Bioactive Derivatives Research Articles

A colon-targeted podophyllotoxin nanoprodrug: synthesis, characterization, and supramolecular hydrogel formation for the drug combination.

Making full use of the undeveloped bioactive natural product derivatives by selectively delivering them to target sites can effectively increase their druggability and reduce the wastage of resources. Azo-based prodrugs are widely regarded as an effective targeted delivery means for colon-related disease treatment. Herein, we report a new-type of azo-based nanoprodrug obtained from bioactive natural products, in which the readily available podophyllotoxin natural products are connected with methoxy polyethylene glycol (mPEG) via a multifunctional azobenzene group. The amphiphilic prodrug can form nanosized micelles in water and will be highly selectively activated by azoreductases, leading to the in situ generation of anticancer podophyllotoxin derivatives (AdP) in the colon after the cleavage of the azo bond. To satisfy the demand of drug carriers for cancer combination therapy in clinics, α-CD is further introduced into this nanoprodrug micelle system to form a supramolecular hydrogel via a cascade self-assembly strategy. Using imaging mass spectrometry (IMS), the colon-specific drug release ability of the hydrogel after oral administration is demonstrated at the molecular level. Finally, the nanoprodrug hydrogel is further used as a carrier to load a hydrophilic anti-cancer drug 5-FU during the hierarchical self-assembly process and to co-deliver AdP and 5-FU for the drug combination. The combination use of AdP and 5-FU provides enhanced cytotoxicity which indicates a significant synergistic interaction. This work offers a new way to enhance the therapeutic effect of nanoprodrugs via drug combination, and provides a new strategy for reusing bioactive natural products and their derivatives.

Molecular Docking and In Vivo Screening of Some Bioactive Phenoxyacetanilide Derivatives as Potent Non-Steroidal Anti-Inflammatory Drugs

Molecular Docking and In Vivo Screening of Some Bioactive Phenoxyacetanilide Derivatives as Potent Non-Steroidal Anti-Inflammatory Drugs

Changes in retinoid metabolism and signaling associated with metabolic remodeling during fasting and in type I diabetes

Liver is the central metabolic hub that coordinates carbohydrate and lipid metabolism. The bioactive derivative of vitamin A, retinoic acid (RA), was shown to regulate major metabolic genes including phosphoenolpyruvate carboxykinase, fatty acid synthase, carnitine palmitoyltransferase 1, and glucokinase among others. Expression levels of these genes undergo profound changes during adaptation to fasting or in metabolic diseases such as type 1 diabetes (T1D). However, it is unknown whether the levels of hepatic RA change during metabolic remodeling. This study investigated the dynamics of hepatic retinoid metabolism and signaling in the fed state, in fasting, and in T1D. Our results show that fed-to-fasted transition is associated with significant decrease in hepatic retinol dehydrogenase (RDH) activity, the rate-limiting step in RA biosynthesis, and downregulation of RA signaling. The decrease in RDH activity correlates with the decreased abundance and altered subcellular distribution of RDH10 while Rdh10 transcript levels remain unchanged. In contrast to fasting, untreated T1D is associated with upregulation of RA signaling and an increase in hepatic RDH activity, which correlates with the increased abundance of RDH10 in microsomal membranes. The dynamic changes in RDH10 protein levels in the absence of changes in its transcript levels imply the existence of posttranscriptional regulation of RDH10 protein. Together, these data suggest that the downregulation of hepatic RA biosynthesis, in part via the decrease in RDH10, is an integral component of adaptation to fasting. In contrast, the upregulation of hepatic RA biosynthesis and signaling in T1D might contribute to metabolic inflexibility associated with this disease.

Bioactive cyclohexene derivatives from a mangrove-derived fungus Cladosporium sp. JJM22

Four new cyclohexene derivatives cladoscyclitols A–D (1–4) and one new ribofuranose phenol derivative 4-O-α-D-ribofuranose-2-pentyl-3-phemethylol (5) were obtained from the EtOAC extract of the mangrove-derived endophytic fungus Cladosporium sp. JJM22. The structures were elucidated by extensive NMR and MS analysis, while the absolute configurations of the stereogenic carbons were established based on quantum-chemical electronic circular dichroism calculations or comparison of the optical rotations with those of related compounds. Compounds 2 and 5 displayed potent inhibitory activity against α-glucosidase with the IC50 values of 2.95 and 2.05 μM, respectively.

