蒺藜果实中甾体皂苷类成分研究

目的研究蒺藜（Tribulus terrestrisL.）果实的皂苷类化合物。方法利用硅胶柱色谱、凝胶柱色谱、中低压色谱、高效液相色谱等手段进行分离,根据理化性质及波谱数据鉴定结构。结果从蒺藜果实中得到4个已知化合物,分别鉴定为（25R）-2α,3β-二醇-5α-螺甾烷-12-酮（门诺皂苷元）-3-O-{β-D-吡喃葡萄糖基-（1→2）-[β-D-吡喃木糖基-（1→3）]-β-D-吡喃葡萄糖基-（1→4）-β-D-吡喃半乳糖苷}（1）、26-O-β-D-吡喃葡萄糖基-（25R）-5α-呋甾-22-甲氧基-2α,3β,26-三醇-3-O-β-D-吡喃葡萄糖基-（1→2）-β-D-吡喃葡萄糖基-（1→4）-β-D-吡喃半乳糖苷（2）、海柯皂苷元-3-O-{β-D-吡喃葡萄糖基-（1→2）-[β-D-吡喃木糖基-（1→3）]-β-D-吡喃葡萄糖基-（1→4）-β-D-吡喃半乳糖苷}（3）、26-O-β-D-吡喃葡萄糖基-（25R）-5α-呋甾-12-羰基-20（22）-烯-3β,26-二醇-3-O-β-D-吡喃葡萄糖基-（1→4）-β-D-吡喃半乳糖苷（4）。结论化合物1和2为首次从该属植物中分离得到,化合物4为首次得到的25位R构型的甾体皂苷类单体化合物。     

In vitro antifungal activity of a novel lipopeptide antifungal agent, FK463, against various fungal pathogens

The antifungal activities of FK463 against various pathogenic fungi were tested by standard broth microdilution methods, and compared with the activities of five currently available antifungal agents; viz., fluconazole (FLCZ), itraconazole, miconazole, amphotericin B and flucytosine. Fourteen clinical isolates of Candida albicans categorized as FLCZ susceptible, FLCZ susceptible-dose dependent and FLCZ resistant were similarly susceptible to FK463 with geometric (GM) MIC values of 0.010, 0.011 and 0.015 microg/ml, respectively. All of 17 clinical isolates of Aspergillus fumigatus were inhibited by FK463 at 0.0078 microg/ml or lower concentrations. The antifungal activity of FK463 against a wider range of medically important yeasts and filamentous fungi were studied using stock fungal strains. While Cryptococcus, Trichosporon, Fusarium, Pseudallescheria and Alternaria species or zygomycetes were scarcely or not inhibited by 16 microg/ml of FK463, two Candida species (C. albicans, C. glabrata), as well as all species of Aspergillus, Paecilomyces and Penicillium, were highly susceptible with GM-MICs of < or = 0.008 microg/ml. The other fungal species including several non-albicans Candida were less susceptible with GM-MICs ranging between 0.016 and 2 microg/ml. MICs of the reference drugs were within the range thus previously reported. These results suggest that FK463 be of use in the treatment of serious fungal infections.     

HPLC测定刺蒺藜总皂苷中的薯蓣皂苷元

目的测定刺蒺藜总皂苷水解后薯蓣皂苷元的含量。方法采用ELSD-HPLC法,并考察其方法学。结果薯蓣皂苷元39.68~942μg.ml-1与峰面积的线性关系良好,方法具有较好的精密度、稳定性、重复性和较高的回收率。结论所建方法准确、简便、易行,可作为刺蒺藜总皂苷的质量控制指标。     

Cispentacin, a new antifungal antibiotic. II. In vitro and in vivo antifungal activities

Cispentacin [-)-(1R,2S)-2-aminocyclopentane-1-carboxylic acid) is a new antifungal antibiotic possessing potent anti-Candida activity. The 50% inhibitory concentration (IC50) and IC100 values of cispentacin against clinical isolates of Candida albicans were in the ranges 6.3 approximately 12.5 and 6.3 approximately 50 micrograms/ml, respectively, by turbidimetric measurement in yeast nitrogen base glucose medium. No significant activity was seen against any yeasts and molds when tested by the agar dilution method using three different agar media: KNOPP's agar, yeast extract-glucose-peptone agar and Sabouraud dextrose agar. This antibiotic demonstrated good therapeutic efficacy against a systemic Candida infection in mice by both parenteral and po administrations. The 50% protection dose (PD50) values after single iv and po administrations were 10 and 30 mg/kg, respectively. It was also effective in a systemic infection with Cryptococcus neoformans and in both lung and vaginal infections with C. albicans in mice. Cispentacin did not induce acute lethal toxicity at 1,000 mg/kg by iv injection and 1,500 mg/kg by ip and po administrations in mice.     

