Design,synthesis and anti-acetylcholinesterase evaluation of some new pyrazolo[4,3-<Emphasis Type="Italic">e</Emphasis>]-1,2,4-triazolo[1,5-<Emphasis Type="Italic">c</Emphasis>]pyrimidine derivatives

The target new hybrid molecule types pyrazolo[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidines phosphonates 4 and 2-(coumarin-3’’-yl)-7-phenylpyrazolo[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidines 5 were prepared via Michaelis–Arbuzov rearrangement (Arbuzov reaction) of pyrazolotriazolopyrimidines chloride 3a–c, with trialkyl phosphate and Knoevenagel reaction of 2-cyanomethyl derivatives 3d–f with salicylic aldehyde, respectively. The precursors 3 were obtained in two steps starting from aminopyrazole 1. Target compounds 4 and 5 were completely characterized by ¹H NMR, ¹³C NMR, ³¹P NMR, IR and HRMS. The anti-acetylcholinesterase activity of compounds 4 and 5 was evaluated, and results found indicated that they have possessed significant activities (IC₅₀ = 1.73–39.86 µM), and the preliminary SAR of these compounds was investigated.     

Design,synthesis, and evaluation of the anticonvulsant and antidepressant activities of pyrido[2,3-<Emphasis Type="Italic">d</Emphasis>]pyrimidine derivatives

A series of pyrido[2,3-d]pyrimidine derivatives (4a–4n, 5a–5n, 6, and 7) were designed and synthesized as potential anticonvulsants and antidepressants. Their pharmacological activities were evaluated by maximal electroshock test, forced swimming test, and tail suspension test in mice. Pharmacological analyses showed that compounds 4-benzyl-6,8-dimethylpyrido[3,2-e]tetrazolo[1,5-a]pyrimidin-5(4H)-one (4a) and 4-(3-fluorobenzyl)-6,8-dimethylpyrido[3,2-e]tetrazolo[1,5-a]pyrimidin-5(4H)-one (4e) exhibited the greatest anticonvulsant activity (PI 12.02 and 12.25, respectively, 30 min after intraperitoneal injection), and were more efficient than the reference drug, carbamazepine. In addition, 4-(4-fluorobenzyl)-6,8-dimethylpyrido[3,2-e]tetrazolo[1,5-a]pyrimidin-5(4H)-one (4f) and 6-(4-fluorobenzyl)-2,4-dimethylpyrido[3,2-e][1,2,4]triazolo[4,3-a]pyrimidin-5(6H)-one (5f) possessed potent antidepressant properties that lead to significant reduction in the duration of the immobility time than did the control (P < 0.001), which possessed activities similar to those of fluoxetine. 4f showed obvious antidepressant activity at doses of 10 mg/kg.     

Synthesis of novel triazolyl pyranochromen-2(1<Emphasis Type="Italic">H</Emphasis>)-ones and their antibacterial activity evaluation

