Crystallographic Investigations of 3β‐acetoxy‐5α‐cholestan‐6‐one‐semicarbazone ‐ A Steroid

The crystal structure of 3b‐acetoxy‐5a‐cholestan‐6‐one‐semicarbazone (C₃₀H₅₁O₃N₃) has been determined by X‐ray diffraction methods. It crystallizes in the orthorhombic space group P2₁2₁2₁ with cell parameters a = 11.641(1), b = 16.552(1) c = 31.181(4) Å and Z = 8. The structure has been refined to an R‐value of 0.050 for 4407 observed reflections. Two molecules in the asymmetric unit have been observed. In both the crystallographically independent molecules, all the three six‐membered rings (A, B and C ) of steroid nucleus exist in chair conformation, while the five‐ membered ring D exists in 13β distorted‐envelope in molecule‐I and 13β, 14α half‐chair conformation in molecule‐II. Three intermolecular N‐H … O hydrogen bonds have been observed.     

Crystal structure of cholest-4-ene-3,6-dione: A steroid

The crystal structure of cholest-4-ene-3,6-dione (C₂₇H₄₄O₂) has been determined by X-ray diffraction methods. The compound crystallizes in the monoclinic crystal system (space group P2₁) with the unit cell parameters a = 10.503(4) Å, b = 8.059(1) Å, c = 14.649(1) Å, β = 105.4(2)°, and Z = 2. The structure has been refined to an R value of 0.035 for 2252 observed reflections. Ring A of the steroid nucleus exists in a sofa conformation, while rings B and C adopt a chair conformation. The five-membered ring D exhibits a half-chair conformation. The molecules in the unit cell are linked together by the C-H?O hydrogen bonds.     

Synthesis and X-ray crystallography of cholest-3,5-diene-7-one-oxime

Cholest-3,5-diene-7-one-oxime (C₂₇H₄₃NO) was prepared using a usual synthetic route and its three-dimensional structure was determined by X-ray diffraction methods. The transparent platelike crystals of this compound crystallized in the monoclinic space group P2₁, with unit cell parameters a = 14.302(2) Å, b = 11.475(2) Å, c = 15.919(4) Å, = 106.04(1)°, (Cu K) = 1.5418 Å, Z = 4. The structure was solved by direct methods and refined to an R-value of 0.075 for 4640 observed reflections. Two crystallographically independent molecules were observed in the asymmetric unit cell. The ring A in both the molecules was found to exist in 1,10 half-chair conformation while ring C in chair conformation. The rings B and D in both the molecules adopted different conformations. Three intermolecular interactions of the type C–H O and C–H N were also observed.     

On plane wave solutions of non-symmetric field equations of unified theories of Einstein,Bonnor and Schrödinger

Summary Various attempts have been made to obtain wave solutions of nonsymmetric unified field equations of Einstein, Bonnor and Schrödinver in different space-times. Lal and Ali, Lal and Khare, Lal and Singh have obtained wave solutions of these field equations in different space-times under certain restrictions. In this paper plane wave solutions of both the weak and strong, nonsymmetric unified field equations of Einstein, Bonnor and Schrödinger have been investigated in a space which is more general than Pandey and Rao plane wave metric. It has been shown that the plane wave solutions of Einstein and Bonnor's equations exist but Schrödinger's field equations have no solution in this space-time.     

Synthesis of 5α-Iodo-6-one Steroids

Abstract: The synthesis of 5-iodo-5α-cholestan-6-one (6), its 3β-acetoxy-(7) and 3β-chloro-(8) analogues, 3β-acetoxy-5-iodo-5α-stigmastan-6-one (9) and its 3β-chloro-(10) analogue by the reacion of silver chromate-iodine and pyridine with the corresponding steroidal olefins (1-5) is described. The structures of these products have been established on the basis of their elemental, analytical and spectral data.     

