36种中药材体外抗菌活性筛选研究

该文研究36种常用中药材80%乙醇提取物在体外抗临床常见致病菌的抗菌活性。采用药敏纸片法测耐药菌的耐药谱,中药粗粉用80%乙醇浸泡提取,提取液减压浓缩得浸膏,通过琼脂打孔法测定提取物抑菌圈,再通过微量倍比稀释法测定最低抑菌浓度(MIC)和最低杀菌浓度(MBC)。结果表明:36种中药材醇提物中,有15种具有广谱抗菌活性,对实验中各标准菌表现出不同程度的抑制作用,对MRSA抗菌活性也较强。其中,岩陀、卷柏、首乌藤、苏木、乌药、夏枯草6种药材的抗菌活性比较突出,抑菌圈均大于11 mm,细菌对其表现为中高度敏感;它们对7株标准菌的MIC/MBC值除个别为12.5 mg·m L~(-1)以外,均小于1.563 mg·m L~(-1),对16株MRSA的MIC/MBC值均小于1.563 mg·m L~(-1),它们的萃取层活性均小于1 mg·m L~(-1)。所筛选出的15种抗菌活性较强的中药材,可为后续研究其活性单体化合物和作用机制,研发有效的抗多重耐药菌的中药制剂以及解决细菌耐药性问题提供一定的参考。     

白及根腐病病原菌的鉴定及抑制效应研究

为明确鉴定白及块茎腐烂病(根腐病)的病原菌,并筛选能够抑制病原菌的中药材提取物。该研究利用常规组织分离法对病原菌进行分离,通过形态学和分子生物学技术对致病菌株进行鉴定,同时观察了7种中药材提取物对病原菌的抑菌效果。结果表明：(1)从感病叶片、叶鞘及块茎中共分离得到14株真菌和4株细菌,病原菌室内和室外回接表明菌株GF-1致病症状与田间一致,致病率均达到100%。(2)经形态学鉴定,菌株GF-1为附球菌属(Epicoccum)病原菌,菌落白色绒絮状,圆形;菌丝匍匐向外、向上生长,气生,无色,有隔膜,有分枝,具有分生孢子和厚垣孢子。(3)菌株GF-1的ITS序列(全长522 bp)与GenBank中已登录的甘蔗的高粱附球菌(E.sorghinum,MN493119.1)序列一致性最高,达99.62%,与已报道的白及叶斑病致病菌高粱附球菌(E.sorghinum, MF948994.1)的一致性为98.88%。(4)培养基中含有0.1～0.2 g·mL^-1的青钱柳等7种中药材提取物,能够完全抑制GF-1菌落的生长;当培养基中含有0.05 g·mL^-1     

23种中草药的体外抗菌活性筛选研究

为考察中草药抗菌物质基础筛选出活性提取物,该研究通过80%乙醇冷浸和95%乙醇回流提取制备23种中草药的提取物,采用琼脂扩散法测量抑菌圈直径,用微量液体培养基倍比稀释法测定最低抑菌浓度(minimum inhibitory concentration,MIC)和最低杀菌浓度(minimum bactericidal/fungicidal concentration,MBC/MFC),并测定了提取物对临床4种常见病原菌体外抗菌活性。结果表明:紫珠草、千斤拔、黄龙尾等9种中草药对金黄色葡萄球菌有较强的抑菌活性,其MIC/MBC值除个别菌是12.5 mg·mL~(-1)外,其他都在0.09～3.12 mg·mL~(-1)之间;千斤拔、大红袍、过江龙等5种中草药对铜绿假单胞菌有较强抑菌活性,其MIC/MBC值在3.12～12.5 mg·mL~(-1)之间;紫珠草、千里光、石楠等13种中草药对大肠埃希菌有较强的抑菌活性,其MIC/MBC值在0.09～6.25 mg·mL~(-1)之间;八角对白色念珠菌有较强抑菌活性,其MIC/MFC值在0.78～12.5 mg·mL~(-1)之间。23种中草药的抗细菌活性较好,尤其是千斤拔、大红袍、过江龙、八角、黄药子对金黄色葡萄球菌、大肠埃希菌、铜绿假单胞菌都具有较好的抑菌活性,具有广谱抗菌活性;但对真菌抑菌效果不明显,仅有八角对白色念珠菌有抑菌活性。此外,提取溶剂浓度、提取温度和提取时间对中草药的提取率和活性均有影响,冷提稍优于热提。     