Synthesis and evaluation for anticonvulsant activity of some N-(5-(substituted)-1,3,4-thiadiazol-2-yl)-2-((5-(substituted)-4H-1,2,4-triazol-3-yl)-amino) acetamide derivatives

Several new promising bioactive derivatives of N-(5-(Substituted)-1, 3, 4-thiadiazol-2-yl)-2-((5-(substitutes)-4H-1, 2, 4-triazol-3-yl) amino) acetamide were synthesized. The compounds were obtained in excellent yields. The synthesized compounds were confirmed on the basis of IR and NMR. Acute toxicity study was done to determine the LD50 of the newly synthesized compounds. Some of the synthesized compounds were evaluated for their anticonvulsant effect by PTZ induced convulsions method. Statistical testing was done by one way ANOVA followed by Dunnett’s test. The compounds D-III showed the highest percentage of protection as compared to PTZ, i.e. 80% at the dose of 20mg/kg among the evaluated compounds compared to control. Keywords: 1, 3, 4-thiadiazole, 1, 2, 4-triazole, Anticonvulsant

Brassica Bioactives Could Ameliorate the Chronic Inflammatory Condition of Endometriosis.

Endometriosis is a chronic, inflammatory, hormone-dependent disease characterized by histological lesions produced by the presence of endometrial tissue outside the uterine cavity. Despite the fact that an estimated 176 million women are affected worldwide by this gynecological disorder, risk factors that cause endometriosis have not been properly defined and current treatments are not efficient. Although the interaction between diet and human health has been the focus of many studies, little information about the correlation of foods and their bioactive derivates with endometriosis is available. In this framework, Brassica crops have emerged as potential candidates for ameliorating the chronic inflammatory condition of endometriosis, due to their abundant content of health-promoting compounds such as glucosinolates and their hydrolysis products, isothiocyanates. Several inflammation-related signaling pathways have been included among the known targets of isothiocyanates, but those involving aquaporin water channels have an important role in endometriosis. Therefore, the aim of this review is to highlight the promising effects of the phytochemicals present in Brassica spp. as major candidates for inclusion in a dietary approach aiming to improve the inflammatory condition of women affected with endometriosis. This review points out the potential roles of glucosinolates and isothiocyanates from Brassicas as anti-inflammatory compounds, which might contribute to a reduction in endometriosis symptoms. In view of these promising results, further investigation of the effect of glucosinolates on chronic inflammatory diseases, either as diet coadjuvants or as therapeutic molecules, should be performed. In addition, we highlight the involvement of aquaporins in the maintenance of immune homeostasis. In brief, glucosinolates and the modulation of cellular water by aquaporins could shed light on new approaches to improve the quality of life for women with endometriosis.

DFT, SERS-concentration and solvent dependent and docking studies of a bioactive benzenesulfonamide derivative

Spectroscopic analysis, DFT studies and surface enhanced Raman scattering (SERS) of antimicrobial bioactive 4-[(5-tert-butyl)2-hydroxybenzylidene]amino-N-(4,6-dimethylpyrimidin-2-yl)benzenesulfonamide (THPB) have been studied on different silver sols. Intensity and hence enhancement variations are observed for Raman and SERS bands. Observed changes in the ring modes may be due to surface π-electron interactions and presence of this indicated that molecule is inclined with respect to the metal surface. Changes in orientation are seen in SERS spectra depending on concentration. The molecular docking results show that binding affinity and interactions with the receptors may be supporting evidence for further studies in design further THPB pharmaceutical applications. Reactivity properties are obtained from DFT analysis.

Bioactive sesquiterpene derivatives from mangrove endophytic fungus Phomopsis sp. SYSU-QYP-23: Structures and nitric oxide inhibitory activities

Eight new sesquiterpene derivatives (2, 4–6 and 10–13), along with five known analogues were isolated from the mangrove endophytic fungus Phomopsis sp. SYSU-QYP-23. Their structures of new compounds were established by spectroscopic methods, and the absolute configurations were confirmed by single-crystal X-ray diffraction analysis and comparison of the experimental ECD spectra. The absolute configuration of the side chain in 1 was first defined by modified Mosher’s method. Compounds 1–7 showed potent inhibitory activities against nitric oxide (NO) production in lipopolysaccharides (LPS) induced RAW 264.7 cells with IC50 values ranging from 8.6 to 14.5 μM. The molecular docking results implied that the bioactive sesquiterpenes may directly bind with targeting residues in the active cavity of iNOS protein.

