A new isobenzofuranone derivative was isolated from Chaenomeles sinensis by using various chromatographic techniques,including silica gel,Sephadex LH-20,MCI-gel resin and RP-HPLC. This compound was determined as 2,2-dimethyl-5-( 2-oxopropyl)-2 H-furo[3,4-h]chromen-7( 9 H)-one( 1) by NMR,MS,IR and UV spectra,and was also evaluated for its antibacterial activity. The results showed that it showed prominent antibacterial activity with MIC90 value of( 53. 7±4. 5) mg·L-1 for methicillin resistant Staphylococcus aureus( MRSA) strain. This value is close to that of levofloxacin [with MIC90 value( 50. 2± 4. 2) mg·L-1].
Anti-Bacterial Agents ; isolation & purification ; pharmacology ; Benzofurans ; isolation & purification ; pharmacology ; Chromatography, High Pressure Liquid ; Methicillin-Resistant Staphylococcus aureus ; drug effects ; Microbial Sensitivity Tests ; Phytochemicals ; isolation & purification ; pharmacology ; Rosaceae ; chemistry

In the present study, four new sesquiterpenoids, chimonols A-D (compounds 1-4), together with four known compounds (5-8) were isolated from the EtOAc extract of Chimonanthus praecox Link. The structures of these new compounds were elucidated on the basis of spectroscopic techniques (UV, IR, MS, and 1D and 2D NMR), and their absolute configurations were established by comparing experimental and calculated electronic circular dichroism (ECD) spectra. Compounds 1-8 were evaluated for antimicrobial activities and the minimum inhibitory concentrations (MICs) were determined by the broth microdilution method in 96-well culture plates. Compounds 1, 2, and 7 exhibited weak antibacterial effects for S. aureus (ATCC 6538), E. coli (ATCC 11775), and P. aeruginosa (ATCC 10145) with MIC values being 158-249 µg·mL. Compounds 3-7 showed activities against C. glabrata (ATCC 2001) and S. aureus (ATCC 43300) with MIC values being 128-197 µg·mL. Compounds 1-4 showed activity against S. aureus (ATCC 25923) with MIC values being 162-254 µg·mL. The present study provided a basis for future evaluation of these compounds as antibacterial agents.
Anti-Bacterial Agents ; chemistry ; isolation & purification ; pharmacology ; Calycanthaceae ; chemistry ; Escherichia coli ; drug effects ; Microbial Sensitivity Tests ; Molecular Structure ; Plant Extracts ; chemistry ; isolation & purification ; pharmacology ; Sesquiterpenes ; chemistry ; isolation & purification ; pharmacology ; Staphylococcus aureus ; drug effects

One new sorbicillin derivative, 2-deoxy-sohirnone C (1), one new diketopiperazine alkaloid, 5S-hydroxynorvaline-S-Ile (2), and two naturally occurring diketopiperazines, 3S-hydroxylcyclo(S-Pro-S-Phe) (3) and cyclo(S-Phe-S-Gln) (4), together with three known compounds were isolated from the Chinese mangrove endophytic fungus Penicillium sp. GD6. Their structures were determined on the basis of extensive spectroscopic analyses and by comparison with literature data. The absolute configuration of 3-hydroxyl moiety in 3 was determined by Mosher's method, while the absolute stereochemistry of 2 and 4 was established by comparison with the CD spectra of natural and synthesized diketopiperazines. Compound 1 showed moderate antibacterial activity against Methicillin-resistant Staphylococcus aureus with a MIC value of 80 μg·mL.
Alkaloids ; chemistry ; isolation & purification ; Anti-Bacterial Agents ; chemistry ; isolation & purification ; pharmacology ; China ; Circular Dichroism ; Diketopiperazines ; chemistry ; isolation & purification ; Methicillin-Resistant Staphylococcus aureus ; drug effects ; Microbial Sensitivity Tests ; Molecular Structure ; Nuclear Magnetic Resonance, Biomolecular ; Penicillium ; chemistry ; Resorcinols ; chemistry ; isolation & purification ; pharmacology ; Rhizophoraceae ; microbiology ; Wetlands

A new isoflavone derivative was isolated from Rosa damascena by using various chromatographic techniques including silica gel, Sephadex LH-20, and preparative RP-HPLC separation. Its structure was identified as 4'-hydroxy-7-(3-hydroxypropanoyl)-6-methoxy-isoflavone using combined examinations of their UV, IR, MS, and NMR spectroscopic data. Biological activity test showed that this compound showed prominent antibacterial activity with MIC₉₀ value of (46±4) mg·L⁻¹ for methicillin resistant Staphylococcus aureus(MRSA) strain. This value is close to that of levofloxacin [with MIC₉₀ value (53±5) mg·L⁻¹].
Anti-Bacterial Agents ; isolation & purification ; pharmacology ; Isoflavones ; isolation & purification ; pharmacology ; Methicillin-Resistant Staphylococcus aureus ; drug effects ; Microbial Sensitivity Tests ; Phytochemicals ; isolation & purification ; pharmacology ; Rosa ; chemistry

