Phenol esters and other constituents from the stem barks of Stereospermum acuminatissimum

A new ester, 2-(4′-hydroxyphenyl)ethyl dotriacontanoate (1), and a new inseparable mixture of octacosan-1,28-dioldiferulate and triacontan-1,30-dioldiferulate (2) were isolated from the stem barks of Stereospermum acuminatissimum, along with 24 known compounds including 4 triterpenoids, 11 anthraquinones, 2 lignans, 3 phenylpropanoids, 2 4-hydroxyphenethyl esters, 1 methoxyphenol, and 1 iridoid. The structures of the new metabolites were determined with the help of spectroscopic data including extensive 2D NMR spectroscopy. The known compounds were identified by comparison of their physical and spectroscopic data with those reported in the literature. The compounds were tested against Candida albicans ATCC 24433, C. albicans ATCC 90028, Candida glabrata ATCC 90030, Candida krusei ATCC 6258, and Candida parapsilosis ATCC 22019. Some of them were moderately active.     

Synthesis of some hydroxamic acid derivatives of benzimidazole and their antibacterial and antifungal activities.

A number of 1H-benzimidazole-2-propanoic acid derivatives have been synthesized by Phillips method, and their antibacterial and antifungal activities have been tested. The chemical structures of the synthesized compounds were elucidated by spectroscopic (IR, NMR, mass) and elementary analysis. Investigation of antimicrobial activity of the compounds was done by agar dilution technique using bacteria (Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Mycobacterium smegmatis ATCC 607) and yeast-like fungi (Candida albicans, Candida tropicalis, Candida pseudotropicalis, Candida kruzei, Candida globrata). Among the compounds tested N-hydroxy-3-(1H-benzimidazol-2-yl)-propionamide (Compound 6) showed considerable activity against both Candida albicans and Candida tropicalis.     

Manoalide derivatives from a sponge, Luffariella sp

A new derivative of manoalide, 24-n-propyl-O-manoalide (1) together with manoalide (4) and four known derivatives (2, 3, 5, 6) were isolated from the methanolic extract of a sponge. Their structures were elucidated on the basis of spectroscopic method. All the compounds showed significant cytotoxicity against HCT-116 cell line by MTS assay. Secomanoalide indicated antifungal activity on fungal lines Candida glabrata,Candida krusei and Candida albicans by invitro antibiotic assay.     

Phenolic compounds from Baseonema acuminatum leaves: isolation and antimicrobial activity

Three new phenolic compounds, 1-galloyl-beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranoside (1), 2-methoxy-5-(1 '2 3'-trihydroxypropyl)-phenyl- 1-0-(6"-galloyl)-beta-D-glucopyranoside (2),and 2-methoxy-5-hydroxymethyl-phenyl-1-O-(6"-galloyl)-beta-D-glucopyranoside (3), together with the known compounds benzyl 6'-O-galloyl-beta-D-glucopyranoside (4), 1,6-di-O-galloyl-beta-D-glucopyranose (5), myrciaphenone B (6), kaempferol 3-0-(6"-galloyl)-beta-D-glucopyranoside (7), quercetin 3-0-(6"-galloyl)-beta-D-glucopyranoside (8), vomifoliol 9-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside, 2,3-dihydrobenzofuran-2-(4'-hydroxy-3'-methoxyphenyl)-3-alpha-L-rhamnopyranosyloxymethyl-7-methoxy-5-propanol, and benzyl-O-alpha-L-rhamnopyranosyl-(1-->6)-Beta-D-glucopyranoside were isolated from the leaves of Baseonema acuminatum P. Choux (Asclepiadaceae). Their structures were determined by 1D- and 2D-NMR spectroscopy and by ESI-MS analysis. The antimicrobial activity of all compounds was evaluated in vitro against bacteria (Staphylococcus aureus two strains, Bacillus cereus, Bacillus subtilis, Escherichia coli, Salmonella thyphimurium) and three strains of Candida albicans. The new compounds 2 and 3, together with the known compound 4, showed antifungal activity against two clinically isolated Candida albicans strains and against C. albicans ATCC 2091; MIC values were in the range of 25-100 microg/mL. Compound 5 was active against the two clinically isolated strains of C. albicans with MICs of 12.5 microg/mL and 25 microg/mL. Compounds 1, 6, 7, and 8 inhibited only one strain of C albicans at the maximum concentration used. None of the phenolic compounds tested was active against the bacteria studied.     

