五倍子乙醇提取物对金葡菌的体外抗菌研究

目的观察五倍子乙醇提取物对金黄色葡萄球菌(MRSA和MSSA)的体外抗菌活性.方法采用中药抑菌实验方法对五倍子乙醇提取物进行了112株金黄色葡萄球菌的最低抑菌浓度测定.结果五倍子乙醇提取物对84株耐甲氧西林的金黄色葡萄球菌(methicillin-resistant staphylococcus aureus,MRSA)和28株甲氧西林敏感的金黄色葡萄球菌(methicillin-sensitive staphylococcus aureus,MSSA)的MIC50、MIC90分别为0.315、0.315和0.63、0.315 mg/mL.结论五倍子乙醇提取物对金黄色葡萄球菌(84株MRSA和28株MSSA)具有较强的抑菌活性.     

Continentalic acid from Aralia continentalis shows activity against methicillin-resistant Staphylococcus aureus

In a continuing search for compounds with antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), a chloroform extract of roots of Aralia continentalis was found to contain continentalic acid (CA, C(20)H(30)O(2)), a diterpenic acid. This compound exhibited potent activity against standard methicillin-susceptible Staphylococcus aureus (MSSA) as well as clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). It was determined that continentalic acid had minimum inhibitory concentrations (MICs) of approximately 8-16 microg/mL against S. aureus, including the MSSA and MRSA standard strains. Therefore, the results obtained in this study suggest that continentalic acid might have potential as an adjunct in the treatment of antibiotic-resistant bacteria.     

A novel antibacterial iridoid and triterpene from Caiophora coronata

Bioassay-guided fractionation of the antibacterial CH(2)Cl(2)-MeOH extract obtained from the aerial parts of the Argentinean plant Caiophora coronata led to the isolation of a new triterpene, 1beta,3beta-dihydroxyurs-12-en-27-oic acid, 1, and a new iridoid, 1alpha-methoxy-6alpha,10-dihydroxyisoepiiridomyrmecin (caiophoraenin), 2, along with the known iridoid isoboonein 3. Their structures were established by spectroscopic techniques (1D and 2D NMR, HRFABMS, FTIR). The MIC values of isolated compounds were determined against methicillin-sensitive (MSSA) and -resistant (MRSA) strains of Staphylococcus aureus, Bacillus subtilis (BS), vancomycin-resistant Enterococcus faecium (VREF), Escherichia coli (EC), E. coli imp (ECimp), and Candida albicans (CA). Compound 1 was found active against BS, MSSA, MRSA, VREF, and ECimp with MIC values of 2, 4, 4, 4, and 16 microg/mL, respectively.     

斜叶檀和杠香不同提取物的体外抗菌活性初探

目的探究传统民族药斜叶檀(又称为斜叶黄檀,Dalbergia pinnata(Lour.)Prain)和杠香(又称为滇黔黄檀,Dalbergia yunnanensis Franch)不同提取物的体外抗菌活性。方法采用纸片扩散法探究斜叶檀及杠香的水蒸气蒸馏挥发油、超临界二氧化碳萃取挥发油、水提物及醇提物对金黄色葡萄球菌(Staphylococcus aureus S.aureus)、耐甲氧西林金黄色葡萄球菌(Methicillin Resistant Staphylococcus aureus,MRSA)、粪肠球菌(Enterococcus faecalis)、大肠埃希菌(Escherichia coli)、铜绿假单胞菌(Pseudomonas aeruginosa)及白念珠菌(Candida albicans,C.albicaus)的抑菌效果,并探究提取物浓度对敏感菌株抑菌活性的影响,同时进行最低抑菌浓度(Minimum Inhibitory Concentration,MIC)及最低杀菌浓度(Minimal Bactericidal Concentration,MBC及Minimal Fungicidal Concentration,MFC)的测定。结果两种药物不同的提取物均表现出不同程度的抑菌活性,且活性强弱与提取物浓度成正相关。二者水提物对两种葡萄球菌抑制效果明显,对粪肠球菌抑制效果稍逊;斜叶檀水蒸馏挥发油对白念珠菌抑制效果极强,抑菌圈直径大于30 mm。斜叶檀水蒸馏挥发油对白念珠菌的MIC和MFC均为220μg·mL-1;水提物对两种葡萄球菌的MIC及MBC均为625μg·mL-1。杠香水提物对两种葡萄球菌的抑菌作用均优于其水蒸馏挥发油。结论斜叶檀、杠香的水蒸馏挥发油及水提物有较好的抗菌活性,拥有进一步开发的潜力。     

