The synthesis of 2′-amino-5α-cholest-6-eno [6,7-d]-thiazole derivatives under microwave irradiation using dry-media conditions

A convenient,rapid and efficient method for the synthesis of substituted steroidal[6,7-d]thiazoles using microwave-induced organic reaction enhancement chemistry has been developed.The additional features of this methodology include a much faster reaction,easy workup,high yield,high purity of the products and an environment friendly approach.     

The synthesis of 2''-amino-5α-cholest-6-eno [6,7-d]-thiazole derivatives under microwave irradiation using dry-media conditions

A convenient, rapid and efficient method for the synthesis of substituted steroidal [6,7-d] thiazoles using microwave-induced organic reaction enhancement chemistry has been developed. The additional features of this methodology include a much faster reaction, easy workup, high yield, high purity of the products and an environment friendly approach.     

The synthesis of 2＇-amino-5α-cholest-6-eno [6,7-d]- thiazole derivatives under microwave irradiation using dry-media conditions

A convenient, rapid and efficient method for the synthesis of substituted steroidal [6,7-d] thiazoles using microwave-induced organic reaction enhancement chemistry has been developed. The additional features of this methodology include a much faster reaction, easy workup, high yield, high purity of the products and an environment friendly approach.     

Structural elucidation of four new furostanol saponins from Tupistra chinensis by 1D and 2D NMR spectroscopy

Four new furostanol saponins (1–4), two pairs of diastereoisomers, were isolated from methanolic extracts of Tupistra chinensis rhizomes and their structures were assigned from ¹H and ¹³C NMR spectra, DEPT, and by 2D COSY, NOESY, HMQC, and HMBC experiments. Copyright © 2008 John Wiley & Sons, Ltd.     

Two New Steroidal Glycosides from Ophiopogon japonicus

The tuber of Ophiopogon japonicus Ker-Gawl. is recorded to have various functions, such as against cardiovascular diseases and anti-bacteria, and used as a potent drug to treat different diseases, especially heart diseases1. Since the first steriodal glycoside was isolated from the plant by Japanese scholars2, much attention has been paid to the studies of the chemical components of O. japonicus in recent decades. Steroidal glycosides as the major glycosides with the aglycones of ruscogenin …     

Synthesis,Structural, and Antibacterial Studies of Some Transition Metal Complexes Derived from Thiosemicarbazone and Semicarbazone

A series of metal complexes of Pd(II), Pt(II), Rh(III), Ir(III), and Ru(III) with thiosemicarbazone and semicarbazone of 2-acetyl thiophene have been synthesized. Their structures were determined on the basis of elemental analyses; molar conductance; magnetic susceptibility measurements; and IR, ¹ H NMR, and electronic spectral studies. On the basis of molar conductance, the complexes may be formulated as [M(L)₂]Cl₂ and [M′(L)₂Cl₂]Cl [where M = Pd(II), Pt(II) and M′ = Rh(III), Ir(III), and Ru(III)] due to their 1:2 and 1:1 electrolytic nature. On the basis of IR, ¹ West, D. X., Liberta, A. E., Padhye, S. B., Chikate, R. C., Sonawane, P. B. V., Kumbhar, A. S. and Yerande, R. G. 1993. Coord. Chem. Rev., 123: 49[Crossref], [Web of Science ®] , [Google Scholar]H NMR, and electronic spectral studies, an octahedral geometry has been assigned for Rh(III), Ir(III), and Ru(III), while square planar geometry has been assigned for the Pd(II) and Pt(II) complexes. The synthesized ligands and their complexes have been screened for bactericidal activity against several bacterial species (i.e., B. macerans, A. aureus, E. coli), and it is shown that the metal complexes act as more active antimicrobial agents than the uncomplexed ligands from which they derive.     

An Insight into the Mechanism of Holamine- and Funtumine-Induced Cell Death in Cancer Cells

Holamine and funtumine, steroidal alkaloids with strong and diverse pharmacological activities are commonly found in the Apocynaceae family of Holarrhena. The selective anti-proliferative and cell cycle arrest effects of holamine and funtumine on cancer cells have been previously reported. The present study evaluated the anti-proliferative mechanism of action of these two steroidal alkaloids on cancer cell lines (HT-29, MCF-7 and HeLa) by exploring the mitochondrial depolarization effects, reactive oxygen species (ROS) induction, apoptosis, F-actin perturbation, and inhibition of topoisomerase-I. The apoptosis-inducing effects of the compounds were studied by flow cytometry using the APOPercentage^TM dye and Caspase-3/7 Glo assay kit. The two compounds showed a significantly greater cytotoxicity in cancer cells compared to non-cancer (normal) fibroblasts. The observed antiproliferative effects of the two alkaloids presumably are facilitated through the stimulation of apoptosis. The apoptotic effect was elicited through the modulation of mitochondrial function, elevated ROS production, and caspase-3/7 activation. Both compounds also induced F-actin disorganization and inhibited topoisomerase-I activity. Although holamine and funtumine appear to have translational potential for the development of novel anticancer agents, further mechanistic and molecular studies are recommended to fully understand their anticancer effects.     

Diverse synthetic approach for sulfur and nitrogen-containing spiroheterocycles from dimedone and their pharmacological evaluation

Novel spiro(3-hydroxy-5,5-dimethyl)-1,5’-(2’-substituated[1,3,4]-oxadiazole/thiadiazolo[3,2-c] thiazolines and 3-hydroxy-5,5-dimethyl-spiro[cyclohex-2-ene-thiazolo/thiazino[3,2-b]-s-tetrazine were prepared from previously reported hydrazone, semicarbazone, carbazone, and spiro-s-tetrazine intermediates derived from dimedone precursor. All the newly synthesized heterocycles have been characterized by analytical and spectral (¹H NMR and ^hC NMR) data and screened their in vitro antibacterial activity against gram negative bacteria Escherichia coli and gram positive bacteria Staphylococcus aureus. Some of the compounds showed moderate to good activities towards the bacteria chosen.     

Two New Steroidal Glycosides from Caryopteris terniflora

Two new steroidal glycosides were isolated from the Chinese medicinal plant Caryopteris terniflora. The spectroscopic and chemical evidences revealed that their structures tobe 6-(β-sitosteroyl-3-O-β-glucopyranosidyl) hexacosanate 1 and 6‘-(stigmasteroyl-3-O-β-glucopy-ranosidyl) linolenate 2, respectively.