Evaluation of the Extracts From Rhizomes of Polygonum bistorta for the Median Lethal Dosages in Swiss Albino Mice

Background: Polygonum bistorta has been used as a remedy for jaundice, smallpox, pimples, measles, cholera, diarrhoea, dysentery, expelling worms, insect stings and snakebites. In this study, the crude extract from P. bistorta and two fractions viz. hexane and chloroform obtained from the crude extract were studied for their median Lethal Dosages (LD50) in Swiss albino mice. Methods: Powdered rhizomes of P. bistorta was macerated with chloroform and the crude extract was dissolved in a solvent mixture of methanol/water (95:5). The mixture was then subjected to solvent-solvent partition, first with hexane followed by chloroform. The crude extract and the hexane and chloroform fractions were evaluated for their LD50 in Swiss albino mice of both sexes. Results: The LD50 of the crude extract and the hexane and chloroform fractions were determined to be 142.82, 200 and 200.17mg per kg of the mice body weight, respectively. Conclusion: The LD50 values of the crude extract and the hexane and chloroform fractions from P. bistorta were determined. The crude extract of P. bistorta had greater lethality than the hexane and chloroform fractions. This is the first report on the LD50 values of Swiss albino mice for P. bistorta.

Deasphalting of Atmospheric Iraqi Residue using Different Solvents

Different solvents (light naphtha, n-heptane, and n-hexane) are used to treat Iraqi Atmospheric oil residue by the deasphalting process. Oil residue from Al-Dura refinery with specific gravity 0.9705, API 14.9, and 0.5 wt. % sulfur content was used. Deasphalting oil (DAO) was examined on a laboratory scale by using solvents with different operation conditions (temperature, concentration of solvent, solvent to oil ratio, and duration time). This study investigates the effects of these parameters on asphaltene yield. The results show that an increase in temperature for all solvents increases the extraction of asphaltene yield. The higher reduction in asphaltene content is obtained with hexane solvent at operating conditions of (90 °C, 4/1 solvent to oil ratio), where the asphaltene yield was 93%. The highest recorded value of API value at 150 ml for all solvents at the highest temperature and duration time; this value is 32 when using n-heptane solvent at 15/1.

Assessing the Intrinsic Strengths of Ion–Solvent and Solvent–Solvent Interactions for Hydrated Mg2+ Clusters

Information resulting from a comprehensive investigation into the intrinsic strengths of hydrated divalent magnesium clusters is useful for elucidating the role of aqueous solvents on the Mg2+ ion, which can be related to those in bulk aqueous solution. However, the intrinsic Mg–O and intermolecular hydrogen bond interactions of hydrated magnesium ion clusters have yet to be quantitatively measured. In this work, we investigated a set of 17 hydrated divalent magnesium clusters by means of local vibrational mode force constants calculated at the ωB97X-D/6-311++G(d,p) level of theory, where the nature of the ion–solvent and solvent–solvent interactions were interpreted from topological electron density analysis and natural population analysis. We found the intrinsic strength of inner shell Mg–O interactions for [Mg(H2O)n]2+ (n = 1–6) clusters to relate to the electron density at the bond critical point in Mg–O bonds. From the application of a secondary hydration shell to [Mg(H2O)n]2+ (n = 5–6) clusters, stronger Mg–O interactions were observed to correspond to larger instances of charge transfer between the lp(O) orbitals of the inner hydration shell and the unfilled valence shell of Mg. As the charge transfer between water molecules of the first and second solvent shell increased, so did the strength of their intermolecular hydrogen bonds (HBs). Cumulative local vibrational mode force constants of explicitly solvated Mg2+, having an outer hydration shell, reveal a CN of 5, rather than a CN of 6, to yield slightly more stable configurations in some instances. However, the cumulative local mode stretching force constants of implicitly solvated Mg2+ show the six-coordinated cluster to be the most stable. These results show that such intrinsic bond strength measures for Mg–O and HBs offer an effective way for determining the coordination number of hydrated magnesium ion clusters.

Transmissive to blackish-green NIR electrochromism in a Co(II)-based interfacial co-ordination thin-film

Herein, a Co(II)-based metallo-polymer (Co-tpy-L ) with three armed non-conjugated terpyridine ligand is synthesized using solvent-solvent interfacial polymerization. The thin-film exhibits a durable transmissive-to-blackish green electrochromism, selectively covering the both...