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.     

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.     

New carbodithioate derivatives: synthesis,characterization, and in vitro antibacterial,antifungal, antitubercular,and antimalarial activity

A series of structurally new, 2-(5-substituted-2,3-dioxoindolin-1-yl)ethyl/propyl 4-(3,4-dichlorophenyl)piperazine-1-carbodithioate derivatives 5a–j were designed and synthesized by conventional technique as well as ultrasound irradiation. All the new compounds were characterized by spectral and elemental analyses. Furthermore, they were evaluated for their in vitro antibacterial, antifungal, antitubercular, and antimalarial activities. The results indicated that some of the synthesized compounds posses promising antimicrobial activity against some gram-positive and gram-negative bacteria. Compounds 5b, 5d, and 5e displayed the highest inhibition (99 %) in the range of 3.10–6.25 μg/ml against Mycobacterium tuberculosis H ₃₇ Rv, while compounds 5b–g displayed promising antimalarial activity in the range of 0.043–0.092 μg/mL against Plasmodium falciparum 3D7. Thus, these molecules can provide prospective leads in chemotherapy against tuberculosis and malaria.     

Synthesis,biological evaluation,and molecular modeling of (<Emphasis Type="Italic">E</Emphasis>)-2-aryl-5-styryl-1,3,4-oxadiazole derivatives as acetylcholine esterase inhibitors

A library of 2,5-disubstituted 1,3,4-oxadiazole derivatives of (E)-2-aryl-5-(3,4,5-trimethoxystyryl)-1,3,4-oxadiazoles 4(a–o) and (E)-2-aryl-5-(2-benzo[d][1,3]dioxol-5-yl)vinyl)-1,3,4-oxadiazoles 5(a–q) were synthesized and evaluated for their in vitro acetylcholinesterase (AChE) inhibitory activity. All the synthesized compounds exhibited moderate to good inhibitory activity toward the AChE enzyme. Among the oxadiazole derivatives examined, compounds 4a, 4g, 5c, and 5m (IC₅₀ values of 24.89, 13.72, 37.65, and 19.63 μM, respectively) were found to be promising inhibitors of AChE. Molecular protein–ligand docking studies were examined for these compounds using GOLD docking software and their binding conformations were determined and the simultaneous interactions mode was also established for the potent derivatives.     

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.     

Syntheses of arylcinnamic acids,using Alum-Cs<Subscript>2</Subscript>CO<Subscript>3</Subscript> as precursors of new 2-heterostyrylbenzimidazoles and their antimicrobial evaluation

A simple and green methodology has been developed for the syntheses of some new 2-styrylbenzimidazoles. In this method, 2-styrylbenzimidazoles 6(a–x) were synthesized by the condensation of o-phenylenediamines 4(a–c) with cinnamic acids 3(a–h) using glycerol containing boric acid (10 mol%) as the reaction medium at 180 °C about 3–5 h. The cinnamic acids 3(a–h) were obtained by the condensation between aromatic aldehydes 1(a–h), and malonic acid using a new heterogeneous catalytic system such as alum-Cs₂CO₃ in water is described. Compounds 6(a–x) were also obtained alternatively by the condensation of 2-methylbenzimidazoles 5(a-c) with 1(a-h) using the same glycerol containing boric acid (10 mol%) as reaction medium at 180 °C for 5–6 h. The catalytic systems mentioned here were found to be highly active, stable, and recyclable under reaction conditions. All the newly synthesized compounds were characterized by IR, Mass, and NMR spectral analyses. All synthesized compounds were screened for their antimicrobial activity against the clinical strains which include gram-positive bacteria (Micrococcus luteus MTCC 2470, Staphylococcus aureus MTCC 96, Staphylococcus aureus MLS-16 MTCC 2940, Bacillus subtilis MTCC 121) and gram-negative bacteria (Escherichia coli MTCC 739, Pseudomonas aeruginosa MTCC 2453, Klebsiella planticola MTCC 530, and Candida albicans MTCC 3017). The results revealed that compounds (6b, 6g, 6h, 6j, 6k, 6n, 6o, 6t) exhibited significant antibacterial activity almost equal to the standard drug, i.e., Ciprofloxacin.     

