Unsymmetrical thiourea derivatives: synthesis and evaluation as promising antioxidant and enzyme inhibitors

Background: Unsymmetrical thioureas 1-20 were synthesized and then characterized by various spectroscopy techniques such as UV, IR, fast atom bombardment (FAB)-MS, high-resolution FAB-MS, 1H-NMR and 13C-NMR. Methods: Synthetic compounds 1-20 were tested for their ability for antioxidant, lipoxygenase and xanthine oxidase activities. Results: Compounds 1, 2, 9, 12 and 15 exhibited strong antioxidant potential, whereas compounds 1-3, 9, 12, 15 and 19 showed good to moderate lipoxygenase activity. Ten compounds demonstrated moderate xanthine oxidase inhibition. Conclusion: Compound 15 displayed the highest potency among the series, exhibiting good antioxidant, lipoxygenase and xanthine oxidase activities. Theoretical calculations using density functional theory and molecular docking studies supported the experimental findings, indicating the potential of the synthesized compounds as potent antioxidants, lipoxygenases and xanthine oxidase agents.

Decreased muscle strength in adjuvant-induced rheumatoid arthritis animal model: A relationship to behavioural assessments

Rheumatoid arthritis (RA) is an autoimmune disorder with unknown aetiology. Patients suffering from RA face persistent pain due to joint inflammation, and tissue destruction. Behavioural phenotyping is an approach to target the role of different behavioural traits associated with disease progression. The study aimed to assess behavioural patterns associated with decreased muscle strength in the adjuvant-induced rheumatoid arthritis animal model. The study was conducted on male Albino Wister rats (n = 30) [Control, Vehicle, and Disease groups]. After taking ethical approvals RA was induced by complete Freund's adjuvant (CFA) intradermally base of tail. The weight of animals, macroscopic analysis of inflammatory signs, and arthritic scores were measured weekly. Grip strength, ganglia-based movement, cataleptic activity, and motor-coordination-related behaviours were assessed among the groups. Radiographs and spleen index assay were performed followed by data analysis using one-way and two-way ANOVA (Analysis of Variance). A significant decrease in weight and an increase in arthritic scores among the diseased group was observed. Behavioural analyses confirmed that diseased animals had significantly decreased grip strength and increased cataleptic activity with less motor coordination. Radiographic images and spleen index assay confirmed the pattern of RA. Therefore, it can be suggested that the development of the disease animal model is an effective approach to identifying the disease progression and associated behavioural changes. Moreover, this prepared laboratory animal model may be utilised for pathway analyses to understand the key role of immune regulators and genetic insight into molecular pathways associated with acute and chronic phases of RA.

Identification of potential drug candidates to treat gastritis and associated oxidative stress based on some novel 2-aryl-1H-naphtho[2,3-d]imidazole: synthesis, in vitro and in silico analysis

To identify potential scaffolds to treat gastritis and oxidative stress, 2-aryl-1H-naphtho[2,3-d]imidazole derivatives (1-15) were synthesized. The synthesis was conveniently carried out by condensing 2,3-diaminonaphthalene with variously substituted aldehydes to yield 15 new 2-aryl-1H-naphtho[2,3-d]imidazole derivatives. Structures of all synthesized compounds were elucidated using MS and NMR spectroscopic techniques. Compounds containing an imidazole moiety have continued to spark interest in the field of medicinal chemistry due to their unique properties. In continuation of this statement, to further explore the biological potential of these types of compounds, newly synthesized imidazole derivatives were evaluated for their inhibitory potential against urease and antioxidant activities. Compounds 4 and 11 were identified as the most potent urease inhibitors in the series, with IC50 values of 34.2 ± 0.72 and 42.43 ± 0.65 μM, respectively. Compounds 1, 3, 6, 11, and 15, with EC50 values in the range of 37-75 μg ml-1, showed significant antioxidant activity. Molecular docking studies of the selected synthesized compounds 3, 4, 9, and 11 were also performed to determine their binding interaction with the jack bean urease. Through docking studies, it was revealed that all the compounds that showed good inhibitory potential against urease fit well within the protein's binding pocket. Furthermore, ADME analysis was carried out to explore the drug-likeness properties of the compounds. The findings of the present work revealed that compounds 4 and 11 could be better options to treat gastritis and associated oxidative stress.

Partial syntheses of aromatic amides: their anti-urease potential and docking studies

The aromatic amide: N-p-trans-coumaroyltyramine (1) was isolated for the first time from the stem bark of Celtis zenkeri (Ulmaceae). Its four new derivatives (1a-d) and previously reported diacetylated product (1e) have been synthesized and characterized spectroscopically followed by their in vitro screening for anti-urease potential. The diacetylated product (1e) was found to be the most potent inhibitor with an IC50 value of 19.5 ± 0.23 μM compared to thiourea used as standard (21.5 ± 0.47 μM). Furthermore, molecular docking studies were conducted revealing striking interactions of the active compounds with catalytically important residues such as His593, Ala636 and Asp633. Subsequently, the prime MM-GBSA calculations provided the ligand binding and strain energies. The molecular dynamic simulations validated the docked and post-docked complexes where compounds 1b, 1c, 1d and 1e remained stable throughout the simulation. This study provides insight into the N-p-trans-coumaroyltyramine derivatives (1b-e) that can block the substrate entry, thereby inhibiting the urease's catalytic activity. Hence, these hit compounds can proceed for further pre-clinical studies for drug discovery against urease.Communicated by Ramaswamy H. Sarma.