In vivo and in vitro antifungal activity of fluconazole

We examined in vivo efficacy and in vitro activity of fluconazole, a novel triazole antifungal agent, and obtained results which are summarized as follows: 1. Fluconazole showed a higher serum concentration than ketoconazole after oral administration to mice. The 50% effective dose of fluconazole administered orally to mice was similar to that of fluconazole injected to mice intraperitoneally in a systemic candidiasis model. 2. Prophylactic effects of fluconazole were excellent against systemic candidiasis, cryptococcosis and aspergillosis in mice in comparison with those of ketoconazole and miconazole. 3. The multiple administration of fluconazole effectively decreased the number of viable cells of Candida albicans colonized in kidneys of mice when the serum level of fluconazole was kept to exceed its IC99 values against the inoculated pathogen. Thus, a good correlation between the in vitro activity of fluconazole and its in vivo efficacy was confirmed. In vivo efficacies of ketoconazole and miconazole, however, failed to reflect their marked in vitro activities. 4. C. albicans No. 32 developed no drug-resistance to fluconazole during transfers in medium containing fluonazole at a concentration of 1 micrograms/ml.     

In vitro antifungal activities of amorolfine against fresh isolates from patients with cutaneous mycosis

In vitro antifungal activities of amorolfine (MT-861), a new morpholine antifungal agent, were examined using an agar-dilution method, in comparison with those of 2 other antifungal agents, clotrimazole (CTZ) and bifonazole (BFZ), against 182 clinical isolates of Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum canis, and Epidermophyton floccosum, which had been freshly isolated from a total of 182 cutaneous mycotic patients with various types of dermatophytes or cutaneous candidiasis. Antifungal activities of the 3 drugs against T. rubrum were in the order of MT-861 greater than CTZ greater than BFZ, with the lowest average MIC values (0.0070 micrograms/ml) obtained with MT-861. The average MIC value of MT-861 for clinical isolates from patients with pedis was roughly 2.3-fold higher than that for those from patients with tinea corporis. Out of 3 drugs tested MT-861 exhibited the most potent activities against clinical isolates of T. mentagrophytes, M. canis, and E. floccosum with average MIC values of 0.0267, 0.0079, and 0.0018 micrograms/ml, respectively. MIC values of MT-861 against isolates of Candida albicans ranged from 0.01 to 10 micrograms/ml, and the average value (0.1762 micrograms/ml) was the lowest of the 3 drugs.     

In vitro activity of sulphimidazole alone and in association with trimethoprim against enteric pathogens.

Sulphimidazole is a new sulphonamide belonging to the class of intestinal sulphonamides and characterized by the fact that it is active even in vitro. It has the heterocyclic ring of 5-nitroimidazoles on amidic nitrogen. Its antibacterial activity is similar to that of the classical sulphonamides but differs in that it also combats certain anaerobic bacteria such as Clostridium botulinum. This effect is completely absent in the case of sulphadiazine and sulphamethoxazole. Also, since p-amino-benzene-sulphonamide is present in the molecule, the drug acts in synergism with trimethoprim against certain aerobic or facultative strains of enteric pathogens.     

In vitro and in vivo antitumor activity of YoshixolTR against murine L1210 leukemic cells.

In this report, antiproliferative effects of YoshixolTR in vitro and in vivo were investigated in murine L1210 cells. A proliferation of L1210 cells in vitro was inhibited by YoshixolTR in a dose- and time-dependent manner. This inhibition showed an arrest at the G0/G1 stage of the cell cycle, followed by a flow cytometric measurement. YoshixolTR induced apoptosis-like cell death identified by histological observations (scanning electron and transmission electron microscopy), DNA fragmentation, and a smaller increase in lactate dehydrogenase (LDH). In the in vivo experiments, YoshixolTR (5 microl/kg of body weight, on days 1, 3, and 5) was injected intraperitoneally in mice inoculated with L1210 cells. No marked prolongation of survival occurred between the control group and treated group. However, a survival curve in the treated group showed a shift toward a possible longer survival time. Additionally, on the basis of apoptosis-like cell death due to YoshixolTR as indicated above, a possibility of immunotherapy as a tumor vaccine has been examined. A vaccination of rabbit anti-serum, which consisted of components from the L1210 cells killed by YoshixolTR, produced a dramatic improvement of viability in the leukemic mice. In conclusion, YoshixolTR has an anti-leukemic potency with a new biological mechanism and an inductive potency of super-antigens as immunotherapeutic agents against malignant tumors.     

