Reversal of multidrug resistance of KBV200 cells by triterpenoids isolated from Poria cocos

Multidrug resistance (MDR) of tumor cells is one of the major problems encountered during cancer chemotherapy. In this paper, we isolated eight triterpenoids from Poria cocos and evaluated their effects on reversing MDR of KBV200 cells. Eight triterpenoids increase significantly vincristine-induced cytotoxicity in drug-resistant KBV200 cells at the concentrations of 12.5 μg/mL and 25 μg/mL. Dehydrotumulosic acid showed the best reversal effect: it increased KBV200 apoptosis induced by vincristine and inhibited P-gp function through enhancing the accumulation and retention of fluorescent P-gp substrate rhodamine 123 in KBV200 cells but had no effect on P-gp expression.     

维生素E琥珀酸酯联合5-氟尿嘧啶抗人肝癌细胞增殖作用的研究

目的观察维生素E琥珀酸酯(VES)联合5-氟尿嘧啶(5-FU)抗人肝癌细胞SMMC-7721的增殖作用。方法体外培养的SMMC-7721细胞以VES联合5-FU分别作用24和48h,MTT法测定细胞增殖的抑制作用;流式细胞仪分析细胞周期、凋亡率以及Fas的表达。结果MTT检测显示,VES6μg/mL作用细胞24h后抑制率为(2.78±0.05)%,随药物浓度的增加和作用时间的延长,抑制率显著增加(P<0.01);相同条件下,VES与5-FU合用较两药单用抑制作用显著增加(P<0.01)。流式细胞仪分析显示,SMMC-7721细胞自然凋亡率为(0.86±0.20)%,VES24μg/mL,5-FU30μg/mL及两者合用作用细胞24h后凋亡率分别为(30.08±2.32)%,(18.23±1.58)%和(63.68±2.88)%(P<0.01),细胞表面Fas表达增加。结论VES联合5-FU通过阻滞细胞周期于G0/G1期、促进细胞表面Fas的表达协同抑制肝癌细胞增殖。     

Activity of ceftobiprole against Streptococcus pneumoniae isolates exhibiting high-level resistance to ceftriaxone

Tracking Resistance in the US Today (TRUST) 2008 surveillance data showed that 6% of Streptococcus pneumoniae were non-susceptible to ceftriaxone [minimum inhibitory concentration (MIC) ≥ 2 μg/mL] and that 8% of the ceftriaxone-non-susceptible isolates exhibited high-level resistance (MIC ≥ 8 μg/mL). Here we describe the activity of ceftobiprole against ceftriaxone-resistant isolates and characterise the genotypic traits associated with resistance. Thirty isolates with ceftriaxone MICs ≥ 8 μg/mL were analysed by sequencing of penicillin-binding protein (PBP) and murM genes. Sequencing of pbp1a, pbp2b and pbp2x showed nine PBP patterns, with the most common (n=17) being: PBP1a T371S (STMK motif), P432T (SRNVP motif); PBP2b T446A (SSNT motif), A619G (KTGTA motif); and PBP2x T338A and M339F (STMK motif), L364F, I371T, R384G, M400T, L546V (LKSGT motif); six isolates had the same pattern without the PBP2b A619G change. For these 23 isolates, MICs were 8 μg/mL for ceftriaxone, 4-8 μg/mL for penicillin and 0.5-2 μg/mL for ceftobiprole. The remaining seven isolates with higher MICs (ceftriaxone 8-32 μg/mL, penicillin 4-32 μg/mL and ceftobiprole 2-4 μg/mL) had fewer PBP active-site motif substitutions. The majority of isolates (17/30) had murM alleles similar to the wild-type, whilst the rest had alleles reflecting a mosaic structure. No murM alleles were associated with higher MICs. Against these 30 isolates, ceftobiprole was 4-16-fold more active than ceftriaxone. Widely described PBP and MurM substitutions probably account for the high ceftriaxone MICs (8 μg/mL) in the majority of isolates. However, seven isolates with ceftriaxone MICs of 8-32 μg/mL had fewer PBP substitutions in active-site motifs, suggesting either that there is another resistance mechanism or that unique PBP mutations may contribute to high-level β-lactam resistance.     