两粤黄檀乙醇提取物化学成分分析及抗炎活性研究

为了研究壮药两粤黄檀的化学成分及其抗炎活性,阐明其药理作用机制,该研究采用小鼠二甲苯致炎耳廓肿胀法、角叉菜胶致炎足肿胀急性炎症模型,观察不同剂量两粤黄檀乙醇提取物对小鼠耳廓肿胀度、肿胀率及足肿胀度的影响,并利用液相色谱-质谱(LC-MS)、热裂解气相色谱-质谱(PY-GC/MS)等技术分析提取物的化学成分,结合网络药理学方法对其抗炎活性成分以及作用机制进行初步研究。结果表明:(1)两粤黄檀乙醇提取物具有良好的抗炎活性,高剂量组(8 g·kg~(-1))可以显著抑制二甲苯致小鼠耳廓肿胀度、角叉菜胶致炎足趾肿胀,其抑制率均高于50%;(2)从两粤黄檀乙醇提取物中共鉴定得到60个化合物,包括毛蕊异黄酮、芒柄花黄素、血根碱、胡椒碱、β-谷甾醇等多种抗炎活性成分;(3)网络药理学分析显示,两粤黄檀发挥抗炎作用的核心靶点为PIK3CA、EGFR、MAPK、SRC、STAT3、CYP19A1、IL2、MAOA等,涉及c GMP-PKG、cAMP、Focal adhesion、Rap1等信号通路。该研究结果为两粤黄檀的进一步开发利用提供了重要参考。     

23种中草药体外抗菌活性筛选

为研究23种中草药的80%乙醇提取物对4种临床常见致病菌的体外抗菌活性,该研究用琼脂扩散法测定抑菌圈直径,微量肉汤培养基倍比稀释法测定最低抑菌浓度(minimum inhibitory concentration,MIC)和最低杀菌浓度(minimum bactericidal/fungicidal concentration,MBC/MFC)。结果表明:滇龙胆草、金丝梅、溪黄草等16种提取物对金黄色葡萄球菌的MIC/MBC值在0.19～3.12 mg·mL^-1之间,有很强的抑菌活性。头花蓼、淡竹叶、半枝莲等14种提取物对铜绿假单胞菌的MIC/MBC值在1.56～6.25 mg·mL^-1之间,有较强的抑菌活性。除槐角外,其余提取物对大肠埃希菌的MIC/MBC值均在3.12～12.5 mg·mL^-1之间,有较强的抑菌活性。黄藤、藿香提取物对白色念珠菌的MIC/MFC值在0.78～6.25 mg·mL^-1之间,有较强的抑菌活性; 滇龙胆草、金丝梅、水杨梅、苦参、胡椒、赶黄草、荜菝、淡竹叶提取物对白色念珠菌的MIC/MFC值在6.25～12.5 mg·mL^-1之间,也具有一定抑菌活性。因此,所选中草药的抑菌效果均较好,大部分均具有广谱抗菌活性。其中,藿香、黄藤的提取物对白色念珠菌抑菌活性较强,金丝梅、水杨梅、仙鹤草、苦参、赶黄草、溪黄草的提取物对金黄色葡萄球菌抑菌活性很强,这几种中草药可为进一步追踪其活性单体化合物和作用机制提供一定的参考。     

Selective inhibitors of germination of legume seeds in activated sludge compost

Water extracts of the compost produced from activated sludge and coffee residue were found to be selectively inhibitory to seed germination of some legumes. Germination rate of white clover (Trifolium repens L.), red clover (Trifolium pratense L.) and alfalfa (Medicago sativa L.) seeds were reduced to 2, 29 and 73% of the control, respectively, by water extracts of the compost (20 g l^–1). However, the extracts did not show any inhibition to seed germination of sorghum (Sorghum bicolor Moench), African millet (Eleusine coracana Gaertn.), and Komatsuna (Brassica rapa L.) at the same concentration. The inhibitors in the compost extracts were separated by ion-exchange chromatography and reverse-phase high performance liquid chromatography (HPLC) and the inhibitory activities of seed germination were tested with white clover seeds. Five inhibitors were isolated and identified as 3,4-dichlorophenylacetic acid (3,4-DCP), 3,4-dichlorobenzoic acid (3,4-DCB), 3,4,5-trichlorophenylacetic acid, 3,4,5-trichlorobenzoic acid and mono-2-ethylhexylphthalate by ¹H-, ¹³C-NMR spectroscopy and mass spectrometry. The inhibitory activities of some authentic chemicals of the inhibitors and the related compounds were compared. The results indicated that the main inhibitor in the compost could be 3,4-DCB, which was contained at the concentration of 6.58 mg kg^–1 compost and showed the strongest inhibitory effect on seed germination of white clover among the tested compounds.     

