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1.
Effect of sulfur dioxide (SO2) on growth and physiological activity in Alnus sieboldiana at Miyakejima Island in Japan 总被引:1,自引:0,他引:1
We used a physiological approach to investigate the effect of sulfur dioxide (SO2) on Alnus sieboldiana Matsum. (A. sieboldiana) and symbiotic Frankia spp. in Miyakejima Island, which was devastated by volcanic action in July of 2000. In April of 2008, three study sites were chosen in the forest of Miyakejima Island, and were categorized as high, medium, or low in relation to their sulfur dioxide concentration (volcanic gas). Nine A. sieboldiana trees were selected from naturally regenerated forest at each site. The higher the SO2 concentration at the study site, the lower was the photosynthetic rate and the maximum photochemical efficiency of PSII (F v/F m) of A. sieboldiana and its apparent quantum yield. The acetylene reduction rate of the Frankia spp. symbiotic with A. sieboldiana was significantly less at the high SO2 concentration (p<0.05). The nitrogen concentration in their leaves remained high, however. There was no significant difference in the chlorophyll concentration (Chl a + b) in leaves from the three sites. The photosynthetic nitrogen use efficiency decreased significantly in sites with a high SO2 concentration, however. As a result, A. sieboldiana regenerated at the sites with high or medium SO2 concentration underwent approximately 50–70 % less growth than at the site with a low SO2 concentration. 相似文献
2.
Photosynthetic rate, transpiration rate and SO2 absorption rate were simultaneously measured under exposure to SO2 (0.1–1.0 μl l ?1) for 5 or 8 hr in six species belonging to C4 or C3 plants (Zea mays, Sorghum vulgare, Amaranthus tricolor, Oryza sativa, Avena sativa andHelianthus annuus). Distinct interspecific differences were found as to the extent of inhibition of photosynthetic rate. Calculation of diffusive resistance to H2O(r) and SO2(r′) showed that the ratio of r′/r was 1.9 irrespective of species and coincided well with the theoretical value based on molecular diffusion. Thus it was made clear that the absorption of SO2 was dependent upon the gas exchange capacity of leaf blade. Using the ratio of r′/r the rate of SO2 absorption could be calculated from transpiration rate and was compared with the inhibition rate of photosynthesis. In three C4 species, the inhibition of photosynthesis increased linearly with the amount of SO2 absorbed during a 5-hour period. The pattern of inhibition of photosynthesis inA. sativa andH. annuus among C3 species was similar to that of C4 species until the amount of SO2 absorbed reached 60 mg-SO2 m?2 above which the inhibition abruptly increased. The inhibition of photosynthesis inO. sativa was exceptionally severe even with only a small amount of SO2 absorbed. 相似文献
3.
Synthesis and antimycobacterial activity of 4-(5-substituted-1,3,4-oxadiazol-2-yl)pyridines 总被引:1,自引:0,他引:1
Navarrete-Vázquez G Molina-Salinas GM Duarte-Fajardo ZV Vargas-Villarreal J Estrada-Soto S González-Salazar F Hernández-Núñez E Said-Fernández S 《Bioorganic & medicinal chemistry》2007,15(16):5502-5508
4-(5-Substituted-1,3,4-oxadiazol-2-yl)pyridine derivatives 1-12 were synthesized and evaluated for their in vitro antimycobacterial activity. Some compounds showed an interesting activity against Mycobacterium tuberculosis H(37)Rv and five clinical isolates (drug-sensitive and -resistant strains). Compound 4 [4-(5-pentadecyl-1,3,4-oxadiazol-2-yl)pyridine] was 10 times more active than isoniazid, 20 times more active than streptomycin, and 28 times more potent than ethambutol against drug-resistant strain CIBIN 112. Compound 5 [4-(5-heptadecyl-1,3,4-oxadiazol-2-yl)pyridine] showed the same behavior as compound 4. Both of the above structures bear a high lipophilic chain bonded to the 5-position of the oxadiazole moiety. This fact implies that there exists a contribution of lipophilicity, which could facilitate the entrance of these molecules through lipid-enriched bacterial cell membrane. 相似文献
4.
Kenichiro Nagai Nobuhiro Koyama Noriko Sato Chisato Yanagisawa Hiroshi Tomoda 《Bioorganic & medicinal chemistry letters》2012,22(24):7739-7741
Synthesis of calpinactam 1, a fungal antimycobacterial metabolite, utilizing solid-phase peptide synthesis is described. To explore the structure–activity relationships of 1, its derivatives with different amino acids were also synthesized on the basis of the same synthetic strategy. These derivatives were examined for antimycobacterial activity against Mycobacterium smegmatis. Among them, only peptide 6d having d-Ala in place of d-Glu showed moderate activity. 相似文献
5.