姜黄素联合伊立替康对结肠癌SW620细胞的体外抑制作用

目的研究姜黄素增强伊立替康对结肠癌SW620细胞的体外抑制作用,并探讨其作用机制。方法 MTT法检测不同质量浓度伊立替康和姜黄素单用或联合用药对SW620细胞增殖的影响;流式细胞仪检测不同质量浓度伊立替康和姜黄素单用或联合用药对SW620细胞凋亡的影响,比较细胞凋亡率;采用蛋白质印记法检测不同质量浓度伊立替康和姜黄素单用或联合用药对SW620细胞内拓扑异构酶I蛋白表达水平的影响。结果伊立替康和姜黄素单用均对SW620细胞增殖具有抑制作用,呈浓度和时间相关性。5、50μg/mL伊立替康分别与0~30μg/mL姜黄素联合处理SW620细胞12、24、48 h均具有协同抑制细胞活性的作用,且呈浓度和时间相关性。高质量浓度比低质量浓度的伊立替康与姜黄素联合用药抑制效果显著(P0.01)。0、20μg/mL姜黄素分别与0、5、50μg/mL伊立替康联合处理SW620细胞12、24、48 h,姜黄素可以增强伊立替康诱导的SW620细胞凋亡率。20μg/mL姜黄素联合5、50μg/mL伊立替康显著上调了SW620细胞内拓扑异构酶-Ⅰ蛋白的表达,协同诱导了SW620细胞内拓扑异构酶-Ⅰ蛋白的表达。结论伊立替康联合姜黄素可以协同增强对SW620细胞活性的抑制作用,协同诱导SW620细胞凋亡,其作用机制可能与伊立替康、姜黄素上调拓扑异构酶-Ⅰ表达有关。     

二氯乙酸钠联合顺铂诱导人肺腺癌A549细胞株凋亡的实验研究

目的研究二氯乙酸钠(Sodium dichloroacetate,DCA-Na)、顺铂(DDP)联合对人肺腺癌A549细胞株增殖和凋亡的影响及其作用机制。方法用MTT法检测DCA-Na、DDP应用对A549细胞增殖抑制作用的影响;流式细胞仪(Annexin V-FITC/PI法)检测DCA-Na、DDP单药及两药联合作用于A549细胞凋亡率的变化;用分光光度法检测DCA-Na作用于A549细胞后半胱氨酸天门冬氨酸蛋白酶(Caspase)-3、-8、-9蛋白的活性。结果DCA-Na、DDP单药组均对A549细胞增殖有抑制作用,且呈明显的剂量-时间依赖性。0.4、2μg/mL的DDP与37.5、75、150μg/mL的DCA-Na联合作用A549细胞24、48、72 h后的抑制率显著高于同浓度DDP单药组(P<0.05),且2μg/mL的DDP与75μg/mL的DCA联合在48 h表现为协同作用。流式细胞仪检测显示,A549细胞联合组凋亡率显著高于各单药组(P<0.05)。DCA-Na作用于A549细胞后,分别在12、24、48、72 h测得Caspase-3、-8、-9蛋白活性显著高于对照组(P<0.05)。结论 DCA-Na对人肺腺癌A549细胞的增殖有抑制作用,并且随着药物浓度增加、作用时间延长,其抑制作用也增加(呈剂量和时间依赖性)。一定浓度范围的DCA-Na和DDP联合作用于人肺腺癌A549细胞能够产生协同作用。DCA-Na可诱导人肺腺癌A549细胞凋亡,且与DDP联合后其诱导凋亡作用更为显著。     