Synthesis and antimicrobial activity evaluation of some new adamantane derivatives

In this study, some new Schiff bases were synthesized as antimicrobial agents using benzaldehyde derivatives and 1- or 2-aminoadamantane. The structures of the synthesized compounds were confirmed by IR, 1H-NMR and elementary analysis. Antimicrobial activities of the synthesized compounds were tested against some bacteria and yeast-like fungi. The antimicrobial activity of the compounds was investigated by broth microdilution method using two Gram positive (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212) and two Gram negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853) bacteria and yeast-like fungi (Candida albicans ATCC 90028, Candida krusei ATCC 6258, Candida parapsilosis ATCC 22019). The antifungal activity of 1-((2-chloro-3,4-dimethoxybenzylidene) amino(adamantane (compound 3) against C. krusei and C. parapsilosis (minimal inhibitory concentration 32 micrograms/ml) was higher than that of the other tested compounds.     

Synthesis of some new Mannich bases derived from 6-acyl-3-(3,5-dimethylpiperidinomethyl)-2(3H)-benzoxazolones+ ++ and their biological activities

A number of 6-acyl-3-(3,5-dimethylpiperidinomethyl)-2(3H)-benzoxazolones have been synthesized by Mannich reaction and their antibacterial and antifungal activities have been tested. Their chemical structures have been proved by means of their IR, NMR, mass spectroscopic data and by elementary analysis. Investigation of antimicrobial activity of compounds was done by tube dilution and paper disc techniques using bacteria (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Staphylococcus faecalis RSKK 10541) and yeast-like fungi (Candida parapsilosis, Candida albicans, Candida pseudotropicalis, Candida stellatoidea). Among the compounds tested 6-(2-chlorobenzoyl)-3-(3,5-dimethylpiperidinomethyl)-2(3H)-benz oxazolone (Compound 2) and 6-(3-chlorobenzoyl)-3-(3,5-dimethylpiperidinomethyl)-2(3H)-benz oxazolone (Compound 3) showed the most favorable activity.     

Cytotoxic cucurbitane-type triterpenoids from Elaeocarpus hainanensis

Bioassay-guided fractionation of the crude extract of Elaeocarpus hainanensis (Elaeocarpaceae), using the proliferation of non-small cell lung cancer A549/ATCC and human hepatocellular carcinoma BEL-7402 cells as a monitor, led to the isolation of ten cucurbitane-type triterpenoids, including three new compounds (1-3) and seven known compounds (4-10). Their structures were determined on the basis of spectroscopic analyses, chemical methods, and comparison with spectroscopic data in literature. The two known compounds, cucurbitacins D (5) and I (10) were found to exhibit the strongest cytotoxicity against A549/ATCC and BEL-7402 cells in vitro with IC50 values of less than 1 microM.     

Synthesis and evaluation of antibacterial activity of some 2-[[alpha-(4-substituted benzoyloxy)-alpha-phenylacetyl or methylacetyl]amino]-5-(4-methoxyphenyl)- 1,3,4-oxadiazoles

In this study, a new series of 1-[[alpha-(4-substitutedbenzoyloxy)-alpha-phenylacetyl or methylacetyl]amino]-5-(4-methoxyphenyl)-1,3,4-oxadiazoles were obtained by condensation of 2-[(alpha-chloro-alpha-phenylacetyl or alpha-bromopropionyl)amino]-5-(4-methoxyphenyl)1,3,4-oxadiazoles with sodium salts of 4-substituted benzoic acids. Structures of the compounds were assigned on the basis of spectral data (UV, IR, 1H NMR, El MS) and elemental analyses. The antibacterial activities of the novel compounds against Staphylococcus aureus ATCC 6538. Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 8739, Klebsiella pneumoniae ATCC 4352, Pseudomonas aeruginosa ATCC 1539, Salmonella typhi, Shigella flexneri and Proteus mirabilis and antifungal activity against Candida albicans ATCC 10231 were tested using disk diffusion method. Compounds 4a, 4d and 4g were found to be active against S. aureus ATCC 6538 (MIC, 78, 39 and 78 microg ml(-1), respectively) and compound 4e against S. epidermidis ATCC 12228 (MIC, 156 microg ml(-1)).     