Raja VP Perumal S Yogeeswari P Sriram D 《Bioorganic & medicinal chemistry letters》2011,21(13):3881-3884
A series of 35 2e,3e,6e-triaryltetrahydro-4(1H)-pyridinones, 2e,3e,5e,6e-tetraaryltetrahydro-4(1H)-pyridinones and their N-nitroso and N-cyano analogs have been prepared. All these 35 compounds obtained were screened for their in vitro activity against Mycobacterium tuberculosis H37Rv (MTB). Among them, the N-nitrosopyridinones are found to be more active against MTB than the corresponding N-CN analogs, which, in turn, were slightly more active than NH analogs. In particular, the N-nitroso compounds, 3d, 4b and 4e with halogen-bearing phenyl rings at 2,6-positions showed maximum activity with MIC values of 3.97, 3.11 and 3.11 μM, being more efficacious than the first line anti-TB drugs, ciprofloxacin, ethambutol and pyrazinamide. A general trend has also been discerned in all the three classes of NH, N-CN and N-NO compounds, in each of which those bearing four aryl rings display higher activity than that having three analogously substituted aryl rings disclosing that lipophilicity could be an important factor underlying antimycobacterial activity. 相似文献
6.
Cocco MT Congiu C Onnis V Pellerano ML De Logu A 《Bioorganic & medicinal chemistry》2002,10(3):501-506
A new series of S-alkylisothiosemicarbazones of 3- and 4-pyridincarboxaldehyde and 4-fluoro- and 4-trifluoromethylbenzaldehyde was synthesized and evaluated for biological activity against various Mycobacterium strains. Inhibitory activity against Mycobacterium tuberculosis H37Rv ATCC 27294 and INH-R ATCC 35822 was compared with activity against clinical isolated Mycobacteria as well as against MOTT. Some of newly prepared compounds showed best inhibitory values against clinical isolated Mycobacteria, besides to low citotoxicity values. 相似文献
7.
Akgün H Karamelekoğlu I Berk B Kurnaz I Sarıbıyık G Oktem S Kocagöz T 《Bioorganic & medicinal chemistry》2012,20(13):4149-4154
Structurally modified phthalimide derivatives were prepared through condensation of phthalic and tetrafluorophthalic anhydride with selected sulfonamides with variable yields. All compounds were screened for their antimycobacterium activity against Mycobacterium tuberculosis H37Ra (ATCC 25177) using a micro broth dilution technique. The fluorinated derivatives (compounds 2c, 2d, 2f and 2h) had antimycobacterium activity comparable with classical sulfonamide drugs. The minimum inhibitory concentration (MIC) of compounds 2c, 2d, 2f and 2h was greater than that of isoniazid (MIC<0.02 μg/mL) and in vitro activity was greater than that of pyrazinamide, another first line antimycobacterium drug (MIC 50-100 μg/mL). The new compounds could be considered new lead compounds in the treatment of multi-drug resistant tuberculosis. 相似文献
8.
9.
《Bioorganic & medicinal chemistry letters》2014,24(1):165-167
A series of six new amidoalcohols was designed and synthesized on the base of the camphor scaffold. Natural amino acids were transformed into their α-hydroxy analogues with retention of configuration, and attached to isobornylamine. The compounds were evaluated for their in vitro activity against Mycobacterium tuberculosis H37Rv. Some of the new compounds show 25 times higher activity than the classical anti-TB drug ethambutol. The activity shifts from micromolar to nanomolar inhibitory concentrations depending on the α-hydroxy acid moiety. Two of the most potent compounds exert low level of cytotoxic activity. These camphane-based amido-alcohols present promising potential lead compounds for further elaboration of antimycobacterial agents. 相似文献
10.