A new isobenzofuranone derivative has been isolated from Phlomis betonicoides by using various chromatographic techniques, including silica gel, Sephadex LH-20, MCI-gel resin and RP-HPLC. This compound was determined as 5-(3-hydroxypropyl)-2,2-dimethyl-2-furo[3,4-]chromen-7(9)-one (1) by NMR, MS, IR and UV spectroscopic data. Compound 1 showed potent antibacterial activity with an MIC₉₀ value of (58.4 ± 4.2) mg·L⁻¹ for methicillin resistant Staphylococcus aureus (MRSA) strain [levofloxacin as a control with MIC₉₀ value of (52.8±4.6) mg·L⁻¹].
Anti-Bacterial Agents ; isolation & purification ; pharmacology ; Benzofurans ; isolation & purification ; pharmacology ; Methicillin-Resistant Staphylococcus aureus ; drug effects ; Microbial Sensitivity Tests ; Phlomis ; chemistry ; Phytochemicals ; isolation & purification ; pharmacology

BACKGROUND: We evaluated the performance of the BD MAX StaphSR Assay (SR assay; BD, USA) for direct detection of Staphylococcus aureus and methicillin resistance not only in S. aureus but also in coagulase-negative Staphylococci (CNS) from positive blood cultures. METHODS: From 228 blood culture bottles, 103 S. aureus [45 methicillin-resistant S. aureus (MRSA), 55 methicillin-susceptible S. aureus (MSSA), 3 mixed infections (1 MRSA+Enterococcus faecalis, 1 MSSA+MRCNS, 1 MSSA+MSCNS)], and 125 CNS (102 MRCNS, 23 MSCNS) were identified by Vitek 2. For further analysis, we obtained the cycle threshold (Ct) values from the BD MAX system software to determine an appropriate cutoff value. For discrepancy analysis, conventional mecA/mecC PCR and oxacillin minimum inhibitory concentrations (MICs) were determined. RESULTS: Compared to Vitek 2, the SR assay identified all 103 S. aureus isolates correctly but failed to detect methicillin resistance in three MRSA isolates. All 55 MSSA isolates were correctly identified by the SR assay. In the concordant cases, the highest Ct values for nuc, mecA, and mec right-extremity junction (MREJ) were 25.6, 22, and 22.2, respectively. Therefore, we selected Ct values from 0-27 as a range of positivity, and applying this cutoff, the sensitivity/specificity of the SR assay were 100%/100% for detecting S. aureus, and 97.9%/98.1% and 99.0%/95.8% for detecting methicillin resistance in S. aureus and CNS, respectively. CONCLUSIONS: We propose a Ct cutoff value for nuc/mec assay without considering MREJ because mixed cultures of MSSA and MRCNS were very rare (0.4%) in the positive blood cultures.
Anti-Bacterial Agents/pharmacology ; Bacteremia/diagnosis/microbiology ; Coagulase/metabolism ; Humans ; Methicillin-Resistant Staphylococcus aureus/drug effects/genetics/*isolation & purification ; Microbial Sensitivity Tests ; Oxacillin/pharmacology ; Reagent Kits, Diagnostic ; Staphylococcus/drug effects/enzymology/genetics/isolation & purification ; Staphylococcus aureus/drug effects/genetics/*isolation & purification

Three new alkyl substituted anthraquinone derivatives, trivially named as symploquinones A-C (Compounds 1-3) were isolated from Symplocos racemosa. The structures of these compounds were determined on the basis of extensive spectroscopic analyses (UV, IR, Mass, H- and C-NMR, and two-dimensional (2D) NMR techniques). The resulting data were also compared with the reported literature. These compounds were then subjected to antibacterial or antibiofilm testing. Compounds 1 and 3 exhibited good antibacterial activity in the concentration range of 160-83 μg·mL against Streptococcus mutans, methicillin resistant Staphylococcus aureus and Proteus mirabilis. Both compounds were further screened for anti-biofilm activity, which revealed promising activities at sub-MIC concentrations. None of the compounds were found to be active against Klebsiella pneumoniae.
Anthraquinones ; chemistry ; isolation & purification ; pharmacology ; Anti-Bacterial Agents ; chemistry ; isolation & purification ; pharmacology ; Biofilms ; drug effects ; growth & development ; Ericales ; chemistry ; Magnetic Resonance Spectroscopy ; Mass Spectrometry ; Methicillin-Resistant Staphylococcus aureus ; drug effects ; physiology ; Microbial Sensitivity Tests ; Proteus mirabilis ; drug effects ; physiology ; Spectrophotometry, Infrared ; Streptococcus mutans ; drug effects ; physiology