Identification and Quantification of Several Mammalian Steroid Hormones in Plants by UPLC-MS/MS

We have developed an effective method for the isolation, identification, and quantification of several mammalian steroid hormones and their metabolites in different plant tissues. The purification protocol was based on solid-phase extraction (SPE) combined with immunoaffinity chromatography (IAC) using immobilized generic polyclonal anti-Δ⁴-3-keto-steroid antibodies covalently bound to Affi-Gel 10 sorbent. The antibodies were characterized by means of enzyme-linked immunosorbent assay (ELISA). The detection limit of the ELISA was 6.0 × 10⁻¹⁰ mol L⁻¹ and cross-reactivity with most Δ⁴-3-keto-steroids was very high as predicted (68–122%). The IAC allowed fast, single-step purification of different plant extracts prior to analysis by ultra-performance liquid chromatography-electrospray tandem mass spectrometry [UPLC-ESI(+)-MS/MS]. In multiple-reaction-monitoring (MRM) mode, the detection limit of the method for most of the steroids analyzed was close to 10 fmol and the response was linear up to 50 pmol injected. The analytical accuracy was validated using tobacco leaf samples spiked with known amounts of authentic and deuterium-labeled standards. The newly developed method was capable of detecting and quantifying at least 12 specified steroid compounds in plant extracts. In the analyzed extracts from three plant species, that is, common foxglove (Digitalis purpurea L.), tobacco (Nicotiana tabacum L.), and elecampane inula (Inula helenium L.), four endogenous steroids were detected, identified, and quantified. Progesterone was found in all three plants at concentrations comparable to those reported in previous studies. Three other steroids, androstendione, 17α-hydroxyprogesterone, and 16-dehydroprogesterone, were identified for the first time in plant extracts. 17α-Hydroxyprogesterone and 16-dehydroprogesterone occurred at significant concentrations in D. purpurea, whereas androstendione was found in N. tabacum and I. helenium but not in D. purpurea.     

Cytotoxicity of extracts from Dolsan leaf mustard Kimchi treated with lactic acid bacteria on lung and gastric cancer cells

The cytotoxicity of extracts from Dolsan leaf mustard Kimchi (DLMK) treated with lactic acid bacteria on A 549 human lung cancer cells and SNU-601 human gastric cancer cells were investigated. Leuconostoc mesenteroides, Leu. Gelidum, and Weissella kimchii previously isolated from properly ripened DLMK were inoculated to DLMK as a starter (1 × 10⁸ CFU/mL). The DLMK was then fractionated by various extracting solvents. The cytotoxicity of MeOH extracts from DLMK on A 549 and SNU-601 cancer cells was found to occur in a dose-dependent manner. Although the cytotoxicity of the MeOH extracts was found to be approximately 20 to 30% at concentrations of 250 μg/mL by MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide) assay, cytotoxicity of chloroform soluble fraction of DLMK treated with W. kimchii showed about 80 to 90%. Consequently, the growth of cancer cells was inhibited significantly in medium containing DLMK extracts. In addition, significant morphological changes such as cell condensation, cell fragmentation, and alterations in the size and shape of the cells were observed in cells grown in medium that contained the DLMK extracts. Taken together, these results suggest that inhibition of the proliferation of cancer cells by apoptosis was induced by DLMK extracts.     

A comparative study on the antimutagenic properties of aqueous extracts of Aspalathus linearis (rooibos), different Cyclopia spp. (honeybush) and Camellia sinensis teas