In vitro and in vivo studies with flutrimazole, a new imidazole derivative with antifungal activity.

1-[(2-Fluorophenyl)(4-fluorophenyl)phenylmethyl]-1H-imidazole (flutrimazole, UR-4056, CAS 119006-77-8) is a new topical imidazole antifungal agent which displays potent broad-spectrum in vitro activity against dermatophytes, filamentous fungi and yeasts, saprophytic and pathogenic to animals and humans (MIC = 0.025-5.0 micrograms/ml). In most of these studies the activity of flutrimazole was comparable to that of clotrimazole and markedly higher than that of bifonazole (MIC differences of greater than or equal to 1 order of magnitude). Tested against Scopulariopsis brevicaulis (8 strains), both flutrimazole and clotrimazole exhibited fungistatic and fungicidal activity, and clotrimazole appeared something less active (MIC = 0.3-2.5 micrograms/ml) than flutrimazole (MIC = 0.15-0.6 micrograms/ml). In animal experiments, topical application of 1% and 2% flutrimazole, as a cream or solution, was highly effective in models of rat vaginal candidiasis and guinea-pig trichophytosis, giving a rate of cured or cured plus markedly improved animals higher than 80%. Flutrimazole shares the mode of action of other imidazole or triazole-containing antifungals, i.e. inhibition of fungal lanosterol 14 alpha-demethylase, as it strongly inhibits ergosterol biosynthesis in a cell-free homogenate of Candida albicans, with an IC50 value of 0.071 mumol/l.     

In vitro antibacterial activity of thiamphenicol glycinate acetylcysteinate against respiratory pathogens.

After 30 years of therapeutic use, thiamphenicol glycinate acetylcysteinate (CAS 20192-91-0) is still widely employed in the treatment of upper and lower respiratory tract infections. This is due to its particular characteristic to exert at pulmonary level, either the antibacterial activity of thiamphenicol (CAS 15318-45-3) and the mucolytic activity of N-acetylcysteine (CAS 616-91-1). The aim of this study was to evaluate the present pattern of susceptibility of several clinical isolates to thiamphenicol and the interference of N-acetylcysteine on this parameter. The studies have been performed in vitro. Equimolar concentrations of N-acetylcysteine and even higher concentrations did not interfere with the antibacterial activity of thiamphenicol against Streptococcus pneumoniae, Streptococcus pyogenes and Haemophilus influenzae. The spectrum of activity of thiamphenicol was similar to that observed in the past and was superior to that of erythromycin and amoxicillin. The activity of thiamphenicol was greater than that of erythromycin against H. influenzae and streptococci and equivalent versus Branhamella catarrhalis. In comparison with amoxicillin the activity of thiamphenicol was higher against H. influenzae and B. catarrhalis and slightly lower against streptococci. The results demonstrate that thiamphenicol maintains its therapeutic value confirming the importance of thiamphenicol glycinate acetylcysteinate in the treatment of respiratory tract infections.     

In vitro inhibitory activities of essential oils from two KoreanThymus species against antibiotic-resistant pathogens

The in vitro inhibitory activities of essential oils from Thymus magnus and T. quinquecostatus as well as their main constituents were evaluated against susceptible and resistant species of Streptococcus pneumoniae, Staphylococcus aureus, Salmonella enteritidis, and Salmonella typhimurium. Notably, the essential oil fraction of T. magnus and its main components displayed significant inhibitory action against both antibiotic-susceptible and resistant strains of S. pneumoniae, S. aureus, and S. typhimurium with minimum inhibitory concentrations (MICs) ranging from 0.125 to 8 mg/mL. The differential MIC values imply that the oil fraction and its main components exhibit distinct patterns of activity against the tested bacterial species. Moreover, the disk diffusion test revealed that the inhibitory activities of oil fraction and components were dose-dependent. Data from the checkerboard titer test confirmed synergism between the antibiotic, norfloxacin, and T. magnus oil or thymol, particularly against the resistant strains of S. aureus.     