Synthesis,structures elucidation,DNA-PK,PI3K and antiplatelet activity of a series of novel 7- or 8-(<Emphasis Type="Italic">N</Emphasis>-substituted)-2-morpholino-quinazolines

The DNA-dependent protein kinase and phosphoinositide 3-kinase family is one of the most frequently activated enzymes in a wide range of human cancers; consequently, inhibition of DNA-dependent protein kinase and phosphoinositide 3-kinase represents an approach for cancer therapy. In this work, we have designed and synthesized a series of novel 7- or 8-(N-substituted)-2-morpholino quinazolines 3a–f, 5a–e, 7a–e, and 9 from 7- or 8-amino-2-morpholino quinazolin-4-ones (2a, 4a), the 3-methyl analogues (2b, 4b) and the 4-alkyloxy analogues (6a–b, 8). The compounds were subsequently assayed for DNA-dependent protein kinase and phosphoinositide 3-kinase activity. Most compounds were less active than expected in spite of the strong structural resemblance to the previously studied 7- or 8-(O-substituted)-2-morpholino-1,3-benzoxazine inhibitors. Loss of DNA-dependent protein kinase activity for the quinazolin-4-ones (3a–d and 5a–d) has been attributed to tautomerization to the aromatic enol (4-OH) tautomers. Aromatization of the heterocyclic ring could alter the conformation, and thus binding position, resulting in reduced compound-receptor hydrogen bonding of the morpholine oxygen and 4-carbonyl oxygen. The hetero-aromatic compounds 7a–e and 9 also did not show any DNA-dependent protein kinase activity at 10?µM, which supports the above hypothesis. Compound 7c (R=CH₂(pyridine-4-yl)) displayed selective phosphoinositide 3-kinase delta activity with 80?% inhibition at 10?µM. Similarly, compounds 5a (8-N-substituted, R=CH₂Ph) and 3a (7-N-substituted, R=CH₂Ph) showed selective phosphoinositide 3-kinase beta activity with 69 and 61?% inhibition, respectively. Antiplatelet inhibition assays showed that compound 7e with the 4-O-benzyloxy group and 8-CH₂(pyridine-3-yl) substituents was found to be the most active (IC₅₀ 35?µM).     

Synthesis,structural elucidation and bioevaluation of 4-amino-1,2,4-triazole-3-thione’s Schiff base derivatives

In this study, a series of ten triazole Schiff base derivatives 6a–j were synthesized through microwave assisted imine formation by reacting substituted amino triazole 5 with different substituted aldehydes. All the synthesized compounds were evaluated for their inhibitory activity against mushroom tyrosinase. Two of the compounds 6a and 6b among the series 6a–j were found to be highly potent tyrosinase inhibitors with IC₅₀ values of 10.09 ± 1.03 and 6.23 ± 0.85 µM, respectively, which were even higher than that of the reference inhibitor kojic acid (IC₅₀ = 16.6 ± 2.8 µM). Compounds 6e and 6f with IC₅₀ values of 20.27 ± 2.78 and 26.02 ± 4.14 µM, respectively, were comparable to the reference inhibitor, and the remaining compounds had a moderate inhibitory activity against mushroom tyrosinase. The most potent compounds (6a, 6b) were used in the kinetic and optical analyses. The inhibition kinetics analyzed with Lineweaver–Burk plots revealed that both compounds 6a and 6b were non-competitive inhibitors of tyrosinase with inhibition constant values of 0.023 and 0.022 mM, respectively.     

Constituents from the leaves of <Emphasis Type="Italic">Clausena lansium</Emphasis> and their anti-inflammatory activity

Five new acyclic amides, clausenalansamides C-G (1–5), clausenaline G (6) and (±)-5-(4-methylphenyl)-γ-valerolactone (7) reported from the natural source for the first time, were characterized from the leaves of Clausena lansium. Their structures were established by spectroscopic and spectrometric methods, and the absolute configurations of new compounds 1–5 were determined by electronic circular dichroism and single-crystal X-ray diffraction analyses. Eighteen compounds were evaluated for their anti-inflammatory activity and only imperatorin (11) and wampetin (12) displayed significant inhibition of fMLP/CB-induced superoxide anion generation with IC₅₀ values of 1.7 ± 0.3 and 6.8 ± 1.1 μM, respectively.     

