Chemical Composition and Biological Activity of Abies alba and A. koreana Seed and Cone Essential Oils and Characterization of Their Seed Hydrolates

The chemical composition, including the enantiomeric excess of the main terpenes, the antimicrobial and antiradical activities, as well as the cytotoxicity of Abies alba and A. koreana seed and cone essential oils were investigated. Additionally, their seed hydrolates were characterized. In the examined oils and hydrolates, a total of 174 compounds were identified, which comprised 95.6–99.9% of the volatiles. The essential oils were mainly composed of monoterpene hydrocarbons, whereas the composition of the hydrolates, differing from the seed oils of the corresponding fir species, consisted mainly of oxygenated derivatives of sesquiterpenes. The seed and cone essential oils of both firs exhibited DPPH‐radical‐scavenging properties and low antibacterial activity against the bacterial strains tested. Moreover, they evoked only low cytotoxicity towards normal fibroblasts and the two cancer cell lines MCF‐7 and MDA‐MBA‐231. At concentrations up to 50 μg/ml, all essential oils were safe in relation to normal fibroblasts. Although they induced cytotoxicity towards the cancer cells at concentrations slightly lower than those required for the inhibition of fibroblast proliferation, their influence on cancer cells was weak, with IC₅₀ values similar to those observed towards normal fibroblasts.     

Salt-dependent binding of iron(II) mixed-ligand complexes containing 1,10-phenanthroline and dipyrido[3,2-a:2',3'-c]phenazine to calf thymus DNA

The salt-dependent binding of racemic iron(II) mixed-ligand complex containing 1,10-phenanthroline (phen) and dipyrido[3,2-a:2',3'-c]phenazine (dppz), [Fe(phen)2(dppz)]2+ to calf thymus DNA (ct-DNA) has been characterized by UV-VIS spectrophotometric titration. The equilibrium binding constant (Kb) of the iron(II) complex to ct-DNA decreases with the salt concentration in the solution. The slope, SK=(deltalog Kb/deltalog [Na2+]) has been found to be 0.49, suggesting that, in addition to intercalation, considerable electrostatic interaction is also involved in the ct-DNA binding of [Fe(phen)2(dppz)]2+. The calculation of non-electrostatic binding constant (Kt(o)) based on polyelectrolyte theory has revealed that the non-electrostatic contribution to the total binding constant (Kb) increases significantly with the increase in [Na+] and reaches 36% at 0.1 M NaCl. On the other hand, the contribution of the non-electrostatic binding free energy (DeltaGt(o)) to the total binding free energy change (DeltaGo) is considerably large, i.e. 87% at [Na+]=0.1 M, suggesting that the stabilization of the DNA binding is mostly due to the contribution of non-electrostatic process. Moreover, the effect of specific ligand substitutions on DeltaGo has been rigorously evaluated using the quantity DeltaDeltaGt(o), i.e. the difference in DeltaGt(o) relative to that of the parent iron(II) complex, [Fe(phen)3]2+, indicating that each substitution of phen by dip and dppz contributes 7.5 and 17.5 kJ mol(-1), respectively to more favorable ct-DNA binding.     

Synthesis and biological evaluation of menthol-based derivatives as inhibitors of plasminogen activator inhibitor-1 (PAI-1)

Compound 1 was identified by high throughput screening as a novel PAI-1 inhibitor. Optimization of the B and C-segments of 1 resulted in a series of structurally simplified compounds with improved potency. The synthesis and SAR data of these compounds are presented here.     

Structure-activity relationships of substituted benzothiophene-anthranilamide factor Xa inhibitors

Compound 1 was identified by high throughput screening as a novel, potent, non-amidine factor Xa inhibitor with good selectivity against thrombin and trypsin. A series of modifications of the three aromatic groups of 1 was investigated. Substitution of chlorine or bromine for fluorine on the aniline ring led to the discovery of subnanomolar factor Xa inhibitors. Positions on the anthranilic acid ring that can accommodate further substitution were also identified.     

Immobilization of anaerobic bacteria on rubberized-coir for psychrophilic digestion of night soil

Low-ambient temperatures, <30 degrees C, are known to cause drastic reduction in the efficiency of anaerobic biodigesters due to low-growth rate of the constituent bacterial consortium. Immobilization of anaerobic bacteria has been attempted in the biodigester operating at 10 degrees C. Various matrices were screened and evaluated for the immobilization of bacteria in digesters. Anaerobic digestion of night soil was carried out with hydraulic retention time in the range of 9-18 days. Among the tested matrices, rubberized-coir was found to be the most useful at 10 degrees C with optimum hydraulic retention time of 15 days. Optimum amount of coir was found as 25 g/L of the working volume of biodigesters. Immobilization of bacteria on the coir was observed by scanning electron microscopy and fluorescent microscopy. The study indicates that rubberized-coir can be utilized to increase biodegradation of night soil at higher organic loading. Another advantage of using this matrix is that it is renewable and easily available in comparison to other synthetic polymeric matrices.     

Atomic resolution crystal structure of HV‐BBI protease inhibitor from amphibian skin in complex with bovine trypsin

Protease inhibitors of the Bowman‐Birk (BBI) family are commonly found in plants and animals where they play a protective role against invading pathogens. Here, we report an atomic resolution (1Å) crystal structure of a peptide inhibitor isolated from a skin secretion of a Chinese bamboo odorous frog Huia versabilis (HV‐BBI) in complex with trypsin. HV‐BBI shares significant similarities in sequence with a previously described inhibitor from a diskless‐fingered odorous frog Odorrana graham (ORB). However, the latter is characterized by more than a 16,000 fold higher K_i against trypsin than HV‐BBI. Comparative analysis of trypsin cocrystal structures of HV‐BBI and ORB and additionally that of Sunflower Trypsin Inhibitor (SFTI‐1) together with accessory information on the affinities of inhibitor variants allowed us to pinpoint the inhibitor moiety responsible for the observed large difference in activity and also to define the extent of modifications permissible within the common protease‐binding loop scaffold of BBI inhibitors. We suggest that modifications outside of the inhibitory loop permit the evolution of specificity toward different enzymes characterized by trypsin‐like specificity. Proteins 2015; 83:582–589. © 2014 Wiley Periodicals, Inc.     

The wound-healing effect of 7,3′,4′-trimethoxyflavone through increased levels of prostaglandin E<Subscript>2</Subscript> by 15-hydroxyprostaglandin dehydrogenase inhibition

Objective

To find an inhibitor of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) that rapidly metabolises Prostaglandin E₂ (PGE₂) as a mediator of wound healing, we examined seven flavonoids for this role.

Results

7,3′,4′-Trimethoxyflavone (TMF) had the lowest IC₅₀ value of 0.34 µM for 15-PGDH inhibition but >400 µM for cytotoxicity, indicating a high therapeutic index. TMF elevated PGE₂ levels in a concentration-dependent manner in both A549 lung cancer and HaCaT cells. It also significantly increased mRNA expression of multidrug resistance-associated protein 4 (MRP4) and of prostaglandin transporter (PGT) slightly in HaCaT cells. In addition, TMF facilitated in vitro wound healing in a HaCaT scratch model, which was completely inhibited by adding both 15-PGDH and NAD⁺ as cofactor, confirming the involvement of PGE₂ in its wound healing effect.

Conclusion

TMF with a high therapeutic index can facilitate wound healing through PGE₂ elevation by 15-PGDH inhibition.