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ABSTRACT: A series of 35 benzimidazole derivatives were synthesized from 2-chloromethyl-1H-benzimidazole in good yields. Their structures were characterized by 1H and 13C NMR and HRESIMS. Antifungal activities of all of the synthesized compounds were evaluated against five phytopathogens fungi (Cytospora sp., Colletotrichum gloeosporioides, Botrytis cinerea, Alternaria solani, and Fusarium solani) using the mycelium growth rate method. Compound 4m displayed strong growth inhibition of C. gloeosporioides, A. solani, and F. solani with IC50 of 20.76, 27.58, and 18.60 μg/mL, respectively. Selective inhibition of B. cinerea instead of the other fungal pathogenes was observed with 7f (IC50 of 13.36 μg/mL), comparable to that of positive control, a commercial agricultural fungicide hymexazol (IC50 of 8.92 μg/mL). Compound 5b exhibited remarkable antifungal properties against Cytospora sp., C. gloeosporioides, B. cinerea, and F. solani with IC50 values of 30.97, 11.38, 57.71, and 40.15 μg/mL, respectively; among the target fungi, 5b was the most active compound and superior to the reference against C. gloeosporioides alone. Structure-activity relationship (SAR) data of these compounds are as follows: (1) introduction of the chlorine atom on para-position in the benzene ring help to increase activity (4f vs 4c; 7f vs 7n), (2) the sulfonyl group is critical for the inhibition of C. gloeosporioides (5b and 5c vs 5a), and (3) the unsubstituted benzene ring improve activity (4m vs 4n, 4e and 4a). Thus, compounds 5b, 4m, and 7f emerged as a new leading structure for the development of new fungicides.
Journal of Agricultural and Food Chemistry 03/2013; · 2.82 Impact Factor
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ABSTRACT: The title compound, C(10)H(13)ClN(2)O, was obtained as a by-product in the reaction of 2-chloro-methyl-1H-benzimidazole, dimethyl sulfate and toluene to synthesise 2-chloro-methyl-1-methyl-benzimidazole. The dihedral angle between the benzene ring and the acetamide group is 89.72 (6)° while that between the aromatic ring and the chloracetyl group is 84.40 (4)°. In the crystal, adjacent mol-ecules are linked by pairs of N-H⋯O hydrogen bonds into inversion dimers.
Acta Crystallographica Section E Structure Reports Online 02/2013; 69(Pt 2):o229. · 0.35 Impact Factor
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ABSTRACT: Several series of forty-five acetophenone derivatives bearing various alkyl or benzyl substituents were conveniently synthesized and their structures characterized by (1) H and (13) C NMR spectroscopy, HRMS and single crystal X-ray analysis. Their in vitro antifungal activities against a panel of phytopathogenic fungi were evaluated by mycelial growth rate assay. Of them 12 derivatives (e.g., 3a-c, 4c and 4e) exhibited more potent antifungal effects on some phytopathogens than a commercial fungicide hymexazol as positive control. In particular, compound 3b with IC(50) values of 10 to 19 μg /mL was found to be the most active in this series and might be a potential lead structure for further optimization. The preliminary structure-activity relationship (SAR) studies of a series of acetophenones are also discussed. © 2012 John Wiley & Sons A/S.
Chemical Biology & Drug Design 10/2012; · 2.28 Impact Factor
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Chemistry of Natural Compounds 04/2012; 46(3):504-506. · 1.03 Impact Factor
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Chemistry of Natural Compounds 04/2012; 43(3):349-350. · 1.03 Impact Factor
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ABSTRACT: Secoscabronine M (1) is a hemiacetal cyathane diterpenoid that was isolated from the fruiting bodies of the basidiomycete Sarcodon scabrosus (Fr.) Karst. Compound 1 possesses a novel structure with a bond cleavage between C-3 and C-4. The structure of the new compound was elucidated by means of spectroscopic methods, including two-dimensional nuclear magnetic resonance experiments. The absolute configuration of 1 was established by analysis of circular dichroism spectroscopy and also by employing time-dependent density functional theory calculations. In addition, compound 1 was confirmed to be an equilibrium mixture of two epimers (15S and 15R) at position C-15 in polar solvents by one-dimensional nuclear magnetic resonance analysis.