Photophysical and biological aspects of α, β-unsaturated ketones: Experimental and in silico approach

In this work, four fluorinated α, β-unsaturated ketones named as 3-(3-bromophenyl)-1-(3-(trifluoromethyl)phenyl)prop-2-en-1-one (1), 3-(4-methoxyphenyl)-1-(3-(trifluoromethyl)phenyl) prop-2-en-1-one (2), 3-(3-bromo-5-chloro-2-hydroxyphenyl)-1-(3-(trifluoromethyl)phenyl) prop-2-en-1-one (3) and 3-(2-hydroxy-5-methylphenyl)-1-(3-(trifluoromethyl)phenyl)prop-2-en-1-one (4) were synthesized by Claisen-Schmidt reaction. The synthesized molecules were then characterized through ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared (FTIR), 1 H-NMR, 13 C-NMR, and mass spectrometry. The antioxidant potential, Urease inhibition, and interaction of compounds 1-4 with Salmon sperm DNA were experimentally explored and supported by molecular docking studies. The synthesized compounds strongly interact with SS-DNA through intercalative mode. It was noticed that compound 1 served as potent Urease inhibitor while compound 4 as better antioxidant among synthesized compounds. Moreover, frontier molecular orbitals, nonlinear optical (NLO) properties, natural bond orbitals, molecular electrostatic potential, natural population analysis, and photophysical properties of synthesized compounds were accomplished through density functional theory and time-dependent density functional theory. The band gap of all the compounds have been worked out using Taucs method. In addition to that, a precise comparative account of UV and IR data obtained from theoretical and experimental findings showed good agreement between theoretical and experimental data. The findings of our studies reflected that compounds 1-4 possess better NLO properties than Urea standard and the band gap data also reflected their prospective use towards optoelectronic materials. The better NLO behavior of compounds was attributed to the noncentrosymmetric structure of synthesized compounds.

Synthesis, Characterization, DPPH Radical Scavenging, Urease Enzyme Inhibition, Molecular Docking Simulation, and DFT Analysis of Imine Derivatives of 4-formylpyridine with Selective Detection of Cu+2 Ions

This study aimed to prepare three imine derivatives (1, 2, and 3) via a condensation reaction of phenyl hydrazine, 2-hydrazino pyridine, and 4-methoxy aniline with 4-formyl pyridine. Electron impact mass spectrometry (EIMS), proton nuclear magnetic resonance (1H-NMR), ultraviolet-visible (UV-Vis) and Fourier transform infrared (FTIR) spectroscopy were utilized for the characterization. The chemosensing properties of [4((2-phenyl hydrazono)methyl) pyridine] (1), [2-(2-(pyridin-4-ylmethylene)hydrazinyl) pyridine] (2), and [4-methoxy-N-yl methylene) aniline] (3) imino bases have been explored for the first time in aqueous media. The photophysical properties of chemosensors (1, 2, and 3) were examined by various cations (Na+, NH4+, Ba+2, Ni+2, Ca+2, Hg+2, Cu+2, Mg+2, Mn+2, and Pd+2). The chemosensor (1) showed very selective binding capability with copper ions at low concentrations (20 μM) without the influence of any other mentioned ions. The maximum complexation was noted with Cu+2 and 1 at pH between 7 to 7.5. The stoichiometry binding ratio between chemosensor (1) and Cu+2 was determined by Job's plot and it was found to be 1:2. The current study explored the use of these Schiff bases for the first time as heterocyclic chemosensors. DPPH radical scavenging, urease enzyme inhibition activities, molecular docking simulation, and density functional theory (DFT) analysis of compounds 1, 2, and 3 were also conducted.

Preussiate, a new urease inhibitory chalcone from Dioscorea preussii Pax

The phytochemical investigation of the aqueous methanolic extract of the aerial parts of Dioscorea preussii, led to the isolation of a new chalcone preussiate (1) along with 10 other compounds including xanthomicrol (2), cholestan-3-one (3), arjunolic acid (4), tormentic acid (5), ursolic acid (6), betulin (7), lupeol (8), p-hydroxybenzoic acid (9), isovanillin (10) and vanillic acid (11), being reported for the first time from this plant. Their structures were established by spectroscopic techniques including 2D NMR spectroscopy. All the isolates were subjected to the biological screening but only showed antioxidant and urease inhibitory properties. The compounds 1,8 and 11 displayed the most potent urease inhibitory properties with IC50 values, 22.4, 33.3 and 35.7 µM, respectively, while 3 was moderately active. The compound 11 showed potent antioxidant activity among all the tested isolates with an IC50 value of 45.3 µM.

Crotofoligandrin, a new endoperoxide crotofolane-type diterpenoid from the twigs of Croton oligandrus Pierre ex. Hutch (Euphorbiaceae)

Crotofoligandrin (1), a new endoperoxide crotofolane-type diterpenoid was isolated from the dichloromethane/methanol (1:1) extract of the twigs of Croton oligandrus Pierre Ex Hutch along with thirteen known secondary metabolites including 1-nonacosanol (2), lupenone (3), friedelin (4), β-sitosterol (5), taraxerol (6), (-)-hardwickiic acid (7), apigenin (8), acetyl aleuritolic acid (9), betulinic acid (10), fokihodgin C 3-acetate (11), D-mannitol (12), scopoletin (13) and quercetin (14). The structures of the isolated compounds were determined based on their spectroscopic data. The crude extract and the isolated compounds were assessed in vitro for their antioxidant, lipoxygenase, butyrylcholinesterase (BChE), urease and glucosidase inhibitory potentials. Compounds 1-3, and 10 displayed activities on all the performed bioassays. All the tested samples showed strong to significant antioxidant activity with compound 1 being the most potent (IC50 39.4 μM).

