Hyperpolarized [1-13C]-pyruvate MRS evaluates immune potential and predicts response to radiotherapy in cervical cancer.

BACKGROUND: Monitoring pyruvate metabolism in the spleen is important for assessing immune activity and achieving successful radiotherapy for cervical cancer due to the significance of the abscopal effect. We aimed to explore the feasibility of utilizing hyperpolarized (HP) [1-13C]-pyruvate magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) to evaluate pyruvate metabolism in the human spleen, with the aim of identifying potential candidates for radiotherapy in cervical cancer. METHODS: This prospective study recruited six female patients with cervical cancer (median age 55 years; range 39-60) evaluated using HP [1-13C]-pyruvate MRI/MRS at baseline and 2 weeks after radiotherapy. Proton (1H) diffusion-weighted MRI was performed in parallel to estimate splenic cellularity. The primary outcome was defined as tumor response to radiotherapy. The Student t-test was used for comparing 13C data between the groups. RESULTS: The splenic HP [1-13C]-lactate-to-total carbon (tC) ratio was 5.6-fold lower in the responders than in the non-responders at baseline (p = 0.009). The splenic [1-13C]-lactate-to-tC ratio revealed a 1.7-fold increase (p = 0.415) and the splenic [1-13C]-alanine-to-tC ratio revealed a 1.8-fold increase after radiotherapy (p = 0.482). The blood leukocyte differential count revealed an increased proportion of neutrophils two weeks following treatment, indicating enhanced immune activity (p = 0.013). The splenic apparent diffusion coefficient values between the groups were not significantly different. CONCLUSIONS: This exploratory study revealed the feasibility of HP [1-13C]-pyruvate MRS of the spleen for evaluating baseline immune potential, which was associated with clinical outcomes of cervical cancer after radiotherapy. TRIAL REGISTRATION: ClinicalTrials.gov NCT04951921 , registered 7 July 2021. RELEVANCE STATEMENT: This prospective study revealed the feasibility of using HP 13C MRI/MRS for assessing pyruvate metabolism of the spleen to evaluate the patients' immune potential that is associated with radiotherapeutic clinical outcomes in cervical cancer. KEY POINTS: • Effective radiotherapy induces abscopal effect via altering immune metabolism. • Hyperpolarized 13C MRS evaluates patients' immune potential non-invasively. • Pyruvate-to-lactate conversion in the spleen is elevated following radiotherapy.

Dearomatization drives complexity generation in freshwater organic matter.

Dissolved organic matter (DOM) is one of the most complex, dynamic and abundant sources of organic carbon, but its chemical reactivity remains uncertain1-3. Greater insights into DOM structural features could facilitate understanding its synthesis, turnover and processing in the global carbon cycle4,5. Here we use complementary multiplicity-edited 13C nuclear magnetic resonance (NMR) spectra to quantify key substructures assembling the carbon skeletons of DOM from four main Amazon rivers and two mid-size Swedish boreal lakes. We find that one type of reaction mechanism, oxidative dearomatization (ODA), widely used in organic synthetic chemistry to create natural product scaffolds6-10, is probably a key driver for generating structural diversity during processing of DOM that are rich in suitable polyphenolic precursor molecules. Our data suggest a high abundance of tetrahedral quaternary carbons bound to one oxygen and three carbon atoms (OCqC3 units). These units are rare in common biomolecules but could be readily produced by ODA of lignin-derived and tannin-derived polyphenols. Tautomerization of (poly)phenols by ODA creates non-planar cyclohexadienones, which are subject to immediate and parallel cycloadditions. This combination leads to a proliferation of structural diversity of DOM compounds from early stages of DOM processing, with an increase in oxygenated aliphatic structures. Overall, we propose that ODA is a key reaction mechanism for complexity acceleration in the processing of DOM molecules, creation of new oxygenated aliphatic molecules and that it could be prevalent in nature.

New 1,2,3-Triazoles from (R)-Carvone: Synthesis, DFT Mechanistic Study and In Vitro Cytotoxic Evaluation.