Eremophilane-type sesquiterpenes from Senecio nemorensis

Three new highly oxygenated eremophilane-type sesquiterpenes, 1 beta,10 beta(8,12)-diepoxy-7 beta,11 beta-dihydroxy-8 beta,12 alpha-dimethoxyeremophilane (1), 1 beta,10 beta-epoxy-7 beta-hydroxy-8 alpha-methoxyeremophil-11 alphaH-12,8 beta-olide (2), and 6 beta-isobutyryloxy-8 alpha-hydroxy-1-oxoeremophil-7(11),9-dien-12,8 beta-olide (3), together with nine known compounds (4-12) were isolated from the roots and aerial parts of Senecio nemorensis L. (Compositae). Structures of compounds 1-3 were elucidated on the basis of spectroscopic evidence including IR, HR-ESI-MS, 1D and 2D NMR techniques and were unequivocally confirmed by single-crystal X-ray diffraction experiments. The antimicrobial activity of the isolated compounds 1-3 and 8-12 was tested against Staphylococcus aureus and Candida albicans.     

Three new antimicrobial metabolites of Phomopsis sp

Two new 10-membered macrolides, named Phomolides A (1) and B (2), and one new derivative of benzofuran (3) were isolated from the culture of Phomopsis sp. hzla01-1, and their structures were elucidated based on spectroscopic analyses, particularly 2D NMR experiments. Compounds 1, 2 and 3 showed significant antimicrobial activities against Escherichia coli CMCC44103, Candida albicans AS2.538, Saccharomyces cerevisiae ATCC9763 with MICs 5~10 mug/ml. The most significant, compound 3 showed strong activity against Bacillus subtilis CMCC63501 with the MIC value 1.25 microg/ml. None of the three compounds showed significant cytotoxicity against the HeLa cell line at 10 microg/ml.     

Phenatic acids A and B, new potentiators of antifungal miconazole activity produced by Streptomyces sp. K03-0132

Two new phenols, designated phenatic acids A and B, were isolated along with known actiphenol, from the culture of Streptomyces sp. K03-0132 by solvent extraction, silica gel column chromatography and HPLC. Their structures were elucidated by spectroscopic analyses including mainly various NMR experiments. They have a common 1-hydroxy 2, 4-dimethyl benzene ring. These compounds potentiate miconazole activity against Candida albicans. Phenatic acid B also showed moderate antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Bacteroides fragilis and Acholeplasma laidlawii.     

Synthesis of some benzimidazole derivatives and their antibacterial and antifungal activities.

A number of new benzimidazole derivatives were synthesized by the reaction of benzimidazole with appropriate alkyl halides. The compounds synthesized were intensified by 1H-NMR, Fourier Transformation Infrared (FT-IR) and micro analysis. All new and related compounds studied in this work were screened for their in vitro antimicrobial activities against the standard strains: Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 29213), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and the yeasts Candida albicans and Candida tropicalis. Eleven of the compounds were found effective to inhibit the growth of Gram-positive bacteria (E. faecalis and S. aureus) at MIC values between 12.5-400 micrograms/ml. None of the compounds exhibited antimicrobial activity against Gram-negative bacteria (E. coli and P. aeruginosa) at the concentrations studied (6.25-800 micrograms/ml). All compounds (except compound 3) were significantly effective against C. tropicalis with MIC values of 6.25-400 micrograms/ml. Eight of the tested compounds showed an antifungal activity against C. albicans with a range of the MICs between 50 and 400 micrograms/ml.     

Synthesis of some new 6-methylimidazo[2,1-b]thiazole-5-carbohydrazide derivatives and their antimicrobial activities

In this study, 14 new compounds having 6-methyl-N2-(alkylidene/cycloalkylidene)imidazo[2,1-b]thiazole-5-carbohydrazide (3a-g), 3-[[(6-methylimidazo[2,1-b]thiazole-5-yl)carbonyl]amino]-4-thiazolidinone (4a-d) and 4-[[(6-methylimidazo[2,1-b]thiazole-5-yl)carbonyl]amino]-1-thia-4-azaspiro[4.4]nonan/[4.5]decan-3-one (4e-g) structures were synthesized. The structures of the compounds were elucidated by UV, IR, 1H-NMR, 13C-NMR, 1H-13C-COSY, mass spectra and elemental analysis. All compounds synthesized were tested for antimicrobial activity against Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 8739, Klebsiella pneumoniae ATCC 4352, Pseudomonas aeruginosa ATCC 1539, Salmonella typhi, Shigella flexneri, Proteus mirabilis ATCC 14153, Candida albicans ATCC 10231 and Mycobacterium tuberculosis H37Rv. Only 4d and 4f demonstrated antimicrobial activity against S. epidermidis ATCC 12228 (MIC: 19.5 microg/ml and 39 microg/ml, respectively).     

