Synthesis and biological evaluation of fatty imidazolines

A series of eight fatty imidazolines were synthesized under microwave-assisted conditions using different fatty acids namely octyl, decyl, dodecyl, tetradecyl and octadecyl, mixed fatty acids prepared from Sterculia foetida (containing cyclopropene-rich fatty acids), coconut (containing medium-chain-rich fatty acids), palm (containing saturated-rich fatty acids) and sunflower (containing unsaturated-rich fatty acids). Coconut, sunflower and non-edible oil S. foetida-based imidazolines were synthesized for the first time. The fatty imidazolines were evaluated for anti-fungal activity and found to be good to excellent (MIC, 4.68–18.75 μg ml^?1) against the tested Candida strains as compared with fluconazole (MIC, 16–64 μg ml^?1) as standard. The fatty imidazolines also exhibited excellent to moderate anti-bacterial activity (MIC, 4.68–75 μg ml^?1) against Staphylococcus aureus MTCC 96, S. aureus MLS 16 MTCC 2940 and Pseudomonas aeruginosa MTCC 2453 as compared with neomycin (MIC, 18.75 μg ml^?1) as standard. The cytotoxic evaluation of the imidazolines against different cancer cell lines such as HeLa (Human Cervical Cancer Cell line), A549 (Human Alveolar Adenocarcinoma Cell line), MDA-MB-231& MCF7 (Human Breast Adenocarcinoma Cell line) and Neuro2a (Mouse neuroblastoma cell line) showed excellent cytotoxicity for dodecyl (3b), tetradecyl (3c), octadecyl (3d) and coconut (3f)-based imidazolines. Sunflower-based imidazoline (3g) exhibited good anti-cancer activity towards A549, Neuro2a and palm-based imidazoline (3h) towards HeLa, A549 and MCF-7 cell lines.     

Antimicrobial acylphloroglucinols from the leaves of Rhodomyrtus tomentosa

Phytochemical study on the leaves of Rhodomyrtus tomentosa resulted in the isolation of fourteen compounds including a new acylphloroglucinol, named tomentosone C (1), and a new flavonol glycoside, namely myricetin-3,7,3′-trimethyl ether-5′-O-β-glucopyranoside (2). Their structures were characterized by spectral data interpretation for new structures and in comparison with published data for known compounds. The antimicrobial activity evaluation revealed that 1 and the known acylphloroglucinol rhodomyrtone (3) exhibited significant antimicrobial activity with MIC 3.66 and 1.83 μg ml^?1, respectively, toward Staphylococcus aureus, responsible for the antimicrobial activity observed with the n-hexane and EtOAc-soluble fraction of the ethanol extract of R. tomentosa leaves.     

Inhibitory effect of N-ethyl-3-amino-5-oxo-4-phenyl-2,5-dihydro-1H-pyrazole-1-carbothioamide on Haemophilus spp. planktonic or biofilm-forming cells

During this study, we have investigated in vitro activity of N-substituted-3-amino-5-oxo-4-phenyl-2,5-dihydro-1H-pyrazole-1-carbothioamide derivatives with N-ethyl, N-(4-metoxyphenyl) and N-cyclohexyl substituents against Gram-negative Haemophilus influenzae and H. parainfluenzae bacteria. A spectrophotometric assay was used in order to determine the bacterial growth and biofilm formation using a microtiter plate to estimate minimal inhibitory concentration (MIC) and minimal biofilm inhibitory concentration (MBIC). Among the tested N-substituted pyrazole derivatives, only N-ethyl-3-amino-5-oxo-4-phenyl-2,5-dihydro-1H-pyrazole-1-carbothioamide showed a significant in vitro activity against both planktonic cells of H. parainfluenzae (MIC = 0.49–31.25 μg ml^?1) and H. influenzae (MIC = 0.24–31.25 μg ml^?1) as well as biofilm-forming cells of H. parainfluenzae (MBIC = 0.24–31.25 μg ml^?1) and H. influenzae (MBIC = 0.49 to ≥31.25 μg ml^?1). The pyrazole compound exerted higher inhibitory effect both on the growth of planktonic cells and biofilm formation by penicillinase-positive and penicillinase-negative isolates of H. parainfluenzae than the activity of commonly used antibiotics such as ampicillin. No cytotoxicity of the tested compound in vitro at concentrations used was found. The tested pyrazole N-ethyl derivative could be considered as a compound for the design of agents active against both pathogenic H. influenzae and opportunistic H. parainfluenzae, showing also anti-biofilm activity. This appears important because biofilms are determinants of bacterial persistence in long-term and recurrent infections recalcitrant to standard therapy.     

