Synthesis and biological evaluation of new quinoline-4-carboxylic acid-chalcone hybrids as dihydroorotate dehydrogenase inhibitors.

Fourteen novel quinoline-4-carboxylic acid-chalcone hybrids were obtained via Claisen-Schmidt condensation and evaluated as potential human dihydroorotate dehydrogenase (hDHODH) inhibitors. The ketone precursor 2 was synthesized by the Pfitzinger reaction and used for further derivatization at position 3 of the quinoline ring for the first time. Six compounds showed better hDHODH inhibitory activity than the reference drug leflunomide, with IC50 values ranging from 0.12 to 0.58 µM. The bioactive conformations of the compounds within hDHODH were resolved by means of molecular docking, revealing their tendency to occupy the narrow tunnel of hDHODH within the N-terminus and to prevent ubiquinone as the second cofactor from easily approaching the flavin mononucleotide as a cofactor for the redox reaction within the redox site. The results of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay revealed that 4d and 4h demonstrated the highest cytotoxic activity against the A375 cell line, with IC50 values of 5.0 and 6.8 µM, respectively. The lipophilicity of the synthesized hybrids was obtained experimentally and expressed as logD7.4 values at physiologicalpH while the solubility assay was conducted to define physicochemical characteristics influencing the ADMET properties.

Untargeted Lipidomics Study of Bipolar Disorder Patients in Serbia.

The Lipidomic profiles of serum samples from patients with bipolar disorder (BD) and healthy controls (C) were explored and compared. The sample cohort included 31 BD patients and 31 control individuals. An untargeted lipidomics study applying liquid chromatography (LC) coupled with high-resolution mass spectrometry (HRMS) was conducted to achieve the lipid profiles. Multivariate statistical analyses (principal component analysis and partial least squares discriminant analysis) were performed, and fifty-six differential lipids were confirmed in BD and controls. Our results pointed to alterations in lipid metabolism, including pathways of glycerophospholipids, sphingolipids, glycerolipids, and sterol lipids, in BD patient sera. This study emphasized the role of lipid pathways in BD, and comprehensive research using the LC-HRMS platform is necessary for future application in the diagnosis and improvement of BD treatments.

Synthesis, Biological Evaluation and Docking Studies of Benzoxazoles Derived from Thymoquinone.

Thymoquinone (TQ), a natural compound with antimicrobial and antitumor activity, was used as the starting molecule for the preparation of 3-aminothymoquinone (ATQ) from which ten novel benzoxazole derivatives were prepared and characterized by elemental analysis, IR spectroscopy, mass spectrometry and NMR (¹H, 13C) spectroscopy in solution. The crystal structure of 4-methyl-2-phenyl-7-isopropyl-1,3-benzoxazole-5-ol (1a) has been determined by X-ray diffraction. All compounds were tested for their antibacterial, antifungal and antitumor activities. TQ and ATQ showed better antibacterial activity against tested Gram-positive and Gram-negative bacterial strains than benzoxazoles. ATQ had the most potent antifungal effect against Candida albicans, Saccharomyces cerevisiae and Aspergillus brasiliensis. Three benzoxazole derivatives and ATQ showed the highest antitumor activities. The most potent was 2-(4-fluorophenyl)-4-methyl-7-isopropyl-1,3-benzoxazole-5-ol (1f). Western blot analyses have shown that this compound inhibited phosphorylation of protein kinase B (Akt) and Insulin-like Growth Factor-1 Receptor (IGF1R ß) in HeLa and HepG2 cells. The least toxic compound against normal fibroblast cells, which maintains similar antitumor activities as TQ, was 2-(4-chlorophenyl)-4-methyl-7-isopropyl-1,3-benzoxazole-5-ol (1e). Docking studies indicated that 1e and 1f have significant effects against selected receptors playing important roles in tumour survival.

Discovery of small molecule inhibitors for the snake venom metalloprotease BaP1 using in silico and in vitro tests.