Aseries of novel 1,4-disubstituted 1,2,3-triazoles were synthesized from an (R)-carvone terminal alkyne derivative via a Cu (I)-catalyzed azide-alkyne cycloaddition reaction using CuSO4,5H2O as the copper (II) source and sodium ascorbate as a reducing agent which reduces Cu (II) into Cu (I). All the newly synthesized 1,2,3-triazoles 9a-h were fully identified on the basis of their HRMS and NMR spectral data and then evaluated for their cell growth inhibition potential by MTS assay against HT-1080 fibrosarcoma, A-549 lung carcinoma, and two breast adenocarcinoma (MCF-7 and MDA-MB-231) cell lines. Compound 9d showed notable cytotoxic effects against the HT-1080 and MCF-7 cells with IC50 values of 25.77 and 27.89 µM, respectively, while compound 9c displayed significant activity against MCF-7 cells with an IC50 value of 25.03 µM. Density functional calculations at the B3LYP/6-31G* level of theory were used to confirm the high reactivity of the terminal alkyne as a dipolarophile. Quantum calculations were also used to investigate the mechanism of both the uncatalyzed and copper (I)-catalyzed azide-alkyne cycloaddition reaction (CuAAC). The catalyzed reaction gives complete regioselectivity via a stepwise mechanism streamlining experimental observations. The calculated free-energy barriers 4.33 kcal/mol and 29.35 kcal/mol for the 1,4- and 1,5-regioisomers, respectively, explain the marked regioselectivity of the CuAAC reaction.

An activatable and tumor-targeting NIR fluorescent probe for imaging of histone deacetylase 6 in cancer cells and in vivo.

An activatable and tumor-targeting near-infrared (NIR) fluorescent probe CyAc-RGD was synthesized for the imaging of histone deacetylase 6 (HDAC6). The probe exhibited higher sensitivity and specificity for HDAC6 detection in cancer cells. Moreover, CyAc-RGD demonstrated good tumor-targeting ability and realized HDAC6 imaging in vivo.

Anti-inflammatory Dimeric Benzophenones from an Endophytic Pleosporales Species.

Eight new polyketides, including three dimeric benzophenones, named dipleosporones A-C (1-3), three benzophenones (4-6), one xanthone (7), and one phenylbenzoate (8), along with seven known polyketides (9-15) were isolated from the fungus Pleosporales sp. YY-4. The structures of the new compounds were established on the basis of spectroscopic methods, including high-resolution electrospray ionization mass spectrometry and one- and two-dimensional nuclear magnetic resonance. This is the first report of a benzophenone dimer connection via a C bridge from natural sources. An anti-inflammatory assay indicated that the dimeric benzophenones (1-3) inhibited lipopolysaccharide-induced NO production in RAW 264.7 cells, with half-maximal inhibitory concentration (IC50) values ranging from 8.8 to 18.1 µM, being more potent than the positive control, dexamethasone (IC50 = 22.2 µM).

Anti-inflammatory Dimeric Tetrahydroxanthones from an Endophytic Muyocopron laterale.

Twelve new dimeric tetrahydroxanthones, muyocoxanthones A-L (1-12), were isolated from the endophytic fungus, Muyocopron laterale. Their structures were characterized on the basis of the interpretation of NMR and HRESIMS data. The absolute configurations of 1-10 and 12 were unambiguously determined by ECD spectrum data and single-crystal X-ray diffraction analysis. Compounds 2, 6, and 11 showed inhibitory activity against the LPS-induced production of nitric oxide (NO) in RAW 264.7 cells with IC50 values of 5.2, 1.3, and 5.1 µM, respectively.

Seco and Nor-seco Isodhilarane-Type Meroterpenoids from Penicillium purpurogenum and the Configuration Revisions of Related Compounds.