PROPOFOL BLOCK OF CARDIAC SODIUM CURRENTS IN RAT ISOLATED MYOCARDIAL CELLS IS INCREASED AT DEPOLARIZED RESTING POTENTIALS

1. The effect of propofol on cardiac whole-cell sodium currents and single sodium channels in rat isolated ventricular myocytes was examined using patch-clamp techniques. 2. Propofol caused a block of the whole-cell sodium current, the potency of block depending on the holding potential. When cells were held at -90 mV, the EC₅₀ was 2.8 μg/mL. When cells were held more hyperpolarized (at -140 mV), the EC50 increased to 44.0 μg/mL. 3. Although the degree of block produced by the same concentration of propofol was different at different holding potentials, the time course of onset and recovery from block was the same. 4. The current/voltage relationship for the sodium current showed a pronounced block of peak current by propofol (40–50 % block of the maximum current by 30 μg/mL propofol), with a minimal shift in the voltage dependence of activation and no shift in reversal potential. 5. The voltage dependence of the steady state inactivation curve was shifted to more hyperpolarized potentials by propofol (shift of 18 and 8 mV by 30 and 10 μg/mL propofol, respectively). 6. Single channel records showed that propofol caused a shortening of the mean channel open time (from a mean of 0.59 to 0.38 ms by 10 μg/mL propofol), but no change in the channel amplitude. 7. It is concluded that propofol produces a block of sodium currents in cardiac myocytes at concentrations that are comparable to those that may be attained during anaesthesia.     

THE NOVEL MARINE NATURAL PRODUCT PLOCAMADIENE A CAUSES HISTAMINE RELEASE FROM MAST CELLS OF THE GUINEA-PIG AND RAT IN VITRO

1. Plocamadiene A is a polyhalogenated monoterpene, (1R, 2S, 4S, 1′E)-2-bromo-l-chloro-4-(2′-chloroethenyl)-I-methyl-5-methylenecyclohexane, isolated from red marine algae of the Plocamium genus. 2. This study examined the activity of plocamadiene A on guinea-pig isolated ileum (GPI) and subsequently on rat isolated peritoneal mast cells. 3. Plocamadiene A (1 μg/mL) produced a slow onset, sustained contraction of the GPI. This was insensitive to atropine (1 μmol/ L) and tetrodotoxin (1 μmol/ L), but was significantly reduced by H₁-histamine receptor antagonists including mepyramine (10 nmol/L), chlorcyclizine (10 nmol/L) and diphenhydramine (0.1 μmol/L). The H₂-histamine receptor antagonists cimetidine (0.1 μmol/L) and ranitidine (10 nmol/L) potentiated the response to plocamadiene A (1 μg/mL). 4. The amplitude of contraction caused by plocamadiene A (1 μg/mL) gradually decreased when the compound was applied repeatedly to the GPI for 5 min every 10 min for 150 min. 5. Contractions to plocamadiene A (1 μg/mL) were reduced to approximately 66% of the time control in ovalbumin-sensitized GPI challenged with ovalbumin to release endogenous contractile agents. 6. Cromolyn (0.1 mmol/ L) inhibited (by 40%) the response in the GPI caused by plocamadiene A (1 μg/mL) as compared with time controls. 7. Spectrofluorometric assay suggested that both plocamadiene A (10 μg/mL) and compound 48/80 (10 μg/mL) caused histamine release from rat peritoneal mast cells in vitro. This release of histamine was reduced by cromolyn (100 μg/mL). 8. This study concluded that plocamadiene A releases histamine from mast cells of the GPI and peritoneal mast cells in the rat.     