Snakebites represent an important public health problem, with a great number of victims with permanent sequelae or fatal outcomes, particularly in rural, agriculturally active areas. The snake venom metalloproteases (SVMPs) are the principal proteins responsible for some clinically-relevant effects, such as local and systemic hemorrhage, dermonecrosis, and myonecrosis. Because of the difficulties in neutralizing them rapidly and locally by antivenoms, the search and design of small molecules as inhibitors of SVMPs are proposed. The Bothrops asper metalloprotease P1 (BaP1) is hereby used as a target protein and by High Throughput Virtual Screening (HTVS) approach, the free access virtual libraries: ZINC, PubChem and ChEMBL, were searched for potent small molecule inhibitors. Results from the aforementioned approaches provided strong evidences on the structural requirements for the efficient BaP1 inhibition such as the presence of the pyrimidine-2,4,6-trione moiety. The two proposed compounds have also shown excellent results in performed in vitro interaction studies against BaP1.

Molecular Diversity of Compounds from Pygidial Gland Secretions of Cave-Dwelling Ground Beetles: The First Evidence.

Three adult cave-dwelling ground beetle species were induced to discharge secretions of their pygidial glands into vials. Dichloromethane extraction was used to obtain the secretions. In total, 42 compounds were identified by GC/MS analysis. Pheggomisetes ninae contained 32 glandular compounds, Laemostenus (Pristonychus) punctatus 13, whereas Duvalius (Paraduvalius) milutini had nine compounds. Caproic, oleic, palmitic, and stearic acids were present in the samples of all analyzed species. Undecane was predominant in the extract of L. punctatus. Palmitic acid was the major component in the secretion of D. milutini. Finally, the most abundant compounds in P. ninae secretion were heptacosene and nonacosadienes. Herein, we present the first data on the identification of pygidial gland secretion components in both troglophilous and troglobite cave-dwelling ground beetles. Some compounds are reported for the first time in the secretions of ground beetles and other higher or lower taxa. The adaptation to underground life has not led to a reduction or changes in the chemical defense mechanism in the analyzed troglophilous and troglobitic Platyninae and Trechinae taxa.

Synthesis of novel tetrahydrobenzazepine derivatives and their cytoprotective effect on human lymphocytes.

Cytoprotective compounds such as amifostine play an important role in chemo- and radiotherapy due to their ability to reduce the side effects of these treatments. Our work was initiated with the intention to design, synthesise and test a new class of heterocyclic compounds that would have an antioxidative profile with the potential to be further developed as cytoprotective agents. The design was based on the privileged tetrahydrobenzazepine scaffold found in many natural products with a wide range of biological properties. This structure was further functionalised with moieties known to possess antioxidative features such as tertiary amine and styrene double bond. A series of eight tetrahydrobenzazepine derivatives of isoquinoline, 3,4-dihydro-ß-carboline and pyridine were synthesised employing the Heck reaction as a key transformation. Some of the prepared compounds were tested for their in vitro effects on chromosome aberrations in peripheral human lymphocytes using the cytochalasin-B blocked micronucleus (MN) assay. Three tetrahydrobenzoazepine derivatives showed significant cytoprotective properties, comparable or even better to those of the radioprotective agent amifostine.

Antioxidative activity of diarylheptanoids from the bark of black alder (Alnus glutinosa) and their interaction with anticancer drugs.