Seco and nor-seco isodhilarane-type meroterpenoids (SIMs and NSIMs) are mainly found in Penicillium fungi and have been characterized by highly congested polycyclic skeletons and a broad range of bioactivities. However, the literature reports inconsistent configuration assignments for some SIMs and NSIMs, due to their complex polycyclic systems and multichiral centers. Herein, we described eight SIMs and NSIMs isolated from the EtOAc extract of Penicillium purpurogenum, which led to the configuration revisions of purpurogenolide C (1a), berkeleyacetal B (2a), chrysogenolide F (3a), and berkeleyacetal C (4a) as compounds 1-4, respectively. Furthermore, extensive re-evaluation of the experimental and computational 13C NMR chemical shifts of the reported 39 SIMs and NSIMs provided an empirical approach for determining the C-9 relative configuration, according to the 13C NMR chemical shifts of C-9, which contributed to the configuration revisions of another three SIMs (5a and 6a) and NSIMs (7a), denoted as compounds 5-7, respectively. Biological assays indicated that compound 3 exhibited cytotoxic activity against HepG2 and A549 cell lines with IC50 values of 5.58 and 6.80 µM, respectively. Compounds 2-4, 8, 9, and 32 showed moderate hepatoprotective activity at 10 µM in the APAP-induced HepG2 cell injury model.

Hydroxamates as a potent skeleton for the development of metallo-ß-lactamase inhibitors.

Bacterial resistance caused by metallo-ß-lactamases (MßLs) has become an emerging public health threat, and the development of MßLs inhibitor is an effective way to overcome the resistance. In this study, thirteen novel O-aryloxycarbonyl hydroxamates were constructed and assayed against MßLs. The obtained molecules specifically inhibited imipenemase-1 (IMP-1) and New Delhi metallo-ß-lactamase-1, exhibiting an IC50 value in the range of 0.10-18.42 and 0.23-22.33 µM, respectively. The hydroxamate 5 was found to be the most potent inhibitor, with an IC50 of 0.1 and 0.23 µM using meropenem and cefazolin as substrates. ICP-MS analysis showed that 5 did not coordinate to the Zn(II) ions at the active site of IMP-1, while the rapid dilution, thermal shift and MALDI-TOF assays revealed that the hydroxamate formed a covalent bond with the enzyme. Cytotoxicity assays indicated that the hydroxamates have low toxicity in MCF-7 cells. This work provided a potent scaffold for the development of MßLs inhibitors.

Gwanakosides A and B, 6-Deoxy-α-l-talopyranose-Bearing Aromatic Metabolites from a Streptomyces sp. and Coculture with Pandoraea sp.

Single-strain cultivation of a mountain soil-derived Streptomyces sp. GA02 and its coculture with Pandoraea sp. GA02N produced two aromatic products, gwanakosides A and B (1 and 2, respectively). Their spectroscopic analysis revealed that 1 is a new dichlorinated naphthalene glycoside and 2 is a pentacyclic aromatic glycoside. The assignment of the two chlorine atoms in 1 was confirmed by the analysis of its band-selective CLIP-HSQMBC spectrum. The sugars in the gwanakosides were identified as 6-deoxy-α-l-talopyranose based on 1H-1H coupling constants, Rotating frame Overhauser enhancement spectroscopy (ROESY) NMR correlations, and chemical derivatization followed by spectroscopic and chromatographic analyses. The absolute configuration of 2, whose production was enhanced approximately 100-fold in coculture, was proposed based on a quantum mechanics-based chemical shift analysis method, DP4 calculations, and the chemically determined configuration of 6-deoxy-α-l-talopyranose. Gwanakoside A displayed inhibitory activity against pathogenic bacteria, including Staphylococcus aureus (MIC = 8 µg/mL) and Mycobacterium tuberculosis (MIC50 = 15 µg/mL), and antiproliferative activity against several human cancer cell lines (IC50 = 5.6-19.4 µM).