PSIX-28 Examining the effects of estradiol, trenbolone acetate, or polyamines on bovine satellite cell differentiation

Abstract The mechanism through which anabolic implants improve skeletal muscle growth of beef animals is incompletely understood. Polyamines (PA) are bioactive amino acid derivatives that act as potent growth stimulants. The objective of this study was to determine effects of anabolic implants, PA and their precursors on bovine satellite cell (BSC) differentiation. Primary BSC were cultured to approximately 80% confluency, at which time they were induced to differentiate in the presence of 3% horse serum (Con) and treated with 10nM TBA, 10 nM E2, or 10nM TBA and 10 nM E2 (ETBA), 10 mM methionine (Met), 8 mM ornithine (Orn), 2 mM putrescine (Put), 1.5 mM spermidine (Spd) or 0.5 mM spermine (Spe). Total mRNA was isolated 0, 2, 4, 8, 12, 24, or 48 h post-treatment and abundance of paired box transcription factor 7 (Pax7) and myogenic differentiation factor (MyoD) were analyzed. Treatment with the hormones (TBA, E2, or ETBA) and PA (Orn, Put, Spd, and Spe) increased (P < 0.05) abundance of MyoD 4 h post-treatment when compared to Con cultures. However, 24 h post-treatment, MyoD abundance was decreased in the presence of hormone treatments when compared to the Con, while the PA treatments increased (P < 0.05) abundance of MyoD when compared to the Con cultures. Treatment with either the hormones or PA had no effect (P > 0.05) on Pax7 abundance at 2, 4, 8, 12, 24, or 48 h post-treatment when compared to Con cultures (P > 0.05). These results indicate that treatment with PA or hormones increases abundance of MyoD, though temporally different indicating that these two classes of growth promoters impact differentiation via alternate physiological pathways. Additional research is underway in order to determine the effects of both PA and hormones on differentiation of primary BSC.

Design, Synthesis and Evaluation of New Bioactive Oxadiazole Derivatives as Anticancer Agents Targeting Bcl-2.

A series of 2-(1H-indol-3-yl)-5-substituted-1,3,4-oxadiazoles, 4a–m, were designed, synthesized and tested in vitro as potential pro-apoptotic Bcl-2 inhibitory anticancer agents based on our previously reported hit compounds. Synthesis of the target 1,3,4-oxadiazoles was readily accomplished through a cyclization reaction of indole carboxylic acid hydrazide 2 with substituted carboxylic acid derivatives 3a–m in the presence of phosphorus oxychloride. New compounds 4a–m showed a range of IC50 values concentrated in the low micromolar range selectively in Bcl-2 positive human cancer cell lines. The most potent candidate 4-trifluoromethyl substituted analogue 4j showed selective IC50 values of 0.52–0.88 μM against Bcl-2 expressing cell lines with no inhibitory effects in the Bcl-2 negative cell line. Moreover, 4j showed binding that was two-fold more potent than the positive control gossypol in the Bcl-2 ELISA binding affinity assay. Molecular modeling studies helped to further rationalize anti-apoptotic Bcl-2 binding and identified compound 4j as a candidate with drug-like properties for further investigation as a selective Bcl-2 inhibitory anticancer agent.

Biscoumarin Derivatives as Potent anti-Microbials: Graphene Oxide Catalyzed Eco-Benign Synthesis, Biological Evaluation and Docking Studies