反义寡核苷酸-聚乙烯亚胺纳米微粒逆转耐甲氧西林金黄色葡萄球菌耐药性的研究

目的：以聚乙烯亚胺（polyethyleneimine,PEI）为载体,将硫代寡聚脱氧核苷酸（PS-ODNs）转染到耐甲氧西林金黄色葡萄球菌（methicillin resistant staphylococcus aureus,MRSA）体内,通过药效学观察PS-ODNs逆转MRSA对β-内酰胺类抗生素的耐药性。方法：制备PEI与PS-ODNs结合的纳米微粒（PEI-ODNs纳米微粒）;PEI-ODNs纳米微粒的粒径分析及结合率的测定;平板克隆形成实验计数菌落数（CFU）;微量法测定细菌生长曲线;液体稀释法测定细菌的最小抑菌浓度（MIC）。结果：PEI-ODNs纳米微粒的粒径为（85±22）nm,PEI与PS-ODNs的结合率最高为（97.3±1.1）%。含苯唑西林（6mg/L）的M-H琼脂板上,30μg/mL的PEI-ODNs纳米微粒组MRSA的菌落数为6.4×10^8/mL,而空白对照组的菌落数为3.3×10^9/mL,二者相比给药组菌落数明显减少,差异具有统计学意义（P〈0.01）,而其他对照组与空白对照组比较差异无统计学意义。实验结果显示PEI-ODNs纳米微粒组的苯唑西林对MRSA生长有抑制作用,30μg/mL的PEI-ODNs纳米微粒可将苯唑西林对MRSA最小抑菌浓度由1024μg/mL降低至16μg/mL。结论：PEI与PS-ODNs的结合率很高且粒径较小,PS-ODNs可以部分逆转MRSA对β-内酰胺类抗生素的耐药性。药效学结果显示PEI可以有效地将反义寡核苷酸转入MRSA体内,可考虑将其作为反义寡核苷酸进入细菌的载体。     

The effect of high concentration and exposure duration of nanoceria on human lens epithelial cells

Nanotechnology has the potential for treating diseases and conditions of ageing. The eye is particularly vulnerable, because chronic pathologies can lead to sight loss. Human lens epithelial cells were exposed to 10, 20, and 100 μg/mL of negatively charged nanoceria for 48 and 72 hours; DNA damage and cell growth were assessed. Concentrations up to 100 μg/mL for 48 hours did not cause measurable genotoxic effects. For exposures of 72 hours, concentrations above 10 μg/mL showed small but statistically significant differences in DNA damage from negative controls. All treated samples were less damaged than positive controls. Cell growth, monitored for up to 7 days, did not show deviations in cell morphology or growth between treated and untreated samples. Whereas time of exposure may have greater effect than dosage, indicating potential for genotoxicity at higher exposures, human lens epithelial cells can sustain normal growth when exposed to concentrations of nanoceria of up to 100 μg/mL. From the Clinical Editor: Human lens epithelial cells were exposed to various concentrations of negatively charged nanoceria for 48 and 72 hours to assess DNA damage and cell growth. The authors demonstrate that epithelial cells can sustain normal growth when exposed to concentrations of up to 100 μg/mL, with time of exposure having a greater effect than dosage, indicating potential genotoxicity at higher exposures.     

Microbiological quantitative analysis of streptomycin

The streptomycin-dependent growth characteristic of an Escherichia coli strain was used to develop a specific and quantitative detection method for streptomycin in liquid medium. In order to overcome the interference of other antimicrobial agents which may be present in the samples to be analyzed, streptomycindependent E. coli ATCC 15745 was transformed by non-conjugative plasmid vector pBR328 encoding for ampicillin, chloramphenicol, and tetracycline resistance The parental E. coli strain retained its initial high level resistance to sulfonamides. We observed a very good correlation between E. coli/pBR328 growth, expressed as an increase in absorbance at 660 nm as a function of time, and (dihydro) streptomycin concentrations ranging from 0 to 5.0 μg per mL. The growth dependency of the test organism on streptomycin was also maintained when ampicillin (100 μg/mL), chloramphenicol (30 μg/mL), sulfisoxazole (100 m/mL), and tetracycline (30 μg/mL) were added in combination with the aminoglycoside antibiotic. This dependency was also evaluated by the determination of beta-lactamase activity (encoded by pBR328) used as a growth marker enzyme after a 20 h incubation period of the test organism with a combination of (dihydro) streptomycin and non-aminoglycosidic antibiotics.     

