Steroids acidic

Stern plane Sternutators Steroid Steroid acids Steroidal antiestrogens Steroidal estrogens... 

Emorfazone has been launched as Pentoil, Pentoyl, Nandron. Synergistic analgesic formulations containing (3) and either acetaminophen (paracetamol), sulpyrine (dipyrone), grafinin or phenylbutazone were claimed in patents [68, 69], The combined use of emorfazone with different non-steroidal acidic antiinflammatory drugs has been reported to be beneficial [70, 71]. 

Personal communication from Dr. J. V. Karabinos. Subsequent work on the reduction of steroid acids by Spero, McIntosh and Levin (ref. 12) has shown that Raney niokel partially deactivated by acetone is particularly suitable for the desulfurization of thiol esters to aldehydes. 

The ECD has seen its greatest utilization in the field of pesticide analysis. Chemicals such as dieldrin, aldrin and DDT are amenable to the ECD. In addition, the environmental hazards of polychlorinated biphenyls (PCBs) have been raised as a result of analyses by the ECD. Organometallics are also good electron absorbers. With the aid of halogen derivatization, many classes of organic compounds such as steroids, acids, amines, phenols, and alkenes have been assayed. 

A solution or suspension of the acid (1 mmol) in carbon tetrachloride (75 ml) containing DIB (0.55 mmol) and iodine (0.5 mmol) was irradiated with two 100 W tungsten-filament lamps for 45 min at reflux temperature. Another portion of DIB (0.55 mmol) was then added and irradiation was continued for 45 min at reflux. The reaction mixture was washed with dilute sodium thiosulphate and water, concentrated and chromatographed (silica gel column, 9 1 hexanes-ethyl acetate) to afford the alkyl iodide. Several steroidal acids with the carboxyl group attached at a 1° or 2° carbon atom gave the corresponding iodides in good yields. Acids with a 3° a-C instead of the iodide afforded alkenes similarly, alkenes were formed with a fivefold excess of DIB in the presence of cupric acetate. Aromatic acids also underwent iododecarboxylation, in moderate yields very effective was the otherwise difficult transformation of 1,8-naphthalenedicarboxylic acid to 1,8-diiodonaphthalene (80%) [68]. Cubyl and homocubyl iodides were also prepared in excellent yield [69]. 

Because of its flexibility, the Torgov synthesis (see Scheme 6) is still used quite frequently for the preparation of modified steroids. Acid cyclization of 3-methoxy-8,14-seco-oestra-l,3,5(10),9(1 l)-tetraene-14,17-dione (96) gave a mixture of the A -bisdehydro-oestrone (97) and A -dehydro-14/8-hydroxy-8a-oestrone (98). Catalytic hydrogenation of (98) afforded 3-methoxy-14 -hydroxy-8a,9)8-oestrone (99a) and 79% of 3-methoxy-14)S-hydroxy-8a,9a-oes-trone (99b). Treatment of (99b) with thionyl chloride in pyridine provided, after hydrolysis, 59% of 3-methoxy-A -dehydro-8a-oestrone (100), which on hydrogenation yielded the 8a,14)S-oestrone analogue (101). 

Cholesterol, whether ingested or formed endogenously, provides the starting material for the biosynthesis of all the other steroids found in mammals. Excess cholesterol is oxidized in the hver to polar compounds called cholic acids. This process converts the terminal side chain in cholesterol to a carboxyhc acid and introduces hydroxyl groups. These polyhydroxylated, steroidal acids play a central role in absorption of fats from the intestine and also excretion of superfluous cholesterol. 

The third modification of the Hunsdiecker reaction is the so-called Sudrez modification,21 where the steroidal acids were treated with hypervalent iodine reagent in CCI4 to prepare steroidal chloride. The Sudrez modification also works for bromination using iodobenzene diacetate, bromine, and CH2Br2 as the solvent under irradiation as exemplified by transformations 14—>15.22 Unlike many variations described before, the Suarez modification tolerates a variety of functional groups. 

Cholanic Acid, S0-Cholan-24-oic acid ursocho-lanic acid 176 -(I -methy].3-carboxypropy])etiocholane. C H Oj mol wt 360.56. C 79.94%, H 11.18%, O 8.87%, Steroidal acid probably formed by the dehydration and hydrogenation of certain bile acids commonly found in animals. Considered to be a chemical trademark certifying the prehistoric presence of some type of animal, see Seifert, Pure Appl. Chem. 34, 633 (1973). This status as a natural product of exclusive animal origins now questioned by its isolation from the embryo of the jequirity bean, Abrus precatorius, Leguminosae Mandava et al. Steroids 23, 357 (1974). 

