Purine Analogues as Amplifiers of Phleomycin. V. Thioethers of Several Heterocyclic Systems with One or Two Rings

1979 ◽  
Vol 32 (12) ◽  
pp. 2713 ◽  
Author(s):  
DJ Brown ◽  
GW Grigg ◽  
Y Iwai ◽  
KN McAndrew ◽  
T Nagamatsu ◽  
...  

Thioethers, appropriate for testing as amplifiers of phleomycin against in vitro cultures of Escherichia coli, are prepared via corresponding thiones in the purine, imidazo[4,5-b(and 4,5-c)]pyridine, pyrazolo[3,4-d]pyrimidine, quinazoline, benzothiazole, benzoxazole, pyrimidine, imidazole, thiazoline, 1,2,4-triazole, s-triazolo[4,3-c(and 1,5-c)]pyrimidine, oxazolo[4,5-b]pyridine, quinoline and 1,3,5-triazine series. Structures are confirmed by N.M.R. spectra. Biological activities are tabulated and discussed in terms of structure.

1979 ◽  
Vol 32 (12) ◽  
pp. 2727 ◽  
Author(s):  
DJ Brown ◽  
Y Iwai

The metabolisms of four 14C-tagged amplifiers of phleomycin are followed in mice. 2-(Benzothiazol- 2'-ylthio)acetamide (1c) gives mainly the corresponding acid (1e) in the urine; 2-(benzoxazol-2'- ylthio)acetamide (1d) likewise gives the acid (1f); N-methyl-2-(s-triazolo[4,3-a]pyrimidin- 3'-ylthio)propionamide (2b) gives unchanged material (c. 20%) plus not the corresponding acid (2c), but its [1,5-a] isomer (3c) in 60% yield; and 2-(5',7'-diethyl-s-triazolo[4,3- a]pyrimidin-3'-ylthio)-acetamide (2i) proves much more stable by giving mainly unchanged material (>60%). Minor metabolites are formed in each case. ��� Syntheses and N.M.R. spectra of the above substrates and related derivatives are reported as well as their activities as amplifiers of phleomycin against in vitro cultures of Escherichia coli.


1980 ◽  
Vol 33 (10) ◽  
pp. 2291 ◽  
Author(s):  
DJ Brown ◽  
WB Cowden ◽  
GW Grigg ◽  
D Kavulak

Syntheses are reported for some simple derivatives of 2-(pyridin-2'- yl)pyrimidine; 4-(pyrazol-1'- yl)pyrimidine; 4-(pyrazol-4'- yl)pyrimidine; 4,5'-bithiazole; 2-, 3-, and 4-(thiazol-4'-yl)pyridine and 2-, 3-, and 4-(thiazol-2'-yl)pyridine. Biological activities, as amplifiers of phleomycin against in vitro cultures of Escherichia coli, are tabulated and discussed.


1978 ◽  
Vol 31 (2) ◽  
pp. 447 ◽  
Author(s):  
DJ Brown ◽  
WC Dunlap ◽  
GW Grigg ◽  
L Danckwerts

Some 2-methylthio and 2-carbamoylalkylthio derivatives of 1-methylimidazole, benzimidazole, benzoxazole, benzothiazole and 6-dimethylaminobenzothiazole have been synthesized by alkylation of the corresponding thiones. Their in vitro activities, as amplifiers of phleomycin against Escherichia coli, varied from slight to high but none was outstanding. 2-(Benzothiazol-2'-ylthio)acetamide (2j)showed maximal activity at c. 0.04 mM with progressive decreases at both higher and lower concentrations.


1998 ◽  
Vol 42 (5) ◽  
pp. 1015-1021 ◽  
Author(s):  
Teruo Kirikae ◽  
Fumiko Kirikae ◽  
Shinji Saito ◽  
Kaoru Tominaga ◽  
Hirohi Tamura ◽  
...  