Synthesis and characterization of flurbiprofen hydrazide derivatives as potential anti-HCV, anticancer and antimicrobial agents

A novel series of new flurbiprofen hydrazide derivatives 2-(2-fluorobiphenyl-4-yl)-N′-[(substituted phenyl/5-nitro-2-furyl)methylene]propanehydrazide (3a–k), 2-(2-fluorobiphenyl-4-yl)-N-(2-substituted-4-oxo-1,3-thiazolidine-3-yl)propanamide (4a–b, 4d–k), 2-[2-(2-fluorobiphenyl-4-yl) propanoyl]-N-substituted hydrazinecarbothioamide (5a–h) and 2-(2-fluorobiphenyl-4-yl)-N′-[(3-methyl-4-oxo-1,3-thiazolidin-2-ylidene]propanehydrazide (6a–b, 6e and 6g) has been synthesized in this study. All synthesized compounds were screened for antimicrobial activity against various bacterial and fungal strains. Additionally, compounds were evaluated for the ability to inhibit Hepatitis C virus NS5B polymerase. The most active 4-thiazolidinone compound was 4k (SGK119) with 67.0 % and thiosemicarbazide compound was 5d (SGK123) with 69.50 % inhibition at 200 μM against hepatitis C virus NS5B RNA polymerase. Anticancer activity of the selected compounds (3i, 3j, 3h, 4d, 4i and 6b) was determined at a single dose towards the full panel of 60 human cancer cell lines by the National Cancer Institute (NCI). 2-(2-Fluoro-4-biphenylyl)-N-[2-[4-(trifluoromethyl)phenyl]-4-oxo-1,3-thiazolidine-3-yl]propanamide 4d, containing thiazolidinone ring, demonstrated the most marked effect with 20.80 % growth percent on leukaemia cancer cell line SR at 10^?5 M. The results demonstrated that none of the compounds tested have anticandidal and antifungal activities, but two of them (4a and 4i) showed antibacterial inhibition against Micrococcus luteus, and Staphylococcus cohnii and Staphylococcus aureus, respectively.     

Efficient synthesis of lactonic and thionolactoniclignans and evaluation of their anti-oxidant,anti-inflammatory and cytotoxic activities

A short and versatile synthesis of α,β-dibenzyl-γ-butyrolactones has been developed starting from inexpensive materials by applying Stobbe condensation and following the novel reductive cyclisation with sodiumborohydride. Natural products Suchilactone (5a), Kaerophyllin (5b), savinin (5d) and anhydropodorhizol (5f) were prepared in racemic form. New thionolactones (6a–6e) were prepared by treating these lignans with Lawesson’s reagent. For all the prepared compounds the antioxidant, anti-inflammatory (5-lipoxygenase inhibition) and cytotoxic (Brine shrimp lethality test) activities were tested. The compounds 5a, 5b, 5c, 5d, 5e and 5f showed good 5-lipoxygenase inhibition activity. The thiono lignan 6d showed impressive cytotoxic activity.     

Synthesis,molecular docking and antimicrobial evaluation of novel benzoxazole derivatives

In this research, previously and newly synthesized 5-amino-2-(4-substitutedphenyl/benzyl)benzoxazoles (3a–3l) and 2-substituted-5-(4-nitro/aminophenylsulfonamido)benzoxazoles (5a–5l, 6a–6l) were evaluated for their antimicrobial activities against Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 29213, Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 29212 and Mycobacterium tuberculosis H37RV ATCC 27294 and their drug-resistant isolates Candida albicans ATCC 10231 and Candida krusei ATCC 6258. The chemical structures of the newly synthesized compounds were characterized by IR, ¹H NMR, ¹³C NMR, LC–MS and elemental analysis. Microbiological results indicated that the compounds possessed a broad spectrum of activity against the tested microorganisms at the minimum inhibitory concentration (MIC) values between 256 and 8 µg/mL. Compounds 3a, 3c and 3f exhibited significant antimycobacterial activity showing MIC value of 8 µg/mL against both M. tuberculosis and its drug-resistant isolate. InhA, the enoyl-acyl carrier protein reductase from M. tuberculosis, is one of the key enzymes in the FASII system involved in mycobacterial fatty acid elongation cycle, which has been validated as an effective antimicrobial target. Molecular docking into active site of InhA was performed on 3FNE.PDB file to understand ligand–protein interactions. The compounds obtained from this research can be used as scaffolds in the design of new potent drugs.     