A series of thirty-three novel triazolyl pyranochromen-2(1H)-one derivatives have been synthesized via Cu (I) catalysed Huisgen 1,3-dipolar cycloaddition reaction. All of the synthesized compounds have been fully characterized from their spectral data and evaluated for antibacterial activity against both gram-positive and gram-negative bacteria. The activity results revealed that amongst all the compounds screened, six compounds, i.e. 2-[4-(((7-ethyl-2,2,6-trimethyl-8-oxo-2,3,4,8-tetrahydropyrano[3,2-g]chromen-10-yl)oxy)methyl)-1H-1,2,3-triazol-1-yl]acetic acid (41), 10-[(1-(1,3-dihydroxypropan-2-yl)-1H-1,2,3-triazol-4-yl)methoxy]-3-ethyl-4,8,8-trimethyl-7,8-dihydropyrano[3,2-g]chromen-2(6H)-one (44), 3-ethyl-4,8,8-trimethyl-10-[(1-((2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)-1H-1,2,3-triazol-4-yl)methoxy]-7,8-dihydropyrano[3,2-g]chromen-2(6H)-one (46), 2-[4-(((7-hexyl-2,2,6-trimethyl-8-oxo-2,3,4,8-tetrahydropyrano[3,2-g]chromen-10-yl)oxy)methyl)-1H-1,2,3-triazol-1-yl]acetic acid (52), 10-[(1-(1,3-dihydroxypropan-2-yl)-1H-1,2,3-triazol-4-yl)methoxy]-3-hexyl-4,8,8-trimethyl-7,8-dihydropyrano[3,2-g]chromen-2(6H)-one (55) and 3-hexyl-4,8,8-trimethyl-10-[(1-((2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)-1H-1,2,3-triazol-4-yl)methoxy]-7,8-dihydropyrano[3,2-g]chromen-2(6H)-one (57), exhibited moderate activity against all the strains studied with zone of inhibition between 10 and 16 mm and MIC values in the range of 75–170 µg/mL as compared to the standard used. The information obtained from structure–activity relationship can be used to design and develop the next generation of compounds with higher antibacterial efficacy.     

Synthesis,molecular docking,antiproliferative, and antimicrobial activity of novel pyrano[3,2-<Emphasis Type="Italic">c</Emphasis>]carbazole derivatives

A new series of pyrano[3,2-c]carbazole derivatives which are biologically valuable and synthetically challenging frameworks have been synthesized by domino Knoevenagel-hetero-Diels-Alder reaction. The key strategy involve copper iodide catalyzed cyclization of O-propargyl derivative of N-Boc-carbazole-3-carboxaldehyde with cyclic 1,3-diketones or pyrazol-5-ones to afford N-Boc-pyrano[3,2-c]carbazole derivatives. The antiproliferative activity of the all synthesized compounds on three cancer cell lines such as PANC 1 (pancreatic), HeLa (cervical), and MDA-MB-231 (breast cancer) was investigated. The results clearly demonstrated that compounds 11b, 11d, and 13d were displayed pronounced antriproliferative activity. In addition, antimicrobial activity of these compounds also assayed against three representative gram-positive organisms and gram-negative organisms. Specifically, compound 11c exhibited significant antimicrobial activity. Molecular docking studies revealed that compound 13d selectively occupy the colchicine binding site of the tubulin polymer.     

Design,docking studies and molecular iodine catalyzed synthesis of benzo[<Emphasis Type="Italic">a</Emphasis>]xanthen-one derivatives as <Emphasis Type="Italic">hyaluronidase</Emphasis> inhibitors

A series of novel benzo[a]xanthen-11(12H)-one derivatives 4a–m were designed and subjected to docking studies. The title compounds were synthesized from 3-aryl-4-formylsydnones 1a–m, β-naphthol and dimedone in presence of molecular iodine as a catalyst and evaluated for their in vitro inhibitory effects on the hyaluronidase.     

Synthesis,antimicrobial and nematicidal evaluation of a new class of triazolo[4,3-<Emphasis Type="Italic">c</Emphasis>]quinazolinylthiazolidinones

In an attempt to find a new class of antimicrobial and nematicidal agents, a series of 2-aryl/heteryl-3-(5-phenyl[1,2,4]triazolo[4,3-c]quinazolin-3-yl)-1,3-thiazolidin-4-ones 5a-k was prepared by one-pot three-component reaction, involving 5-phenyl[1,2,4]triazolo[4,3-c]quinazolin-3-amine 4, aryl/heteroaryl aldehydes and thioglycolic acid, and characterized by physicochemical as well as spectral means. All the newly synthesized compounds 5a–k were tested in vitro for their antimicrobial activity against three representative Gram-positive (Bacillus subtilis, Staphylococcus aureus, Micrococcus luteus), Gram-negative (Proteus vulgaris, Salmonella typhimurium, Escherichia coli) bacteria and four fungal strains (Candida albicans, Aspergillus fumigatus, Trichophyton rubrum, Trichophyton mentagrophytes). These compounds 5a–k, were also evaluated for their nematicidal activity against two nematodes (Ditylenchus myceliophagus, Caenorhabditis elegans). Except phenyl substituted, all the ten aryl/heteroaryl substituted compounds 5b–k showed significant antimicrobial and nematicidal properties against tested microorganisms. Particularly, compounds 5b, 5c, 5g, 5h, 5j and 5k containing electron-withdrawing substituents like chlorophenyl, nitrophenyl, furyl and 1,3-benzodioxole exhibited promising activity comparable to employed standards Ampicillin, Amphotericin B and Levamisole, and emerged as potent antimicrobial and nematicidal agents.     