A heterogeneous, inexpensive and eco-friendly graphene oxide (GO) catalyst empowered the formation of bioactive biscoumarin derivatives involving domino Knoevenagel–Michael condensation using 4-hydroxycoumarin and aromatic aldehydes in H2O: EtOH solvent system. The prepared GO was well characterized by Fourier transform infrared (FT-IR), X-ray diffraction spectroscopy (XRD), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM) and thermogravimetric analysis (TGA). In this efficient, green, and sustainable one-pot synthesis, the target products were obtained in excellent yields (76–97%) in short reaction time (10–20 min.) and the catalyst can be easily recoverable and reusable for five consecutive cycles. Moreover, the use of economical and easily available substrate, low catalyst loading, shorter reaction time, gram scale applicability and high atom economy are the additional advantages of this greener approach. The inhibitory activity of the synthesized compounds was tested against two species of Gram-negative bacteria (E.Coli MTCC 46 and P. aeruginosa MTCC 2488), two species of Gram-positive bacteria (S. aureus MTCC 6980 and B. megaterium MTCC) and fungus (A. niger MTCC 1344) using the broth microdilution method. The electron withdrawing substituents like -CN, –F, and –Cl exhibited excellent activity against gram negative bacteria as compared to gram positive bacteria. Additionally, in silico studies were carried out on the selected DNA gyrase (1KZN) and human lanosterol 14 alpha-demethylase CYP51 (3LD6) to study the docking interactions of the synthesized compounds. It was observed that out of all the docked compounds, 4e (−23.966 kcal/mol) and 4i (−24.976 kcal/mol) showed highest docking score against 1KZN and 3LD6 protein, respectively.

The effect of a duodenal-jejunal bypass liner on lipid profile and blood concentrations of long chain polyunsaturated fatty acids

Duodenal-jejunal bypass liners (DJBLs) prevent absorption in the proximal small intestine, the site of fatty acid absorption. We sought to investigate the effects of a DJBL on blood concentrations of essential fatty acids (EFAs) and bioactive polyunsaturated fatty acids (PUFAs). Sub-study of a multicentre, randomised, controlled trial with two treatment groups. Patients aged 18-65 years with type-2 diabetes mellitus and body mass index 30-50kg/m2 were randomised to receive a DJBL for 12 months or best medical therapy, diet and exercise. Whole plasma PUFA concentrations were determined at baseline, 10 days, 6 and 11.5 months; data were available for n=70 patients per group. Weight loss was significantly greater in the DJBL group compared to controls after 11.5 months: total body weight loss 11.3±5.3% versus 6.0±5.7% (mean difference [95% CI]=5.27% [3.75, 6.80], p<0.001). Absolute concentrations of both EFAs, linoleic acid and α-linolenic acid, and their bioactive derivatives, arachidonic acid, eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid, were significantly lower in the DJBL group than in the control group at 6 and 11.5 months follow-up. Total serum cholesterol, LDL-cholesterol and HDL-cholesterol were also significantly lower in the DJBL group. One year of DJBL therapy is associated with superior weight loss and greater reductions in total serum cholesterol and LDL-cholesterol, but also depletion of EFAs and their longer chain derivatives. DJBL therapy may need to be offset by maintaining an adequate dietary intake of PUFAs or by supplementation. ClinicalTrials.gov Identifier NCT02459561.

Oxidized Juncuenin B Analogues with Increased Antiproliferative Activity on Human Adherent Cell Lines: Semisynthesis and Biological Evaluation.

Phenanthrenes have become the subject of intensive research during the past decades because of their structural diversity and wide range of pharmacological activities. Earlier studies demonstrated that semisynthetic derivatization of these natural compounds could result in more active agents, and oxidative transformations are particularly promising in this regard. In our work, a natural phenanthrene, juncuenin B, was transformed by hypervalent iodine(III) reagents using a diversity-oriented approach. Eleven racemic semisynthetic compounds were produced, the majority containing an alkyl substituted p-quinol ring. Purification of the compounds was carried out by chromatographic techniques, and their structures were elucidated by 1D and 2D NMR spectroscopic methods. Stereoisomers of the bioactive derivatives were separated by chiral-phase HPLC and the absolute configurations of the active compounds, 2,6-dioxo-1,8a-dimethoxy-1,7-dimethyl-8-vinyl-9,10-dihydrophenanthrenes (1a–d), and 8a-ethoxy-1,7-dimethyl-6-oxo-8-vinyl-9,10-dihydrophenanthrene-2-ols (7a,b) were determined by ECD measurements and TDDFT-ECD calculations. The antiproliferative activities of the compounds were tested on different (MCF-7, T47D, HeLa, SiHa, C33A, A2780) human gynecological cancer cell lines. Compounds 1a–d, 4a, 6a, and 7a possessed higher activity than juncuenin B on several tumor cell lines. The structure–activity relationship studies suggested that the p-quinol (2,5-cyclohexadien-4-hydroxy-1-one) moiety has a considerable effect on the antiproliferative properties, and substantial differences could be identified in the activities of the stereoisomers.