Cholinesterase activity as a potential biomarker for neurotoxicity induced by pesticides in vivo exposed Oreochromis niloticus (Nile tilapia): assessment tool for organophosphates and synthetic pyrethroids

Organophosphates (OPs) and synthetic pyrethroids (SPs) are the most popular broad spectrum pesticides, used in agriculture as they have a strong pesticidal activity while also being biodegradable in the environment. The present study aimed to demonstrate the effects of these pesticides on the Acetylcholinesterase (AChE) activity in brain, gills and body muscles of Oreochromis niloticus - an important enzyme for the assessment and biomonitoring pollution caused by neurotoxins in the environment. The fish were exposed for 24 and 48 h to the LC₀ concentrations of the malathion (1.425 mg/L), the chlorpyrifos (0.125 mg/L) and the λ-cyhalothrin (0.0039 mg/L), respectively. The activity of the AChE was significantly increased (p < 0.05) at 24 h and decreased at 48 h (except for the chlorpyrifos-treated brain and gills while tissues had shown no activity at 48 h's exposure) in all pesticides-treated tissues. The maximum increase in the activity and inhibition in the AChE activity were recorded as +92% and -52% in the chlorpyrifos and the lambda-cyhalothrin exposed brain tissues, respectively. Thus, the alterations in the AChE activities indicated that the applied pesticides are highly neurotoxic to fish and the enzyme (AChE) could be used as a useful biomarker for estimation of water pollution.

Zenkeramide: a new iso-benzofuranone propanamide and urease inhibitory constituents of Celtis zenkeri Engl stem bark (Ulmaceae)

A new iso-benzofuranone propanamide: 3-(3-oxo-1, 3-dihydroisobenzofuran-1-yl) propanamide (zenkeramide) (1) along with three known compounds: Trans-N-coumaroyltyramine (2), β-Sitosterol (3) and β-sitosterol-3-0-β-D-glucopyranoside (4) were isolated from the ethyl acetate fraction of the stem-bark of Celtis zenkeri Engl (Ulmaceae). The structure of the new compound was elucidated by extensive spectroscopic analysis. The compounds were examined for Urease Inhibitory Activity. Compounds 1 and 2 showed moderate activities (IC₅₀ values (μM) of 42.3 ± 0.19 and 45.2 ± 0.55, respectively), while compounds 3 and 4 were potent inhibitors of the Jack bean urease (IC₅₀ values (μM) of 20.3 ± 0.37and 27.6 ± 0.52, respectively), when compared to the standard inhibitor (thiourea- IC₅₀ 21.5 ± 0.47). The isolation of all the compounds from C. zenkeri and the urease activity of compounds 1 and 2 are reported for the first time.

Isolation of secondary metabolites from Syzygium aromaticum (L.) Merr. & L.M.Perry. (cloves), and evaluation of their biological activities

Phytochemical investigation of dried flower buds of Syzygium aromaticum (L.) Merr. & L.M.Perry. (clove) led to the isolation and identification of fourteen known compounds, oleanolic acid (1), betulinic acid (2), para methyl benzoic acid (3), sabrinic acid (4) eucalyptolic acid (5), nigricin (6), 3-O-trans-para-coumaroylmaslinic acid (7), methyl maslinate (8), maslinic acid (9), 3, 4, 5-trimethoxy-3',4'-O,O-methylideneflavellagic acid (10), lantanone (11) 3,4,3'-trimethoxyellagic acid (12), 11-oxo-oleanolic acid (13), and β-sitosterol-3-O-β-D-glucopyranoside (14). Their structures were identified by ¹H NMR, ¹³C NMR, Mass spectroscopic techniques, and comparison with the literature data. Compounds 3, and 7-9 showed a strong mortality against root knot nematode, Meloidogyne incognita at 0.125% concentration after 72 hours (88-92% inhibition). Compound 4 showed a good anti-glycation activity with IC₅₀ = 142.0 ± 1.8 µM when compared with standard, i.e. rutin (IC₅₀ = 54.59 ± 2.20 µM). Compound 10 showed a comparable urease inhibitory activity (IC₅₀ = 26.1 ± 0.19 µM) with the positive control thiourea (IC₅₀ = 24.5 ± 0.34 µM).

1,3,5-Thiadiazinane thione derivatives as significant urease inhibitors

We report the promising urease inhibitory activity of four sets of tetrahydro thiadiazine thiones (THTT) namely 3,5-disubstituted tetrahydro-2H-1,3,5-thiadiazine thiones: THTT 5-8 (set A) having alkyl/aryl substituents at N-3 and N-5 positions; THTT 9-12 (set B) and THTT 13-14 (set C) with 3-carboxylic acid derivatives and tetrahydro-2H-1,3,5-thiadiazine-6-thione esters 15-16 (set D). Gratifyingly, all four sets of THTT were recognized as promising inhibitors of urease enzyme. Among 12 tested compounds; THTT 6, 8, 10, 14 and 15 from each set respectively, demonstrated significant urease inhibitory activity with IC₅₀ values between 11.2-29.8μM which is mostly found higher than that for thiourea, a standard urease inhibitor with IC₅₀ value of 22.4μM. Furthermore, compound 7 showed almost the same level of inhibition (IC₅₀ = 22.5μM) as of standard. In addition, molecular docking study supported the phenomenon that thiadiazinane ring itself is an active pharmacophore that binds through CH₂ groups and S atom via carbon-hydrogen/π-sulfur interactions respectively to the active site of the urease enzyme. The optimistic results from this study suggest the use of thiadiazinane skeleton as a guided template for the advancement of new urease inhibitors in drug discovery.