New phenylpropanoids from <Emphasis Type="Italic">Bulbophyllum retusiusculum</Emphasis>

Two new phenylpropanoids, retusiusines A (1) and B (2), and a pair of new phenylpropyl enantiomers, (±)-retusiusine C (3a and 3b), together with eight known compounds, dihydroconiferyl dihydro-p-coumarate (4), methyl 3-(4-hydroxyphenyl) propionate (5), 3-(4-hydroxyphenyl)-propanoic acid (6), dihydroferulic acid (7), methyl 3-(4-methoxyphenyl) propionate (8), 3-(3,4-dimethoxyphenyl)-2-propenal (9), trans-p-coumaric acid (10) and dihydroconiferyl alcohol (11), were isolated from the tubers of Bulbophyllum retusiusculum. The absolute configurations of the new compounds were determined by calculating their electronic circular dichroism (ECD), spectra and specific optical rotations and comparing the calculated values with the experimental data. Compound 2 exhibited potent antifungal activity against Candida albicans (16 μg/mL). Compound 3 showed moderate antibacterial activity against Bacillus subtilis (64 μg/mL).     

Synthesis,antibacterial evaluation,and SAR study of some novel 3-aryl/heteroaryl-9-methyl-1,2,4-triazolo-[4,3-<Emphasis Type="Italic">a</Emphasis>]-quinoline derivatives

A series of new quinolin-2-yl moiety linked hydrazones of various aryl/heteroaryl aldehydes has been prepared which on treatment with iodobenzene diacetate in dichloromethane yielded novel triazolo[4,3-a]quinoline derivatives. All the synthesized compounds were characterized on the basis of their FT-IR, ¹H, ¹³C NMR, and mass spectral data. Compounds thus obtained were tested in vitro for their antibacterial activity against three Gram-positive bacterial, namely Enterococcus, Bacillus subtilis, and Staphylococcus aureus, and three Gram-negative bacterial strains, namely Psuedomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae using agar well diffusion method. The percentage similarity of all compounds was also assessed on the basis of physico-chemical and steric parameters as compared to a standard drug, Cefixime using Chem 3D software. Most of the compounds possessed good percentage similarity and exhibited admirable antibacterial activity when compared with the standard drug. Compounds (4a, 4b, 3a, 3c, and 3d) containing pyrazole moiety were found to be most effective against Gram-positive bacteria, S. aureus and B. subtilis.     

Antioxidant <Emphasis Type="Italic">C</Emphasis>-glycosylflavones of <Emphasis Type="Italic">Drymaria cordata</Emphasis> (Linn.) Willd

