- Radical oxidative decarboxylation of α-hydroxylactones. Influence of oxygen-carbon β-bond effect
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α-Hydroxylactones undergo decarboxylation when submitted to the system (diacetoxy-iodo)benzene (DIB)/iodine under mild conditions. β-Oxygen substituents were observed to deactivate the decarboxylation reaction.
- Francisco, Cosme G.,Freire, Raimundo,Rodriguez, Maria S.,Suarez, Ernesto
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Read Online
- Synthesis of 5α-androstan-3β,17β-diol from tigogenin
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5α-Androstan-3β,17β-diol (3b-adiol), a known inhibitor of prostate cancer cell growth, was synthesized from tigogenin. Its structure was confirmed by NMR and IR spectroscopy and mass spectroscopy. Springer Science+Business Media, Inc. 2007.
- Merlani,Amiranashvili,Men'Shova,Kemertelidze
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Read Online
- Sisal saponin by a single synthesis method for the production of alcohol ketone acetic ester
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The invention relates to a production method for synthesizing pregnenolone acetate with ticogenin, which comprises the following steps: by using ticogenin as a raw material, acetic acid as a solvent and acetic anhydride as an acylating agent, carrying out pressurized ring-opening reaction, and carrying out oxydrolysis with chromic anhydride to obtain a compound reaction solution; extracting, washing with alkali, washing with water, filtering, concentrating under reduced pressure, crystallizing, and centrifuging to obtain a pregnenolone acetate crude product; and finally, recrystallizing to obtain the pregnenolone acetate. The method provided by the invention has the advantages of proper reaction conditions, high total yield, high product purity and low production cost, and is suitable for industrial production.
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Paragraph 0030-0034
(2017/02/24)
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- Unraveling the structure-activity relationship of tomatidine, a steroid alkaloid with unique antibiotic properties against persistent forms of Staphylococcus aureus
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Staphylococcus aureus (S. aureus) is responsible for difficult-to-treat and relapsing infections and constitutes one of the most problematic pathogens due to its multiple resistances to clinically available antibiotics. Additionally, the ability of S. aureus to develop small-colony variants is associated with a reduced susceptibility to aminoglycoside antibiotics and in vivo persistence. We have recently demonstrated that tomatidine, a steroid alkaloid isolated from tomato plants, possesses anti-virulence activity against normal strains of S. aureus as well as the ability to potentiate the effect of aminoglycoside antibiotics. In addition, tomatidine has shown antibiotic activity against small-colony variants of S. aureus. We herein report the first study of the structure-activity relationship of tomatidine against S. aureus.
- Chagnon, Félix,Guay, Isabelle,Bonin, Marc-André,Mitchell, Gabriel,Bouarab, Kamal,Malouin, Fran?ois,Marsault, éric
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p. 605 - 620
(2014/06/23)
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- A practical solution for aqueous reactions of water-insoluble high-melting-point organic substrates
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A practical solution to the problem of performing aqueous reactions for very sparingly soluble high-melting-point (VSSHMP) organic substrates has been developed, which entails mechanically stirring a mixture of the substrate, the corresponding reagent(s), water, catalytic Aliquat 336 and sand. When the melting points of the substrates which include steroids, ketones, aldehydes, aromatics and alkaloids are around 200 °C, the reactions can be performed at 20 °C. The substrate solubility can be as low as 1 × 10-10 mol L-1. The Royal Society of Chemistry 2012.
- Cui, Xiaoxue,Li, Bo,Liu, Tianzhen,Li, Chunbao
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supporting information; experimental part
p. 668 - 672
(2012/06/01)
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- MEDICINAL APPLICATIONS OF BENZOIC ACID HYDRAZONES SYNTHESIZED ON THE BASIS OF STEROIDAL TIGOGENIN
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Novel benzoic acid hydrazones of 5α-androstan-3,17-dione have been prepared on the basis of steroidal tigogenin of the plant Yucca gloriosa. The hydrazones of the General Formula (I), General Formula (II) and General Formula (III) as shown in the accompanying FIGURE of the drawing are synthesized. The hydrazones have shown promising anti-T.B., anti-cancer and anti-HIV activity revealing immense potential as more efficacious, less toxic drugs with fewer undesirable side effects. They could also prove valuable in correcting hormonal abnormalities that cause severe health problems.
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Page/Page column 2
(2011/08/04)
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- Further study on synthesis and evaluation of 3,16,20-polyoxygenated steroids of marine origin and their analogs as potent cytotoxic agents
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A series of new polyoxygenated steroid derivatives with various steroid skeleton moieties were synthesized. Antitumor activity of the compounds against three tumor cell lines (Breast cancer MCF7, lung cancer NCI and oral cancer KB) were evaluated. Compoun
- Bunyathaworn, Potjamarn,Boonananwong, Suthinee,Kongkathip, Boonsong,Kongkathip, Ngampong
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experimental part
p. 432 - 444
(2010/06/13)
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- MEDICINAL APPLICATIONS OF BENZOIC ACID HYDRAZONES SYNTHESIZED ON THE BASIS OF STEROIDAL TIGOGENIN
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Novel benzoic acid hydrazones of 5α-androstan-3, 17-dione have been prepared on the basis of steroidal tigogenin of the plant Yucca gloriosa. The hvdrazones of the General Formula (I), General Formula (II) and General Formula (III) as shown in the accompanying Figure of the drawing are synthesized. The hydrazones have shown promising anti-T.B., anti-cancer and anti-HIV activity revealing immense potential as more efficacious, less toxic drugs with fewer undesirable side effects. They could also prove valuable in correcting hormonal abnormalities that cause severe health problems.
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Page/Page column 6
(2009/12/27)
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- Acetoxylation reactions of 17α, 21-dichloro-20-oxopregnanes and their relatives
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Acetoxylation reactions of 17a,21-dichloro-20-oxopregnanes and their relatives under different conditions using anhydrous sodium and potassium acetate are being studied in order to produce cortisone of triamcinolone side chain.
- Hazarika, Saroj,Goswami, Papori,Chowdhury, Pritish
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p. 1706 - 1710
(2007/10/03)
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- ISOLATION AND CHARACTERIZATION OF A FUROSTANOL GLYCOSIDE FROM FENUGREEK
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From the seed of fenugreek, a new glycoside has been isolated and shown to have the structure, (25S)-22-O-methyl-5α-furostan-3β,22,26-triol 3-O-α-rhamnopyranosyl(1-->2)3)>-β-D-glucopyranoside-26-O-β-D-glucopyranoside.Key Word Index - Trigonella foenumgraecum; Fabaceae; fenugreek; furostanol glycoside; spirostanol
- Hardman, Roland,Kosugi, Junzo,Parfitt, Robert T.
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p. 698 - 700
(2007/10/02)
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- Process for the preparation of 17β-hydroxy-3-oxo-17α-pregn-4-ene-21-carboxylic acid γ-lactone
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A new process utilizing certain novel intermediates for the preparation of 17β-hydroxy-3-oxo-17α-pregn-4-ene-21-carboxylic acid γ-lactone is described herein. The procedure utilizes readily available and inexpensive sarsasaponin as starting material.
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