Antimutagenic activity of aqueous extracts of the South African herbal teas, Aspalathus linearis (rooibos) and Cyclopia spp. (honeybush) was compared with that of Camellia sinensis (black, oolong and green) teas in the Salmonella mutagenicity assay using aflatoxin B₁ (AFB₁) and 2-acetylaminofluorene (2-AAF) as mutagens. The present study presents the first investigation on antimutagenic properties of C. subternata, C. genistoides and C. sessiliflora. The herbal teas demonstrated protection against both mutagens in the presence of metabolic activation, with the exception of “unfermented” (green/unoxidised) C. genistoides against 2-AAF, which either protected or enhanced mutagenesis depending on the concentration. Antimutagenic activity of “fermented” (oxidised) rooibos was significantly (P < 0.05) less than that of Camellia sinensis teas against AFB₁, while for 2-AAF it was less (P < 0.05) than that of black tea and similar (P > 0.05) to that of oolong and green teas. Antimutagenic activity of unfermented C. intermedia and C. subternata exhibited a similar protection as fermented rooibos against AFB₁. Against 2-AAF, fermented rooibos exhibited similar protective properties than unfermented C. intermedia and C. sessiliflora. Unfermented rooibos was less effective than the C. sinensis teas and fermented rooibos, but had similar (P > 0.05) antimutagenicity to that of fermented C. sessiliflora against AFB₁ and fermented C. subternata against 2-AAF. Fermented C. intermedia and C. genistoides exhibited the lowest protective effect against 2-AAF, while fermented C. intermedia exhibited the lowest protection when utilising AFB₁ as mutagen. Aspalathin and mangiferin, major polyphenols in rooibos and Cyclopia spp., respectively, exhibited weak to moderate protective effects when compared to the major green tea catechin, (−)epigallocatechin gallate (EGCG). Antimutagenic activity of selected herbal tea phenolic compounds indicated that they contribute towards (i) observed antimutagenic activity of the aqueous extracts against both mutagens and (ii) enhancement of the mutagenicity of 2-AAF by unfermented C. genistoides. Antimutagenic activity of the South African herbal teas was mutagen-specific, affected by fermentation and plant material, presumably due to changes and variation in phenolic composition.     

Identification of novel sex pheromone components from a tussock moth, Euproctis pulverea

Two EAG-active compounds were found in the solvent extract of abdominal tips of virgin females of the tussock moth Euproctis pulverea (Leech) (Lepidoptera: Lymantriidae), and identified as (Z,Z,Z)-11,14,17-icosatrienyl isobutyrate and (Z,Z,Z)-11,14,17-icosatrienyl 4-methylvalerate at 190 and 80 ng female^–1, respectively, by means of GC-MS analyses and chemical derivatization. Esters of n-butyric acid, n-valeric acid, n-hexanoic acid and a methylheptanoic acid were also found at 3, 2, 0.4 and 9 ng female^–1 as minor EAG-inactive compounds. Two active compounds were also detected in the hexane extract of female anal tufts at 17 and 6 ng female^–1, respectively. In Okinawa, the binary blend of the synthetic compounds attracted male moths to the sticky traps, but single compounds did not. The significance of these findings in relation to parasitism by Telenomus euproctidis (Hymenoptera: Scelionidae) is discussed.     

Betulinic and oleanolic acids isolated from Forsythia suspensa Vahl inhibit urease activity of Helicobacter pylori

Sixteen medicinal herbs were selected from a database on traditional herbal materials as well as literature on Korean plant resources. Then ethanol (70%, v/v) extracts of these herbs were tested for inhibition of the urease activity of Helicobacter pylori. The urease activity of H. pylori was strongly (82%) inhibited by extract of Forsythia suspensa Vahl. Active compounds in extract of Forsythia suspensa Vahl were first separated by batch mode solvent extraction, followed by purification by silica gel and octadecyl silica gel column chromatography using solvents of different polarity. According to NMR analysis of the last chromatographic fraction, we identified the presence of betulinic acid and oleanolic acid, which are known to have anti-inflammatory, anti-cancer, and anti-HIV viral activities.     

Comparison of the substrate specificity of the two bacterial desulfurization systems

Using cell-free extracts of a desulfurizing mesophile, Rhodococcus erythropolis KA2-5-1 (the Dsz system) and Escherichia coli JM109, which possesses the desulfurizing genes of a thermophile Paenibacillus sp. A11-2 (the Tds system), the reactivity of desulfurizing enzymes toward 4,6-dialkyl dibenzothiophenes (4,6-dialkyl DBTs) and 7-alkyl benzothiophenes (7-alkyl BTs) was investigated. Both systems desulfurized all the 4,6-dialkyl DBTs, except 4,6-dibutyl DBT. Although some alkylated BTs were degraded by the Dsz system, no desulfurized compounds were detected. The reactivity of the Tds system toward alkylated BTs was higher than that of DBT. In contrast to the Dsz system, the Tds system yielded desulfurized compounds from all of the alkylated BTs examined.     