Cytotoxic prenylated xanthones from Calophyllum inophyllum

A new prenylated xanthone (1), named caloxanthone N, together with two known constituents, gerontoxanthone C (2) and 2-hydroxyxanthone (3), was isolated from the ethanolic extract of the twigs of Calophyllum inophyllum. Their structures were completely elucidated using a combination of 1D, 2D NMR techniques (COSY, HMQC, HMBC, and ROESY) and HR-ESI-MS analyses. Compounds 1 and 2 exhibited cytotoxicity against chronic myelogenous leukemia cell line (K562) with IC₅₀ values of 7.2 and 6.3 μg ml^? 1, respectively.     

A new spirocyclic compound from the liquid culture of entomogenous fungus Isaria cateniannulata

A new spirocyclic compound named (2S, 5S, 7S)-3α-hydroxyl-exogonic acid (1) was isolated from the liquid culture of entomogenous fungus Isaria cateniannulata. The structure and relative stereochemistry of 1 were elucidated by extensive spectroscopic analysis and by comparison of its NMR data with those of known compound. Compound 1 showed weak inhibitory activity against HeLa with IC₅₀ value of 80.5 μg ml^? 1.     

Role of Nanostructures for Anti-proliferation of Bacteria and Their Quantitative Study Validated by Statistical Analysis

The simple and sensitive UV–visible spectrophotometric analytical methods have been adopted for the determination and validation of ZnO nanostructures (nanorods (NRs), nanosphere (NSs), and nanonuts (NNTs)), concentration, which are used to control the bacterial growth of Escherichia coli. This method is based on processing conditions of nanostructures of ZnO using precursors zinc acetate dihydrate (Zn(AC₂)₂·2H₂O), zinc nitrate hexahydrate (Zn(NO₃)₂·6H₂O), sodium hydroxide, hexamethylenetetramine (HMT), methanol, etc. The optical density (OD) of the resulting solution of ZnO nanostructures with E. coli bacteria were measured at 600 nm against the reagent blank, prepared under the same conditions. The use of statistical analysis for evaluation of the resulting solution (ZnO-NRs, ZnO-NSs, and ZnO-NNTs with E. coli) was optimized and validated by various operational parameters. Beer’s law was followed (Concentration range from 0.25–2.0 μg ml^?1) with apparent molar absorptivity of 4.38?×?10² l mol^?1 cm^?1 for ZnO-NRs, 2.70?×?10² l mol^?1 cm^?1 for ZnO-NSs, and 3.10?×?10² l mol^?1 cm^?1 for ZnO-NNTs, respectively. The calibration curve shows linearity over the concentration range of 0.25–1.50 μg ml^?1 for ZnO-NRs and 0.25–2.0 μg ml^?1 for ZnO-NSs and ZnO-NNTs. Detection limit (LOD) and quantitation limit (LOQ) were found to be 0.022:0.068 μg ml^?1 for ZnO-NRs, 0.028:0.087 μg ml^?1 for ZnO-NSs, and 0.044:0.137 μg ml^?1 for ZnO-NNTs analyzed by spectrophotometric method, respectively.     

N-甲基-N-(α-取代萘甲基)取代苄胺类化合物的合成及抗真菌活性

报道25个N-甲基-N-(α-取代萘甲基)取代苄胺类化合物的合成及抗真菌活性。抑菌测试结果表明,目标化合物对于8种试验菌种均有不同程度的抑菌活性,化合物6,7,8,10,11和21等活性为naftifine的4～20倍,化合物8,10,11和21等活性为butenafine的2～10倍,化合物8,9,10,11和21等对Sporotrichum schencki及Aspergilus fumigatus的活性为clotrimazole的8～15倍,化合物7,8,9和21等对Cryptococus neoformans亦表现出较高活性,MIC为0.31～1.25μg·ml^-1。     