Desenvolvimento de inibidores duais de histona desacetilase 6 (HDAC6) e tirosina quinase (TQ) com vistas ao tratamento do câncer / Design of histone deacetylase 6 (HDAC6) and tyrosine kinase (TK) dual inhibitors for cancer treatment

Câncer é a denominação atribuída a um conjunto de doenças que são responsáveis pela segunda maior causa de morte no Brasil e no mundo. A quimioterapia figura entre uma das estratégias utilizadas para o tratamento e cura do câncer, sendo amplamente empregada em estratégias terapêuticas isoladas, ou em associação à radioterapia e cirurgia. A enzima histona desacetilase 6 (HDAC6) é responsável por desacetilar a cadeia lateral de N-acetillisinas em -tubulinas, desempanhando papel crítico na dinâmica do citoesqueleto celular, estando superexpressa em uma série de neoplasias. Neste sentido, na última década os receptores tirosina quinase (TQ) foram os principais alvos de fármacos aprovados para o tratamento do câncer e de doenças autoimunes e continuam atraindo a atenção de grupos de pesquisa dada a exorbitante diversidade do quinoma humano. É sabido que a monoterapia seja com inibidores de HDAC, seja com inibidores TQ, apresenta problemas de toxicidade, reações adversas, ineficácia, resistência e/ou recidiva. Diversos estudos relatam o desenvolvimento de inibidores duais de HDAC-TQ, almejando tanto a simplificação do tratamento, quanto sinergismo terapêutico e redução de efeitos adversos. Assim, o presente trabalho apresenta o planejamento, síntese e avaliação da citotoxicidade de inibidores duais, potencialmente seletivos para HDAC6 e receptores TQ. No total, 23 compostos foram sintetizados entre 2 a 4 etapas. Todos os compostos finais foram caracterizados por RMN (1H e 13C) e espectrometria de massas de alta resolução (HRMS). A citotoxicidade foi determinada pelo ensaio de MTT, em linhagens derivadas de tumores sólidos (HCT116 e MCF-7) e hematológicos (Jurkat e Namalwa). Os compostos apresentaram citotoxicidade em concentrações micro e nanomolares em todas as linhagens testadas, sendo que a linhagem MCF-7 foi a mais resistente à ação dos compostos, e as linhagens hematológicas foram as mais sensíveis. Os inibidores 4d-f foram os mais ativos na triagem por MTT, com IC50 iguais a 20, 30 e 50 nM, respectivamente, em células Jurkat. Estudos mecanísticos do efeito citotóxico indicaram que os compostos 4d-f exercem atividade de forma tempo-dependente, e majoritariamente por ação antiproliferativa, embora estímulos apoptóticos também tenham sido observados nos estudos. Simulações de ancoramento molecular (docking) e de relação entre as estruturas químicas dos compostos e suas respectivas atividades biológicas (REA) permitiram identificar padrões moleculares, propriedades físico-químicas e eletrônicas que potencialmente possuem relação com a atividade biológica dos compostos, permitindo futuras otimizações do arcabouço molecular desta série de compostos. Tomados em conjunto, os resultados deste trabalho revelam o potencial terapêutico de inibidores duais de HDAC6-TQ. Notadamente, os compostos apresentados aqui podem ser os primeiros potenciais inibidores duais de HDAC6-TQ a serem reportados na literatura

Cancer is the name of a series of diseases that are the second main cause of death in Brazil and worldwide. Chemotherapy is one of the main strategies to treat and cure cancer, and has been widely applied as a single therapeutic agent, and in association with radiotherapy and surgery. Histone deacetylase 6 (HDAC6) deacetylates N-acetyllysine side chains of tubulin, playing crucial role on cytoskeletal dynamics, and could be overexpressed in several cancers. Tyrosine kinase receptors (TK) have been the main targets of FDA-approved drugs through the last decade for both cancer and autoimmune diseases, and have been attracting special attention of research groups due to the exorbitant diversity of the human kinome. It is known that either HDAC or TK single therapy have toxicity issues, adverse effects, inefficacy, resistance and/or recidive. Therefore, many studies report the design of HDAC-TK dual inhibitors aiming simpler treatments, synergism of action and side effects reduction. Herein, the design, synthesis and cytotoxic evaluation of dual and selective HDAC6-TK inhibitors are presented. A total of 23 compounds were designed and synthesized through 2 to 4 steps. All final compounds were characterized by 1H/13C NMR and high-resolution mass spectrometry (HRMS). The cytotoxicity of compounds was determined by MTT assay for both solid (HCT116 and MCF-7 cells) and hematological cancers (Jurkat and Namalwa cells). Compounds exhibited micro and nanomolar ranges of cytotoxicity for all cell lines tested. MCF-7 cells were the most resistant against the treatment, and hematological cells were more susceptible to the cytotoxic effect of the compounds. Compounds 4d-f were the most actives in the MTT screening against Jurkat cells (IC50 = 20, 30 and 50 nM, respectively). Mechanistic studies regarding the cytotoxic effects of 4d-f indicated that the compounds induced cell death in a time-dependent manner mainly via cytostatic activity even though apoptotic stimuli were observed also. Molecular docking and structure-activity relationships (SARs) allowed the identification of molecular patterns, and physicochemical and electronic properties that potentially modulate the biological activity of these compounds, allowing further optimizations of the molecular scaffold for these series of compounds. Taken together, the results of this study reveal the therapeutic potential of HDAC6-TK dual inhibitors. Noteworthy, the compounds reported herein could be the first HDAC6-TK dual inhibitors ever reported in literature