Atricephenols A and B, two phenolic compounds from Indigofera atriceps Hook.f. (Fabaceae)

The phytochemical investigation of a previously unstudied species of the genus Indigofera, I. atriceps Hook.f. was undertaken and two new phenolic compounds, atricephenols A (1) and B (2) were isolated, along with nine known secondary metabolites viz., (-)-melilotocarpan D (3), genistein (4), melilotocarpan A (5), maackiain (6), p-hydroxybenzaldehyde (7), bornesitol (8), β-sitosterol (9), sitosterol-3-O-β-D-glucopyranoside (10) and stigmasterol-3-O-β-D-glucopyranoside (11). Their structures were elucidated by extensive NMR spectroscopic analyses and HRESIMS, and by comparing their data with those reported in the literature. Compounds 1, 4, 7-11 were tested for their antibacterial efficacies and for their potential to inhibit the enzyme urease. Compounds 7 and 9 showed significant antibacterial activity against Salmonella typhi (ZOIs of 13 and 15 mm, respectively), while the best urease inhibition was measured for compound 9 with an IC₅₀ value of 18.6 µM, which is higher than that of the potent inhibitor, thiourea (IC₅₀ = 21.5 µM).

Effects of Se nanoparticles supplementation on growth performance, hematological parameters and nutrient digestibility of Labeo rohita fingerling fed sunflower meal based diet

The aim of the present study is to assess the effects of selenium nanoparticles on the growth, hematology and nutrients digestibility of Labeorohita fingerlings. Fingerlings were fed with seven isocaloric sunflower meal-based diet supplemented with different concentrations of nanoparticles naming T1 to T7 (0, 0.5, 1, 1.5, 2, 2.5, and 3 mg/kg), with 5% wet body weight while chromic oxide was used as an indigestible marker. After experimentation for 90 days T3 treated group (1mg/kg -1Se-nano level) showed the best result in hematological parameters (WBC's 7.97 ×103mm-3, RBC's 2.98 ×106 mm-3 and Platelet count 67), nutrient digestibility (crude protein: 74%, ether extract: 76%, gross energy: 70%) and growth performance (weight gain 13.24 g, weight gain% 198, feed conversion ratio 1.5, survival rate 100%) as compared to the other treatment groups. Specific growth rates were found significantly higher in T5 than in other groups. The present study indicated positive effect of 1 mg/kg Se-nanoparticles on growth advancement, hematological parameters, and nutrients digestibility of L. rohita fingerlings.

Multi-activity tetracoordinated pallado-oxadiazole thiones as anti-inflammatory, anti-Alzheimer, and anti-microbial agents: Structure, stability and bioactivity comparison with pallado-hydrazides

Herein, we report a comparative study based on structure, thermal and solution stability, and biopotency against lipoxygenase (LOX), butyrylcholinesterase (BChE) and microbes for Pd(II) compounds of N,O,S bearing 5-(C₅H₄XR)-1,3,4-oxadiazole-2-thiones (L') of type [PdL'Cl₂] (P'n) and N,O bearing respective hydrazides (L) of type trans-[PdL₂Cl₂] (Pn) {X = C, R = 4-I, 2-Br, 4-NO₂, 3-NO₂, 2-Cl, 3-Cl (n = 1-6, serially); X = N (n = 7)}. Spectral techniques (IR, EI-MS, NMR) and physicochemical evaluations successfully characterized the new compounds. The L' behaved as bidentate S-N donors bonded through exocyclic sulfur and N-3' nitrogen, while L acted as amino N donors. UV-vis (solution speciation) and thermal degradation profiles consistently confirmed the greater stability for P'n than Pn compounds. These compounds manifested varying degree in vitro potential to inhibit LOX, BChE and several bacteria and fungi, affected mainly by Pd(II) presence, M-L binding mode, nature and position of R, or halo groups electronegativity. Molecular docking with human 5-LOX and BChE further validated the respective experimental inhibition findings and explored several putative mechanistic interactions (H-bonding, π-stacking, π-alkyl, π-S, etc.) at the enzyme active sites. Pn generally offered superior antimicrobial and anti-LOX (anti-inflammatory) potential than respective P'n compounds, with P3/P'5, P(2,3,7)/P'3, and P6 being comparable, better and equivalent to ampicillin, nystatin and baicalein, the reference antibacterial, antifungal and anti-LOX drugs, respectively. Contrarily, the anti-BChE activity of P'n was found better than Pn compounds, showing P'2/P1 as the most promising anti-Alzheimer drug candidates. This study bares important structural and mechanistic aspects in optimizing antimicrobial, anti-inflammatory and anti-Alzheimer activities, highlighting some potential future pallado-drug candidates.

A new dammarane type triterpene glucoside from the aerial parts of Gouania longipetala (Rhamnaceae)

3-O-β-D-glucopyranosyl gouanogenin A (1), a new naturally occurring dammarane class of triterpene glucoside, has been isolated from the aerial parts of Gouania longipetala along with six known secondary metabolites 2-7. Their structure was elucidated through spectroscopic data including 1 D- and 2 D-NMR. The compounds 1 and 6 showed significant antioxidant potential in DPPH radical scavenging assay. On the other hand, the compound 4 revealed potent inhibitory potential against the enzyme urease, while 1 and 3 were significantly active.