Chirality 04/2012; 24(5):386-90. · 2.35 Impact Factor
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ABSTRACT: Thirty-nine fungal metabolites 1-39, including two new alkaloids, 12β-hydroxy-13α-methoxyverruculogen TR-2 (6) and 3-hydroxyfumiquinazoline A (16), were isolated from the fermentation broth of Aspergillus fumigatus LN-4, an endophytic fungus isolated from the stem bark of Melia azedarach. Their structures were elucidated on the basis of detailed spectroscopic analysis (mass spectrometry and one- and two-dimensional NMR experiments) and by comparison of their NMR data with those reported in the literature. These isolated compounds were evaluated for in vitro antifungal activities against some phytopathogenic fungi, toxicity against brine shrimps, and antifeedant activities against armyworm larvae (Mythimna separata Walker). Among them, sixteen compounds showed potent antifungal activities against phytopathogenic fungi (Botrytis cinerea, Alternaria solani, Alternaria alternata, Colletotrichum gloeosporioides, Fusarium solani, Fusarium oxysporum f. sp. niveum, Fusarium oxysporum f. sp. vasinfectum, and Gibberella saubinettii), and four of them, 12β-hydroxy-13α-methoxyverruculogen TR-2 (6), fumitremorgin B (7), verruculogen (8), and helvolic acid (39), exhibited antifungal activities with MIC values of 6.25-50 μg/mL, which were comparable to the two positive controls carbendazim and hymexazol. In addition, of eighteen that exerted moderate lethality toward brine shrimps, compounds 7 and 8 both showed significant toxicities with median lethal concentration (LC(50)) values of 13.6 and 15.8 μg/mL, respectively. Furthermore, among nine metabolites that were found to possess antifeedant activity against armyworm larvae, compounds 7 and 8 gave the best activity with antifeedant indexes (AFI) of 50.0% and 55.0%, respectively. Structure-activity relationships of the metabolites were also discussed.
Journal of Agricultural and Food Chemistry 03/2012; 60(13):3424-31. · 2.82 Impact Factor
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ABSTRACT: Nine secondary metabolites, including four steroids, four phenolics and one cerebroside, were isolated from the methanol extract of the fruiting bodies of the basidiomycete Sarcodon joedes. The isolated compounds were identified by spectroscopic analyses as (22E,24R)-6β-methoxyergosta-7,22-diene-3β,5α-diol (1), 2',3'-diacetoxy-3,4,5',6',4″-pentahydroxy-p-terphenyl (2), cerebroside B (3), ergosta-7,22-dien-3β-ol (4), ergosterol peroxide (5), (22E,24R)-3β-hydroxy-ergosta-5,22-dien-7-one (6), benzoic acid (7), methyl p-hydroxybenzoate (8) and 3,4-dihydroxybenzoic acid (9). The cytotoxic activities of these compounds were evaluated. All these compounds were isolated from this fungus for the first time.
Natural product research 02/2012; · 1.01 Impact Factor
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ABSTRACT: Biotransformation of paeonol (1) with the white-rot basidiomycete Coriolus versicolor afforded two metabolites, 2,4-dihydroxyacetophenone (2) and 2,5-dihydroxy-4-methoxyacetophenone (3), which were identified by spectroscopic methods. Compound 3 showed higher antioxidative, antibacterial, antifungal activities than 1 or 2. The results demonstrate for the first time that C. versicolor has the capacities to catalyze hydroxylation and demethylation reactions on the aromatic compound.
Natural product communications 08/2011; 6(8):1129-30. · 1.24 Impact Factor
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ABSTRACT: Two novel cyathane diterpenoids, designated scabronines K (1) and L (2), were isolated from the fruiting bodies of the basidiomycete Sarcodon scabrosus together with four known analogues, sarcodonins G (3), A (5), M (6), and scabronine H (4). Their structures were elucidated on the basis of extensive spectroscopic analysis including 2D-NMR (HMBC, HSQC, ROESY, (1)H,(1)H-COSY) and MS experiments. The isolated compounds were evaluated for nerve growth factor (NGF)-mediated neurite outgrowth using rat pheochromocytoma (PC12) cells as a model system of neuronal differentiation. Among these compounds, only sarcodonins G and A (3 and 5) at 25 μM showed significant neurite outgrowth (neuritegenesis)-promoting activity in the presence of 20 ng/mL NGF after 24h treatment. Their structure-neurite inducing activity relationship was also discussed.
European journal of medicinal chemistry 07/2011; 46(7):3112-7. · 3.27 Impact Factor
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ABSTRACT: A new rare 20-membered macrocyclic lactam incorporating a diene conjugated olefin, designated sannastatin (1), together with the known structurally related vicenistatin (2), has been isolated from the cultures of Streptomyces sannanensis, a bacteria found in the feces of Ailuropoda melanoleuca. The structure of the new compound was established on the basis of extensive spectroscopic analyses including 1D- and 2D-NMR ((1)H-(1)H COSY, TOCSY, HSQC, HMBC, and NOESY) experiments. Compounds 1 and 2 displayed significant growth inhibitory activity against the brine shrimp (Artemia salina) larvae.
Bioorganic & medicinal chemistry letters 07/2011; 21(13):3905-8. · 2.65 Impact Factor
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ABSTRACT: The biotransformation of 3β-acetoxypregna-5,16-diene-20-one (1) by using a filamentous fungus Penicillium citrinum resulted in the production of four metabolites 2-5. The structures of these compounds were elucidated by different spectroscopic analysis (1D- and 2D-NMR) and HR-ESI-MS as 3β,7β-dihydroxy-pregn-5,16(17)-dien-20-one (2), 3β-hydroxy-7α-methoxy-pregn-5,16(17)-dien-20-one (3), 3β,7β,11α-trihydroxy-pregn-5,16(17)-dien-20-one (4), and a known 3β,7α-dihydroxy-pregn-5,16(17)-dien-20-one (5). The 7-O-methylation is a novel reaction in the field of microbial transformation of pregnane steroids.