In vitro antibacterial effects of Cinnamomum extracts on common bacteria found in wound infections with emphasis on methicillin-resistant Staphylococcus aureus

Ethnopharmacological relevance

Cinnamomum species have been widely used in many traditional systems of medicine around the world. In the Malaysian traditional system of medicine, the leaves, stem bark and stem wood of Cinnamomum iners, Cinnamomum porrectum, Cinnamomum altissimum and Cinnamomum impressicostatum have been used to treat wound infections. To study the antibacterial effects of Cinnamomum iners, Cinnamomum porrectum, Cinnamomum altissimum and Cinnamomum impressicostatum against common bacteria found in wound infections with primary focus on methicillin-resistant Staphylococcus aureus (MRSA).

Materials and methods

The crude extracts from the leaves, stem-bark and stem-wood of Cinnamomum iners, Cinnamomum porrectum, Cinnamomum altissimum and Cinnamomum impressicostatum were obtained using sequential extraction with hexane, ethylacetate, methanol and water. The volatile oils were obtained by hydro-distillation. The antibacterial activities of extracts were investigated using disk diffusion assays and broth microdilution assays.

Results

The volatile oils obtained from the stem-bark of Cinnamomum altissimum, Cinnamomum porrectum and Cinnamomum impressicostatum have shown significant antibacterial activity against a wide range of Gram positive and Gram negative bacteria including MRSA. A few test extracts have shown better activity against MRSA as compared to methicillin sensitive Staphylococcus aureus (MSSA). Amongst all the test extracts, Cinnamomum impressicostatum stem-bark water extract produced the largest inhibition zone of 21.0 mm against MRSA while its inhibition zone against MSSA was only 8.5 mm. The minimum inhibitory concentration (MIC) of this extract against MRSA was 19.5 μg mL⁻¹ and the corresponding minimum bactericidal concentration (MBC) was 39.0 μg mL⁻¹.

Conclusions

This study has scientifically validated the traditional use of Cinnamomum species in treating wound infections. Of high scientific interest was the observation that the antibacterial effect of Cinnamomum impressicostatum stem-bark crude water extract against MRSA was significantly higher than its effect against MSSA, suggesting that the extract contains a compound(s) with higher specific neutralising activity against the drug resistance markers of MRSA.     

特应性皮炎皮损处金葡菌定植率及药敏分析

目的;探讨特应性皮炎（AD）皮损处病原茼分布特点,并检测主要病原菌的药物敏感性。方法：多中心随机双盲对AD患者皮损处采取微生物标本,并收取同期住院的非AD患者皮肤创伤处微生物标本,分别作AD组与对照组,标本接种于血平板、普通巧克力平板和麦康凯平板分区划线分离培养,应用MircoScanwalkaway96进行鉴定,并对所分离到的主要病原菌应用微量稀释法测定抗菌药物最低抑菌浓度（MIC）值,结果按美国临床实验室标准化研究所中的标准,耐甲氧西林用琼脂筛选试验证实（苯唑西林6btg／mL）。结果：于2010年9月-2011年9月从皮肤科门诊343例年龄2～15岁之间AD患者皮损部位获得331株病原菌。AD皮损处细菌检出率为96．5％,其中金葡菌176株占53．2％,其中MRSA65株,所占金葡菌的36．9％;对照组1373例患者分离到的病原菌总1195株,革兰阴性杆茼为主,金黄色葡萄球菌为197株,仅占所有病原菌的16．5％,其中MRSA119株,所占比例高迭60．4％。AD组金黄色葡萄球菌感染率远高于对照组（X2—133．38,P〈0．001）,但MRSA所占金黄色葡萄球菌的比例却显著低于对照组（x0=39．263,P〈O．01）。AD组金黄色葡萄球菌对四环素、克林霉素、庆大、环丙沙星、左旋氧氟沙星、阿莫西林／棒酸、亚胺培南、头胞唑啉和复方新诺明等的耐药率低于对照组,其中AD组MssA菌株对红霉素、四环素、氯霉素、克林霉素等抗生素MIC均值高于对照组。结论：金葡菌感染与AD病情密切相关,AD患者高比例的金葡菌更可能是社区获得或源自身感染。针对金葡菌感染的AD患者,为保留万古霉素仅用于危及生命的感染,可选用奎奴普丁／达福普汀、利福平、复方新诺明和Linezolid等敏感抗生素控制感染,防止感染灶的扩散与病情加重。     