Antioxidant and antimicrobial properties of dihydroquercetin esters

Abstract Flavonoids display various beneficial biological properties, such as antioxidant activity and low cytotoxicity, which make them useful ingredients in foods, pharmaceuticals, and functional cosmetics. In particular, dihydroquercetin (DHQ) is found in various forms, and its derivatives exhibit interesting biological properties. Herein, we report the synthesis of acetylated and butyrylated dihydroquercetin derivatives and their antimicrobial and antioxidant properties. The DHQ derivatives were identified using 1H and 13C NMR spectroscopies and high-performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry. The chemical stabilities of the acetylated dihydroquercetin derivatives were found to depend on the number of acetate groups, with 3,3',4',4,7-pentaacetyldihydroquercetin found to be the most stable acetylated dihydroquercetin. Furthermore, 7,3',4'-triacetyl- dihydroquercetin exhibited potent antioxidant activity, with an IC50 of 56.67 ± 4.79 µg/mL in the 1,1-diphenyl-2-picrylhydrazyl assay, with DHQ exhibiting a value of 32.41 ± 3.35 µg/mL. The reactive-oxygen-species-scavenging activity of 7,3',4'-triacetyldihydroquercetin was highest among the esters in the ferric reducing ability of plasma assay, but lower than that of DHQ. Overall, both DHQ and 7,3',4'-triacetyldihydroquercetin exhibited antimicrobial behavior against S. aureus and P. acnes using the paper disc assay. DHQ displayed a higher antimicrobial activity, with minimum inhibitory concentrations of 625 µg/mL (P. acnes), 2,500 µg/mL (S. aureus), and 5,000 µg/mL (E. coli). DHQ and acetylated dihydroquercetins are potentially useful as complex antioxidant and antimicrobial materials

Lentzeacins A-E, New Bacterial-Derived 2,5- and 2,6-Disubstituted Pyrazines from a BGC-Rich Soil Bacterium Lentzea sp. GA3-008.

Pyrazines (1,4-diazirines) are an important group of natural products that have tremendous monetary value in the food and fragrance industries and can exhibit a wide range of biological effects including antineoplastic, antidiabetic and antibiotic activities. As part of a project investigating the secondary metabolites present in understudied and chemically rich Actinomycetes, we isolated a series of six pyrazines from a soil-derived Lentzea sp. GA3-008, four of which are new. Here we describe the structures of lentzeacins A-E (1, 3, 5 and 6) along with two known analogues (2 and 4) and the porphyrin zincphyrin. The structures were determined by NMR spectroscopy and HR-ESI-MS. The suite of compounds present in Lentzea sp. includes 2,5-disubstituted pyrazines (compounds 2, 4, and 6) together with the new 2,6-disubstituted isomers (compounds 1, 3 and 5), a chemical class that is uncommon. We used long-read Nanopore sequencing to assemble a draft genome sequence of Lentzea sp. which revealed the presence of 40 biosynthetic gene clusters. Analysis of classical di-modular and single module non-ribosomal peptide synthase genes, and cyclic dipeptide synthases narrows down the possibilities for the biosynthesis of the pyrazines present in this strain.