Diarylheptanoids belong to polyphenols, a group of plant secondary metabolites with multiple biological properties. Many of them display antioxidative, cytotoxic, or anticancer actions and are increasingly recognized as potential therapeutic agents. The aim of this study was to evaluate antioxidant and cytoprotective activity of two diarylheptanoids: platyphylloside 5(S)-1,7-di(4-hydroxyphenyl)-3-heptanone-5-O-ß-D-glucopyranoside (1) and its newly discovered analog 5(S)-1,7-di(4-hydroxyphenyl)-5-O-ß-D-[6-(E-p-coumaroylglucopyranosyl)]heptane-3-one (2), both isolated from the bark of black alder (Alnus glutinosa). To that end, we have employed a cancer cell line (NCI-H460), normal human keratinocytes (HaCaT), and peripheral blood mononuclear cells. The effects on cell growth were assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay. Cell death was examined by annexin V/propidium iodide staining on a flow cytometer. Reactive oxygen species production was examined by dihydroethidium staining. Mitochondrial structure and doxorubicin localization were visualized by fluorescent microscopy. Gene expression of manganese superoxide dismutase and hypoxia-inducible factor-1α was determined by reverse transcription polymerase chain reaction. Diarylheptanoids antagonized the effects of either doxorubicin or cisplatin, significantly increasing their IC50 values in normal cells. Diarylheptanoid 1 induced the retention of doxorubicin in cytoplasm and reduced mitochondrial fragmentation associated with doxorubicin application. Diarylheptanoid 2 reduced the reactive oxygen species production induced by cisplatin. Both compounds increased the messenger ribonucleic acid expression of enzymes involved in reactive oxygen species elimination (manganese superoxide dismutase and hypoxia-inducible factor-1α). These results indicate that neutralization of reactive oxygen species is an important mechanism of diarylheptanoid action, although these compounds exert a considerable anticancer effect. Therefore, these compounds may serve as protectors of normal cells during chemotherapy without significantly diminishing the effect of the applied chemotherapeutic.

Isolation, characterization, and in vitro cytotoxicity of new sesquiterpenoids from Achillea clavennae.

Further phytochemical investigation of the aerial parts of Achillea clavennae has resulted in the isolation of three new sesquiterpene lactones: two highly oxygenated germacranolides (1, 2) and the iso-seco-guaianolide 9(R)-acetoxy-3-O-methyl-iso-seco-tanapartholide (3). Eight known compounds were also found, of which 9α-acetoxycanin (5), sintenin (6), and oleanolic acid (7) were detected for the first time. The structures of the isolated compounds were elucidated by combined spectroscopic methods (1D and 2D NMR, HRESIMS, CIMS, and FTIR). While the predominant metabolite germacranolide sintenin (6) was not cytotoxic, the new iso-seco-guaianolide (3) displayed cytotoxicity comparable to that of cisplatin and the lactone apressin (4), inducing partly apoptotic death in human U251 and rat C6 glioma cell lines.

Diarylheptanoids from green alder bark and their potential for DNA protection.

Nine diarylheptanoids, 1-9, catechin (11), and a phenolic glucoside, 10, were isolated from the bark of green alder (Alnus viridis). Four of the isolated compounds, i.e., 2, 5, 8, 10, are new. The structures of 1-11 were determined on the basis of spectroscopic data. All isolated compounds were evaluated for their in vitro protective effects on chromosome aberrations in peripheral human lymphocytes using cytokinesis-block micronucleus (CBMN) assay. Almost all of them exerted a pronounced effect of decreasing DNA damage of human lymphocytes, acting stronger than the known synthetic protector amifostine.

Chemical defense in millipedes (Myriapoda, Diplopoda): do representatives of the family Blaniulidae belong to the 'quinone' clade?

The defensive secretions of two blaniulid millipedes, Nopoiulus kochii and Cibiniulus phlepsii, were characterized by GC-FID and GC/MS analyses, which showed the presence of a complex mixture of benzoquinones, hydroquinones, and oleates. Altogether, 13 compounds were identified. The major compound in the secretions of both analyzed species was 2-methyl-1,4-benzoquinone (toluquinone). The second major constituent in the N. kochii secretion was 2-methyl-3,4-(methylenedioxy)phenol, while in that of C. phlepsii, it was 2-methoxy-3-methyl-1,4-benzoquinone. The defensive secretion of N. kochii also showed a high content of hydroquinones (13.5%) in comparison to that of C. phlepsii (0.8%). Hexyl oleate and octyl oleate were detected for the first time in defensive millipede fluids. The chemical composition of the defensive secretions supports the chemotaxonomic position of the family Blaniulidae in the 'quinone' millipede clade.