FR209602 and related compounds, novel antifungal lipopeptides from coleophoma crateriformis no. 738. II. In vitro and in vivo antifungal activity

The biological activities of the novel echinocandin-like lipopeptides, FR209602, FR209603 and FR209604, were evaluated. These compounds showed antifungal activity against Candida albicans and Aspergillus fumigatus attributed to inhibition of 1,3-beta-glucan synthesis. The minimum effective concentrations of these compounds against C. albicans and A1. fumigatus ranged from 0.02 to 0.04 microg/ml by microbroth dilution assay, and the IC50 values on C. albicans 1,3-beta-glucan synthase were 0.49, 0.64 and 0.72 microg/ml, respectively. FR209602 and FR209603 showed good efficacy by subcutaneous injection against C. albicans in a murine systemic infection model, with ED50 values of 2.0 and 1.9 mg/kg, respectively.     

In vitro and in vivo activities of clarithromycin against the Mycobacterium avium complex

Clarithromycin (CAM) was assessed for in vitro antimicrobial activity against various mycobacterial species. Except for Mycobacterium tuberculosis, CAM displayed MICs for test mycobacteria comparable to those of sparfloxacin (SPFX) but lower than those of rifampicin (RMP) and ofloxacin (OFLX). CAM at 0.25 mug/ml (1 MIC) exhibited bactericidal action against M. intracellulare growing in 7H9 medium and at 1 or 10 mug/ml (4 and 40 MIC, respectively) CAM displayed antimicrobial activity against the organism phagocytosed in murine macrophages, while RMP failed to manifest such an effect. When CAM was given s.c. or by gavage to mice infected i.v. with M. intracellulare at doses of 0.2 to 2 mg/mouse once daily, six times per week, it exhibited significant therapeutic efficacy in terms of decreased incidence of gross lung lesions and reduced bacterial loads in the lungs and spleen.     

Water-soluble pleuromutilin derivative with excellent in vitro and in vivo antibacterial activity against gram-positive pathogens

Although earlier pleuromutilin analogues showed potent in vitro antibacterial activity against some Gram-positive pathogens, their in vivo efficacy was low because of insufficient pharmacokinetic properties. We designed novel thioether pleuromutilin derivatives having a purine ring as a polar and water solubilizing group and identified a promising pleuromutilin analogue 6 with good solubility in water ( approximately 50 mg/mL). Compound 6 exhibited excellent in vitro and in vivo antibacterial activity against some Gram-positive strains, including drug-resistant pathogens.     

In vitro and in vivo antimicrobial activities of cefmetazole against Bacteroides fragilis

Cefmetazole was investigated on stability to beta-lactamases produced by Bacteroides fragilis and on therapeutic effects in mice infected with B. fragilis. 1. Cefmetazole, like other cephamycins, was found extremely stable to beta-lactamases obtained from B. fragilis. 2. Cefmetazole showed good antimicrobial activities to 50 strains of B. fragilis and extremely high stability to their beta-lactamases. 3. Cefmetazole showed an excellent protecting effect to infections due to beta-lactamase producing B. fragilis. 4. Cefmetazole exhibited an excellent chemotherapeutic effect against polymicrobial infections in mice due to E. coli (beta-lactamase -)and B. fragilis (beta-lactamase +).     

In vitro antifungal susceptibilities of Candida albicans and other fungal pathogens to polygodial, a sesquiterpene dialdehyde

In vitro antifungal activities of polygodial were investigated against several fungal pathogens. Polygodial showed strong antifungal activity, comparable to amphotericin B, against yeast-like fungi Candida albicans, C. utilis, C. krusei, Cryptococcus neoformans, Saccharomyces cerevisiae and also filamentous fungi including Trichophyton mentagrophytes, T. ruburum, and Penicillium marneffei. Other strains such as Aspergillus fumigatus, A. flavus, P. chrysogenum, C. lipolytica, and C. tropicalis showed moderate to low susceptibility to polygodial. The anti-fungal activity of polygodial was generally not reduced by several susceptibility-testing conditions such as medium, incubation temperature, inoculum size, and medium pH. However, polygodial's antifungal activity was strongly increased at acidic conditions. Unlike amphotericin B, polygodial did not show any hemolytic activity and also its antifungal activity was not diminished in the presence of ergosterol. Based on killing kinetics against growing and nongrowing C. albicans, polygodial showed strong and rapid fungicidal activity.