N-Aryl-3,4-dihydroisoquinoline Carbothioamide Analogues as Potential Urease Inhibitors

N-Aryl-3,4-dihydroisoquinoline carbothioamide analogues 1-22 were synthesized by a simple one-step reaction protocol and subjected to in vitro urease inhibition studies for the first time. All compounds 1-22 were found active and showed significant to moderate urease inhibitory potential. Specifically, analogues 1, 2, 4, and 7 were identified to be more potent (IC₅₀ = 11.2 ± 0.81-20.4 ± 0.22 μM) than the standard thiourea (IC₅₀ = 21.7 ± 0.34 μM). The structure-activity relationship showed that compounds bearing electron-donating groups showed superior activity. Molecular docking study on the most active derivatives revealed a good protein-ligand interaction profile against the corresponding target with key interactions, including hydrogen bonding, hydrophobic, and π-anion interactions.

Evaluation of C-reactive protein in breast cancer by enzyme linked immunoassay technique

OBJECTIVE

To explore the serum levels of C-reactive protein in breast cancer patients, and to investigate the relationship between inflammation and progression of breast cancer.

METHODS

The case-control study was conducted at Bahria University Medical and Dental College, Karachi, from September 2015 to December 2018, and comprised breast cancer patients in group A and and an equal number of age-matched healthy women in control group B. C-reactive protein levels were evaluated in serum samples using enzyme-linked immunosorbent assay in both the groups and micro ribonucleic acid levels in serum were quantified using real time polymerase chain reaction. Data was analysed using SPSS 16.

RESULTS

Of the 170 subjects, 85(50%) were in each of the two groups. C-reactive protein and micro ribonucleic acid expression were significantly different in group A (p<0.001). There was no correlation (r = 0.162, p>0.01) between the tumour markers in group B (p>0.05).

CONCLUSIONS

Significantly raised C-reactive protein levels showed there was a link between inflammation and breast cancer.

New bioactive monoterpene indole alkaloid from Rinorea yaundensis Engl

Extraction of the aerial part of Rinorea yaundensis has led to the isolation of a new monoterpene indole alkaloid (1) along with 10 known compounds (2-11) for the first time from this plant. Their structures were determined by HRMS and NMR spectroscopic analyses as yaundentine hydrochloride (1), N_b-oxide of iso-reserpiline (2), iso-reserpiline (3), iso-carapanaubine (4), lichenxanthone (5), stigmastane-3,6-dione (6), methyl β-orcinol carboxylate (7), β-sitosterol-3-O-β-D-glucoside (8), betulinic acid (9), ursolic acid (10) and benzoic acid (11) while the stereochemistry and absolute configuration of 1 was confirmed by single crystal x-ray crystallography and circular dichroism CD spectrum. Yaundentine hydrochloride (1) exhibited pronounced antioxidant, urease and lipoxygenase inhibitory activities with IC₅₀ values of 35.6 ± 0.23, 20.3 ± 0.58 and 29.6 ± 0.77 µM, respectively. Compound 1 also showed good antimicrobial activity against some Gram positive and negative bacteria.

Muricazine, a new hydrazine derivative from Ranunculus muricatus L. with antioxidant, lipoxygenase and urease inhibitory activities

Ranunculus muricatus L., an important member of family Ranunculaceae upon submission to phytochemical studies, led to the isolation of a novel natural hydrazine derivative, muricazine (1). Chemical structure of the compound was established with the aid of advanced spectroscopic techniques. It was evaluated for in vitro antioxidant, lipoxygenase, and urease (jack-bean) inhibitory activities. Results suggested that compound 1 could scavenge the DPPH free radical (42.1 ± 0.12 μM) to a great extent as compared to the standard (40.6 ± 0.91 μM). However, it showed moderate inhibitory potential against lipoxygenase (65.2 ± 0.45 μM) and urease (54.8 ± 0.23 μM) enzymes.

Native wild plants in Karachi, Pakistan: Rich source of antioxidant raw material

Extracts of nine plants were studied for DPPH radical scavenging and reducing abilities. Pentatropis spiralis, Calotropis procera, Helitropium curassavicum, Withania somnifera and Chenopodium album showed reducing power ranging from 34% to 146%. Suaeda fruticosa, Trianthema portulacastrum, Pluchea lanceolata and Rumex dentatus has excellent antioxidant potential proved by their DPPH scavenging and reducing power. 1000µg/10µl chloroform extract of S. fruticosa gave 92% scavenging with IC50 value less than 0.7µg/10µl while its hexane extract possessed 80% reducing activity at 100µg/10µl concentration. DPPH free radical scavenging by methanolic extract of Trianthema portulacastrum was 60% and 76% at 1000 and 100µg/10µl respectively with IC50 value of 0.03µg/10µl while the reducing activity of 124% at 100µg/10µl. Methanolic extract of P. lanceolata showed 91% and 70% scavenging activity at 1000 and 100µg/10µl with IC50 value of 0.7µg/ 10µl. Reducing power is comparable with the reference BHA standard that is 98% at 100µg/10µl concentration. Rumex dentatus' extracts are excellent DPPH scavengers and hydrogen donators produced 156% reduction. Chloroform extract was inefficient antioxidant. These results make these plants a candidate for future research for treating ailments due to imbalance in free radicals.

Muriolide, a novel antioxidant lactone from Ranunculus muricatus

Muriolide (1), a new aromatic lactone, has been isolated from the ethyl acetate fraction of Ranunculus muricatus. The compound was structurally characterized with the help of UV, IR, mass, 1D- and 2D-NMR data. It was tested in vitro for antioxidant and lipoxygenase inhibitory potential. Compound 1 showed good DPPH radical scavenging activity (IC₅₀=56.9 μM), however it was moderately active against lipoxygenase enzyme (IC₅₀=68.3 μM).