“玉容消痤颗粒”体外抗菌作用研究

目的：研究玉容消痤颗粒体外对金黄色葡萄球菌、表皮葡萄球菌及痤疮丙酸杆菌（P.acne）的抗菌作用。方法：金黄色葡萄球菌和表皮葡萄球菌各取1个菌苔,接种在2 ml MH营养肉汤培养基中,培养6 h;P.acne取1个菌苔,接种在2 ml 硫乙醇酸钠培养基中,厌氧培养48 h;金黄色葡萄球菌和表皮葡萄球菌取10-5、10-6倍稀释度的菌液0.05 ml涂布平皿37℃培养24 h计活菌数,P.acne取10-5、10-6倍稀释度的菌液0.05 ml放入平皿与培养基混匀37℃厌氧培养48 h计活菌数。选30-300个菌落/皿的平板计算结果。以丹参酮为对照药分别测定玉容消痤颗粒和丹参酮胶囊对金黄色葡萄球菌、表皮葡萄球菌和P.acne最低抑菌浓度（MIC）和最低杀菌浓度（MBC）。结果：玉容消痤组,各菌株的5.63-90 mg·ml-1药液的试管未见长菌,其MIC为5.63 mg·ml-1,丹参酮胶囊组,各菌株的45-90 mg·ml-1药液的试管未见长菌。其MIC为45 mg·ml-1;玉容消痤对金黄色葡萄球菌、表皮葡萄球菌和P.acne的MBC均为11.25 mg·ml-1,丹参酮胶囊对金黄色葡萄球菌、表皮葡萄球菌和P.acne的MBC均为90 mg·ml-1。结论：玉容消痤颗粒抗菌作用肯定,最低抑菌浓度及最低杀菌浓度均明显低于丹参酮胶囊。     

Antibacterial activity of phytochemicals isolated from Erythrina zeyheri against vancomycin-resistant enterococci and their combinations with vancomycin

Six phytochemicals were isolated from the roots of Erythrina zeyheri (Leguminosae) by repeated silica gel column chromatography using various eluting solvents. Extensive spectroscopic studies revealed that all were isoflavonoids. The antibacterial activity of the six compounds against vancomycin-resistant enterococci (VRE) was estimated by determining the minimum inhibitory concentration (MIC). Of the six isoflavonoids, erybraedin A ((6aR, 11aR)-3,9-dihydroxy-4,10-di(gamma,gamma-dimethylallyl)pterocarpan) exhibited the highest growth inhibitory potency against VRE with an MIC value of 1.56-3.13 microg/mL, followed by eryzerin C ((3R)-7,2',4'-trihydroxy-6,8-di(gamma,gamma-dimethylallyl)isoflavan) (MIC 6.25 microg/mL). These compounds also inhibited the growth of methicillin-resistant Staphylococcus aureus (MRSA) at 3.13-6.25 microg/mL. The antibacterial effects of the two compounds against VRE and MRSA were based on bacteriostatic action. When erybraedin A or eryzerin C was combined with vancomycin, the fractional inhibitory concentration (FIC) index against VRE ranged from 0.5306 to 1.0 and from 0.5153 to 0.75, respectively. The combinations also showed FIC indices of 0.6125-1.0 against MRSA. The results indicate that, depending on the case, both compounds act either synergistically or additively with vancomycin against VRE and MRSA. Erybraedin A and eryzerin C show evidence of being potent phytotherapeutic agents against infections caused by VRE and MRSA.     

Antimicrobial activities of naphthazarins from Arnebia euchroma

Bioassay-directed fractionation of extract of Arnebia euchroma led to the isolation of alkannin (1), shikonin (2), and their derivatives (3-8) as the active principles against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The stereochemistry of alpha-methylbutyryl alkannin (8) is revealed for the first time, and the antimicrobial activity of 8 was compared with its corresponding diastereomer (9). The derivatives 3-9 showed stronger anti-MRSA activity [minimum inhibitory concentrations (MICs) ranged from 1.56 to 3.13 microg/mL] than alkannin or shikonin (MIC = 6.25 microg/mL). Anti-MRSA activity of derivatives was bactericidal with minimum bactericidal concentration (MBC)/MIC < or = 2. In a time-kill assay, the bactericidal activity against MRSA was achieved as rapidly as 2 h. The derivatives 3-9 were also active against vancomycin-resistant Enterococcus faecium (F935) and vancomycin-resistant Enterococcus faecalis (CKU-17) with MICs similar to those with MRSA. Aromatic ester derivatives were also synthesized for antimicrobial activity comparison. None of these compounds were active against Gram-negative bacteria tested. Their cytotoxicity was also evaluated on selected cancer cell lines, and they expressed their activity in the range 0.6-5.4 microg/mL (CD(50)). Our results indicate that the ester derivatives of alkannin are potential candidates of anti-MRSA and anti-VRE agents with antitumor activity.     