Pyrrolizidine alkaloids and fatty acids from the endemic plant species Rindera umbellata and the effect of lindelofine-N-oxide on tubulin polymerization.

The examination of the aerial parts, roots, and seeds of the endemic plant Rindera umbellata is reported in this paper for the first time. Phytochemical investigation of R. umbellata led to the isolation and characterization of ten pyrrolizidine alkaloids and eleven fatty acids in the form of triglycerides. Pyrrolizidine alkaloids 1-9 were found in the aerial parts, 7 and 8 in the roots, and 6-10, together with eleven fatty acids, in the seeds of this plant species. The structures of compounds 1-10 were established based on spectroscopic studies (¹H- and ¹³C-NMR, 2D NMR, IR and CI-MS). After trans-esterification, methyl esters of the fatty acids were analyzed using GC-MS. The effect of lindelofine-N-oxide (7) on tubulin polymerization was determined.

Metabolomic Profiling of Bipolar Disorder by 1H-NMR in Serbian Patients.

Bipolar disorder (BD) is a brain disorder that causes changes in a person's mood, energy, and ability to function. It has a prevalence of 60 million people worldwide, and it is among the top 20 diseases with the highest global burden. The complexity of this disease, including diverse genetic, environmental, and biochemical factors, and diagnoses based on the subjective recognition of symptoms without any clinical test of biomarker identification create significant difficulties in understanding and diagnosing BD. A 1H-NMR-based metabolomic study applying chemometrics of serum samples of Serbian patients with BD (33) and healthy controls (39) was explored, providing the identification of 22 metabolites for this disease. A biomarker set including threonine, aspartate, gamma-aminobutyric acid, 2-hydroxybutyric acid, serine, and mannose was established for the first time in BD serum samples by an NMR-based metabolomics study. Six identified metabolites (3-hydroxybutyric acid, arginine, lysine, tyrosine, phenylalanine, and glycerol) are in agreement with the previously determined NMR-based sets of serum biomarkers in Brazilian and/or Chinese patient samples. The same established metabolites (lactate, alanine, valine, leucine, isoleucine, glutamine, glutamate, glucose, and choline) in three different ethnic and geographic origins (Serbia, Brazil, and China) might have a crucial role in the realization of a universal set of NMR biomarkers for BD.

NMR Metabolomics in Serum Fingerprinting of Schizophrenia Patients in a Serbian Cohort.

Schizophrenia is a widespread mental disorder that leads to significant functional impairments and premature death. The state of the art indicates gaps in the understanding and diagnosis of this disease, but also the need for personalized and precise approaches to patients through customized medical treatment and reliable monitoring of treatment response. In order to fulfill existing gaps, the establishment of a universal set of disorder biomarkers is a necessary step. Metabolomic investigations of serum samples of Serbian patients with schizophrenia (51) and healthy controls (39), based on NMR analyses associated with chemometrics, led to the identification of 26 metabolites/biomarkers for this disorder. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) models with prediction accuracies of 0.9718 and higher were accomplished during chemometric analysis. The established biomarker set includes aspartate/aspartic acid, lysine, 2-hydroxybutyric acid, and acylglycerols, which are identified for the first time in schizophrenia serum samples by NMR experiments. The other 22 identified metabolites in the Serbian samples are in accordance with the previously established NMR-based serum biomarker sets of Brazilian and/or Chinese patient samples. Thirteen metabolites (lactate/lactic acid, threonine, leucine, isoleucine, valine, glutamine, asparagine, alanine, gamma-aminobutyric acid, choline, glucose, glycine and tyrosine) that are common for three different ethnic and geographic origins (Serbia, Brazil and China) could be a good start point for the setup of a universal NMR serum biomarker set for schizophrenia.

Leaf-surface guaianolides from Amphoricarpos neumaeyri showing protective effect on human lymphocytes DNA.