Growth of four microorganisms in polyethylene glycol-electrolyte lavage solution

The growth of Staphylococcus epidermidis, Serratia marcescens, Pseudomonas aeruginosa, and Candida albicans in reconstituted polyethylene glycol-electrolyte lavage solution (PEG-ELS) stored under refrigeration and at room temperature was studied. A standard inoculum of each organism was added to one of four 4-L containers (one organism per container). From each container 28 aliquots of 25-mL each were removed and stored under refrigeration or at room temperature. One container was not inoculated and served as a control. Duplicate aliquots of the inoculated and the control solutions were filtered and incubated for quantification of organisms on days 0, 1, 2, 4, 8, 16, and 30. Solutions stored at room temperature supported the growth of S. marcescens and Ps. aeruginosa. The counts of these organisms increased to approximately 10(6) colony-forming units (CFU)/mL over 16 days. The counts of Staph. epidermidis in solutions stored at room temperature increased slightly over the first 24 hours and declined steadily to zero after day 4. C. albicans reached a maximum colony count of 5.84 cfu/mL on day 16 and steadily declined to 0.92 cfu/mL on day 30. Solutions stored under refrigeration did not support the growth of any microorganisms. Microbial growth was not detected in any of the control solutions over the 30-day study period. The polyethylene glycol-electrolyte lavage solution studied here should be refrigerated after reconstitution to minimize microbial growth. This solution may be used for up to 30 days after reconstitution when it is stored under refrigeration.     

硝酸镓和万古霉素抑制表皮葡萄球菌生物膜形成的协同作用

目的观察硝酸镓和万古霉素联合应用对表皮葡萄球菌生物膜形成的影响。方法采用半定量的分光光度法计算生物膜的形成程度。将低于最小抑菌浓度的古霉素和硝酸镓联合使用,观察它们对表皮葡萄球菌生物膜形成的影响。结果硝酸镓（2μmol/L）和万古霉素（1μg/m l）联合应用对表皮葡萄球菌生物膜形成的抑制率达到99.9%,明显高于单独使用的效果。结论硝酸镓可以提高万古霉素对表皮葡萄球菌生物膜形成的抑制效果。     

蛹虫草提取物对高糖诱导内皮细胞衰老的影响

目的：探讨蛹虫草乙酸乙酯提取物（CME）对高糖诱导人脐静脉内皮细胞（HUVECs）衰老的影响。方法：用高糖（40mmol／L）诱导建立HUVECs衰老体外模型,以冬虫夏草提取物（CSE）（50μg／mL）为阳性对照,观察CME（12．5～100μg／mL）对内皮细胞衰老的干预作用。四甲基偶氮唑蓝（MTT）比色法检测细胞增殖;SA—β-半乳糖酐酶（SA—β—gal）染色法检测细胞衰老特异性的SA—β—gal活性;流式细胞术检测细胞周期分布和细胞内活性氧（ROS）含量。结果：经高糖干预24、48、72h后,HUVECs增殖活性OD值明显低于对照组;而且在高糖孵育96h后,SA—β-gal染色阳性细胞率明显增加;孵育48h后,处于G0／G1期细胞的百分率和ROS相对水平明显增加（P〈0．01）。与高糖组相比,CME（25～50μg／mL）孵育48和72h后细胞OD值显著提高（P〈0．05）;CME（12．5～100μg／mL）孵育96h后SA-β-gal染色阳性细胞率显著降低（P〈0．01）;孵育48h后Go／G1期的细胞百分率（P〈0．01）、细胞内ROS水平显著降低（P〈0．05）;CME25、50／μg／mL效果优于CME12．5、100〉g／mL（P〈0．05）,且与CSE50ptg／mL作用相近（P〉0．05）。结论：蛹虫草乙酸乙酯提取物可促进内皮细胞生长增殖,可能与其降低细胞内ROS水平,减轻细胞氧化应激损伤有关,从而减轻内皮细胞衰老。     