Isopimaric acid from Pinus nigra shows activity against multidrug-resistant and EMRSA strains of Staphylococcus aureus

The diterpene isopimaric acid was extracted from the immature cones of Pinus nigra (Arnold) using bioassay-guided fractionation of a crude hexane extract. Isopimaric acid was assayed against multidrug-resistant (MDR) and methicillin-resistant Staphylococcus aureus (MRSA). The minimum inhibitory concentrations (MIC) were 32-64 microg/mL and compared with a commercially obtained resin acid, abietic acid, with MICs of 64 microg/mL. Resin acids are known to have antibacterial activity and are valued in traditional medicine for their antiseptic properties. These results show that isopimaric acid is active against MDR and MRSA strains of S. aureus which are becoming increasingly resistant to antibiotics. Both compounds were evaluated for modulation activity in combination with antibiotics, but did not potentiate the activity of the antibiotics tested. However, the compounds were also assayed in combination with the efflux pump inhibitor reserpine, to see if inhibition of the TetK or NorA efflux pump increased their activity. Interestingly, rather than a potentiation of activity by a reduction in MIC, a two to four-fold increase in MIC was seen. It may be that isopimaric acid and abietic acid are not substrates for these efflux pumps, but it is also possible that an antagonistic interaction with reserpine may render the antibiotics inactive. 1H-NMR of abietic acid and reserpine taken individually and in combination, revealed a shift in resonance of some peaks for both compounds when mixed together compared with the spectra of the compounds on their own. It is proposed that this may be due to complex formation between abietic acid and reserpine and that this complex formation is responsible for a reduction in activity and elevation of MIC.     

In Vitro Antibacterial Activity and Synergistic Antibiotic Effects of Phlorotannins Isolated from Eisenia bicyclis Against Methicillin‐Resistant Staphylococcus aureus

Six phlorotannins, isolated from Eisenia bicyclis, were evaluated for antibacterial activity against methicillin‐resistant Staphylococcus aureus (MRSA). The minimum inhibitory concentrations (MIC) of the compounds were in the range 32 to 64 µg/mL. Phlorofucofuroeckol‐A (PFF) exhibited the highest anti‐MRSA activity, with an MIC of 32 µg/mL. An investigation of the interaction between these compounds and the β‐lactam antibiotics ampicillin, penicillin, and oxacillin revealed synergistic action against MRSA in combination with compound PFF. To our knowledge, this is the first report on the anti‐MRSA activity of phlorotannins from E. bicyclis. The results obtained in this study suggest that the compounds derived from E. bicyclis can be a good source of natural antibacterial agents against MRSA. Copyright © 2012 John Wiley & Sons, Ltd.     

Inhibitory effects of Caesalpinia sappan on growth and invasion of methicillin-resistant Staphylococcus aureus

In the present study, we investigated antimicrobial activity of Caesalpinia sappan against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and effect of Caesalpinia sappan extract on the invasion of MRSA to human mucosal fibroblasts (HMFs). Chloroform, n-butanol, methanol, and aqueous extracts of the Caesalpinia sappan showed antimicrobial activity against standard methicillin-sensitive Staphylococcus aureus (MSSA) as well as MRSA. Methanol extract of Caesalpinia sappan demonstrated a higher inhibitory activity than n-butanol, chloroform, and aqueous extracts. In the checkerboard dilution method, methanol extract of Caesalpinia sappan markedly lowered the minimal inhibitory concentrations (MICs) of ampicillin and oxacillin against MRSA. To determine whether methanol extract of Caesalpinia sappan inhibits the MRSA invasion to HMFs, the cells were treated with various sub-MIC concentrations of methanol extract and bacterial invasion was assayed. MRSA invasion was notably decreased in the presence of 20-80 microg/ml of Caesalpinia sappan extract compared to the control group. The effect of Caesalpinia sappan extract on MRSA invasion appeared dose-dependent. These results suggest that methanol extract of Caesalpinia sappan may have antimicrobial activity and the potential to restore the effectiveness of beta-lactam antibiotics against MRSA, and inhibit the MRSA invasion to HMFs.     