Analysis of composition of CH2Cl2 surface extract of leaves of Amphoricarpos neumayeri Vis. revealed 16 sesquiterpene lactones with guaianolide skeleton, so called amphoricarpolides, typical for this genus. Four of them, 13-16, were new derivatives and their structures were elucidated by detailed analyses of IR, NMR and MS data. Amphoricarpolide (9), its 15-O-acetyl derivative (5), and two 9ß-hydroxyamphoricarpolides, 3,15-di-O-acetyl- and 3-O-acetyl-15-O-isovaleroyl derivatives (3 and 6, respectively) were tested for in vitro protective effect on chromosome aberrations in peripheral human lymphocytes using cytochalasin-B blocked micronucleus (CBMN) assay. The tested compound exerted a beneficial effect by decreasing DNA damage of human lymphocytes.

Defensive secretions in three species of polydesmids (Diplopoda, Polydesmida, Polydesmidae).

Nine compounds were detected in three different millipede species: Polydesmus complanatus (L.), Brachydesmus (Stylobrachydesmus) avalae Curcic & Makarov, and Brachydesmus (Stylobrachydesmus) dadayi Verhoeff. Benzaldehyde, benzyl alcohol, benzoylnitrile, benzyl methyl ketone, benzoic acid, benzyl ethyl ketone, mandelonitrile, and mandelonitrile benzoate were identified by GC-FID and GC-MS analyses. Hydrogen cyanide was detected qualitatively by the picric acid test. Benzyl ethyl ketone, benzyl methyl ketone, and benzyl alcohol were detected for the first time in polydesmidan millipedes. Benzoylnitrile was the major component in all three hexane extracts. These compounds are suspected to be active in the defensive secretions of these millipede species.

Polymeric Nanocarriers of Drug Delivery Systems in Cancer Therapy.

Conventional chemotherapy is the most common therapeutic method for treating cancer by the application of small toxic molecules thatinteract with DNA and causecell death. Unfortunately, these chemotherapeutic agents are non-selective and can damage both cancer and healthy tissues,producing diverse side effects, andthey can have a short circulation half-life and limited targeting. Many synthetic polymers have found application as nanocarriers of intelligent drug delivery systems (DDSs). Their unique physicochemical properties allow them to carry drugs with high efficiency,specificallytarget cancer tissue and control drug release. In recent years, considerable efforts have been made to design smart nanoplatforms, including amphiphilic block copolymers, polymer-drug conjugates and in particular pH- and redox-stimuli-responsive nanoparticles (NPs). This review is focused on a new generation of polymer-based DDSs with specific chemical functionalities that improve their hydrophilicity, drug loading and cellular interactions.Recentlydesigned multifunctional DDSs used in cancer therapy are highlighted in this review.

Composition, Antioxidant Potential, and Antimicrobial Activity of Helichrysum plicatum DC. Various Extracts.

Helichrysum plicatum DC. is widely used in folk medicine in treating a variety of health disorders. The aim of this study was to examine the influence of different extraction solvents on the chemical composition, antioxidant potential, and antimicrobial activities of H. plicatum. Aerial parts were separately extracted with ethanol, dichloromethane, and sunflower oil. The oil extract (OE) was re-extracted with acetonitrile. A total of 142 compounds were tentatively identified in ethanolic (EE), dichloromethane (DCME), and acetonitrile (ACNE) extracts using HPLC-DAD/ESI-ToF-MS. The dominant compound class in all extracts were α-pyrones, alongside flavonoids in EE, terpenoids in DCME and ACNE, and phloroglucinols in DCME. The antioxidant potential of the extracts was assessed by the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) assay. EE and DCME possessed the most potent radical scavenging capacity. Antimicrobial activity was investigated on eight bacterial, two yeast, and one fungal species. All extracts exhibited high antifungal and notable antibacterial activities compared to control substances, with DCME being the most potent. DCME exhibited stronger antimicrobial activity against P. aeruginosa than the standard chloramphenicol.

Chemical Composition, Total Phenols and Flavonoids Contents and Antioxidant Activity as Nutritive Potential of Roasted Hazelnut Skins (Corylus avellana L.).