Synthesis and antimycobacterial activity of new quinoxaline-2-carboxamide 1,4-di-N-oxide derivatives 总被引:1,自引:0,他引:1
As a continuation of our research and with the aim of obtaining new antituberculosis agents which can improve the current chemotherapeutic antituberculosis treatments, new series of quinoxaline-2-carboxamide 1,4-di-N-oxide derivatives were synthesized and evaluated for in vitro antituberculosis activity against Mycobacterium tuberculosis strain H(37)Rv, using the radiometric BACTEC 460-TB methodology. Active compounds were also screened by serial dilution to assess toxicity to a VERO cell line. The results indicate that some compounds exhibited a good antituberculosis activity and the arylcarboxamide analogues 3, 8, and 9 were the most active compounds (EC(90)/MIC1). Also, the cytotoxic effects indicate that these compounds have a good Selectivity Index (SI). 相似文献
11.
Foroumadi A Kargar Z Sakhteman A Sharifzadeh Z Feyzmohammadi R Kazemi M Shafiee A 《Bioorganic & medicinal chemistry letters》2006,16(5):1164-1167
Two series of 2- and 3-[5-(nitroaryl)-1,3,4-thiadiazol-2-ylthio, sulfinyl and sulfonyl] propionic acid alkyl esters were synthesized and screened for antituberculosis activity against Mycobacterium tuberculosis H37Rv using the BACTEC 460 radiometric system. The MIC values for the compounds showing more than 90% inhibition were determined. The result of comparison between two groups of data exhibited that among the synthesized derivatives, the compound propyl 3-[5-(5-nitrothiophen-2-yl)-1,3,4-thiadiazol-2-ylthio]propionate was the most active one (MIC=1.56 microgml(-1)). 相似文献
12.
A number of 6-(2-furyl)-9-(p-methoxybenzyl)purines carrying a variety of substituents in the 2- or 8-position have been synthesized and their ability to inhibit growth of Mycobacterium tuberculosis in vitro has been determined. It is demonstrated that sterical hindrance in the purine 8-position reduces activity and that C-8 should be unsubstituted. In the purine 2-position small, hydrophobic substituents are beneficial. The electronic properties of the 2-substituents appear to have only a minor influence on bioactivity. The compounds studied exhibit low toxicity toward mammalian cells (VERO cells) and are essentially inactive toward Staphylococcus aureus and Escherichia coli. The most active and selective antimycobacterial in the series detected to date is the novel 2-methyl-6-furyl-9-(p-methoxybenzyl)purine with MIC=0.20 microg/mL against M. tuberculosis and IC(50) against VERO cells >62.5 microg/mL. Also the novel 2-fluoro analog and the previously known 2-chloro compound, both with MIC=0.39 microg/mL, are highly interesting drug candidates. 相似文献
13.
Katiyar D Tiwari VK Tripathi RP Srivastava A Chaturvedi V Srivastava R Srivastava BS 《Bioorganic & medicinal chemistry》2003,11(20):4369-4375
A series of 3,5-disubstituted thiadiazine thiones (4-24) have been synthesized by reaction of primary amines with carbon disulphide followed by cyclocondensation of the resulting intermediate with formaldehyde and primary amines or amino acids. The compounds were screened for antitubercular activity in vitro against Mycobacterium tuberculosis H37Rv. Three compounds 4, 12 and 18 showed antimycobacterial activity with MIC 12.5 microg/mL. Compound 4, was tested in vitro against five multidrug resistant (MDR) strains of M. tuberculosis and was found to be active. Compound 4 also exhibited activity in vivo. While all the mice died in the untreated group, the mean survival time (MST) of the compound treated mice was enhanced, 33% mice were surviving in treated group and the load of bacilli in the lung was considerably less in the compound treated group than in the untreated control group. 相似文献
14.
Hess S Akermann MA Wnendt S Zwingenberger K Eger K 《Bioorganic & medicinal chemistry》2001,9(5):1279-1291
A series of new water-soluble thalidomide prodrugs was prepared. All compounds were derivatized on the nitrogen of the glutarimide ring. Esters of natural amino acids and succinic acid derivatives have been introduced by reaction with the hydroxymethyl thalidomide 2. Nicotinic acid derivatives were prepared from halomethyl derivatives. Additionally, a methoxymethyl derivative and a carboxymethyl derivative were prepared directly from thalidomide. Most compounds showed a very large increase in water solubility compared to thalidomide itself (0.012mg/mL). The amorphous hydrochlorides of the N-methylalanine ester 8, valine ester 9, and glycylglycine ester 10, respectively, were the most soluble compounds showing solubility greater than 300mg/mL, which equals an increase greater than 15,000-fold. The lipophilicity of the prodrugs has been determined by their HPLC capacity factors k'. The stability of selected compounds was determined. The hydrolysis rates follow pseudo-first order kinetics. In order to assess the immunological activity, the prodrugs were tested using tumor necrosis factor-alpha and interleukin-2 inhibition assays. Selected compounds were additionally investigated on their abililty to inhibit the local Shwartzman reaction, an assay to determine the vascular permeability. The prodrugs retained high effectiveness in the inhibition of TNF-alpha release. Our results indicated that the more stable prodrugs exhibited higher activity in the immunological assays. Some compounds showed higher activity than thalidomide itself, suggesting a high affine binding to the pharmacophore. In conclusion, the prodrugs exhibited high water solubility and high activity and might therefore be used in therapeutic applications. 相似文献
15.