Antibacterial terpenes from the oleo-resin of Commiphora molmol (Engl.)

Two octanordammaranes, mansumbinone (1) and 3,4-seco-mansumbinoic acid (2), and two sesquiterpenes, beta-elemene (3) and T-cadinol (4) have been isolated from the oleo-resin of Commiphora molmol (Engl.). The structures of these compounds were established unambiguously by a series of 1D and 2D-NMR analyses. We have also unambiguously assigned all (1)H and (13)C NMR resonances for 2 and revised its (13)C data. The crude extract of the oleo-resin of C. molmol displayed potentiation of ciprofloxacin and tetracycline against S. aureus, several Salmonella enterica serovar Typhimurium strains and two K. pneumoniae strains. The antibacterial activity of terpenes 1-4 was determined against a number of Staphylococcus aureus strains: SA1199B, ATCC25923, XU212, RN4220 and EMRSA15 and minimum inhibitory concentration (MIC) values were found to be in the range of 4-256 microg/ml. The highest activity was observed by the seco-A-ring octanordammarane 2 with an MIC of 4 microg/ml against SA1199B, a multidrug-resistant strain which over-expresses the NorA efflux transporter, the major characterized antibiotic pump in this species. This activity compared favorably to the antibiotic norfloxacin with an MIC of 32 microg/ml. Compound 2 also displayed weak potentiation of ciprofloxacin and tetracycline activity against strains of Salmonella enterica serovar Typhimurium SL1344 and L10.     

Antimicrobial effectiveness of six paradols. 1: A structure-activity relationship study

The pattern of antimicrobial effectiveness of (0)-, (2)-, (3)-, (4)-, (8)- and (9)-paradols was studied. (3)- Paradol was more active than the other homologues with a minimum inhibitory concentration (MIC) of 1 mg/ml when tested against Proteus vulgaris, Pseudomonas aeruginosa, Staphylococcus aureus and Botryodiplodia theobromae. At 0.2 mg/ml, (3)-paradol completely inhibited the spore germination of Trichophyton mentagrophytes and after 3 h of exposure at 0.5 mg/ml, it inhibited the growth of a heavy inoculum of Staphylococcus aureus (1 X 10(9) cells/ml).     

麦卢卡蜂蜜促进耐甲氧西林金黄色葡萄球菌生成小菌落突变株的研究

  目的：探索麦卢卡蜂蜜促进耐甲氧西林金黄色葡萄球菌生成小菌落突变株的可能性及其对抗生素耐受性的影响。  方法：在含有和不含有亚最小抑菌浓度(sub-MIC)麦卢卡蜂蜜的营养肉汤(NB)中,培养小菌落突变株(SCVs),然后测定最小抑菌浓度(MIC)及最小杀菌浓度(MBC),比较是否有改变;检测这些SCVs与前体细胞相比,对抗生素的耐受性是否改变;并验证SCVs是否为金黄色葡萄球菌。  结果：最小抑菌浓度从6%增长到了6.5%。但是最小杀菌浓度并未有显著改变(P>0.05)。所有的SCVs均被验证为金黄色葡萄球菌。SCVs对苯唑西林的耐药性增强无统计学意义。  结论：麦卢卡蜂蜜可促进耐甲氧西林金黄色葡萄球菌(MRSA)的SCVs的发展,但对随后使用麦卢卡蜂蜜或苯唑西林的治疗都没有明显的耐药性改变。     

Antimicrobial and antioxidant activities of traditional Thai herbal remedies for aphthous ulcers

Four medicinal plants (Quercus infectoria, Kaempferia galanga, Coptis chinensis and Glycyrrhiza uralensis) as well as one traditional Thai treatment for aphthous ulcers based on these four plants were tested for antimicrobial activity. MIC values for a range of bacteria and Candida albicans were determined, with both type strains and clinical isolates being used. Antioxidant activity was determined using the ABTS radical scavenging assay. Among the four plants, Q. infectoria showed antimicrobial activity against Staphylococcus aureus with an MIC of 0.41 mg/mL, while C. chinensis showed antifungal activity against C. albicans with an MIC of 6.25 mg/mL. Activity was also shown against a range of other organisms including Salmonella typhi, Serratia marcescens, Vibrio cholerae, Vibrio parahaemolyticus, Pseudomonas aeruginosa and Enterococcus faecalis. The antimicrobial activity of the traditional aphthous ulcer preparation (a powder) was comparable to that for the individual plant extracts, however, incorporation of the powder into a gel formulation resulted in the loss of almost all activity. All extracts, with the exception of K. galanga, also showed good antioxidant activity. This study supports the traditional use of these plants and suggests that they may also be useful in the treatment of other infections.     