New and antifungal xanthones from Calophyllum caledonicum

Two new xanthones, namely caledonixanthones E (1) and F (2), were isolated from the stem bark of Calophyllum caledonicum (Guttiferae). The structural elucidation of these compounds was mainly established on the basis of 1D, 2D NMR and HRMS spectroscopic analysis. Among the isolated compounds, eight other known xanthones were also identified in the course of this phytochemical study. In addition to this report, a preliminary evaluation of the antifungal properties of these polyphenolic compounds against Aspergillus fumigatus and Candida albicans is presented.     

Synthesis and antimicrobial activity of 4-carbethoxymethyl-2-[(alpha-haloacyl)amino] thiazoles and 5-nonsubstituted/substituted 2-[(4-carbethoxymethylthiazol-2-yl)imino]-4-thiazolidinones

4-Carbethoxymethyl-2-[(chloroacetyl/alpha-chloropropionyl/al pha- bromobutyryl/alpha-chloro-(alpha-phenylacetyl)amino]thiazoles (I-IV) were synthesized by reacting 4-carbethoxymethyl-2-aminothiazole with chloroacetyl chloride, alpha-chloropropionyl chloride, alpha-bromobutyryl bromide and alpha-chloro-alpha-phenylacetyl chloride, respectively. Furthermore, I-IV were refluxed with ammonium thiocyanate to give 2-[(4-carbethoxymethylthiazol-2-yl)imino]-4-thiazolidinones (V-VIII). V was refluxed with various aromatic aldehydes to give 5-arylidene-2-[(4-carbethoxymethylthiazol-2-yl)imino]-4-t hiazolidinones (IX-XIV). The structures of synthesized compounds were confirmed by elemental analyses, hydrolysis, UV, IR, 1H-NMR and EI mass spectral data. The antimicrobial activities of the compounds were assessed by microbroth dilution technique using Mueller-Hinton broth and Mueller-Hinton Agar. In this study, Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 8739, Klebsiella pneumoniae ATCC 4352, Pseudomonas aeruginosa ATCC 1539, Salmonella typhi, Shigella flexneri, Proteus mirabilis and Candida albicans ATCC 10231 were used as test microorganisms. Among the tested compounds, XI and XIV showed activity against S. aureus (MIC: 78 micrograms/ml, 1.6 micrograms/ml), whereas compound V had an activity against S. flexneri (MIC: 39 micrograms/ml) and compound I against C. albicans (MIC: 125 (micrograms/ml). Compounds I, IV-XIV were also evaluated for antituberculosis activity against Mycobacterium tuberculosis H37Rv using the BACTEC 460 radiometric system and BACTEC 12B medium. Only compounds I and XIV showed 86% and 67% inhibition in the primary screen.     

Synthesis,antibacterial and antifungal activities of electron-rich olefins derived benzimidazole compounds

New benzimidazole derivatives were synthesised by electron-rich olefines (7, 8 and 9) with appropriate reagents. The compounds synthesised were identified by 1H NMR, 13C NMR, FT-IR spectroscopic techniques and elemental analysis. All compounds studied in this work were screened for their in vitro antimicrobial activities against the standard strains: Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 29213), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and the yeasts Candida albicans and Candida tropicalis. Eleven of the compounds inhibited the growth of gram-positive bacteria (E. faecalis and S. aureus) at MIC values between 50 and 400 microg/ml. None of the compounds exhibit antimicrobial activity against Gram-negative bacteria (E. coli and P. Aeruginosa) at the concentrations studied (6.25-800 microg/ml). Nine of the tested compounds showed an antifungal activity with a range of the MICs between 50 and 400 microg/ml.     

Synthesis and evaluation of antimicrobial activity of new 4-nitroso and 4-diazopyrazole derivatives.

Some N-(pyrazol-5-yl)-2-nitrobenzamides, variably substituted in the pyrazole nucleus as well as in the amidic group, were reacted in acetic acid media with potassium nitrite and hydrochloric acid. The different chemical behaviour of the reacted pyrazole derivatives in relation to the substitution pattern in both the pyrazole nucleus and the amidic group, was observed. All compounds isolated from the reaction mixtures (4-nitroso, 4-nitro, 4-diazo and 4-chloro derivatives) were evaluated by the agar diffusion method for their "in vitro" growth inhibitory activity against Candida albicans (our collection), Candida tropicalis ATCC 13803, Saccharomyces cerevisiae ATCC 36375, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853. The 1-methylpyrazole derivatives showed larger inhibition zones than the 1-phenyl ones in the antimicrobial tests.     