不同浓度舒芬太尼复合罗哌卡因用于分娩镇痛的临床研究

目的观察不同浓度舒芬太尼和低浓度罗哌卡因配伍用于分娩镇痛的临床效果,探讨分娩镇痛中与低浓度罗哌卡因配伍的舒芬太尼最适宜浓度。方法选择80例ASAⅠ～Ⅱ级、头位、单胎、足月妊娠初产妇,年龄20～32岁,采用随机数字表法将80例受试者按1∶1∶1∶1比例分4组,分别为0.15%罗哌卡因复合安慰剂组(S0组);0.15%罗哌卡因复合舒芬太尼0.1μg/mL组(S1组);0.15%罗哌卡因复合舒芬太尼0.3μg/mL组(S2组);0.15%罗哌卡因复合舒芬太尼0.5μg/mL组(S3组)。并对产妇的生命体征、镇痛效果、产程变化、运动神经阻滞程度、分娩方式、新生儿Apgar评分等项目进行观察。结果 S2、S3组在麻醉后10 min时VAS评分较低,与S0组、S1组相比,差异有统计学意义;S1、S2、S3各组在麻醉后30、60 min时,VAS评分差异无统计学意义,但与S0组相比,差异有统计学意义;S3组皮肤瘙痒发生率明显增加;第一、二产程,新生儿Apgar评分四组差异无统计学意义。结论 S2组与S3组比较,0.3μg/mL舒芬太尼复合0.15%罗哌卡因用于硬膜外镇痛分娩安全有效,不良反应少。     

Biological activity assessment and phenolic compounds characterization from the fruit pericarp of Litchi chinensis for cosmetic applications

Context: Litchi chinensis Sonn. (Spindaceae) is an important economic fruit of Thailand. Therapeutic effects of the fruits are contributed by anti-inflammatory phenolics.

Objective: To extract the litchi fruit pericarp in order to identify biologically actives substances with potential for cosmetic application.

Materials and methods: The litchi pericarp was macerated by 70% ethanol (EtOH) and partitioned using n-hexane and ethyl acetate (EtOAc). In vitro antioxidant activities were assessed by 1, 1-diphenyl-2-picrylhydrazyl (DPPH), ABTS and ferric reducing ability of plasma (FRAP) assays including tyrosinase inhibitory effect. Cellular radical scavenging capacity was monitored in a normal human fibroblast cell culture (NHF). Total phenolic content was determined and characterized by HPLC.

Results: The EtOAc fraction was a significant antioxidant, stronger than ascorbic acid (p < 0.01), as assessed by ABTS (IC₅₀ = 7.137 ± 0.021 μg/mL), DPPH (IC₅₀ = 2.288 ± 0.063 μg/mL) and FRAP (EC_1mMFeSO4 = 8013.183 ± 58.804 μg/mL) assays. It demonstrated an antityrosinase effect (IC₅₀ = 197.860 ± 1.230 μg/mL) and showed no cytotoxic activity toward Vero and NHF cells, at a maximum tested concentration (50 μg/mL), with cellular antioxidant activity. Total phenolic content was highest in the most potent antioxidant fraction. Quercetin, rosmarinic and gallic acids were found. Total phenolic content is highly related to FRAP, antityrosinase, and ABTS activities.

Discussion and conclusion: Pericarp from litchi fruit can be obtained abundantly from agricultural waste, and the strong antioxidant activity demonstrated in this report may have application in topical cosmetic products. This ecological antioxidant can be prepared using a feasible method resulting in less waste and increased agro-industrial profitability.     