Exploring Aurone Derivatives as Potential Human Pancreatic Lipase Inhibitors through Molecular Docking and Molecular Dynamics Simulations.

Inhibition of human pancreatic lipase, a crucial enzyme in dietary fat digestion and absorption, is a potent therapeutic approach for obesity treatment. In this study, human pancreatic lipase inhibitory activity of aurone derivatives was explored by molecular modeling approaches. The target protein was human pancreatic lipase (PDB ID: 1LPB). The 3D structures of 82 published bioactive aurone derivatives were docked successfully into the protein catalytic active site, using AutoDock Vina 1.5.7.rc1. Of them, 62 compounds interacted with the key residues of catalytic trial Ser152-Asp176-His263. The top hit compound (A14), with a docking score of −10.6 kcal⋅mol−1, was subsequently submitted to molecular dynamics simulations, using GROMACS 2018.01. Molecular dynamics simulation results showed that A14 formed a stable complex with 1LPB protein via hydrogen bonds with important residues in regulating enzyme activity (Ser152 and Phe77). Compound A14 showed high potency for further studies, such as the synthesis, in vitro and in vivo tests for pancreatic lipase inhibitory activity.

Effect of omega-3 lcpufa supplementation on maternal fatty acid and oxylipin concentrations during pregnancy

Omega-3 long chain polyunsaturated fatty acids (LCPUFA) have been associated with a reduction in risk for preterm birth. However, there is limited understanding of how fatty acids and their bioactive derivatives (oxylipins) change over the course of pregnancy. Here we document the changes in concentration of fatty acids and oxylipins during pregnancy and how fatty acid status and oxylipin concentrations are affected by supplementation with omega-3 LCPUFA. We also investigate the degree to which fatty acid and oxylipin changes across pregnancy are influenced by baseline omega-3 status. We profiled the fatty acids in all lipids in dried blood spots (total blood fatty acids) by gas chromatography and free (unesterified) fatty acids and their associated oxylipins in separate dried blood spot samples by LC-MS-MS collected from a random sample of 1263 women with a singleton pregnancy who participated in the ORIP (Omega-3 fats to Reduce the Incidence of Prematurity) trial. ORIP is a double-blind, randomized controlled trial involving 5544 participants and designed to determine the effect of supplementing the diets of pregnant women with omega-3 LCPUFA on the incidence of early preterm birth. Maternal whole blood finger prick samples were collected at baseline (~14 weeks gestation) and at completion of the study intervention period (34 weeks gestation). The concentration of most total and free polyunsaturated fatty acids and their associated oxylipins declined over the course of pregnancy. Omega-3 LCPUFA supplementation increased total DHA and 7-HDHA and mitigated the decline in free DHA, 4-HDHA and 14-HDHA. The intervention had minimal or no effect on free EPA, LA, AA and their associated oxylipins. Omega-3 LCPUFA supplementation in women with higher omega-3 status at baseline was associated with a significant increase in 7-HDHA and 4-HDHA between the treatment and control whereas there were no differences between groups in 7-HDHA and 4-HDHA in women with intermediate or lower baseline omega-3 status. Our data suggest a differential response with or without omega-3 supplementation for DHA and DHA-derived oxylipins, which may have an important role to play in modulating pregnancy duration. Further work is needed to understand their role, which may allow us to better tailor omega-3 supplementation for preterm birth prevention.

Visible-Light-Driven Anti-Markovnikov Hydrocarboxylation of Acrylates and Styrenes with CO 2

Light-driven carbon dioxide (CO2) capture and utilization is one of the most fundamental reactions in Nature. Herein, we report the first visible-light-driven photocatalyst-free hydrocarboxylation ...