A new C-glycosylflavone, drymaritin E (6-C-(3-keto-β-digitoxopyranosyl)-4′-O-(β-d-glucopyranosyl)-7-methoxyl-5,4′-dihydroxylflavone) 1 was isolated from the oily upper phase (SU) of the MeOH extract from aerial parts of Drymaria cordata together with two known compounds (cassiaoccidentalin A 2 and anemonin 3) and an inseparable mixture of two known C-glycosylflavones 5,4′-dihydroxy-7-methoxyflavone-6-C-(2′′-O-α-l-rhamnopyranosyl)-β-d-glucopyranoside 4a and 5,7,3′,4′-tetrahydroxyflavone-6-C-(2′′-O-α-l-rhamnopyranosyl)-β-d-glucopyranoside 4b. The alkaline hydrolysis of 3 led to a new hemisynthetic derivative, sodium anemonate (sodium 2-((1’E) 2′-sodium-carboxylate-vinyl)-5-oxo-cyclohex-1-ene carboxylate) 3a. The chemical structures were determined by spectroscopic methods (¹H NMR, ¹³C NMR, ¹H-¹H COSY, HMBC, HSQC, and NOESY) and mass spectrometry (ESI–MS). C-glycosylflavones had significant free radical-scavenging activities on the radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). However, SU and compounds 3 and 3a exhibited no activity. In particular, compound 1 exhibited a concentration-dependent radical scavenging activity on DPPH with EC₅₀ of 31.43 µg/mL.     

Alkyl phenols,alkenyl cyclohexenones and other phytochemical constituents from <Emphasis Type="Italic">Lannea rivae</Emphasis> (chiov) Sacleux (Anacardiaceae) and their bioactivity

Six novel compounds, 3-nonadec-14′-(Z)-enyl phenol (1a); 4,5-dihydroxy-4,2′-epoxy-5-[16′-Z-18′-E-heneicosenyldiene]-cyclohex-2-enone (2), 2,4,5-trihydroxy-2-[16′-Z-heneicosenyl]-cyclohexanone (3); 4S,6R-dihydroxy-6-[12′-Z-heptadecenyl]-cyclohex-2-enone (4a); 4S,6R-dihydroxy-6-[14′-Z-nonadecenyl]-cyclohex-2-enone (4b); and 1,2,4-trihydroxy-4-[16′-Z-heneicosenyl]-cyclohexane (5) were identified from the roots and stems of Lannea rivae in addition to the known cardanols, 3-heptadec-12′-Z-enyl phenol (1b), 3-pentadec-10′-Z-enyl phenol (1c) and 3-pentadecyl phenol (1d), sitosterol (6), sitosterol glucoside (7), taraxerone (8), taraxerol (9), E-lutein (10), myricetin (11), myricetin-3-O-α-rhamnopyranoside (12), myricetin-3-O-β-galactopyranoside (13) and (-)-epicatechin-3-O-gallate (14). The ketones 4a and 4b were isolated as a mixture and were qualitatively separated and identified by GCMS. Myricetin (11) and epicatechin gallate (14) displayed over 90 % DPPH radical-scavenging activity at 50 μg mL^?1, while its glycosides (12 and 13) showed percentages of over 70 % in the same assay. The same compounds 11 and 14 showed antibacterial activity similar to erythromycin and vancomycin against Gram-positive bacteria and were also active against Gram-negative bacteria, but not as much as the cefuroxime, ciprofloxacin and nalidixic acid standards. Compounds 1a–d, 4a–b and 5 were all relatively non-toxic, while 2 (the epoxy cyclohex-2-enone) and 3 (the trihydroxy cyclohexanone) showed more toxicity than the others. These two toxic compounds, 2 and 3 also showed antiplasmodial activity with IC₅₀ values between 0.48 and 2.05 μg mL^?1. The mixture of dihydroxy cyclohex-2-enones 4a and 4b, which was far less toxic than 2 and 3, also showed promising antiplasmodial activity and may be a possible lead for further investigation as an antiplasmodial drug.     