Effects of Platycodin D on S100A8/A9-induced inflammatory response in murine mammary carcinoma 4T1 cells

Activation of the inflammatory signaling pathway is the most vital part of the pre-metastatic events of breast cancer. Platycodin D (PlaD) shows favorable pharmacological activities in anti-inflammatory and anti-tumor effect. The main purpose of this study was to survey the effects of PlaD on S100A8/A9-induced inflammation in mouse mammary carcinoma 4T1 cells. S100A8/A9 immunolocalization and expression in pre-metastatic lung tissue were assessed by immunofluorescence staining and ELISA. 4T1 cells were treated with 2.5 μg/mL recombinant S100A8/A9 heterodimer and 7.5, 10, or 12.5 μM of PlaD. After 24 h of incubation, cell viability, migration, and invasion were evaluated by CCK-8, wound-healing, and transwell assay, respectively. Nuclear translocation of NF-κB p65 was determined by immunostaining and western blot. The levels of pro-inflammatory cytokines including IL-1β, IL-6, and TNF-α were detected by ELISA. The results showed that S100A8/A9 was actively increased and released into the extracellular space during the pre-metastatic phase of breast cancer. PlaD treatment attenuated S100A8/A9-induced growth, migration, and invasion of 4T1 cells. Furthermore, PlaD decreased the levels of IL-1β, IL-6, and TNF-α by inhibiting nuclear translocation of NF-κB p65. In conclusion, this study demonstrated that PlaD inhibited S100A8/A9-induced inflammatory response in 4T1 cells by suppressing the expression of IL-6, IL-1β, and TNF-α via inhibition of NF-κB signaling pathways.     

Synthesis and in-vitro antibacterial activity of 7-(3-aminopyrrolo[3,4-c]pyrazol-5(2H,4H,6H)-yl)-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid derivatives

A series of novel 7-(3-aminopyrrolo[3,4-c]pyrazol-5(2H,4H,6H)-yl)-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid derivatives was designed, synthesized and characterized by (1)H-NMR, MS and HRMS. These fluoroquinolones were evaluated for their in-vitro antibacterial activity against representative Gram-positive and Gram-negative strains. Generally, all of the target compounds display rather weak potency against the tested Gram-negative strains, but most of them exhibit good potency in inhibiting the growth of S. aureus including methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis including methicillin-resistant S. epidermidis (MRSE) (MIC: 0.125-8 μg/mL). In particular, the compound 9g is 2 to 32 fold more potent than gemifloxacin (GM), moxifloxacin (MX), gatifloxacin (GT), and levofloxacin (LV) against S. pneumoniae 08-3, K. pneumoniae 09-23, and P. aeruginosa ATCC27853, 4 to 32 fold more potent than MX, GM, and LV against K. pneumoniae 09-21, and more active than or comparable to the four reference drugs against P. aeruginosa 09-32.     

Antimicrobial constituents from the tubers of Bletilla ochracea

A new 2-(2-methylpropyl)butanedioic acid derivative, bletillin A ( 1), and a new bibenzyl, bletillin B ( 2), together with seventeen known compounds ( 3- 19), were isolated from the tubers of Bletilla ochracea Schltr. Their structures were established by detailed spectroscopic analyses. Phenanthrenes ( 12- 14) exhibited antibacterial activities against gram-positive bacteria Staphylococcus aureus, S. epidermidis, and Bacillus subtilis, with MIC values of 12.5-25 μg/mL.     

藤茶双氢杨梅树皮素对Hela细胞及A2780细胞增殖的抑制作用

目的探讨藤茶双氢杨梅树皮素（ampelopsin,APS）的抗肿瘤作用。方法以四甲基偶氮唑蓝比色法（MTT法）、克隆形成法观察APS对Hela细胞及A2780细胞的体外抑制作用。结果APS均能明显抑制体外培养的Hela细胞及A2780细胞的生长,MTT法的半数抑制浓度（IC50）分别为24．6μg／mL和1．2μg／mL,集落形成法中APS质量浓度在4．4～22．2μg／mL时抑制率均为100％。结论藤茶APS对体外培养的Hela细胞及A2780细胞均有明显的抑制作用。