The effects of lappaconitine (LA) and N-deacetyllappaconitine (DLA) on footshock-induced analgesia (FSIA) were studied by the rat tail flick test. Rats subjected to 90 s nonescaping footshock had a significant increase in tail flick latency. Naloxone (4 μg, i.c.v.) partially antagonized the FSI...

Analytical high-speed counter-current chromatography (HSCCC) was used for the systematic selection and optimization of the two-phase solvent system to separate alkaloids from Aconitum sinomontanum Nakai. The optimum solvent systems CHCl3–MeOH–0.3 M/0.2 M HCl (4:1.5:2, v/v) thus obtained led to...

Steffimycin interferes with amino acid incorporation mediated by synthetic polyribonucleotides in cell-free bacterial systems. This inhibition is a secondary activity of the antibiotic, which acts primarily as a suppressor of RNA synthesis in bacteria and bacterial cell-free systems. Inhibition ...

The antibiotic steffimycin B binds to double-stranded DNA as evidenced by difference spectroscopy and an increase of the thermal stability of DNA in the presence of the antibiotic. Salmon sperm DNA · steffimycin B complexes show a drastic decrease in template activity for Escherichia coli DNA p...

SummaryThe complexes formed between steffimycins and DNA were studied using various physicochemical techniques. The binding process has been followed spectrophotometrically or fluorimetrically. The binding parameters n and K, evaluated according to McGhee and Von Hippel, show a good affinity of ...

Preliminary findings on the possible important role of the N-3 sugar moiety of coformycin in its tight-binding interaction with adenosine deaminase (ADA) are reported. The compound 3-β-D-Ribofuranosyl-5,6,7,8tetrahydro-4H-imidazo[4,5-d][1,3]diazepin-5-one-8-ol (1), its 3-benzyl analogue (6), an...

1.1. The purified mussel adenosine deaminase (mol. wt: 140,000) was stable in the pH range of 4.0–6.0 at 17°C. The optimum pH was 6.0 for adenosine and 6.5 for deoxyadenosine.2.2. Adenine, 2′- and 5′-AMP, 5′-ADP and 5′-ATP were not deaminated.3.3. The α (Vmax/Km) and β (Vmax) parameters ...

The non-steady state nature of the inhibition of milk xanthine oxidase by allopurinol and alloxanthine was demonstrated, and the kinetic data presented are consistent with the known mechanisms of inhibitions by these inhibitors. With the use of human erythrocytic adenosine deaminase and its tigh...

The inhibition of S-adenosylhomocysteine hydrolase and accumulation of dATP in thymus, spleen and other tissues of mice treated with the adenosine deaminase inhibitor coformycin were studied in parallel with the competence of thymocytes and spleen leucocytes to undergo mitogen-induced transforma...

Adenosine deaminase is a purine salvage enzyme that catalyzes the deamination of adenosine and deoxyadenosine. Deficiency of the enzyme activity is associated with T-cell and B-cell dysfunction. Mutant adenosine deaminase has been isolated from heterozygous and homozygous deficient lymphoblast c...

Coformycin [(R)-3-(β-d-erythropentofuranosyl)-3,6,7,8-tetrahydroimidazo [4,5 d]-[1,3] diazepin-8-(R)-ol] is an inhibitor of adenosine deaminase and thus increases the antiviral potency of a series of adenosine analogues. The influence of chemically synthesized coformycin triphosphate on RNA-pol...

Four carbocyclic analogues of the ribonucleoside coformycin, including the recently isolated natural product 2, have been synthesised in racemic form. The syntheses were achieved in a convergent and direct manner via palladium(0) catalysed coupling between diazepinones 15 and 16 and the allylic ...

The in vitro activity of many pore-forming toxins, in particular, the rate of increase in the membrane conductance induced by the channel-forming domain (P178) of colicin E1 is maximum at an acidic pH. However, after P178 binding at acidic conditions, a subsequent pH shift from 4 to 6 on both si...

The surface properties of colicin E1, a 522-amino acid protein, and its interaction with monolayers of Escherichia coli (E. coli) total lipid and 1,2-Dimyristoyl-sn-Glycero-3-Phosphocholine (DOPC) were studied using the Langmuir–Blodgett (LB) technique. Colicin E1 is amphiphilic, forming a prot...

The feasibility of using colicins to create an antimicrobial lubricant to prevent extraluminal catheter contamination during urinary catheter insertion was assessed. Levels of resistance of uropathogenic Escherichia coli to antibiotics and colicins were compared and it was revealed that antibiot...

Current evidence suggests that the closed-state membrane model for the channel-forming domain of colicin E1 involves eight amphipathic α-helices (helices I–VII and X) that adopt a two-dimensional arrangement on the membrane surface. Two central hydrophobic α-helices in colicin E1 (VIII and IX...

BackgroundOsteoporosis can lead to spontaneous fractures in adults with cerebral palsy (CP). Undercarboxylated osteocalcin (ucOC) is a useful marker for vitamin K insufficiency in osteoporosis. The primary objective of this study was to determine the effect of vitamin K2 on bone mineral density ...

Osteoporosis is accompanied by insufficient osteogenic capacity. Several lines of evidence suggested that solutions to enhance osteoblastogenesis were important strategies for osteoporotic bone defect repair. This study investigated the effect of combined treatment with vitamin K2 and PTH on bon...

2-Hydroxypropyl-β-cyclodextrin (2HP-β-CyD) and 2,6-di-O-methyl-β-cyclodextrin (DIMEB) were tested as solubilizing agents for dihydroergotamine mesylate, with the aim of improving the pharmacotechnical properties of this drug. The pH dependence of the complexation was investigated on the basis...

Migraine is a widespread neurological disease with negative effects on quality of life and productivity. Moderate to severe acute migraine attacks can be treated with dihydroergotamine mesylate (DHE), an ergot derivative that is especially effective in non-responders to triptan derivatives. To o...