Two new naphthalenic lactone glycosides from <Emphasis Type="Italic">Cassia obtusifolia</Emphasis> L. seeds

Two new naphthalenic lactone glycosides, (3S)-9,10-dihydroxy-7-methoxy-3-methyl-1-oxo-3,4-dihydro-1H-benzo[g]isochromene-3-carboxylic acid 9-O-β-d-glucopyranoside (1) and (3R)-cassialactone 9-O-β-d-glucopyranoside (2) were isolated from seeds of Cassia obtusifolia Linn., along with five known compounds: (3R)-cassialactone 9-O-β-d-gentiobioside (3), emodin 1-O-β-gentiobioside (4), 1-hydroxyl-2-acetyl-3,8-dimethoxy-naphthalene 6-O-β-d-apiofuranosyl-(1?→?2)-β-d-glucopyranoside (5), rubrofusarin 6-O-β-d-gentiobioside (6), rubrofusarin 6-O-β-d-triglucoside (7). Structures of 1 and 2 were elucidated by NMR and HR-ESI-MS spectroscopic analysis. Their stereochemistry was determined by CD experiment. All compounds were tested for their ability to inhibit the formation of advanced glycation end-products in vitro. Compounds 1, 2, 3, 5, and 6 showed significant in vitro inhibitory activities (IC₅₀ values of 11.63, 23.40, 7.32, 89.03, and 38.89 µM, respectively).     

Synthesis and evaluation of <Emphasis Type="Italic">p</Emphasis>-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dialkyl substituted chalcones as anti-cancer agents

Several new N,N-dialkyl substituted chalcones (chalconoids or benzylideneacetophenones) have been synthesized via the condensation of corresponding N,N-dialkylbenzaldehyde with various aryl methyl ketones. All the chalcones have been synthesized from readily available and cheap starting materials under environmentally benign conditions in very high yields without work up and column chromatographic purification. Synthesized compounds have been tested for their biological activity against pathogenic microorganisms such as Escherichia coli, Bacillus subtilis, and Mycobacterium smegmatis. Anti-cancer activity of these compounds has also been tested against multiple myeloma (RPMI-8226) and human mammary adenocarcinoma (MCF-7) cell lines. The most hydrophilic molecules 23 and 24 showed very good anti-cancer activity against MCF-7 cell lines at low micro-molar concentrations. All the compounds have also been evaluated for their activity against Beta-secretase 1 enzyme. One of the synthesized compounds showed Beta-secretase 1 enzyme inhibition activity at micro-molar concentration.     

Identification of <Emphasis Type="Italic">N</Emphasis>-arylsulfonylpyrimidones as anticancer agents

For confirming the role of five membered ring of imidazolidinone moiety of N-arylsulfonylimidazolidinones (7) previously reported with highly potent anticancer agent, a series of N-arylsulfonylpyrimidones (10a–g) and N-arylsulfonyltetrahydropyrimidones (11a–e) were prepared and their anti-proliferating activity was measured against human cancer cell lines (renal ACHN, colon HCT-15, breast MDA-MB-231, lung NCI-H23, stomach NUGC-3, and prostate PC-3) using XTT assay. Among them, 1-(1-acetylindolin-5-ylsulfonyl)-4-phenyltetrahydropyrimidin-2(1H)-one (11d, mean GI₅₀ = 3.50 µM) and ethyl 5-(2-oxo-4-phenyltetrahydropyrimidin-1(2H)-ylsulfonyl)-indoline-1-carboxylate (11e, mean GI₅₀ = 0.26 µM) showed best growth inhibitory activity against human cancer cell lines. Considering the activity results, N-arylsulfonyltetrahydropyrimidones (11) exhibited more potent activity compared to N-arylsulfonylpyrimidones (10) and comparable activity to N-arylsulfonylimidazolidinones (7). Especially, tetrahydropyrimidin-2(1H)-one analogs containing acylindolin-5-ylsulfonyl moiety at position 1 demonstrated their strong growth inhibitory activity against human cancer cell lines.     