Regioselective functionalization of aryl azoles as powerful tool for the synthesis of pharmaceutically relevant targets

Aryl azole scaffolds are present in a wide range of pharmaceutically relevant molecules. Their ortho-selective metalation at the aryl ring is challenging, due to the competitive metalation of the more acidic heterocycle. Seeking a practical access to a key Active Pharmaceutical Ingredient (API) intermediate currently in development, we investigated the metalation of 1-aryl-1H-1,2,3-triazoles and other related heterocycles with sterically hindered metal-amide bases. We report here a room temperature and highly regioselective ortho-magnesiation of several aryl azoles using a tailored magnesium amide, TMPMgBu (TMP = 2,2,6,6-tetramethylpiperidyl) in hydrocarbon solvents followed by an efficient Pd-catalyzed arylation. This scalable and selective reaction allows variation of the initial substitution pattern of the aryl ring, the nature of the azole moiety, as well as the nature of the electrophile. This versatile method can be applied to the synthesis of bioactive azole derivatives and complements existing metal-mediated ortho-functionalizations.

A New Reactive Ketenaminal: Synthesis, Coupling Reaction, Tautomeric Study, Docking and Antimicrobial Evaluation of the Products.

One of the most successful reagents used in the synthesis of the reactive enaminone is DMF-DMA, but it is very expensive with harmful effects on the human health and reacts with special compounds to generate the enaminone such as active methylene centers. In this article, we synthesized a new ketenaminal by simple method with inexpensive reagents (through desulfurization in diphenylether). Thus, a novel reactive ketenaminal (enaminone) was synthesized from the desulfurization of 2-((2-(4-chlorophenyl)-2-oxoethyl)thio)-5,7-bis(4-methoxyphenyl)pyrido[2,3-d]pyrimidin- 4(3H)-one with diphenylether. The starting keteneaminal was coupled with diazotized anilines via the known coupling conditions to give a new series of 2-(4-chlorophenyl)-1-(2-(arylhydrazono)-2- oxoethyl)-5,7-bis(4-methoxy-phenyl)pyrido[2,3-d]pyrimidin-4(1H)-ones. The structures of the new compounds were elucidated based on their IR, 1H-NMR, 13CNMR, and Mass spectra. Moreover, the potency of these compounds as antimicrobial agents has been evaluated. The results showed that some of the products have high activity nearly equal to that of the used standard antibiotic. Additionally, the docking study was done to get the binding mode of the synthesized compounds with the binding site of the DHFR enzyme. The results of molecular docking of the synthesized arylhydrazono compounds are able to fit in DHFR binding site with binding energies ranging from -4.989 to -8.178 Kcal/mol. Our goal was achieved in this context by the synthesis of new ketenaminal from inexpensive reagents, which was utilized in the preparation of bioactive arylhydrazone derivatives.

Antiviral evaluation of bioactive azo derivatives to treat endemic poultry viruses

Antiviral evaluation of bioactive azo derivatives to treat endemic poultry viruses

Annular oxygenation and rearrangement products of cryptotanshinone by biotransformation with marine-derived fungi Cochliobolus lunatus and Aspergillus terreus

Structural modification of natural products by biotransformation with fungi is an attractive tool to obtain novel bioactive derivatives. In the present study, cryptotanshinone (1), a quinoid abietane diterpene from traditional Chinese medicine Salvia miltiorrhiza (Danshen), was transformed by two marine-derived fungi. By using Cochliobolus lunatus TA26-46, one new oxygenated and rearranged product (2), containing a 5,6-dihydropyrano[4,3-b]chromene moiety, together with one known metabolite (10), were obtained from the converted broth of cryptotanshinone (1) with the isolated yields of 1.0% and 2.1%, respectively. While, under the action of Aspergillus terreus RA2905, seven new transformation products (3–9) as well as 10 with the fragments of 2-methylpropan-1-ol and oxygenated p-benzoquinone were produced and obtained with the isolated yields of 0.1%–1.3%. The structures of the new compounds were elucidated by comprehensive spectroscopic analysis including High Resolution Electrospray Ionization Mass Spectroscopy (HRESIMS), Nuclear Magnetic Resonance (NMR) and Electronic Circular Dichroism (ECD). The metabolic pathways of cryptotanshinone by these two fungi were presumed to be the opening and rearrangement of furan ring, and/or oxygenation of cyclohexane ring. Cryptotanshinone (1) and its metabolites displayed anti-inflammatory activities against NO production in LPS-stimulated BV-2 cells and antibacterial activities towards methicillin-resistant Staphylococcus aureus. These findings revealed the potential of marine fungi to transform the structures of natural products by biotransformation.