Five New Terpenes with Cytotoxic Activity from Pestalotiopsis sp.

Five new compounds called Pestalotis A-E (1-5), comprising three monoterpene-lactone compounds (1-3), one tetrahydrobenzofuran derivative (4), and one sesquiterpene (5), were isolated from the EtOAc extract of Pestalotiopsis sp. The structures of the new compounds were elucidated by analysis of their NMR, HRMS, and ECD spectra, and the absolute configurations were established through the comparison of experimental and calculated ECD spectra. All compounds were tested for antitumor activity against SW-480, LoVo, HuH-7, and MCF-7. The results showed that compounds 2 and 4 exhibited potent antitumor activity against SW-480, LoVo, and HuH-7 cell lines. Furthermore, compound 4 was assessed against HuH-7, and the results indicated that the rate of apoptosis was dose-dependent.

Two New Isoprenoid Flavonoids from Sophora flavescens with Antioxidant and Cytotoxic Activities.

Sophora flavescens is a regularly used traditional Chinese medicine. In an attempt to discover adequate active agents, the isoprenoid flavonoids from S. flavescens were further investigated. In this work, two new compounds (1-2, kurarinol A-B) together with 26 known ones (3-28) were isolated and elucidated on the basis of extensive NMR, UV and MS analyses. Furthermore, the antioxidant activity of all constituents was assessed through ABTS, PTIO and DPPH methodologies and also were evaluated for cytotoxic activity by three tumor cell lines (HepG2, A549 and MCF7) and one human normal cell line (LO2 cells). As a result, a multitude of components revealed significant inhibitory activity. In particular, compound 1-2 (kurarinol A-B), two new flavanonols derivatives, exhibited the most potent ABTS inhibitory activity with IC50 of 1.21 µg/mL and 1.81 µg/mL, respectively. Meanwhile, the new compound 1 demonstrated remarkable cytotoxicity against three cancer cells lines with IC50 values ranging from 7.50-10.55 µM but showed little effect on the normal cell. The two new isoprenoid flavonoids could be promising antioxidant and anti-tumor nature agents.

Dianthiamides A-E, Proline-Containing Orbitides from Dianthus chinensis.

Orbitides are plant-derived small cyclic peptides with a wide range of biological activities. Phytochemical investigation of the whole plants of Dianthus chinensis was performed with the aim to discover new bioactive orbitides. Five undescribed proline-containing orbitides, dianthiamides A-E (1-5), were isolated from a methanolic extract of Dianthus chinensis. Their structures were elucidated by extensive analysis of 1D and 2D NMR and HRESI-TOF-MS as well as ESI-MS/MS fragmentation data. The absolute configuration of the amino acid residues of compounds 1-5 was determined by Marfey's method. All compounds were tested for their cytotoxic activity, and dianthiamide A (1) exhibited weak activity against A549 cell line with IC50 value of 47.9 µM.

Precious metal complexes of bis(pyridyl)allenes: synthesis and catalytic and medicinal applications.

The incorporation of donor-type substituents on the allene core opens up the possibility of coordination complexes in which the metal is bonded to the donor groups, with or without interaction with the double bond system. Despite the challenges in the synthesis of such allene-containing metal complexes, their unique 3D environments and dual functionality (allene and metal) could facilitate catalysis and interaction with chemical and biological systems. Bis(pyridyl)allenes are presented here as robust ligands for novel Pd(II), Pt(IV) and Au(III) complexes. Their synthesis, characterisation and first application as catalysts of benchmark reactions for Pd, Pt and Au are presented with interesting reactivity and selectivities. The complexes have also been probed as antimicrobial and anticancer agents with promising activities, and the first studies on their unusual interaction with several DNA structures will open new avenues for research in the area of metallodrugs with new mechanisms of action.

Design, synthesis and biological evaluation of N-oxide derivatives with potent in vivo antileishmanial activity.