The chemistry and biological activities of Citrus clementina Hort. Ex Tanaka (Rutaceae), a vegetatively propagated species

We report the chemistry and biological activities of a Cameroonian Citrus clementina Hort. Ex Tanaka, a vegetatively propagated species. The compounds isolated from this plant were determined to be the known 5-hydroxy-6,7,8,3',4'-pentamethoxyflavone (1), tangerine (3), nobilletin (4), 5,7,8,4'-tetramethoxyflavone (5), citracridone I (6), 5-hydroxynoracronycine (7), citracridone III (8), xanthyletin (10), suberosin (9), E-suberenol (11), E-methoxysuberenol (13), 6-formylumbelliferone (12), aurantiamide acetate (2), limonin (14), stigmasterol, β-sitosterol and β-sitosterol-3-O-β-D-glucoside. The structures of the compounds were established on the basis of their NMR spectroscopic data and comparison with published data. Methanol leaf extract and compounds 1, 2, 4, 6, 7 and 10 were evaluated for their anti-inflammatory, antioxidant, urease and anti-diabetic effects. Compound 10 showed antioxidant activity, anti-inflammatory effect, urease activity and anti-diabetic activity with IC₅₀ values of 47.3 µM, 33.5 µM, 25.2 µM and 33.9 µM respectively, values that were comparable to the respective positive standards.

Bioactive constituents from Manilkara obovata (Sabine & G.Don) J.H.Hemsl

The phytochemical investigation of the methanolic extracts of roots, stem bark, leaves and twigs of Manilkara obovata has led to the isolation of one new friedelane triterpene, lacefriedelic acid or 3β,23-dihydroxy D:A-friedooleanan-28-oic acid (1) and one new prenylated xanthone, lacexanthone or 4,7-dihydroxy-2,3,3,9,9-pentamethyl-2,2-dihydrofurano[2,3-a]pyrano[2,3-i]xanthen-13(9H)-one (2) alongside twenty-four known compounds. Compounds 1-11 are reported here for the first time from the genus Manilkara. The structures of all compounds were determined by spectroscopic analyses and X-ray crystallography. The methanolic extracts of twigs and leaves showed anti-oxidant activity of 93.2 and 91.1%, respectively, at 100 µg/mL when measured by DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate), while the twig extract displayed 86.3% at 100 µg/mL against the urease inhibition assay. Some isolated compounds (1-4, 15 and 20) showed significant to moderate anti-oxidant activity and urease inhibition assay. It is estimated that significantly active anti-oxidants and urease inhibitors metabolized by the plant may find future application in food industry.

Kostchyienones A and B, new antiplasmodial and cytotoxicity of limonoids from the roots of Pseudocedrela kotschyi (Schweinf.) Harms

Two new limonoids, kostchyienones A (1) and B (2), along with 12 known compounds 3-14 were isolated from the roots of Pseudocedrela kostchyi. Compound (7) was isolated for the first time from a natural source. Their structures were elucidated on the basis of spectroscopic evidence. Compounds 1-6 and 13-14 gave IC50 values ranging from 0.75 to 5.62 μg/mL for antiplasmodial activity against chloroquine-sensitive (Pf3D7) and chloroquine-resistant (PfINDO) strains of Plasmodium falciparum. Compound 5 showed moderate potential cytotoxicity against the HEK239T cell line with an IC50 value of 22.2±0.89 μg/mL. The antiplasmodial efficacy of the isolated compounds supports the medicinal value of this plant and its potential to provide novel antimalarial drugs.

Flavonoids and triterpenes from Combretum fragrans with anti-inflammatory, antioxidant and antidiabetic potential

Despite the well-documented benefits of Combretum fragrans in Cameroon, only few scientific works have been done on it. In this study we isolated eight compounds from the leaves extract of C. fragrans: velutin (1), belamcanidin (2), cirsilineol (3), cirsimaritin (4), 3β-acetoxy-20,24-epoxy-11,25-hydroxy-dammarane (5), combretin A (6), combretin B (7) and a mixture of arjunolic acid (8a) and asiatic acid (8b). Compounds 6 and 7 presented potent anti-inflammatory, antioxidant and antidiabetic activities. Compounds 1, 3, 5 and the mixture of 8a and 8b were significantly active, and compounds 2 and 4 presented moderate activity for reactive oxygen species inhibitory and free-radical scavenging. All compounds were isolated using chromatographic techniques; their structures were elucidated by spectroscopic techniques and their spectroscopic data compared with those of the literature. Anti-inflammatory activity was evaluated via the oxidative burst assay using a luminol-amplified chemiluminescence technique, antioxidant activity by free-radical scavenging activity (DPPH) and antidiabetic activity via α-glucosidase inhibition. All of the isolated compounds (1-8) were reported to exhibit significant antioxidant activity. Compounds 1, 3, and 5-8 exhibited potent chemiluminescence inhibition effect, and only compounds 6 and 7 inhibited α-glucosidase. Thus, C. fragrans can be used as an effective natural source of anti-inflammatory, antioxidant and antidiabetic compounds.