Total syntheses of surinone B,alatanones A–B,and trineurone A

The total syntheses of four polyketides, surinone B (1), alatanones A–B (2–3), and trineurone A (4) were accomplished through an efficient and unified strategy via one-pot C-acylation reaction coupling 1,3-cyclohexadiones with EDC-activated acids under mild conditions. Alatanone A (2) was found to be a potent anti-microbial agent against Gram-positive and Gram-negative bacteria with MIC 31.25 μg/ml while alatanone B (3) was found to be a potent anti-fungal agent against Cladosporium cladosporioides with MIC 62.5 μg/ml compared to cycloheximide MIC 125 μg/ml. Our methodology allows performing kilogram scale of these scarce polyketides for the development of new antimicrobials.     

Three new cyclopentenone derivatives from Actinoalloteichus nanshanensis NEAU 119

Three new cyclopentenone derivatives (1–3) were isolated from the rare actinomycete Actinoalloteichus nanshanensis NEAU 119. Their structures were elucidated by extensive spectroscopic analysis. Compound 1 showed moderate cytotoxic activity against human lung adenocarcinoma cell line A549, human leukemia cell line K562, and human renal carcinoma cell line ACHN with an IC₅₀ of 14.67, 11.87, and 23.36 μg ml^? 1, respectively.     

腺嘌呤衍生物的合成及体外抗疱疹病毒活性

以腺嘌呤为母体,在其9位引入活性基团N-取代缩氨基硫脲(TSC),设计合成了12个6-氨基-9(N^4'-取代乙醛缩氨基硫脲)嘌呤衍生物(4a～1),并进行了体外抗单纯疱疹病毒I型(HSV-1),II型(HSV-2),水痘-带状疱疹病毒(VZV)活性试验及细胞毒性试验。结果表明,除化合物4e及4f对HSV-1及VZV有较高活性外,其余化合物对上述两种病毒的活性均不明显。另外,将4e与4f分别与无环鸟苷(ACV)联合用药,其最小抑制浓度(MIC)及细胞毒性(MCC)均显著下降。     

Two new monoterpenes from Sibiraea laevigata

Two new monoterpenes, 3-(2-oxo-4-methyl-3-pentenyl)furan-5H-2-one (1) and 3-[(2E)-4-hydroxyl-4-methyl-2-pentenyl)]furan-5H-2-one (2), along with eight known compounds (3–10), were isolated from the stalks and infructescence of Sibiraea laevigata. Their structures were elucidated by spectroscopic methods including extensive 1D and 2D NMR techniques. In addition, all of these isolates were evaluated for their cytotoxic and antioxidant activities. The results showed that compounds 5–7 displayed cytotoxicity with IC₅₀ values ranging from 34.8 to 43.2 μg ml^?1 against tumor cell lines. Furthermore, 5 and 9 showed antioxidant activities.     

Efficacy of osthol,a potent coumarin compound,in controlling powdery mildew caused by Sphaerotheca fuliginea

The efficacy of osthol, a natural coumarin compound, in controlling powdery mildew was evaluated in 2004–2005 in Anhui and Hebei Provinces of China. In both years, the treatments (osthol 15.0 and 18.0 g ai ha^? 1) showed a stable control efficiency of 75.42, 81.24% and 76.36, 84.84%, respectively, at the Institutes of Plant Protection of Hebei Academy of Agricultural Sciences. In field experiments, osthol was as effective as difenoconazole in controlling powdery mildew and was more effective than triadimefon against Sphaerotheca fuliginea. Protection was expressed as a significant reduction (up to 87% compared with the control) in the mildewed leaf area in young pumpkin plants. Osthol strongly inhibited spore germination and mycelial growth of S. fuliginea in vitro, damaged the cell wall and the organelles of the pathogen. At 48 h after incubation, 50 μg ml^? 1 osthol could completely inhibit spore germination. These findings suggested that the effect of osthol on powdery mildew may be associated with the direct fungitoxic property against the pathogen. We conclude that osthol would be an attractive natural compound for practical agronomic use against powdery mildew.     

