J. Appl. Cryst.の発刊に際して

: The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

Imidazole ring is an important five-membered aromatic heterocycle widely present in natural products and synthetic molecules. The unique structural feature of imidazole ring with desirable electron-rich characteristic is beneficial for imidazole derivatives to readily bind with a variety of enzymes and receptors in biological systems through diverse weak interactions, thereby exhibiting broad bioactivities. The related research and developments of imidazole-based medicinal chemistry have become a rapidly developing and increasingly active topic. Particularly, numerous imidazole-based compounds as clinical drugs have been extensively used in the clinic to treat various types of diseases with high therapeutic potency, which have shown the enormous development value. This work systematically gives a comprehensive review in current developments of imidazole-based compounds in the whole range of medicinal chemistry as anticancer, antifungal, antibacterial, antitubercular, anti-inflammatory, antineuropathic, antihypertensive, antihistaminic, antiparasitic, antiobesity, antiviral, and other medicinal agents, together with their potential applications in diagnostics and pathology. It is hoped that this review will be helpful for new thoughts in the quest for rational designs of more active and less toxic imidazole-based medicinal drugs, as well as more effective diagnostic agents and pathologic probes.

Comprehensive Review in Current Developments of Imidazole‐Based Medicinal Chemistry

Triplet excitons in organic molecules underscore a variety of processes and technologies as a result of their long lifetime and spin multiplicity Organic phosphorescence, which originates from triplet excitons, has potential for the development of a new generation of organic optoelectronic materials and biomedical agents However, organic phosphorescence is typically only observed at cryogenic temperatures and under inert conditions in solution, which severely restricts its practical applications In the past few years, room-temperature-phosphorescent systems have been obtained based on organic aggregates Rapid advances in molecular-structure design and aggregation-behaviour modulation have enabled substantial progress, but the mechanistic picture is still not fully understood because of the high sensitivity and complexity of triplet-exciton behaviour This Review analyses key photophysical processes related to triplet excitons, including intersystem crossing, radiative and non-radiative decay, and quenching processes, to illustrate the intrinsic structure–property relationships and draw clear and integrated design principles The resulting strategies for the development of efficient and persistent room-temperature-phosphorescent systems are discussed, and newly emerged applications based on these materials are highlighted Advances in molecular-structure design and modulation of the aggregation behaviour have enabled much progress in the observation of room-temperature phosphorescence from organic aggregates This Review analyses key photophysical processes related to triplet excitons, illustrating the intrinsic structure–property relationships and identifying strategies to design efficient and persistent room-temperature-phosphorescent systems

Room-temperature phosphorescence from organic aggregates

Photoluminescence (PL), up-conversion PL (UCPL), and phosphorescence are three kinds of phenomena common to light-emitting materials, but it is very difficult to observe all of them simultaneously when they are derived from a single material at room temperature. For the first time, triple-mode emission (that is, PL, UCPL, and room temperature phosphorescence (RTP)) is reported, which relies on a composite of the luminescent carbon dots (CDs) prepared from m-phenylenediamine and poly(vinyl alcohol) (PVA). Moreover, the CDs-PVA aqueous dispersion is nearly colorless and demonstrates promise as a triple-mode emission ink in the field of advanced anti-counterfeiting.

Triple-Mode Emission of Carbon Dots: Applications for Advanced Anti-Counterfeiting

In the title compound, C21H20Cl3NO2, the piperidin-4-one ring adopts a boat conformation. The two 2-chloro­phenyl groups are approximately perpendicular to each other, making a dihedral angle of 74.07 (8)°.

https://journals.iucr.org/e/issues/2010/06/00/bt5245/bt5245.pdf

1-Chloro-acetyl-2,6-bis-(2-chloro-phen-yl)-3,5-dimethyl-piperidin-4-one oxime.

A series of 2,6-diaryltetrahydropyran-4-one thiosemicarbazones ( 11–27 ) were synthesized and characterized for evaluation of potential antibacterial activity against Staphylococcus aureus , Escherichia coli , Pseudomonas aeruginosa , Salmonella typhi , Bacillus subtilis and Klebsiella pneumonia and antifungal activity against Cryptococcus neoformans , Candida albicans , Rhizopus sp., Aspergillus niger and Aspergillus flavus were evaluated. Compounds 21 and 22 showed maximum inhibition potency at low concentration (6.25 μg/ml) against P. aeruginosa . For antifungal activity, 20 and 21 were effective against C. neoformans and 22–24 against C. albicans at minimum concentration. Further, the results of QSAR studies of these synthesized compounds indicated the importance of weakly polar component of surface area, hydrophobicity and ionization potential parameters in defining their antimicrobial activity.