Steroids 01/2011; 76(1-2):43-7. · 2.83 Impact Factor
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ABSTRACT: Thirty-eight phenolic compounds (including 31 flavonoids) were examined for their DPPH radical-scavenging activities, and structure-activity relationships were evaluated. Specifically, the presence of an ortho-dihydroxyl structure in phenolics is largely responsible for their excellent anti-radical activity. 3-Hydroxyl was also essential to generate a high radical-scavenging activity. An increasing number of hydroxyls on flavones with a 3',4'-dihydroxyl basic structure, the presence of a third hydroxyl group at C-5', a phloroglucinol structure, glycosylation and methylation of the hydroxyls, and some other hydroxyls, for example 5-, and 7-hydroxyl in ring A, decreased the radical-scavenging activities of flavonoids and other phenolics.
Natural product communications 11/2010; 5(11):1759-65. · 1.24 Impact Factor
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ABSTRACT: Two new polyketide-derived pigments, named rufoolivacins B (), and D (), with a 4',10-coupled aryl linkage between polysubstituted 1-naphthol and 1,4- or 1,2-anthraquinone, together with nine known metabolites including rufoolivacins A () and C (), have been isolated from the fruiting bodies of the Chinese toadstool Cortinarius rufo-olivaceus (basidiomycetes). Their structures were characterized on the basis of spectroscopic methods, including 2D-NMR experiments (COSY, NOESY, HSQC, and HMBC). The axial chirality of and was assigned through analysis of their CD spectra and ZINDO and TDDFT calculations. Compounds and were found to be unusual natural products incorporating an ortho-anthraquinone chromophore. All the metabolites were shown to be toxic toward the brine shrimp.
Organic & Biomolecular Chemistry 08/2010; 8(15):3543-51. · 3.70 Impact Factor
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ABSTRACT: The title compound, C(15)H(12)F(2)O(3), has been obtained by the reaction of 2,4-dihy-droxy-lacetonephenone, potassium carbonate and 3,5-difluoro-benzyl bromide. The hy-droxy group is involved in an intra-molecular O-H⋯O hydrogen bond in each of the two independent mol-ecules in the asymmetric unit. The dihedral angle between the aromatic rings is 0.5 (2)° in one molecule and 1.9 (2)° in the other. In the crystal, weak C-H⋯O inter-actions link the mol-ecules into tetra-meric units aligned perpendicular to b.
Acta Crystallographica Section E Structure Reports Online 01/2010; 66(Pt 9):o2468. · 0.35 Impact Factor
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ABSTRACT: The title compound, C(13)H(11)Cl(2)N(3)O(2), was obtained by the reaction of eugenol and cyanuric chloride. The dihedral angle between the benzene and triazine rings is 87.56 (4)°. Two C atoms of the allyl group are disordered over two sites in a 0.72 (2):0.28 (2) ratio.
Acta Crystallographica Section E Structure Reports Online 01/2010; 66(Pt 11):o2946. · 0.35 Impact Factor
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ABSTRACT: Two new natural compounds, a symmetrical disulfide dimer didodecyl 3,3''-dithiodipropionate (1) and a pregnane steroid 5,16-pregnadien-3beta-ol-20-one acetate (2), were isolated together with two known compounds, ergosta-4,6,8(14),22-tetraen-3-one (3) and ergosterol peroxide (4), from the ethyl acetate soluble extract of fermentation broth of an endophytic fungus, Sphaceloma sp. LN-15 isolated from the leaves of Melia azedarach L. and grown in pure culture. Their structures were determined on the basis of spectroscopic methods including 1D and 2D nuclear magnetic resonance spectroscopy (NMR) experiments and by mass spectrometric measurements (MS). These fungal metabolites were isolated for the first time from the genus Sphaceloma. The structure of 1 was also confirmed by chemical synthesis.
Lipids 07/2009; 44(8):745-51. · 2.13 Impact Factor
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ABSTRACT: A novel cytotoxic chlorinated azaphilone derivative named chaetomugilin D (1), together with three known metabolites, chaetomugilin A (2), chaetoglobosins A (3) and C (4), has been isolated by a bioassay-guided fractionation from the EtOAc extract of the cultures of Chaetomium globosum, an endophytic fungus found in the leaves of Ginkgo biloba. Structure of 1 was established by analyses of spectroscopic methods, including 2D-NMR experiments (COSY, NOESY, HMQC, and HMBC). Compounds 1-4 displayed significant growth inhibitory activity against the brine shrimp (Artemia salina) and Mucor miehei.
Bioorganic & medicinal chemistry letters 03/2009; 19(6):1572-4. · 2.65 Impact Factor
