567-72-6Relevant academic research and scientific papers
Neuroactive Type-A γ-Aminobutyric Acid Receptor Allosteric Modulator Steroids from the Hypobranchial Gland of Marine Mollusk, Conus geographus
Niu, Changshan,Leavitt, Lee S.,Lin, Zhenjian,Paguigan, Noemi D.,Sun, Lili,Zhang, Jie,Torres, Joshua P.,Raghuraman, Shrinivasan,Chase, Kevin,Cadeddu, Roberto,Karthikeyan, Manju,Bortolato, Marco,Reilly, Christopher A.,Hughen, Ronald W.,Light, Alan R.,Olivera, Baldomero M.,Schmidt, Eric W.
, p. 7033 - 7043 (2021)
In a program to identify pain treatments with low addiction potential, we isolated five steroids, conosteroids A-E (1-5), from the hypobranchial gland of the mollusk Conus geographus. Compounds 1-5 were active in a mouse dorsal root ganglion (DRG) assay that suggested that they might be analgesic. A synthetic analogue 6 was used for a detailed pharmacological study. Compound 6 significantly increased the pain threshold in mice in the hot-plate test at 2 and 50 mg/kg. Compound 6 at 500 nM antagonizes type-A γ-aminobutyric acid receptors (GABAARs). In a patch-clamp experiment, out of the six subunit combinations tested, 6 exhibited subtype selectivity, most strongly antagonizing α1β1γ2 and α4β3γ2 receptors (IC50 1.5 and 1.0 μM, respectively). Although the structures of 1-6 differ from those of known neuroactive steroids, they are cell-type-selective modulators of GABAARs, expanding the known chemical space of neuroactive steroids.
Kinetic evaluation of 3β-hydroxycholest-5-en-7-one (7-ketocholesterol) stability during saponification
Park,Guardiola,Park,Addis
, p. 623 - 629 (1996)
To clarify conflicting information regarding 7-ketocholesterol (7-KC) recovery from saponification, we evaluated the stability of 7-KC in methanolic alkaline medium. We added 1 N alcoholic KOH to 7-KC or lard spiked with 7-KC and held the mixtures at 45, 55, 65, and 75°C for different times to simulate various saponification conditions. Gas-chromatographic determination of residual 7-KC with 5α-cholestane as the internal standard (IS) showed that the higher the saponification temperature, the greater the 7-KC degradation. Hot saponification at 75°C for 30 min caused extensive destruction and left only 31% 7-KC. 7-KC loss during saponification could be described by pseudo first-order kinetics, and the dependence of degradation rate on temperature (T, K) by k (h-1) = (2.6 × 1017) exp (-1.36 × 104/T). As predicted by the kinetic equation, 7-KC loss during room-temperature saponification (21°C) was practically negligible; following the exposure of 7-KC or lard spiked with 7-KC to 1 N alcoholic KOH for 18 h, about 97% 7-KC was recovered. 6-Ketocholestanol, when used as an IS, should be looked at carefully because of potential tautomerization, leading to the formation of two enol isomers when in extended contact with trimethylsilyl derivatization reagents.
P -TsOH-Catalyzed one-pot transformation of di- and trihydroxy steroids towards diverse A/B-ring oxo-functionalization
Sarkar, Antara,Das, Jayanta,Ghosh, Pranab
, p. 9051 - 9060 (2017/08/29)
A solid support-mediated p-TsOH-catalyzed milder transformative protocol was developed to furnish diverse ring-A and/or ring-B oxo-functionalized steroids. To furnish interesting isomers involving the A/B-ring of biomolecules in a one-pot approach, only solid supports (and not solution!) were found to be effective. p-TsOH/SiO2-oxidation of 4β-hydroxycholesterol, the major oxysterol in human circulation, into a mixture of cholest-4-en-3-one, cholest-4-ene-3,6-dione, and 5α-cholestane-3,6-dione was the starting point for the investigations herein. The reaction protocol was optimized in detail, and efforts were carried out toward gaining an understanding of the mechanistic aspects favoring the solid support, and a possible synergetic catalytic system involving p-TsOH and SiO2 was expected to be a key part. Application of the novel methodology to 4β,7α-dihydroxy steroids resulted in the desired diverse ketosteroids through oxidation/oxidative dehydration, which generalized the process as a facile multi-oxo-functionalization steroidal transformation.
Oxysterols: Synthesis and anti-leishmanial activities
Ghosh, Pranab,Ghosh, Ashim,Mandal, Amitava,Sultana, Sirin Salma,Dey, Somaditya,Pal, Chiranjib
, p. 65 - 73 (2016/03/04)
Oxygenated sterols (2-16) were synthesized by skeletal rearrangement of steroidal allylic alcohols. All the derivatives were screened for their anti-leishmanial activities. Compounds 3, 11 and 12 showed potent activities. Compound 12 was found least toxic and induced highest nitric oxide (NO) at 48 h. Least toxicity of compound 12 on splenocytes validated its best anti-amastigote effect and induction of NO.