An anti-mycobacterial bisfunctionalized sphingolipid and new bromopyrrole alkaloid from the Indonesian marine sponge <Emphasis Type="Italic">Agelas</Emphasis> sp.

In the course of our studies on anti-mycobacterial substances from marine organisms, the known dimeric sphingolipid, leucettamol A (1), was isolated as an active component, together with the new bromopyrrole alkaloid, 5-bromophakelline (2), and twelve known congeners from the Indonesian marine sponge Agelas sp. The structure of 2 was elucidated based on its spectroscopic data. Compound 1 and its bis TFA salt showed inhibition zones of 12 and 7 mm against Mycobacterium smegmatis at 50 μg/disk, respectively, while the N,N’-diacetyl derivative (1a) was not active at 50 μg/disk. Therefore, free amino groups are important for anti-mycobacterial activity. This is the first study to show the anti-mycobacterial activity of a bisfunctionalized sphingolipid. Compound 13 exhibited weak PTP1B inhibitory activity (29% inhibition at 35 μM).     

Design,synthesis and biological activity of <Emphasis Type="Italic">N</Emphasis>-(3-substituted-phenyl)benzenesulfonamides as selective and reversible LSD1 inhibitors

Lysine specific demethylase 1 plays a crucial role in regulating histone methylation at residues K4 and K9 on histone H3 and over-expresses in a variety of cancers. Here we designed, synthesized and evaluated a series of N-(3-substituted-phenyl)benzenesulfonamides as reversible lysine specific demethylase 1 inhibitors. All the compounds exhibited lysine specific demethylase 1 inhibition with the half maximal inhibitory concentration (IC₅₀) values between 7.5 and 68?μM. Three most active compounds 2a, 2c and 2i displayed only modest effect on flavin adenine dinucleotide-dependent enzymes mono-amine oxidases A and B, and their reversibilities of lysine specific demethylase 1 inhibition were confirmed. Molecular docking was also carried out to predict the binding mode of 2a into the active site of lysine specific demethylase 1. Taken together, N-(3-substituted-phenyl)benzenesulfonamides including 2a represent a new class of selective and reversible lysine specific demethylase 1 inhibitors with pharmaceutical research.     

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).     

Anti-inflammatory activity of compounds from the rhizome of <Emphasis Type="Italic">Cnidium officinale</Emphasis>

Five new compounds, 9,3′-dimethoxyhierochin A (1), 6-oxo-trans-neocnidilide (2), (±)-(3E)-trans-6-hydroxy-7-methoxydihydroligustilide (3), (±)-cnidiumin (4), and 6-(1-oxopentyl)-salicylic acid methyl ester (5), together with twenty known compounds (6–25), were isolated from the rhizome of Cnidium officinale. The chemical structures of new compounds were established by NMR spectroscopic techniques, mass spectrometry, Mosher’s method, and CD spectrum. Their anti-inflammatory activities were evaluated against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in macrophage RAW 264.7 cells. Compounds 7, 13, and 14 showed inhibitory effects with IC₅₀ values of 5.1, 24.5, and 27.8 μM, respectively. In addition, compounds 7, 13, and 14 reduced LPS-induced inducible nitric oxide synthase (iNOS) expression and cyclooxygenase-2 (COX-2) protein in a concentration-dependent manner.     