Synthesis, Stereochemistry, Antimicrobial Evaluation and QSAR Studies of 2,6‐Diaryltetrahydropyran‐4‐one Thiosemicarbazones.

https://journals.iucr.org/x/issues/2016/08/00/bt4019/bt4019.pdf

4-Chloro-N-(isoquinolin-3-yl)butanamide

Background Garcinia pedunculata (GP) Roxb. is a traditional medicinal plant used for treating gastrointestinal disorders. The fruit is always consumed in dried form in cuisines and as medicine. Objectives To study the effect of drying conditions (shade, oven, and traditional sun drying) on the nutritional profile of GP while assessing the choice of solvent extraction for the maximum phytocompounds extraction; their in vitro biological activities and chemical profiling. Materials and Methods The fruits were cut into thin 0.9 ± 0.3 cm slices and dried in the shade (25–30°C), sun (34–40°C), and oven (70–80°C). The extraction was done using methanol, hydromethanol, ethanol, hydroethanol, and water. HPLC and LC-ESI-MS/MS were used to identify the bioactive compounds. Results In this study, the impact of three drying conditions has been investigated and established that shade-dried (ShD) has a better-preserved nutritional profile. In terms of phytochemical extraction, comparatively higher amounts of phenols (394.00 ± 12.28 mg Gallic acid equivalent (GAE)/g of dried sample) and flavonoids (72.62 ± 2.06 mg Quercetin/g of dried sample) were recorded in the shade-dried hydromethanolic extract (ShDMH), which was directly in line with the better antioxidant activity (IC50 for 1,1-diphenyl-2-picrylhydrazyl (DPPH), 647.99 ± 7.66 µg/mL, 2,2’-azino-bis(3-ethylbenzothiazoline)6-sulfonic acid (ABTS), 762.02 ± 18.74 µg/mL) and enzyme-inhibitory potential (IC50 for α- glucosidase 1908.06 ± 13.26 µg/mL and for lipase 613.59 ± 7.57 µg/mL) of this extract. Conclusion The conclusive evidence from this study indicates that shade drying and extraction with hydromethanolic solvent preserves most of the nutritional components and has a higher extraction yield with well-conserved phytochemical composition. Also, these bioactive compounds such as hydroxycitric acid, GB-1a, garcinone A, 9-hydroxycalabaxanthone, chlorogenic acid, and garcinol are present in these extracts. This fruit, although beneficial is still underutilized, and this outcome is believed to be significantly valuable for the further aspects of GP fruit-based nutraceutical or phytopharmaceutical development.

Influence of Drying Condition on Nutritional and Chemical Profile of Garcinia pedunculata Roxb. Fruit

A new series of 1-allyl-2,6-diarylpiperidone $O$ -allyl oximes 13–18 were synthesized from 2,6-diarylpiperidones through various steps. The structures of all the compounds are characterized by their IR, NMR, (1D & 2D NMR) and mass spectral studies. Based on the spectral values and coupling constants all the compounds exist in chair conformation except 18 in boat conformation. Also, all the synthesized compounds are screened for their antimicrobial activity against several bacterial and fungal strains. p-Chloro-2,6-diphenyl substituted compound 15, showed remarkable activity against A.niger and compound 17 against Pseudomonas and A.flavus strains.

Senthamaraikannan Kabilan

Papers

1-Chloro-acetyl-2,6-bis-(2-chloro-phen-yl)-3,5-dimethyl-piperidin-4-one oxime.

Synthesis, Stereochemistry, Antimicrobial Evaluation and QSAR Studies of 2,6‐Diaryltetrahydropyran‐4‐one Thiosemicarbazones.

4-Chloro-N-(isoquinolin-3-yl)butanamide

Influence of Drying Condition on Nutritional and Chemical Profile of Garcinia pedunculata Roxb. Fruit

Synthesis, spectral characterization and antimicrobial evaluation of some novel N-allyl-2,6-diarylpiperidone O-allyl oximes