Cholesterol transformations during heat treatment
Derewiaka,Molińska
, p. 233 - 240 (2015/01/09)
The aim of the study was to characterise products of cholesterol standard changes during thermal processing. Cholesterol was heated at 120 °C, 150 °C, 180 °C and 220 °C from 30 to 180 min. The highest losses of cholesterol content were found during thermal processing at 220 °C, whereas the highest content of cholesterol oxidation products was observed at temperature of 150 °C. The production of volatile compounds was stimulated by the increase of temperature. Treatment of cholesterol at higher temperatures i.e. 180 °C and 220 °C led to the formation of polymers and other products e.g. cholestadienes and fragmented cholesterol molecules. Further studies are required to identify the structure of cholesterol oligomers and to establish volatile compounds, which are markers of cholesterol transformations, mainly oxidation.
Synthesis of steroidal and nonsteroidal vicinal heterocyclic alcohols, N-(1-cycloalkenyl)heterocycles and their antibacterial studies
Saikia, Pallabi,Kaishap, Partha Pratim,Goswami, Jonalee,Singh, Anil Kumar,Deka Boruah, Hari Prasanna,Gogoi, Sanjib,Boruah, Romesh C.
, p. 36 - 45 (2014/05/06)
A solvent free steroidal and nonsteroidal epoxide ring opening reaction by nitrogen containing heterocycles under microwave irradiation is described. Some of the epoxide ring opening compounds were converted to their corresponding N-(1-cycloalkenyl)heterocycles via an acid catalyzed dehydration reaction. The antimicrobial activities of the epoxide ring opening compounds and N-(1-cycloalkenyl)heterocyclic compounds were tested by agar diffusion assay. Compounds 6, 9-12, 24 and 27 showed moderate inhibition against the growth of pathogenic bacteria Escherichia coli, Pseudomonas syringae, Bacillus subtilis, Proteus vulgaris and Staphylococcus aureus.
Semisynthesis and quantitative structure-activity relationship (QSAR) study of some cholesterol-based hydrazone derivatives as insecticidal agents
Yang, Chun,Shao, Yonghua,Zhi, Xiaoyan,Huan, Qu,Yu, Xiang,Yao, Xiaojun,Xu, Hui
supporting information, p. 4806 - 4812 (2013/09/02)
In continuation of our program aimed at the discovery and development of natural-product-based insecticidal agents, four series of novel cholesterol-based hydrazone derivatives were synthesized, and their insecticidal activity was tested against the pre-third-instar larvae of oriental armyworm, Mythimna separata (Walker) in vivo at 1 mg/mL. All the derivatives showed the better insecticidal activity than their precursor cholesterol. Quantitative structure-activity relationship (QSAR) model demonstrated that six descriptors such as RDF085v, Mor06u, Mor11u, Dv, HATS0v and H-046, are likely to influence the insecticidal activity of these compounds. Among them, two important ones are the Mor06u and RDF085v.
Sterols as anticancer agents: Synthesis of ring-B oxygenated steroids, cytotoxic profile, and comprehensive SAR analysis
Carvalho, Jo?o F. S.,Silva, M. Manuel Cruz,Moreira, Jo?o N.,Sim?es, Sérgio,Sá E Melo, M. Luisa
supporting information; experimental part, p. 7632 - 7638 (2011/02/21)
The cytotoxicity of oxysterols was systematically studied in tumor and normal cells. Synthetic strategies to prepare this library included oxidations at ring B and a new method to yield 6β-hemiphthalates directly from Δ5-steroids. Most oxysterols were cytotoxic and showed selectivity toward cancer cells, LAMA-84 cells (leukemia) being particularly sensitive to 4, 8, 22, and 27 (IC50 5.6 μM). The structural requirements to induce selective toxicity are discussed to shed light on the development of new anticancer drugs.
First catalytic and green synthesis of aryl-(Z)-vinyl chlorides and its plausible addition-elimination mechanism
Su, Weike,Jin, Can
, p. 993 - 996 (2007/10/03)
(Chemical Equation Presented) Via a catalytic cycle in the presence of scandium triflate (2 mol %)/DMF (1 mol %)/benzoyl chloride (5 mol %), aromatic ketones were treated with bis(trichloromethyl) carbonate (BTC) to afford aryl-(Z)-vinyl chlorides. All metal triflates tested in the reaction showed highly catalytic activity. A plausible addition-elimination mechanism was proposed. The present work describes the first catalytic and green route to the synthesis of aryl-(Z)-vinyl chlorides.
Ergosteroids VII: perchloric acid-induced transformations of 7-oxygenated steroids and their bio-analytical applications--a liquid chromatographic-mass spectrometric study.
Marwah, Ashok,Marwah, Padma,Lardy, Henry
, p. 233 - 248 (2007/10/03)
Sulfate esters of 7-oxo-delta(5)-steroids can be selectively and quantitatively hydrolyzed to the corresponding free steroids in the presence of carboxylic acid esters by solvolysis with perchloric acid in ethyl acetate at room temperature. Sulfates as well as carboxylic acid esters, methyl ethers, and ketals can be quantitatively converted to the corresponding 3,5-diene-7-one derivatives by heating with perchloric acid in methanol at 65 degrees C. The dienes have a strong UV absorption with maximum centered around 284 nm. These reactions have been used for the characterization and structural elucidation of 7-oxygenated-delta(5)-steroids that are present in complex biomatrices and can also be used for the quantitative estimation of total 7-oxo-delta(5)-steroids (free as well as conjugated) in biological matrices.
