- Crystal structure of 3β-acetoxy-17α-hydroxy-16α- methylallopregnan-20-one hemihydrate
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3β-Acetoxy-17α-hydroxy-16α-methylallopregnan-20-one, C24H38O4?0.5H2O, is an intermediate towards the synthesis of dexamethasone, an important corticosteroid. The compound crystallizes in the monoclinic space group C2 with unit cell parameters: a = 10.665(2) A, b = 7.497(1) A, c = 28.200(4) A, β = 92.74(2)°, Z = 4. The crystal structure has been solved by direct methods and refined to R = 0.0419 for 1579 observed reflections. All rings of the steroid skeleton are trans connected. Rings A, B, and C are all in the chair conformation. Ring D is in envelop conformation. The acetoxy and acetyl substituents are twisted with respect to the average molecular plane of the steroid. The twist along the length of the steroid molecule is negligible [C19-C10???C13-C18 = 2.3°]. In the crystal structure, the water molecule lies on a twofold axis which links the molecules into infinite supramolecular chains through OW-H???O and O- H???OW hydrogen bonds.
- Bandhoria, Pankaj,Gupta, Vivek K.,Gupta,Varghese
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- Stereoselective synthesis of some methyl-substituted steroid hormones and their in vitro cytotoxic activity against human gastric cancer cell line MGC-803
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A series of 3-, 7-, 15-, and 16-methyl-substituted steroid analogs were synthesized via a highly stereoselective 1,6-conjugate addition. Under the catalysis of CuBr, AlMe3 reacted with four steroid dienone precursors to afford either the corresponding α-epimer of C-3 and C-7 methyl-substituted steroids as the major products, and the ratio of α/β was up to 10/1. No β-epimer has been detected for methyl addition at C-16. However, under the same reaction conditions, enantioselective methyl addition at C-15 afforded the 15β-epimer as the major product. The preliminary SAR analysis showed that the methyl substituents at C-7α and C-15β positions lead to a dramatical increase in potency against human gastric cancer cell line MGC-803.
- Li, Chun,Qiu, Wenwei,Yang, Zhengfeng,Luo, Jian,Yang, Fan,Liu, Mingyao,Xie, Juan,Tang, Jie
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experimental part
p. 859 - 869
(2010/10/18)
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- Dehydroepiandrosterone (DHEA) congeners for prevention and/or treatment of ulcers
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The present invention is related to acute therapeutic uses of dehydroepiandrosterone (DHEA) congeners. These uses include methods for treating or preventing ulcers which comprise administering to a subject either at risk or in need thereof having an ulcer a therapeutic amount of DHEA congener.
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- Method for reducing mast cell mediated allergic reactions
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The present invention is directed to a method for reducing mast cell mediated allergic reactions, including mast cell mediated allergy and asthma. Mast cell mediated allergic reactions, including type I hypersensitivity reasponse to allergens and asthma, are reduced by administering a dehydroepiandrosterone (DHEA) derivative to a patient in a manner which quickly raises blood levels of the active agent.
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- Method for enhancing or accelerating re-epithelialization or re-endothelialization of a tissue
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The present invention is related to a method for enhancing or accelerating re-epithelialization or re-endothelialization of a tissue. Examples of re-epithelialization in which the invention is particularly suited include, but are not limited to, re-epithelialization of (a) skin following surgical wounds, (b) skin abrasions caused by mechanical trauma, caustic agents or burns, (c) cornea following cataract surgery or corneal transplants, (d) mucosal epithelium (respiratory, gastrointestinal, genitourinary, mammary, oral cavity, ocular tissue, liver and kidney) following infection, nonpathological etiologies or drug therapy, (e) skin following grafting and (f) renal tubule following acute tubular necrosis. Examples of re-endothelialization in which the invention is particularly suited include, but are not limited to, re-endothelialization (or regrowth of endothelium) in blood vessels following angioplasty, and the lysis of fibrin clots or lysis or mechanical disruption of thrombi in coronary arteries. In accordance with the present invention, the time to complete re-epithelialization or re-endothelialization is enhanced or accelerated by administering a dehydroepiandrosterone (DHEA) derivative.
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- Methods for preventing progressive tissue necrosis, reperfusion injury, bacterial translocation and respiratory distress syndrome
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The present invention is related to a method for preventing or reducing the effects of ischemia. The ischemia may be associated with injury or reperfusion injury, such as occurs as a result of infarctions, thermal injury (bums), surgical trauma, accidental trauma, hemorrhagic shock and the like. The invention is also related to methods for preventing, or reducing bacterial translocation, adult respiratory distress syndrome, adherence of blood cells and platelets to endothelial cells and pulmonary hypertension. In accordance with the present invention, these conditions are prevented or reduced by administering a dehydroepiandrosterone (DHEA) derivative as defined herein.
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