ABSTRACT The supernatants taken from Pseudomonas aeruginosa andEscherichia coli cultures in human sera or chemically defined M9 medium in the presence of ceftazidime (CAZ) contained high levels of endotoxin, while those taken from the same cultures in the presence of imipenem (IPM) yielded a very low level of endotoxin. The biological activities of endotoxin in the supernatants were compared with those of phenol water-extracted lipopolysaccharide (LPS). The endotoxin released from the organisms as a result of CAZ treatment (CAZ-released endotoxin) contained a large amount of protein. The protein, however, lacked endotoxic activity, since the endotoxin did not show any in vivo toxic effects in LPS-hyporesponsive C3H/HeJ mice sensitized with d-(+)-galactosamine (GalN) or any activation of C3H/HeJ mouse macrophages in vitro. The activities of CAZ- and IPM-released endotoxin (as assessed by a chromogenicLimulus test) were fundamentally the same as those ofP. aeruginosa LPS, since their regression lines were parallel. The CAZ-released endotoxin was similar to purified LPS with respect to the following biological activities in LPS-responsive C3H/HeN mice and LPS-hyporesponsive C3H/HeJ mice: lethal toxicity in GalN-sensitized mice, in vitro induction of tumor necrosis factor- and NO production by macrophages, and mitogen-activated protein kinase activation in macrophages. The macrophage activation by CAZ-released endotoxin as well as LPS was mainly dependent on the presence of serum factor and CD14 antigen. Polymyxin B blocked the activity. These findings indicate that the endotoxic activity of CAZ-released endotoxin is due primarily to LPS (lipid A).


2015 ◽  
Vol 10 (6) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Prabodh Satyal ◽  
Bhuwan K. Chhetri ◽  
Noura S. Dosoky ◽  
Ambika Poudel ◽  
William N. Setzer

The essential oil from the dried rhizome of Nardostachys grandiflora, collected from Jaljale, Nepal, was obtained in 1.4% yield, and a total of 72 compounds were identified constituting 93.8% of the essential oil. The rhizome essential oil of N. grandiflora was mostly composed of calarene (9.4%), valerena-4,7(11)-diene (7.1%), nardol A (6.0%), 1(10)-aristolen-9-ol (11.6%), jatamansone (7.9%), valeranal (5.6%), and cis-valerinic acid (5.7%). The chemical composition of N. grandiflora rhizome oil from Nepal is qualitatively very different than those from Indian, Chinese, and Pakistani Nardostachys essential oils. In this study we have evaluated the chemical composition and biological activities of N. grandiflora from Nepal. Additionally, 1(10)-aristolen-9-ol was isolated and the structure determined by NMR, and represents the first report of this compound from N. grandiflora. N. grandiflora rhizome oil showed in-vitro antimicrobial activity against Bacillus cereus, Escherichia coli, and Candida albicans (MIC = 156 μg/mL), as well as in-vitro cytotoxic activity on MCF-7 cells.


Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5010
Author(s):  
Giulio Petronio Petronio ◽  
Marco Alfio Cutuli ◽  
Irene Magnifico ◽  
Noemi Venditti ◽  
Laura Pietrangelo ◽  
...  

Berberine is an alkaloid of the protoberberine type used in traditional oriental medicine. Its biological activities include documented antibacterial properties against a wide variety of microorganisms; nonetheless, its use against Escherichia coli strains isolated from urinary infections has not yet been widely investigated in vivo. The emergence of antimicrobial resistance requires new therapeutic approaches to ensure the continued effectiveness of antibiotics for the treatment and prevention of urinary infections. Moreover, uropathogenic Escherichia coli (UPEC) has developed several virulence factors and resistance to routine antibiotic therapy. To this end, several in vitro and in vivo tests were conducted to assess the activity of berberine on uropathogenic E. coli strains. Galleria mellonella as an infection model was employed to confirm the in vivo translatability of in vitro data on berberine activity and its influence on adhesion and invasion proprieties of E. coli on human bladder cells. In vitro pre-treatment with berberine was able to decrease the adhesive and invasive UPEC ability. In vivo treatment increased the larvae survival infected with UPEC strains and reduced the number of circulating pathogens in larvae hemolymph. These preliminary findings demonstrated the efficacy and reliability of G. mellonella as in vivo model for pre-clinical studies of natural substances.


Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 698
Author(s):  
Han Yong Park ◽  
Kyung-Su Kim ◽  
Gunes Ak ◽  
Gokhan Zengin ◽  
Zoltán Cziáky ◽  
...  

This study aimed to establish a rapid in vitro plant regeneration method from rhizome buds of Kaempferia parviflora to obtain the valuable secondary metabolites with antioxidant and enzyme inhibition properties. The disinfection effect of silver oxide nanoparticles (AgO NPs) on rhizome and effects of plant growth regulators on shoot multiplication and subsequent rooting were investigated. Surface sterilization of rhizome buds with sodium hypochlorite was insufficient to control contamination. However, immersing rhizome buds in 100 mg L−1 AgO NPs for 60 min eliminated contamination without affecting the survival of explants. The number of shoots (12.2) produced per rhizome bud was higher in Murashige and Skoog (MS) medium containing 8 µM of 6-Benzyladenine (6-BA) and 0.5 µM of Thidiazuron (TDZ) than other treatments. The highest number of roots (24), with a mean root length of 7.8 cm and the maximum shoot length (9.8 cm), were obtained on medium MS with 2 µM of Indole-3-butyric acid (IBA). A survival rate of 98% was attained when plantlets of K. parviflora were acclimatized in a growth room. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) was used to determine the chemical profile of K. parviflora leaf extracts. Results showed that several biologically active flavonoids reported in rhizomes were also present in leaf tissues of both in vitro cultured and ex vitro (greenhouse-grown) plantlets of K. parviflora. We found 40 and 36 compounds in in vitro cultured and ex vitro grown leaf samples, respectively. Greenhouse leaves exhibited more potent antioxidant activities than leaves from in vitro cultures. A higher acetylcholinesterase inhibitory ability was obtained for greenhouse leaves (1.07 mg/mL). However, leaves from in vitro cultures exhibited stronger butyrylcholinesterase inhibitory abilities. These results suggest that leaves of K. parviflora, as major byproducts of black ginger cultivation, could be used as valuable alternative sources for extracting bioactive compounds.


Author(s):  
Jinyan Yun ◽  
Liao Wei ◽  
Wei Li ◽  
Duqiang Gong ◽  
Hongyu Qin ◽  
...  

Lignin from different biomasses possess biological antioxidation and antimicrobial activities, which depend on the number of functional groups and the molecular weight of lignin. In this work, organosolv fractionation was carried out to prepare the lignin fraction with a suitable structure to tailor excellent biological activities. Gel permeation chromatography (GPC) analysis showed that decreased molecular weight lignin fractions were obtained by sequentially organosolv fractionation with anhydrous acetone, 50% acetone and 37.5% hexanes. Nuclear magnetic resonance (NMR) results indicated that the lignin fractions with lower molecular weight had fewer substructures and a higher phenolic hydroxyl content, which was positively correlated with their antioxidation ability. Both of the original lignin and fractionated lignins possessed the ability to inhibit the growth of Gram-negative bacteria (Escherichia coli and Salmonella) and Gram-positive bacteria (Streptococcus and Staphylococcus aureus) by destroying the cell wall of bacteria in vitro, in which the lignin fraction with the lowest molecular weight and highest phenolic hydroxyl content (L3) showed the best performance. Besides, the L3 lignin showed the ability to ameliorate Escherichia coli-induced diarrhea damages of mice to improve the formation of intestinal contents in vivo. These results imply that a lignin fraction with a tailored structure from bamboo lignin can be used as a novel antimicrobial agent in the biomedical field.


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