Leishmaniasis is a neglected disease that affects 12 million people living mainly in developing countries. Herein, 24 new N-oxide-containing compounds were synthesized followed by in vitro and in vivo evaluation of their antileishmanial activity. Compound 4f, a furoxan derivative, was particularly remarkable in this regard, with EC50 value of 3.6 µM against L. infantum amastigote forms and CC50 value superior to 500 µM against murine peritoneal macrophages. In vitro studies suggested that 4f may act by a dual effect, by releasing nitric oxide after biotransformation and by inhibiting cysteine protease CPB (IC50: 4.5 µM). In vivo studies using an acute model of infection showed that compound 4f at 7.7 mg/Kg reduced ~90% of parasite burden in the liver and spleen of L. infantum-infected BALB/c mice. Altogether, these outcomes highlight furoxan 4f as a promising compound for further evaluation as an antileishmanial agent.

Trimeric and Dimeric Carbazole Alkaloids from Murraya microphylla.

Seventeen new carbazole alkaloid derivatives, including a trimeric carbazole racemate, (±)-microphyltrine A (1), 15 dimeric carbazole racemates, (±)-microphyldines A-O (2-16), and a C-6-C-3″-methyl-linked dimeric carbazole, microphyldine P (17), were isolated from the leaves and stems of Murraya microphylla (Merr. et Chun) Swingle. The structures of the new compounds were elucidated on the basis of HRESIMS and NMR data analysis. The optically pure isomers of these isolated carbazole alkaloids were obtained by chiral HPLC separation and their absolute configurations were determined by electronic circular dichroism (ECD) data analysis.

Characterization and immunomodulatory activity of sulfated galactan from the red seaweed Gracilaria fisheri.

Polysaccharides from the red seaweed Gracilaria fisheri possess many functions, which include antioxidant, antiviral, and antibacterial activities. However, detailed data on their immunomodulatory activities are scarce. Here, we isolated sulfated galactans (SG) from G. fisheri. We found that the predominant SG from G. fisheri, termed SG-1, had an estimated molecular mass of 100 kDa and activated murine J774A.1 macrophages via the dectin-1 signaling pathway. Furthermore, we observed enhancement of nitric oxide (NO) secretion, increased expression of inducible nitric oxide synthase (iNOS) mRNA, and increased mRNA levels of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukins IL-1ß and IL-6 by SG-1 in macrophages. Moreover, there was higher expression of intercellular adhesion molecule 1 (ICAM-1) and co-stimulatory molecules (B7-1 and B7-2) mRNA. Treatment with G. fisheri SG-1 at 50 µg/mL generally achieved or exceeded the pro-inflammatory activities of 100 ng/mL lipopolysaccharide. Our study demonstrates immune-stimulatory activities of G. fisheri SG that may be of value for immune-potentiating treatment in humans or livestock.

Purification and comparative study of bioactivities of a natural selenized polysaccharide from Ganoderma Lucidum mycelia.

The development of selenized polysaccharides is a promising strategy for the dietary selenium supplementation. The purpose of this research is to determine the influence of selenium on the structure and bioactivity of a polysaccharide fraction (MPN) isolated from Ganoderma lucidum mycelia. After biological selenium enrichment, the selenium content in the selenized polysaccharide (SeMPN) was 18.91 ± 1.8 µg/g. SeMPN had a slightly lower molecular weight than MPN, but the carbohydrate content and monosaccharide composition remained identical. Additionally, the band at 606 cm-1 in MPN changed to 615 cm-1 in SeMPN as revealed by FT-IR spectra. No significant changes were observed in the types and ratios of glycosidic linkages, as determined by NMR spectroscopy. Extracellular and intracellular antioxidant assays demonstrated that SeMPN was more effective than MPN in scavenging free radicals, inhibiting AAPH-induced erythrocyte hemolysis, and protecting catalase (CAT) and glutathione peroxidase (GSH-Px) activity in H2O2-injured PC12 cells. Additionally, SeMPN had a higher increase effect on RAW 264.7 cells's pinocytic and phagocytic capacity, as well as their production of NO, TNF-α, and IL-6. SeMPN could be as potential functional selenium supplementation.