Facile one-pot syntheses of new C-28 esters of oleanolic acid and studies on their antiproliferative effect on T cells

Structure-activity relationship studies on oleanolic acid (1) have resulted in facile syntheses of its new C-28 esters 2-7 by way of one-pot reaction of 1 with a variety of alkylating agents. Oleanolic acid and its new esters were studied for their in vitro antiproliferative effect on healthy human peripheral blood mononuclear cell isolated phytohemagglutinin activated T cells. Results showed that compounds 1, 3, and 5 exhibited significant inhibitory activity on T-cell proliferation. Compound 5 was found to be the most potent, with an IC50 value of 4.249 μg/mL, among all tested compounds, and its activity could be attributed to the presence of bromine atom in the molecule.

Crotoliganfuran, a new clerodane-type furano-diterpenoid from Croton oligandrus Pierre ex Hutch

The phytochemical investigation of the methanol extract of the bark of Croton oligandrus Pierre ex Hutch yielded a new clerodane-type diterpenoid crotoliganfuran (1) along with ten other compounds including 12-epicrotocorylifuran (2), lupeol (3), syringic acid (4), aleuritolic acid acetate (5), aleuritolic acid (6), scopoletin (7), geddic acid (8), β-sitosterol (9), vanilic acid (10) and stigmastane-3,6-dione (11). Their structures were established by spectroscopic means. The extract and all the isolates were screened for their inhibitory properties against butyrylcholinesterase and urease enzymes, respectively. The extract and compounds 1, 4 and 7 displayed the most potent urease inhibitory properties with IC₅₀ values, 22.2, 26.7 and 28.5 µM, respectively. Compound 9 was the most active of all the tested compounds against butyrylcholinesterase enzyme with an IC₅₀ value of 36.3 µM.[Formula: see text].

Synthesis, lipoxygenase inhibition activity and molecular docking of oxamide derivative

In this study, a range of oxamide ligands were synthesized by the reaction of amines with oxalyl chloride in basic medium. Spectroscopic and analytical techniques such as IR, 1H-NMR and ESI-MS techniques were used for characterization of the synthesized oxamides. The synthesized oxamides were screened for Lipoxygenase inhibition. Biological screening revealed that the oxamides possessed good lipoxygenase inhibition activities, whereas, the unsubstituted oxamide did not show any distinct lipoxygenase inhibition activity. Molecular docking studies of the oxamides were also carried out for lipoxygenase inhibition. The results obtained from molecular docking were well correlated with the empirical data.

Heterochelates of metals as an effective anti - Urease agents couple with their docking studies

The current article discusses the activities of several synthesized metal heterochelates in in-vitro as anti-ulcer agents followed by their docking study. For this purpose, two important ligands like 8-hydroxyquinoline and DL-methionine were used in synthesis of heterochelates of metal including Cr (III), Mn (II), Fe (III), Co (II), Ni (II), Cu (II), Zn (II), Cd (II) and Pb (II). It was observed that these complexes showed excellent urease inhibition activities in which thiourea was the standard having IC50 value 21.6 ± 0.12μM. The Cu (II) complex showed potent inhibitory activity (22.6 ± 0.72 μM) when compared with the standard thiourea (21.6±0.12μM) among the nine synthesized complexes while Mn (II), Fe (III), Cd (II) and Pb (II) also showed better inhibitory activities. The urease inhibitory activities of hetercochelates also tested and validated by docking analysis.

Chemistry, Alpha-glucosidase and Radical Scavenging Properties of Uranyl(VI) Hydrazide Complexes

BACKGROUND

Antioxidant, anti-inflammatory, antiviral and antitumoral activities among others are essential characteristics in the development of novel therapeutic compounds. Acid hydrazides can form complexation with certain metal ions that positively enhance these biological characteristics.

OBJECTIVE

Five new complexes of uranium with hydrazide ligands were synthesized at room temperature.

METHODS

The characterization was done by spectroscopic methods (ESI-Mass, IR, 1H-NMR, 13CNMR), CHN analysis and conductivity measurements. Metal complexes along with their respective ligands were further screened for their antioxidant (DPPH, superoxide and nitric oxide free radicals) properties and enzyme inhibition (α-glucosidase) activities.

RESULTS

Elemental and spectral data indicate octahedral geometry around uranyl (UO2 2+) species. Magnetic moments indicate the diamagnetic nature of uranyl(VI) ion in the complex in solid state. IC50 values showed potential antioxidant behavior of uranyl complexes demonstrating interesting structure-activity relationships. In general, hydrazide ligands were not active against superoxide and nitric oxide radicals while varying degree of results were observed against DPPH radical whereas all uranyl-complexes showed promising radical scavenging activities against all of them. Promising inhibitory potential was displayed by UO2 +2 hydrazide complexes against α- glucosidases whereas free hydrazide ligands were inactive.

CONCLUSION

Structure function relationship demonstrates that the nature of ligand, position of substituent, electronic and steric effects are significant factors affecting the radical scavenging and enzyme inhibition activities of the compounds.

Synthesis, Urease Inhibition and Molecular Modelling Studies of Novel Derivatives of the Naturally Occurring β-Amyrenone

Urease enzyme (UE) has been reported to be a potent virulence factor for Helicobacter pylori (HP) bacteria indicated to be responsible for various gastrointestinal diseases. Therefore, the spread of HP, currently regarded by the World Health Organization as a class 1 carcinogen, could be better controlled by targeting UE. It is in this line that we have synthesized three new derivatives (2-4) of the naturally occurring olean-12-en-3-one (1), which was previously isolated from the figs of Ficus vallis-choudae Delile (Moraceae). Among the synthesized compounds, 3 and 4 contain an indole moiety. Their structures were unambiguously assigned by spectroscopic and spectrometric techniques (1D-NMR, 2D-NMR and MS). The starting material and the synthesized compounds were screened for UE inhibition activity, and showed significant activities with IC₅₀ values ranging from 14.5 to 24.6 μM, with compound (1) being the most potent as compared to the positive control thiourea (IC₅₀ = 21.6 μM). Amongst the synthetic derivatives, compound 4 was the most potent (IC₅₀ = 17.9 μM), while the others showed activities close to that of the control. In addition, molecular docking study of target compounds 2-4 was performed in an attempt to explore their binding mode for the design of more potent UE inhibitors.