Structure and bioactivity of triterpenoids from the stems of Schisandra sphenanthera

Two new triterpenoids, schisphendilactone A and B (1 and 2), together with three known triterpenoids, were isolated from the stems of Schisandra sphenanthera. Their structures were elucidated by spectroscopic methods, and the absolute configuration of 1 was determined by single-crystal X-ray diffraction. Compound 2 showed moderate inhibitory activity against SW480 cancer cell line, and compound 5 exhibited promising anti-HIV-1 activity with EC₅₀ value of 0.52 μg ml^?1 and therapeutic index value of 117.12.     

Two pairs of rare naturally occurring 4-hydroxy-4-methyl-2,5-heptanedione derivatives from the red alga Chondria crassicaulis

Two pairs of rare naturally occurring racemic lipids, (±)-4,7-dihydroxy-4-methyl-2,5-heptanedione (1), and (±)-7-butoxy-4-hydroxy-4-methyl-2,5-heptanedione (2) were isolated from the red alga Chondria crassicaulis Harv. The structures of the racemic mixtures of 1 and 2 were elucidated by detailed spectroscopic techniques, including 1D and 2D NMR (¹H and ¹³C NMR, ¹H–¹H COSY, HSQC, and HMBC) as well as mass spectrometry and optical rotation experiments, and by comparison with data for related known analogs. This is the first report of naturally occurring 4-hydroxy-4-methyl-2,5-heptanedione derivatives. Antifungal, PTP1B inhibitory, and receptor tyrosine kinase inhibitory activities of these two compounds were investigated. The results showed that compounds 1 and 2 exhibited good selective inhibition against RET tyrosine kinase activity with IC₅₀ values of 9.56 and 8.93 μM, respectively. Compound 1 also displayed moderate antifungal activity against Cryptococcus neoformans (32609), showing a MIC₈₀ value of 32 μg/ml.     

Note: A new triterpene from Luculia pinciana Hook.

A new triterpene named luculiaoic acid A (1), showing inhibitory activity of a leukaemia cell line, along with eleven known compounds, has been isolated from the ethyl acetate extract of the stems of Luculia pinciana Hook. All the structures were elucidated on the basis of NMR, MS, and IR methods. The activity to inhibit Staphylococcus aureus and Candida albicans of all compounds showed that ursolic acid inhibits the growth of Staphylococcus aureus with an MIC of 0.5?mg?ml^?1 and an MBC of 10?mg?ml^?1, and scopletin inhibits Candida albicans with an MIC of 1?mg?ml^?1 and an MBC of 5?mg?ml^?1.     

Efficient Synthesis and Biological Evaluation of a Novel Series of 1,5‐Benzodiazepine Derivatives as Potential Antimicrobial Agents

A series of novel 1,5‐benzodiazepine derivatives were rationally designed and synthesized following the principle of the superposition of bioactive substructures by the combination of 1,5‐benzodiazepine, pyridine (phenyl), and an ester group. The structures of the target compounds were determined by ¹H NMR, ¹³C NMR, MS, IR, and elemental analysis. All the synthesized compounds were evaluated for their antimicrobial activities in vitro against the fungi C. neoformans, C. neoformans clinical isolates (ATCC 32264), C. albicans (ATCC 10231), Gram‐negative bacterium E. coli (ATCC 44752), and Gram‐positive bacterium S. aureus (ATCC 25923). The results of the bioactive assay demonstrated that most of the tested compounds exhibited variable inhibitory effects on the growth of the tested microorganisms. All the active compounds showed better antifungal activity than antibacterial activity. Notably, compound 2b displayed the highest activity (MIC = 30 μg/mL) against C. neoformans and (MIC = 31 μg/mL) against C. neoformans clinical isolates. In addition, compound 2a also showed excellent activity against C. neoformans and C. neoformans clinical isolates with minimum inhibitory concentration of 35 and 36 μg/mL, respectively. Compounds 2a and 2b were further studied by evaluating their cytotoxicities, and the results showed that they have relatively low level cytotoxicity for BV2 and 293T cell. Preliminary structure‐activity relationship study on three diverse sets (C‐2, C‐3, and C‐8 positions) of 1,5‐benzodiazepines was performed. The results revealed that the presence of a ‐CH₃ group at the C‐8 position had a positive effect on the inhibitory activity of these compounds. Additionally, the 2‐pyridyl group at the C‐2 position may be a pharmacophore and ‐COOC₂H₅ at C‐3 position is the best substituent for the maintenance of antimicrobial activities.     