Interaction of gangliosides with plasma low density lipoproteins

The role of gangliosides in the reception of low density lipoproteins (LDL) was studied using as targets mouse ascites hepatoma 22a (MAH) cells which bind LDL through a specific high affinity receptor. Low density lipoprotein binding and uptake by MAH cells decreased after brief treatment of the cells with neuraminidase to partially remove surface sialic acid residues. The LDL uptake capability of the neuraminidasetreated MAH cells was fully restored after incorporation of exogeneous G_M1- and G_D1a-gangliosides into the cell surface. In contrast, free (extracellular) gangliosides inhibited LDL uptake by native MAH cells. This inhibitory effect was seen at ganglioside concentrations corresponding to the ganglioside content of serum and was most pronounced with gangliosides whose sialic acids were linked to a terminal galactose residue (G_M3, G_D1a, G_T1b) but was smaller or absent with gangliosides whose sialic acids were attached to an internal galactose (G_M1, G_M2). The binding of gangliosides to LDL was structure and concentration dependent, saturable and trypsin sensitive. The LDL-ganglioside interaction was further investigated by steady state fluorescence spectroscopy. Changes in the LDL fluorescence polarization were observed with as little as 0.01 M concentrations of the gangliosides. The magnitude and nature of the effect depended on the type of ganglioside. We conclude that the LDL surface possesses sites recognizing specific carbohydrate sequences of glycoconjugates and that changes in the cell surface concentrations of sialic acids significantly modulate the LDL uptake. It is postulated that shedding of gangliosides into the blood stream may be a factor involved in regulation of cholesterol homeostasis.Abbreviations MAH mouse ascites hepatoma 22a - LDL low density lipoprotein - ASM anthrylvinyl-labeled sphingomyelin [N-12-(9-anthryl-trans-dodecanoyl-sphingosine-1-phosphocholine] - RITC rhodamine isothiocyanate. The designation of gangliosides follows the IUPAC-IUB recommendation [1]: G_M3, II³NeuAc-LacCer, II³-N-acetylneuraminosyllactosylceramide - G_M2 II³-NeuAc-GgOse₃Cer, II³-N-acetylneuraminosylgangliotriaosylceramide - G_M1 II³-NeuAc-GgOse₄Cer, II³-N-acetylneuraminosylgangliotetraosylceramide - G_D1a, II³ IV³(NeuAc)₂-GgOse₄Cer, II³, IV³-di(N-acetylneuraminosyl)gangliotetraosylceramide - G_T1b II³(NeuAc)₂, IV³ NeuAc-GgOse₄Cer, II³-di-N-acetylneuraminosyl, IV³-N-acetylneuraminosylgangliotetraosylceramide     

Oxidation of amines by yeasts grown on 1-aminoalkanes or putrescine as the sole source of carbon,nitrogen and energy

The maximum growth rate of Trichosporon cutaneum CBS 8111 in chemostat cultures was 0.185 h^-1 on ethylamine and 0.21 h^-1 on butylamine, that of Candida famata CBS 8109 was 0.32 h^-1 on putrescine.The amine oxidation pattern of the ascomycetous strains studied, viz. Candida famata CBS 8109, Stephanoascus ciferrii CBS 4856 and Trichosporon adeninovorans CBS 8244 was independent of the amine that had been used as the growth substrate. It resembled that of benzylamine/putrescine oxidase found in other ascomycetous yeasts. However, differences in pH optimum and substrate specificity were observed between the amine-oxidizing systems of these three species.The amine oxidation pattern of cell-free extracts of Trichosporon cutaneum CBS 8111 varied with the amine that was used as growth substrate. The enzyme system produced by Cryptococcus laurentii CBS 7140 failed to oxidize isobutylamine and benzylamine, and showed a high pH optimum.The synthesis of amine oxidase in the four yeast strains studied was not repressed by ammonium chloride and was weakly repressed by glucose but was strongly repressed if both compounds were present in the growth medium.     