A new indole glycoside from the seeds of <Emphasis Type="Italic">Raphanus sativus</Emphasis>

A new indole glycoside, β-d-glucopyranosyl 2-(methylthio)-1H-indole-3-carboxylate, named raphanuside A (1), as well as eight known compounds, β-d-fructofuranosyl-(2 → 1)-(6-O-sinapoyl)-α-d-glucopyranoside (2), (3-O-sinapoyl)-β-d-fructofuranosyl-(2 → 1)-α-d-glucopyranoside (3), (3-O-sinapoyl)-β-d-fructofuranosyl-(2 → 1)-(6-O-sinapoyl)-α-d-glucopyranoside (4), (3,4-O-disinapoyl)-β-d-fructofuranosyl-(2 → 1)-(6-O-sinapoyl)-α-d-glucopyranoside (5), isorhamnetin 3,4′-di-O-β-d-glucoside (6), isorhamnetin 3-O-β-d-glucoside-7-O-α-l-rhamnoside (7), isorhamnetin 3-O-β-d-glucoside (8) and 3'-O-methyl-(?)-epicatechin 7-O-β-d-glucoside (9) were isolated from the seeds of Raphanus sativus. Furthermore, compounds 1–3 and 6–9, were isolated from this plant for the first time. The structures of compounds 1–9 were identified using 1D and 2D NMR, including ¹H–¹H COSY, HSQC, HMBC and NOESY spectroscopic analyses. The inhibitory activity of these isolated compounds against interleukin-6 (IL-6) production in TNF-α stimulated MG-63 cells was also examined.     

Synthesis,docking study,and DNA photocleavage activity of some pyrimidinyl hydrazones and 3-(quinolin-3-yl)-5,7-dimethyl-1,2,4-triazolo[4,3-<Emphasis Type="Italic">a</Emphasis>]pyrimidine derivatives

In the present study, synthesis of a series of some novel 3-(Quinolin-3-yl)-5,7-dimethyl-1,2,4-triazolo[4,3-a]pyrimidine derivatives (4a–e) has been achieved by oxidative cyclization of new pyrimidinyl hydrazone intermediates (3a–e) using hypervalent iodine reagent(III) under mild conditions. The structures of all synthesized compounds were established on the basis of IR, NMR (¹H and ¹³C), mass spectral data, and elemental analysis. All compounds were evaluated for their DNA photocleavage activity. Compounds 4a, 4b, 4d and 3a–e were found to possess good activity at 40 μg/μl concentration and were mainly responsible for the conversion of supercoiled form of DNA into open circular form. Further, docking study was carried out using Molegro Virtual Docker version 2010.4.2.0 using PDB (1AB4) in support of the results obtained.     

Synthesis and biological evaluation of novel <Emphasis Type="SmallCaps">d</Emphasis>-glucose-derived 1,2,3-triazoles as potential antibacterial and antifungal agents

A series of novel d-glucose-derived 1,2,3-triazoles have been synthesized in excellent yields via Cu(I)-catalyzed 1,3-dipolar cycloaddition by using methyl α-d-glucopyranoside as starting material. All the new compounds were confirmed by ¹H NMR, ¹³C NMR, IR, MS, and HRMS spectra, and their antimicrobial activities were screened against Gram-Positive, Gram-Negative bacteria, and fungi. Bioactive assay manifested that some of the synthesized glucose-derived 1,2,3-triazoles exhibited good antibacterial and antifungal activities. Notably, compound 5k gave the most potent efficiency with MIC₅₀ value of 6 µM against Candida albicans, which was nine-fold more active than the reference drug Fluconazole. It also exhibited good antibacterial activity against Escherichia coli with the MIC₅₀ value of 10.8 µM compared to Chloramphenicol while the corresponding hydrochloride 4k revealed remarkable inhibitory against Bacillus subtilis with an MIC₅₀ value of 11 µM.     