Anti-inflammatory activity of caffeic acid derivatives isolated from the roots of <Emphasis Type="Italic">Salvia miltiorrhiza</Emphasis> Bunge

Ten caffeic acid derivatives (1–10) were isolated from the roots of Salvia miltiorrhiza by using various chromatographic methods and their chemical structures were spectroscopically elucidated. The absolute configurations of chiral centers were determined by comparison with reported coupling constants, optical rotation values, and CD techniques. Anti-inflammatory activities were evaluated using nitric oxide (NO), inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 inhibition assays, and by determining the expression of heme oxygenase (HO)-1. Two new caffeic acid derivatives, 8-epiblechnic acid 9-methyl ester (4) and 8-epiblechnic acid 9′-methyl ester (5), and eight known derivatives, caffeic acid methyl ester (1), shimobashiric acid B (2), rosmarinic acid methyl ester (3), salvianolic acid C (6), methyl salvianolate C (7), lithospermic acid monomethyl ester (8), lithospermic acid dimethyl ester (9), and dimethyl lithospermate B (10), were isolated from the ethyl acetate fraction of S. miltiorrhiza. All caffeic acid derivatives were evaluated for their inhibitory effect on NO production. Compounds 2 and 3 inhibited NO production with IC₅₀ values of 1.4 and 0.6 μM, respectively. These compounds also strongly inhibited the production of iNOS and COX-2. In addition, compound 3 induced the expression HO-1 in a concentration-dependent manner at 0.1, 0.3, and 1.0 μM.     

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.     

Kinetics and molecular docking of dihydroxanthyletin-type coumarins from <Emphasis Type="Italic">Angelica decursiva</Emphasis> that inhibit cholinesterase and BACE1

In the present study, we investigated the anti-Alzheimer’s disease (AD) potential of six dihydroxanthyletin-type coumarins, 4′-hydroxy Pd–C-III (1), decursidin (2), Pd–C-I (3), 4′-methoxy Pd–C-I (4), Pd–C-II (5), and Pd–C-III (6) from Angelica decursiva by evaluating their ability to inhibit acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and β-site amyloid precursor protein cleaving enzyme 1 (BACE1). Coumarins 1–6 exhibited dose-dependent inhibition of AChE, BChE, and BACE1. IC₅₀ values were 1.0–4.01 µM for AChE, 5.78–13.91 µM for BChE, and 1.99–17.34 µM for BACE1. Kinetic studies revealed that 1 was noncompetitive inhibitor for AChE, while 2–6 were mixed-type inhibitors of AChE. Compounds 1, 5 and 6 had mixed-type inhibitory effects against BChE; 2 was a competitive inhibitor; and 3 and 4 were noncompetitive inhibitors. Against BACE1, compounds 1, 2, 3, 5 showed mixed-type inhibition and 4, 6 were noncompetitive inhibitors. Molecular docking simulation of the compounds demonstrated negative-binding energies indicating high proximity to the active site and tight binding to the enzyme. These data suggested that the compounds inhibited AChE, BChE, and BACE1, providing a preventive and therapeutic strategy for AD treatment.     

Degranulation inhibitors from the arils of <Emphasis Type="Italic">Myristica fragrans</Emphasis> in antigen-stimulated rat basophilic leukemia cells

A methanol extract of mace, the aril of Myristica fragrans (Myristicaceae), was found to inhibit the release of β-hexosaminidase, a marker of antigen-IgE-stimulated degranulation in rat basophilic leukemia cells (RBL-2H3, IC₅₀ = 45.7 μg/ml). From the extract, three new 8-O-4′ type neolignans, maceneolignans I–K (1–3), were isolated, and the stereostructures of 1–3 were elucidated based on spectroscopic and chemical evidence. Among the isolates, maceneolignans A (5), D (6), and H (8), (?)-(8R)-?^8′-4-hydroxy-3,3′,5′-trimethoxy-8-O-4′-neolignan (13), (?)-(8R)-?^8′-3,4,5,3′,5′-pentamethoxy-8-O-4′-neolignan (14), (?)-erythro-(7R,8S)-?^8′-7-acetoxy-3,4-methylenedioxy-3′,5′-dimethoxy-8-O-4′-neolignan (17), (+)-licarin A (20), nectandrin B (24), verrucosin (25), and malabaricone C (29) were investigated as possible degranulation inhibitors (IC₅₀ = 20.7–63.7 μM). These inhibitory activities were more potent than those of the antiallergic agents tranilast (282 μM) and ketotifen fumalate (158 μM). Compounds 5, 25, and 29 also inhibited antigen-stimulated tumor necrosis factor-α production (IC₅₀ = 39.5–51.2 μM), an important process in the late phase of type I allergic reactions.