In silico and BSA binding study of some new biological analogs of 1,2,4-triazolependant with azinane through microwave and conventional synthesis

Microwave and conventional techniques were employed to synthesize a novel array of compounds 7a-g with 1,2,4-triazole and piperidine rings having great biological importance. The microwave assisted method has a better operational scope with respect to time and yield comparative to the conventional method. 1H-NMR, 13C-NMR and IR techniques were employed to justify the structure of synthesized compounds. The antioxidant, butyrylcholinesterase inhibition and urease inhibition potential of every synthesized compound was evaluated. Every member of the synthesized series was found potent against mentioned activities. Compound 7g was the most active anti-urease agent having IC50 (μM) value 16.5±0.09 even better than the thiourea with an IC50(μM) value of 24.3±0.24. The better urease inhibition potential of 7g was also elaborated and explained by docking and bovine serum albumin (BSA) binding studies.

New bioactive triaryl triglyceride esters: Synthesis, characterization and biological activities

<p class="Abstract">Four new bioactive aryl triester derivatives of glycerol and benzoic acids were synthesized. The synthetic compounds were studied for their antimicrobial and urease inhibition activities. Esterification was carried out by using carbonyldiimidazole to enhance the acyl elimination addition reaction with benzoic acid derivatives. The structure of triglycerides were studied by EI-MS, ¹H, ¹³C-NMR, FT-IR and elemental analysis. All synthetic compounds showed urease inhibition activity with highest value of IC₅₀value 22.4 ± 0.45 μM which is nearest to standard thiourea IC₅₀value (21.6 ± 0.12 μM).  Except compound (3d), all other compounds exhibited antimicrobial activity against <em>Streptococcus pneumoniae, Staphylococcus epidermidis, Bacillus pumilus, Escherichia coli, Pseudomonas aeruginosa</em> and <em>Candida albican</em>.</p><p><strong>Video Clip of Methodology:</strong></p><p>7 min 59 sec   <a href="https://youtube.com/v/PvGTYUxO7-4">Full Screen</a>   <a href="https://youtube.com/watch?v=PvGTYUxO7-4">Alternate</a>  </p>

Oligoamide, a new lactam from the leaves of Angylocalyx oligophyllus

A new lactam, oligoamide (1), along with three known compounds (2-4), stigmasterol-3-O-β-D-glucopyranoside (2), formononetin (3) and (-)-pinitol (4) were isolated from the CH₂Cl₂/CH₃OH (1:1) extract of the leaves of Angylocalyx oligophyllus by chromatographic separation. Their structures were elucidated on the basis of spectroscopic analysis (UV, IR, MS, 1D, and 2D NMR). Compound 1 was found to have weak antioxidant and urease inhibitory potential.

Sessilifol A and B, Urease Inhibitory Pimarane-type Diterpenes from Hymenocrater sessilifolius

New pimarane type diterpenes named sessilifol A (1) and B (2) have been isolated from the EtOH soluble fraction of Hymenocrater sessilifolius Benth., along with eight known constituents cirsimaritin (3), gardenin C (4), β-sitosterol (5), saringosterol (6), β-sitosterol glucoside (7), ursolic acid (8), sucrose (9) and vanillic acid (10). Their structures were elucidated on the basis of 1H- and 13C-NMR spectra and by 2D-NMR experiments. The structure of 1 was further confirmed by single crystal X-ray diffraction technique. The compound 2 showed potent inhibitory potential against the enzyme urease while 1, 3, 4 and 10 were moderately active.

Vanadium(V) complexes with hydrazides and their spectroscopic and biological properties

The present study explores the synthesis and inhibitory potential of vanadium(V) complexes of hydrazides (1c-12c) against oxidative enzymes including xanthine oxidase and lipoxygenase (LOX). In addition, non-enzymatic radical scavenging activities of these complexes were also determined. On the basis of spectral, elemental and physical data, synthesized vanadium(V) complexes are tentatively assigned to have an octahedral geometry with two hydrazide ligands and two oxo groups forming a negatively charged sphere complex with ammonium as counter ion. This is further verified by the conductivity studies of the complexes. Results show that hydrazide ligands (1-12) and their respective vanadium(V) complexes (1c-12c) posses scavenging and inhibition potential against DPPH and LOX, respectively. However, contrary to that uncoordinated ligands showed no activity against nitric oxide, superoxide and xanthine oxidase whereas their complexes showed varying degree of activity. These studies indicate that geometry of complex, nature and position of substituent groups play a vital role in scavenging and inhibition potential of these compounds.

Dioclins A and B, new antioxidant flavonoids from Dioclea reflexa

Dioclins A (1) and B (2), the new flavonoids, have been isolated from the ethyl acetate soluble fraction of the roots of Dioclea reflexa along with 3,5-dihydroxy-4 methoxybenzoic acid (3), lupeol (4) and the rare dipeptide, auratiamide acetate (5). Their structures have been elucidated by spectroscopic techniques. The compounds 1 and 2 showed a significant antioxidant activity in DPPH radical scavenging assay.