Two new ursane-type triterpenoid saponins from <Emphasis Type="Italic">Elsholtzia bodinieri</Emphasis>

Two new ursane-type triterpenoid saponins, bodiniosides M (1) and N (2), along with three known saponins, oblonganosides I (3), pseudobuxussaponin B (4) and bodinioside A (5), were isolated from the aerial parts of Elsholtzia bodinieri. The structures of compounds 1 and 2 were characterized by spectroscopic data as well as acid hydrolysis and GC analysis as 3-O-β-d-xylopyranosyl-19α-hydroxy-23-acetoxy-urs-12(13)-en-28-oic acid 28-O-α-l-rhamnopyranosyl-(1-2)-β-d-glucopyranoside and 3-O-β-d-glucopyranosyl-2α,19α-dihydroxy-urs-12(13)-en-28,20β-lactone. Compounds 1 and 5 exhibited potent anti-HCV activities in vitro with a selective index of 6.53 and 4.41, respectively.     

Microwave-assisted synthesis,molecular docking and antimicrobial activity of novel 2-(3-aryl,1-phenyl-1<Emphasis Type="Italic">H</Emphasis>-pyrazol-4-yl)-8<Emphasis Type="Italic">H</Emphasis>-pyrano[2,3-f]chromen-4-ones

An efficient synthetic protocol of microwave-assisted synthesis of some novel 2-(3-aryl,1-phenyl-1H-pyrazol-4-yl)-8H-pyrano[2,3-f]chromen-4-ones 6a–j in excellent yields starting from 3-(3-aryl,1-phenyl-1H-pyrazol-4-yl)-1-(5-hydroxy-2H-chromen-6-yl)-propenones 5a–j was described. This approach offers the advantages of short reaction time (3–5 min), mild reaction conditions, high yields (80–88 %) and convenient operation. All the synthesized compounds were tested in vitro for their antimicrobial activity. The compounds 5h (Ar = 3-ethoxyphenyl), 6c (Ar = 4-chlorophenyl), 6e (Ar = 4-hydroxyphenyl) and 6i (Ar = 3,4-methoxyphenyl) were found to be potent against tested bacterial strains, and compounds 5g (Ar = 4-ethoxyphenyl), 6c (Ar = 4-chlorophenyl) and 6i (Ar = 3,4-methoxyphenyl) were found to be potent against tested fungal strains. The final compounds were subjected to molecular docking studies for the inhibition of enzyme DNA gyrase. The in silico molecular docking results are matching with the in vitro antimicrobial studies, and they may be considered as good inhibitor of DNA gyrase.     

Two new phenylpropane glycosides from <Emphasis Type="Italic">Allium tuberosum</Emphasis> Rottler

A phytochemical investigation of Allium tuberosum Rottler afforded two new phenylpropane glycosides, named tuberonoid A (1) and B (2), along with four known flavonoids, kaempferol 3-O-β-sophoroside (3), 3-O-β-d-(2-O-feruloyl)-glucosyl-7,4′-di-O-β-d-glucosylkaempferol (4), 3-O-β-sophorosyl-7-O-β-d-(2-O-feruloyl)glucosyl kaempferol (5), kaempferol 3,4′-di-O-β-d-glucoside (6). The identification and structural elucidation of the new compounds were carried out based on spectral data analyses (¹H and ¹³C NMR, ¹H–¹H COSY, HMQC) and HR-MS.     

A new class of phenylhydrazinylidene derivatives as inhibitors of <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> biofilm formation

In the struggle against the emergence of the antibiotic resistance, new molecules targeting biofilm formation could be useful as adjuvant of conventional antibiotics. This study focused on a new class of 2-phenylhydrazinylidene derivatives as antivirulence agents. The compound 12e showed interesting activities against biofilm formation of all tested Staphylococcus aureus strains with IC₅₀ ranging from 1.7 to 43 µM; compounds 12f and 13a resulted strong inhibitors of S. aureus ATCC 6538 and ATCC 29213 biofilm formation with IC₅₀ of 0.9 and 0.8 µM, respectively. A preliminary study on the mechanism of action was carried on evaluating the inhibition of sortase A transpeptidase. Compound 12e resulted not to be toxic at 1 mg/ml by using an in vivo model (the wax moth larva model, Galleria mellonella).