The present study evaluates natural composition of Serbian roasted hazelnut skins (HS) with potential role in application as functional nutrient of various food products. Total phenols (TPC) and flavonoids contents (TFC) in HS extracts obtained with different ethanol concentrations (10%-I, 50%-II and 96%-III) and their antioxidant activities were investigated. The highest total phenols content (706.0 ± 9.7 mgGAE/gextract) was observed in 96% ethanol HS extract. Ethanol HS extracts showed very high antioxidant activity with effective concentrations (EC50) ranged between 0.052 and 0.066 mg/mL. The phenol and flavonoid content of roasted HS extracts I-III was determined by HPLC-ESI-MS/MS analyses. Contents of lipids, proteins, carbohydrates, metals, and C, H, N, S elements in roasted HS were also determined. Relatively high C/N, C/P and C/N/P ratios, rich metal contents and fatty acids composition indicated that hazelnut skin might be a good candidate for use as either human or fungal functional nutrient. In addition, possible application of phenolic HS extracts as UV booster was studied by recording UV spectra (220-440 nm) of 10 mg/L of HS extracts I-III combined with 10 mg/L of chemical sunscreen agent benzophenone-3 and in vitro sun protection factor (SPF) was calculated.

Chemistry and morphology of the pygidial glands in four Pterostichini ground beetle taxa (Coleoptera: Carabidae: Pterostichinae).

Morphology of the pygidial glands and chemical composition of their secretions in adults of four ground beetle representatives of the Pterostichini tribe (Coleoptera: Carabidae) were analysed. Molops (Stenochoromus) montenegrinus, Pterostichus (Cophosus) cylindricus, P. (Feronidius) melas and P. (Pseudomaseus) nigrita were chemically tested, while the latter three species were morphologically investigated. Pterostichus (C.) cylindricus, P. (P.) nigrita and M. (S.) montenegrinus were chemically studied for the first time. Altogether, 23 chemical compounds were isolated using gas chromatography-mass spectrometry (GC-MS), of which some are new for Pterostichini or even Carabidae. Methacrylic acid was present in all species analysed. It was predominant in the secretion extract of P. (C.) cylindricus and P. (F.) melas. Isobutyric and 2-methylbutyric acids were the major components in the secretion of M. (S.) montenegrinus. Undecane, methacrylic and tiglic acids were the main components in the secretion of P. (P.) nigrita. The simplest chemical mixture was found in P. (C.) cylindricus (two compounds), while the most complex one was detected in P. (P.) nigrita (15 compounds). No significant differences in the chemical composition of the pygidial gland secretions were evidenced in P. (C.) cylindricus sampled from the same area and in the same season in two different years. Morphology of the pygidial glands of the studied species was analysed for the first time. Morphological features of the pygidial glands were observed using bright-field microscopy and nonlinear microscopy and described in details.

New aurone epoxide and auronolignan from the heartwood of Cotinus coggygria Scop.

New aurone epoxide, 2,10-oxy-10-methoxysulfuretin (14), and new auronolignan (15), named cotinignan A, were isolated by silica gel column and semipreparative HPLC chromatography from the methylene chloride/methanol extract of Cotinus coggygria Scop. heartwood. In addition, thirteen known secondary metabolites namely sulfuretin, 2,3-trans-fustin, fisetin, butin, butein, taxifolin, eriodictyol, 3',5,5',7-tetrahydroxyflavanone, 3',4',7-trihydroxyflavone, 3-O-methyl-2,3-trans-fustin, 3-O-galloyl-2,3-trans-fustin, ß-resorcylic acid and 3-O-ß-sitosterol glucoside were isolated as well. Their structures were elucidated by 1D and 2D NMR, HR-ESI-MS, IR and UV. Ten out of eleven isolated flavonoids possess 7, 3' and 4' hydroxy groups. These structural features could be considered as chemotaxonomic characteristic of flavonoids from C. coggygria. Cotinignan A (15) represents new subclass of secondary metabolites - auronolignans.