Antifungal activity of methanol extracts from spikes of Triticum spelta and Triticum aestivum genotypes differing in their response to Fusarium culmorum inoculation

The total concentrations of free phenolic compounds and peroxidase were determined in spikes (collected at the flowering stage) of some spelt and common wheat cultivars differing in their response to F. culmorum infection. The antifungal activity of methanol extracts obtained from spikes was also evaluated. The tested genotypes differed significantly in their response to inoculation. The most resistant were Torka and Zebra among common wheat cultivars, and Weisser Grannenspelz among spelt cultivars. The average content of free phenolic compounds in spikes of spelt and common wheat was 1246.56 μg g⁻¹ and 1236.58 μg g⁻¹, respectively. The cultivars whose spikes contained the largest amounts of phenols showed the weakest response to F. culmorum infection. No significant differences were observed with regard to peroxidase content, which was 5.22 U g⁻¹ in common wheat spikes and 5.14 U g⁻¹ in spelt spikes. Methanol extracts from spikes of all wheat cultivars contained antifungal substances. The extracts from spelt spikes inhibited the growth of F. culmorum on PDA to a lesser degree than the extracts from common wheat spikes. This corresponds to the results of field trials, in which T. spelta generally exhibited a stronger response to F. culmorum infection than common wheat. The high correlation (r = 0.816) between mycelium growth inhibition on the medium and F. culmorum infection indicates that an evaluation of the antifungal activity of extracts from spikes may be used for the selection of breeding materials directed towards increased resistance to Fusarium head blight.     

爵床的甲醇提取物对小菜蛾的生物活性作用

为探明爵床(Justicia procumbens)甲醇提取物对小菜蛾的生物活性,采用室内生测法测定了爵床甲醇提取物对小菜蛾的触杀、拒食、胃毒、生长发育抑制和产卵忌避作用。结果表明,爵床甲醇提取物对小菜蛾幼虫具有较强的触杀、拒食、胃毒和生长发育抑制活性,对小菜蛾成虫具有较强的产卵忌避活性。在触杀试验中,药后1、2 d和3 d爵床甲醇提取物对小菜蛾3龄幼虫的致死中浓度(LC50)分别为5.17、4.05和3.06 mg/m L;在拒食试验中,药后1 d和2 d提取物对3龄幼虫的选择性拒食中浓度(AFC50)分别为2.64和3.13 mg/m L,药后1 d和2 d提取物对3龄幼虫的非选择性拒食中浓度(AFC50)分别为3.70、4.54 mg/m L;在胃毒试验中,药后4、5、6 d和7 d提取物对3龄幼虫的致死中浓度(LC50)分别为8.13、3.65、2.88、2.23 mg/m L;在生长发育抑制试验中,药后1 d和2 d提取物对3龄幼虫的抑制中浓度(IC50)分别为2.02、1.40 mg/m L;在产卵忌避试验中,药后1、2 d和3 d提取物对小菜蛾成虫的选择性产卵忌避中浓度(AOC50)分别为2.61、3.66、4.58 mg/m L,药后1、2和3 d提取物对小菜蛾成虫的非选择性产卵忌避中浓度(AOC50)分别为3.19、4.52、5.65 mg/m L。由此证实,爵床提取物对小菜蛾具有显著的毒杀活性,具有开发为新型高效、低毒植物源农药的潜在价值。     

The effect of nitrogen and sucrose concentrations on the growth of Eucomis autumnalis (Mill.) Chitt. plantlets in vitro, and on subsequent anti-inflammatory activity in extracts prepared from the plantlets

Large amounts of anti-inflammatory activity are present in extractsprepared from Eucomis plants. Extracts prepared from in vitroplantlets grown on a modified Murashige and Skoog medium supplementedwith 1 mg &ell^–1 NAA and 1 mg &ell^–1 BA, were tested intwo cyclooxygenase assays (COX-1 and COX-2). Ethanol extracts showedhigh levels of COX-1 and COX-2 inhibitory activity, with a COX-2/COX-1inhibition ratio of 1.1. Further experimental work aimed to determine thefactors affecting the accumulation of anti-inflammatory compounds inin vitro plantlets. High concentrations of sucrose (40 g &a,p;ell^–1) inthe culture medium significantly increased the number of shoots initiated,but had no effect on the subsequent anti-inflammatory activity. Lowconcentrations of sucrose (10 g &ell^–1) led to a significantdecrease in COX-1 inhibition. Changig the amount of nitrogen in the medium(but not the ratio of nitrate to ammonium ions) had no significant effect onthe COX-1 inhibitory activity of the extracts.     

The in vitro antifungal activity of 30 Chinese herb extracts to Saprolegnia sp.

