidae, with ZOI values of 8.33, 16.50, and 10.83 mm, respectively. Cytotoxicity assays demonstrated that viridobruunine A (5), exfoliazone (6), viridomycin A (11), and X-14881E (13) exhibited significant cytotoxicity against human malignant melanoma (A375), ovarian cancer (SKOV-3), and gastric cancer (MGC-803) cell lines, with IC50 values ranging from 4.61 to 19.28 µmol·L-1. Furthermore, bioinformatic analysis of the complete genome of S. tanashiensis suggested a putative biosynthetic gene cluster (BGC) responsible for the production of compounds 1-12. These findings indicate that the secondary metabolites of insect-associated S. tanashiensis BYF-112 hold promise as potential sources of novel antibacterial and anticancer agents.

In-Depth Analysis of Molecular Network Based on Liquid Chromatography Coupled with Tandem Mass Spectrometry in Natural Products: Importance of Redundant Nodes Discovery.

The identification of molecules within complex mixtures is a major bottleneck in natural products (NPs) research. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has emerged as the main tool for the high-throughput characterization of NPs. The large amount of data sets by LC-MS/MS presents a challenge for data processing and interpretation, and the LC-MS/MS molecular network (MN) is one of the most prominent tools for analyzing large MS/MS data sets, widely used for rapid classification, identification, and structural speculation of unknown compounds. However, the existence of a large number of redundant nodes leads to false-positive results. To solve this problem, we proposed the in-depth analysis of MN. In this study, in-depth analysis of MN of five NPs representing the common structures of saponin, steroid, flavonoid, alkaloid, and phenolic acid revealed the presence of redundant nodes (including other adducts, isotope, and in-source fragmentation) in addition to the normal nodes, which can lead to false-positive identification results. Additionally, the reasons for different redundant nodes are discussed and experimentally verified, and it was found that the impact of redundant nodes can be mitigated by optimizing the experimental conditions and employing Feature-Based Molecular Networking. Furthermore, Ion Identity Molecular Networking can rapidly discover and screen redundant nodes, simplifying the in-depth analysis of MN and improving the network connectivity of structurally related molecules. Finally, a combination formulation of 7 NPs is used as an example to provide a guide for in-depth analysis of MN for comprehensive characterization of complex systems. This study highlights the importance of an in-depth analysis of MN for better understanding and utilization of MS/MS data in complex systems to reduce the false-positive rate of identification by screening and filtering redundant nodes.