Antibacterial activity of plants used in traditional medicines of Ghana with particular reference to MRSA

ETHNOPHARMACOLOGICAL RELEVANCE: : In an ethno botanical survey carried out in the Akwapim-North district of the Republic of Ghana, 25 plant species, used in traditional medicine to treat skin disease and/or to treat antimicrobial (viral, bacterial or protozoan) infections were identified. AIM OF STUDY: : To investigate the antimicrobial activity of traditional Ghanaian medicines with special interest in anti-methicillin-resistant Staphylococcus aureus (MRSA) activity. MATERIALS AND METHODS: : Chloroform, ethanol and aqueous extracts (including use of a Stomacher) of these plants were prepared and agar-well diffusion tests, MIC's and MBC's were used to investigate antimicrobial activity. RESULTS: Extracts of 13 plant species inhibited the growth of one or more of the following bacteria: MRSA, methicillin-sensitive Staphylococcus aureus (MSSA), Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa and Proteus vulgaris. Extracts from 11 of these 13 plant species also inhibited the growth of three or more of 14 additional clinical isolates of MRSA. Aqueous extracts of Alchornea cordifolia were active against all 21 bacterial strains tested and showed the highest levels of antibacterial activity overall with MIC's against MRSA in the range of 1.6-3.1 mgml(-1) and MBC's in the range of 6.3-12.5 mgml(-1). CONCLUSIONS: : The presence of antibacterial activity in extracts of Elaeophorbia drupifera, Rauwolfia vomitoria and the leaves of Solanum verbascifolium, plants traditionally used to treat skin infections, are reported for the first time. Extracts from Alchornea cordifolia, also used to treat wounds, had the widest spectrum of antibacterial activity.     

Antibacterial activity of Curcuma longa L. against methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) has been emerging worldwide as one of the most important hospital and community pathogens. Therefore, new agents are needed to treat MRSA associated infections. The present study investigated the antimicrobial activity of ethyl acetate, methanol and water extracts of Curcuma longa L. (C. longa) against MRSA. The ethyl acetate extract of C. longa demonstrated a higher antibacterial activity than the methanol extract or water extract. Since the ethyl acetate extract was more active than the other extracts, the study examined whether the ethyl acetate extract could restore the antibacterial activity of beta-lactams and alter the MRSA invasion of human mucosal fibroblasts (HMFs). In the checkerboard test, the ethyl acetate extract of C. longa markedly lowered the MICs of ampicillin and oxacillin against MRSA. In the bacterial invasion assay, MRSA intracellular invasion was significantly decreased in the presence of 0.125-2 mg/mL of C. longa extract compared with the control group. These results suggest that the ethyl acetate extract of C. longa may have antibacterial activity and the potential to restore the effectiveness of beta-lactams against MRSA, and inhibit the MRSA invasion of HMFs.     

Structural characterization and antimicrobial evaluation of atractyloside, atractyligenin, and 15-didehydroatractyligenin methyl ester

We report the first complete structure elucidation of the ent-kaurane diterpenoid glycoside atractyloside (1) by means of NMR and X-ray diffractometry techniques. Extensive one- and two-dimensional NMR experiments were employed to assign the proton and carbon signals of 1, and crystallography experiments established the configurations of all stereogenic centers. Furthermore, we present a novel semisynthetic route for the preparation of the highly cytotoxic aglycone derivative of 1, 15-didehydroatractyligenin methyl ester (3). All compounds were tested for their antibiotic activity against Enterococcus faecalis, Escherichia coli, and several strains of Staphylococcus aureus, including fluoroquinolone-resistant (SA1199B) and two epidemic MRSA (EMRSA-15 and -16) strains. Compound 3 exhibited moderate activity against all of the Staph. aureus strains with an MIC value of 128 mg/L.     

Methylsulfomycin I, a new cyclic peptide antibiotic from a Streptomyces sp. HIL Y-9420704

Methylsulfomycin I (1) is a new cyclic peptide antibiotic isolated from the fermentation broth of a Streptomyces sp. HIL Y-9420704. Its structure was elucidated by NMR and GC-MS. The in vitro activity (MIC) against a wide range of Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-, and teicoplanin-resistant strains, is described.