In vitro pharmacological screening of three newly synthesised pyrimidine derivatives

The antibacterial and antifungal activities of three new pyrimidine derivatives, namely, 2,6-bis(4,6-dimethylpyrimidin-2-ylthio)benzene-1,4-diol (1),3,5-bis(4,6-dimethylpyrimidin-2-ylthio)-2-methylbenzene-1,4-diol (2) and 3,5-bis(4,6-dimethylpyrimidin-2-ylthio)-2-methoxybenzene-1,4-diol (3), synthesised by electrochemical method are presented here. The compounds were screened for their activities against Gram-positive and Gram-negative bacteria, Bacillus subtilis, Staphylococcusaureus, Escherichia coli and a pathogenic fungus Aspergillus niger. The results show that these compounds have significant activity against these bacteria and fungus. The minimum inhibitory concentration of compound 1 was determined as 62.5 μg/mL against B. subtilis, 125 μg/mL against E. coli and 250 μg/mL against S. aureus establishing its promising activities higher than susceptible ranges.     

Magnetic and thermoelectric properties of REMoN3 (RE = La,Ce, Pr,Nd, and Sm): A first-principles study

We investigated the magnetic and thermoelectric properties of REMoN₃ (RE = La, Ce, Pr, Nd, Sm) perovskites using the full potential linearized augmented plane wave (FP-LAPW) method. To overcome the problem of underestimation of electronic interaction, we employed the DFT + U approach to accurately map the electronic structure of these compounds. Our study shows an increasing trend in the magnetic moments with the increasing number of unpaired electrons in RE. Among these compounds, SmMoN₃ possesses a large magnetic moment, which is suitable for applications such as memory devices and sensors. Interestingly, all these perovskites display ferromagnetic behavior except CeMoN₃, which exhibits an antiferromagnetic nature. Furthermore, our analysis indicates n-type thermoelectric behavior in all these materials. The compound, namely PrMoN₃, exhibits a high figure of merit among REMoN₃, which can be improved by modifying the lattice sites.     

Fabrication of Xanthan stabilized green gold nanoparticles based tolbutamide delivery system for enhanced insulin secretion in mice pancreatic islets

Abstract

Tolbutamide is an oral anti-diabetic agent for the treatment of type 2 diabetic patients. Its lower absorption results in its inferior therapeutic efficacy. Nano-carrier systems have the subject of greater interests for enhancing efficacy of such drugs. Current study was designed to improve the tolbutamide therapeutic efficacy through its delivery in Gum Xanthan (GX) stabilized green gold nanoparticles (AuNPs). GX stabilized AuNPs were characterized for surface plasmon resonance (SPR), morphology, size, polydisoersity index (PDI) and zeta potential through UV spectrophotometer, atomic force microscope (AFM) and zetasizer respectively. They were used for loading tolbutamide and loaded nanoparticles were investigated for morphology, size, PDI, zeta potential and drug loading efficiency. FT-IR analysis was used for conforming GX functional groups involvement in AuNPs stabilization and drug-excepients interactions. Tolbutamide loaded in the synthesized nanoparticles was investigated for its insulin secretion potentials in isolated mice islets. Synthesized AuNPs were found in nano-size range with spherical morphology, increased surface negativity and loaded increased concentration of drug without changing its chemical nature. They markedly enhanced the tolbutamide insulin secretion potentials as compared to simple drug solution. Results confirm that the developed nano-carrier system is highly efficient in achieving higher therapeutic efficacy of drugs like tolbutamide.     

X-ray crystallography of cholest-3,5-diene-7-one

The molecular structure of cholest-3,5-diene-7-one (C₂₇H₄₂O) is determined by X-ray diffraction. The compound crystallizes in the orthorhombic crystal system (space group P2₁2₁2₁) with unit cell parameters a = 11.281(5) Å, b = 11.350(5) Å, c= 18.518(5) Å, and Z = 4. The structure is solved by direct methods and refined to an R-value of 0.054 for 1070 observed reflections [F_o > 4σ(F_o)]. Ring A adopts a distorted half-chair conformation, ring B exists in sofa conformation, ring C acquires a chair conformation, and the five-membered ring D occurs in distorted half-chair conformation. The crystal structure is stabilized by van der Waals forces.