Chinese traditional medicines have been used for several thousands of years in Asian countries, not only in humans but also in many animal species. These compounds prevent and control different types of diseases including internal diseases as well as some infectious diseases, where the aetiological agent is viral, bacterial, parasitic or mycotic. Rhizoma coptidis is believed to inhibit Shigella dysenteriae and that Radix isatidis can prevent flu caused by the influenza virus. It is thus hypothesized that some of these traditional herbal compounds will have anti‐fungal activity. Saprolegniosis is a disease common in fish and their eggs in both fresh and brackish water; a newer, safer medication against Saprolegnia is needed after the prohibition in many countries of the extremely effective fungicide, malachite green. In the present study an attempt is made to identify herbal compounds that have anti‐Saprolegnia activity. A strain of Saprolegnia, CCF1301, was isolated from the skin of infected grass carp (Ctenopharyngodon idella) and identified as Saprolegnia ferax by the 26S rDNA D1/D2 region and ITS region. This strain was used to evaluate the antifungal activity of thirty Chinese traditional herbal medicine extracts, and a modified dish dilution method was developed for the evaluation. Saprolegnia‐infected rapeseeds with visible hyphae were transplanted onto prepared PDA plates containing 2 g L^?1 herbal plant extracts and incubated at 20°C for 48 h. Each herbal plant species was tested in triplicate. Those herbal plant extracts that showed negative mycelium presence at 2 g L^?1 were further tested for minimum inhibitory concentration (MIC) evaluation. The results showed that Syzygium aromaticum, Magnolia officinalis, Melaphis chinensis, Euphorbia fischeriana Steud, and Sophora flavescentis exhibited enhanced growth inhibition at 2 g L^?1 and MIC values of 500, 62.5, 250, 62.5, 250 mg L^?1 concentrations, respectively. It was obvious that Magnolia officinalis and Euphorbia fischeriana Steud exhibited the best antifungal activity. Since there is a high natural toxicity in Euphorbia fischeriana Steud, its applicability as the main ingredient in an aquaculture therapeutic formulation requires further research. Thus, Magnolia officinalis would appear to be the more valuable antifungal herbal species with which to pursue further research.     

Selective cleavage of 10-methyl benzo[b]naphtho[2,1-d]thiophene by recombinant Mycobacterium sp. strain

Recombinant Mycobacterium sp. strain MR65 carrying dszABCD genes was used for desulfurization of 10-methylbenzo[b]naphtho[2,1-d]thiophene (10-methyl BNT) in the hexadecane phase. The specific activity was 25% of that of dibenzothiophene (DBT). One of two major metabolites of 10-methyl BNT produced by strain MR65 was identified as 1-methoxy-2-(3-methylphenyl)naphthalene by ¹H and ¹³C NMR. The other major metabolite and two minor metabolites were determined as 1-hydroxy-2-(3-methylphenyl)naphthalene, 2-(2-methoxy-3-methylphenyl)naphthalene and 2-(2-hydroxy-3-methylphenyl)naphthalene, respectively, by HPLC and GC-MS. The production ratio of the two desulfurization metabolite isomers was 0.99:0.01, calculated on the basis of peak GC areas. These results indicated that the C-S bond adjacent to the naphthalene skeleton was selectively cleaved to form the two major compounds.     

Over-production of the D1:2 protein makes Synechococcus cells more tolerant to photoinhibition of photosystem II

Over-expression of the psbAIII gene encoding for the D1 protein (form II; D1:2) of the photosystem II reaction centre in the Synechococcus sp. PCC 7942 was studied using a tac promoter and the lacI ^Q system. Over-expression was induced with 40 g/ml IPTG in the growth medium for either 6 or 12 h at growth irradiance (50 mol photons m^-2 s^-1). This treatment doubled the amount of psbAII/III mRNA and the D1:2 protein in membranes but decreased the amount of psbAI messages and the D1:1 protein. The total amount of both heterodimeric reaction centre proteins, D1 and D2, remained constant under growth light conditions, indicating that the number of PSII centres in the membranes was not affected, only the form of the D1 protein was changed from D1:1 to D1:2 in most centres. When the cells were photoinhibited either at 500 or 1000 mol photons m^-2 s^-1, in the presence or absence of the protein synthesis inhibitor lincomycin, the D1:2 protein remained at a higher level in cells in which over-expression had been induced by IPTG. These cells were also less prone to photoinhibition of PSII. It is suggested that the tolerance of cells to photoinhibition increases when most PSII reaction centres contain the D1:2 protein at the beginning of high irradiance. This tolerance is further strengthened by maintaining psbAIII gene over-expression during the photoinhibitory treatment.