Antibacterial diterpenes from the roots of Salvia viridis

Three new diterpenes, salviviridinol, viridinol, viridone, five known diterpenes, sugiol, 1-oxoferruginol, ferruginol, aethiopinone and microstegiol, abietane and rearranged abietane diterpenes were isolated from the roots of Salvia viridis. These compounds were assayed against S. aureus ATCC 6538 P, E. coli ATCC 8739, P. mirabilis ATCC 14153, K. pneumonia ATCC 4352, P. aeruginosa ATCC 27853, S. epidermidis ATCC 12228, E. faecalis ATCC 29212 and a yeast C. albicans ATCC 10231. 1-Oxoferruginol showed activity against B. subtilis, S. aureus, S. epidermidis and a modest activity against P. mirabilis, migrostegiol had a little activity against B. subtilis. The structures of the compounds were established by 1D and 2D NMR spectroscopic techniques.     

Synthesis and antimicrobial activity of [2-[2-(N,N-disubstituted thiocarbamoyl-sulfanyl)-acylamino] thiazol-4-yl]acetic acid ethyl esters

[2-[2-(N, N-Disubstituted thiocarbamoyl-sulfanyl)acylamino ]thiazol-4-yl]acetic acid ethyl esters (3a-x) were synthesized by the reaction of potassium salts of N, N-disubstituted dithiocarbamoic acids with [2-(2-chloroalkanoyl)amino-thiazol-4-yl]acetic acid ethyl esters. The structures of the synthesized compounds were confirmed by elemental analyses, UV, IR, (1)H-NMR, and EI mass spectral data. The antimicrobial activities of all the compounds were investigated by microbroth dilution technique using Mueller-Hinton broth and Mueller-Hinton agar. In this study, Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 8739, Klebsiella pneumoniae ATCC 4352, Pseudomonas aeruginosa AT CC 1539, Salmonella typhi, Shigella flexneri, Proteus mirabilis ATCC 14153 and Candida albicans ATCC10231 were used as test microorganisms. Among the tested compounds 3a, d, e, f, h, k, w activity against S. epidermidis ATCC 12228 (MIC: 156 mg/L, 78 mg/L, 62.5 mg/L, 78 mg/L, 62.5 mg/L, 312 mg/L, 250 mg/L, respectively), compound 3d had some activity against S. aureus ATCC 6538 (MIC: 156 mg/L) and C. albicans ATCC 10231(MIC: 156 mg/L). Compounds 3l, 3x also evaluated for antituberculosis activity against Mycobacterium tuberculosis H37Rv using the BACTEC 460 radiometric system and BACTEC 12B medium. The preliminary results indicated that all of the tested compounds were inactive against the test organism.     

Nigerasperones A approximately C, new monomeric and dimeric naphtho-gamma-pyrones from a marine alga-derived endophytic fungus Aspergillus niger EN-13

Three new naphtho-gamma-pyrones, 5-hydroxy-6,8-dimethoxy-2-hydroxymethyl-4H-naphtho[2,3-b]pyran-4-one (1, nigerasperone A), 3,3'-dihydro-2,2',5,5'-tetrahy-droxy-8,8',10,10'- tetramethoxy-2,2'-dimethyl-(6',9-bi-4H-naphtho[1,2-b]pyran)-4,4'-dione (2, nigerasperone B), and 3'-hydro-2',5,5',8-tetrahydroxy-6,6',8'-trimethoxy-2,2'-dimethyl-(7,10'-bi-4H-naphtho[2,3-b]pyran)-4,4'-dione (3, nigerasperone C), together with nine related known compounds were characterized from Aspergillus niger EN-13, an endophytic fungus isolated from the marine brown alga Colpomenia sinuosa. Their structures were elucidated by detailed analysis of spectroscopic data and by comparison with literature reports. In the cytotoxic assay, these compounds did not show remarkable inhibitory effects against A549 and SMMC-7721 tumor cell lines. However, 3 and several known compounds showed weak antifungal activity against Candida albicans and moderate activity on DPPH scavenging.