Razafimahefa D Ralambomanana DA Hammouche L Pélinski L Lauvagie S Bebear C Brocard J Maugein J 《Bioorganic & medicinal chemistry letters》2005,15(9):2301-2303
A new series of ferrocenyl diamino alcohols and diamines were synthesized and their inhibitory potencies were probed with Mycobacterium tuberculosis. Interestingly, ferrocenyl diamines 6a and b display significant activities against M. tuberculosis H37Rv. 相似文献
16.
Sbardella G Mai A Artico M Loddo R Setzu MG La Colla P 《Bioorganic & medicinal chemistry letters》2004,14(6):1537-1541
Pursuing our search program for new antitubercular drugs we decided to explore the potentiality of oxazolidinone moiety by synthesizing novel 3-(1H-pyrrol-1-yl)-2-oxazolidinone analogues of PNU-100480. The new derivatives were tested against atypical mycobacteria as well as against drug resistant Mycobacterium tuberculosis and some of them exhibited a fairly good activity against Mycobacterium avium complex (MAC). 相似文献
17.
A series of 7-O-alkoxy-4-methylumbelliferone derivatives were prepared using a convenient one step synthesis. Additionally the bromo- and azido derivatives 7-O-(4-bromobutoxy)-, 7-O-(6-bromohexyloxy)- and 7-O-(6-azidohexyloxy)-4-methylumbelliferone derivatives were prepared. In vitro evaluation of antimycobacterial activity determined % inhibition and MIC vs M. tuberculosis H37Rv with toxicity (IC50) assessed in VERO cells. The coumarins with longer alkyl chains (nonyl and decyl) showed the optimum inhibitory activity in this series (MIC 3.13?μg/mL) and IC50>10?μg/mL. 相似文献
18.
A series of 7-O-alkoxy-4-methylumbelliferone derivatives were prepared using a convenient one step synthesis. Additionally the bromo- and azido derivatives 7-O-(4-bromobutoxy)-, 7-O-(6-bromohexyloxy)- and 7-O-(6-azidohexyloxy)-4-methylumbelliferone derivatives were prepared. In vitro evaluation of antimycobacterial activity determined % inhibition and MIC vs M. tuberculosis H37Rv with toxicity (IC50) assessed in VERO cells. The coumarins with longer alkyl chains (nonyl and decyl) showed the optimum inhibitory activity in this series (MIC 3.13 microg/mL) and IC50 > 10 microg/mL. 相似文献
19.
Marieli O. Rodrigues Jéssica B. Cantos Caroline R. Montes D’Oca Karina L. Soares Tatiane S. Coelho Luciana A. Piovesan Dennis Russowsky Pedro A. da Silva Marcelo G. Montes D’Oca 《Bioorganic & medicinal chemistry》2013,21(22):6910-6914
This work describes the synthesis of a series of fatty acid hydrazide derivatives of isoniazid (INH). The compounds were tested against Mycobacterium tuberculosis H37Rv (ATCC 27294) as well as INH-resistant (ATCC 35822 and 1896 HF) and rifampicin-resistant (ATCC 35338) M. tuberculosis strains. The fatty acid derivatives of INH showed high antimycobacterial potency against the studied strains, which is desirable for a pharmaceutical compound, suggesting that the increased lipophilicity of isoniazid plays an important role in its antimycobacterial activity. 相似文献
20.
Asai A Nagamura S Kobayashi E Gomi K Saito H 《Bioorganic & medicinal chemistry letters》1999,9(20):2995-2998
The water-soluble duocarmycin B1 prodrugs such as glycoside 3, phosphate 4 and carbamate 5 were synthesized for improving biological and pharmaceutical profiles of duocarmycin. Among these prodrugs, N-methylpiperazinylcarbamoyl derivative 5 exhibited potent antitumor activity against several human tumors in vivo. 相似文献