Synthesis and Antifungal Activities of Myristic Acid Analogs

Myristic acid analogs that are putative inhibitors of N-myristoyl-transferase were tested in vitro for activity against yeasts (Saccharomyces cerevisiae, Candida albicans, Cryptococcus neoformans) and filamentous fungi (Aspergillus niger). Several (±)-2-halotetradecanoic acids including (±)-2-bromotetradecanoic acid ( 14c ) exhibited potent activity against C. albicans (MIC = 39 μM). C. neoformans (MIC = 20 μM), S. cerevisiae (MIC = 10 μM), and A. niger (MIC < 42 μM) in RPMI 1640 media. Improved synthetic methods have been developed for the synthesis of 12-fluorododecanoic acid ( 12a ) and 12-chlorododecanoic acid ( 12c ). Three novel fatty acids, 12-chloro-4-oxadodecanoic acid ( 8a ), 12-phenoxydodecanoic acid ( 12i ), and 11-(4-iodophenoxy)undecanoic acid ( 13d ) were also synthesized and tested.     

Anticholinesterase,antioxidant, analgesic and anti-inflammatory activity assessment of Xeranthemum annuum L. and isolation of two cyanogenic compounds

Context: Xeranthemum annuum L. (Asteraceae) (XA) is an ornamental and medicinal species with limited bioactivity and phytochemical data.

Objective: Identification of anticholinesterase, antioxidant, anti-inflammatory and analgesic effects of the flower and root–stem (R-S) extracts of XA.

Materials and methods: Anticholinesterase (at 100?μg mL^?1) and antioxidant (at 1000?μg mL^?1) effects of various extracts were evaluated via microtiter assays, while anti-inflammatory and analgesic effects of the R-S extracts were tested using carrageenan-induced hind paw oedema (100 and 200?mg kg^?1) and p-benzoquinone (PBQ) writhing models (200?mg kg^?1) in male Swiss albino mice. The R-S ethanol extract of XA was subjected to isolation studies using conventional chromatographic methods.

Results: Most of the extracts showed inhibition over 85% against butyrylcholinesterase and no inhibition towards acetylcholinesterase. The flower chloroform and the R-S ethyl acetate extracts were most effective (97.85?±?0.94% and 96.89?±?1.09%, respectively). The R-S ethanol extract displayed a remarkable scavenging activity against DPPH (77.33?±?1.99%) and in FRAP assay, while the hexane extract of the R-S parts possessed the highest metal-chelating capacity (72.79?±?0.33%). The chloroform extract of the R-S caused a significant analgesic effect (24.4%) in PBQ writhing model. No anti-inflammatory effect was observed. Isolation of zierin and zierin xyloside, which were inactive in anticholinesterase assays, was achieved from the R-S ethanol extract.

Discussion and conclusion: This is the first report of anticholinesterase, antioxidant, analgesic and anti-inflammatory activities and isolation of zierin and zierin xyloside from XA. Therefore, XA seems to contain antioxidant and BChE-inhibiting compounds.     

Comparative study of three analysis methods (TTGE, flow cytometry and HPLC) for xenobiotic impact assessment on phytoplankton communities

The impacts of the fungicide Opus^® (epoxiconazole) on marine phytoplankton communities were assessed in a 12-day field experiment using in situ microcosms maintained underwater at 6 m depth. Three community analysis methods were compared for their sensitivity threshold in fungicide impact detection. When phytoplankton communities were exposed to 1 μg l^?1 of epoxiconazole, no effects could be demonstrated using TTGE (Temporal Temperature Gradient gel Electrophoresis), flow cytometry or HPLC. When exposed to 10 μg l^?1, TTGE fingerprints from PCR amplified 18S rDNA of communities exhibited significant differences compared with controls (ANOSIM, P = 0.028). Neither flow cytometry counts, nor HPLC pigment profiles allowed to show significant differences in microcosms exposed to 10 μg l^?1 of epoxiconazole. When exposed to 100 μg l^?1, all three methods allowed to detect significant differences in treated microcosms, as compared to controls. The TTGE analysis appears in this study as the most sensitive method for fungicide impact assessment on eukaryote microbial communities.