Two new steroidal alkaloids, isoconkuressine and N-formylconessimine, together with 6 known steroidal alkaloids including conkuressine, conessine, isoconessimine, conimine, conarrhimine, and funtudienine, were isolated from the seeds of Holarrhena antidysenteriaca Wall.ex A.DC. Their intrinsic antibacterial activities and synergistic effects with penicillin and vancomycin were analyzed in methicillin sensitive staphylococcus aureus (MSSA) and methicillin resistant staphylococcus aureus (MRSA). Two of the steroidal alkaloids including one new compound (N-formylconessimine) showed potential antibacterial activity and possessed synergistic effects with penicillin and vancomycin, respectively.
Alkaloids ; isolation & purification ; pharmacology ; Anti-Bacterial Agents ; chemistry ; isolation & purification ; pharmacology ; Holarrhena ; chemistry ; Methicillin-Resistant Staphylococcus aureus ; drug effects ; Microbial Sensitivity Tests ; Plant Extracts ; chemistry ; isolation & purification ; pharmacology ; Staphylococcus aureus ; drug effects

We isolated and identified the symbiotic and adnascent microorganisms from an unidentified sponge collected from 10-meter-deep seawater of the Paracel Islands in China. A total of 16 strains were obtained and identified. Through bacteriostatic activity assay, one of the strains, Dermacoccus sp. X4, was found to effectively inhibit the growth of Staphylococcus aureus. Subsequently, its secondary metabolites were purified by silica gel partition, octadecylsilane (ODS) reverse phase, Sephadex™LH-20 size exclusion, and C18 reverse phase chromatography. Using liquid chromatography, mass spectrometry, and nuclear magnetic resonance, three of the purified compounds were structurally characterized to be one 3-(4-hydroxybenzyl) hexahydropyrrolo [1,2-a]pyrazine-1,4-dione and two indole acid glycerides. This is the first report about indole acid glyceride isolated from microbial secondary metabolites, enriching marine drug candidate resources.
Actinomycetales ; chemistry ; Animals ; China ; Chromatography, Liquid ; Indoles ; isolation & purification ; pharmacology ; Magnetic Resonance Spectroscopy ; Mass Spectrometry ; Porifera ; microbiology ; Seawater ; Secondary Metabolism ; Staphylococcus aureus ; drug effects

Staphylococcus aureus, or methicillin-resistant S. aureus (MRSA), is a significant pathogen in both nosocomial and community infections. Community-associated MRSA (CA-MRSA) strains tend to be multi-drug resistant and to invade hospital settings. This study aimed to assess the antimicrobial resistance and molecular characteristicsof nasal S. aureus among newlyadmitted inpatients.In the present study, 66 S. aureus isolates, including 10 healthcare-associated MRSA (HA-MRSA), 8 CA-MRSA, and 48 methicillin-sensitive S. aureus (MSSA) strains, were found in the nasal cavities of 62 patients by screening 292 newlyadmitted patients. Antimicrobial resistance and molecular characteristics of these isolates, including spa-type, sequence type (ST) and SCCmec type, were investigated. All isolates were sensitive to linezolid, teicoplanin, and quinupristin/dalfopristin, but high levels of resistance to penicillin and erythromycin were detected. According to D-test and erm gene detection results, the cMLSB and iMLSB phenotypes were detected in 24 and 16 isolates, respectively. All 10 HA-MRSA strains displayed the cMLSB phenotypemediated by ermA or ermA/ermC, while the cMLSB CA-MRSA and MSSA strains carried the ermB gene. Molecular characterization revealedall 10 HA-MRSA strains were derived from the ST239-SCCmec III clone, and four out of eight CA-MRSA strains were t437-ST59-SCCmec V. The results suggest that patients play an indispensable role in transmitting epidemic CA-MRSA and HA-MRSA strains.
Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/genetics ; Drug Resistance, Multiple, Bacterial/genetics ; Humans ; Inpatients ; Methicillin-Resistant Staphylococcus aureus/*drug effects/genetics/isolation & purification ; Methyltransferases/genetics ; Microbial Sensitivity Tests ; Nasal Cavity/*microbiology ; Staphylococcal Infections/diagnosis/microbiology ; Staphylococcus aureus/*drug effects/genetics/isolation & purification