The two rearrangements (Scheme 1) can however be complimentary. Thus, wittig rearrangement of the steroidal acid (46) gives exclusively the threo-hydroxy-acid (47) whereas enolate Claisen rearrangement of the... 

Heinrich Otto Wieland (Germany) for his investigations of the constitution of the bile acids and related substances. The bile acids are a set of steroid acids whose synthesis begins in the liver with the production of chloic acid chenodeoxycholic acid (all of which derive from cholesterol). Wieland isolated and determined the structure of a number of these biochemically significant compounds. During his career he also isolated toxins from poisonous frogs and mushrooms. 

A chiral host could readily be available from a naturally occurring compound. The use of steroidal acid, deoxycholic acid (Fig. 3d), yielded coinprehensive polymers, particularly, optically active polymers from pro-chiral monomers. Many derivatives of deoxy cholic acid have the corresponding characteristic inclusion abilities. For example, use of apocholic acid (Fig. 3e), cholic acid (Fig. 3f), and chenodeoxycholic acid (Fig. 3g) enabled us to perform one-dimensional inclusion polymerization of various diene and vinyl monomers. 

The conversion of 3a,7a,12a-trihydroxy-5)5-cholestanoic acid into cholic acid (cholyl coenzyme A) occurs by means of a /9-oxidation with release of propionic acid (propionyl coenzyme A) (Fig. 2). Although no definite experimental evidence is available, it may be assumed that the reactions involve the coenzyme-A esters of the steroid acids. Only one of the intermediates in the /9-oxidation of 3a,7a,12a-trihydroxy-5/9-cholestanoic acid has been isolated. Masui and Staple (88,89) have shown that the mitochondrial fraction of rat liver homogenate supplemented with the 100,000g supernatant fluid catalyzes the conversion of 3a,7a,12a-trihydroxy-5/9-cholestanoic acid into one of the two C-24 epimers of 3a,7a,12a,24-tetrahydroxy-5/9-choles-tanoic acid. It is probable that the C-24 isomer formed is the 24a-hydroxy compound (89,90). The transformation of 3a,7a,12a,24a-tetrahydroxy-5/9-cholestanoic acid into cholic acid is catalyzed by the 100,000g supernatant fluid of rat liver homogenate (89). No studies have yet been carried out to compare the enzymes catalyzing /9-oxidation of 3a,7a,12a-trihydroxy-5/9-... 

Bile salts with a steroid structure appear to be confined to vertebrates (76). In some evolutionarily more primitive vertebrates, the major bile salts are sulfate esters of polyhydroxy C27- and C26-steroids and/or taurine-conjugated C27-steroid acids. In other primitive vertebrates, C24 bile acids, usually cholic acid and/or allocholic acid, or mixtures of primitive bile salts (bile alcohols and C27 bile acids) and modern bile salts (C24 bile acids) occur. Most of the work concerning the structure and occurrence of primitive bile salts has been carried out in the laboratories of G. A. D. Haslewood and T. Kazuno, and Haslewood and collaborators have accumu-... 

From Figure 1.4, we can see the different compounds and structures that are formed by the different raw materials. The steroid acid products are straight structures, while the octanoic acid products are short and thick. 

TEM micrographs of nanorods, (a) Octanoic acid, (b) Laurie acid, (c) and (d) Steroid acid (Luetal., 2007). 

We found that a natural steroidal acid, deoxycholic acid and its derivative, apocholic acid (Figure 1), can serve as effective host components for inclusion polymerization [1-4]. These hosts meet the requirements for the synthesis of stereoregular as well as optically... 

Chemically, the bile acids are hydroxylated derivatives of cholanic acid, a tetracyclic steroid acid of 24 carbon atoms. The acids occur in nature largely as the water-soluble sodium salts of peptide conjugates of glycine and taurine. The free acids are liberated by saponification or specific enzyme hydrolysis. The chemistry of the bile acids has been reviewed in Chapter 1 of this volume (1). In view of their highly polar nature, special attention is called to the recent discovery of the cholic acid conjugates of ornithine (2, 3) and the 3a-sulfate esters of glycolithocholic and taurolithocholic acids (4). 

Molecular architecture of steroidal acids and their derivatives selective acquisition of polymorphic inclusion crystal of cholic acid... 

Decarboxylation.—Selenoesters (RCOSePh), derived from carboxylic acids by way of the acid chloride, are transformed to the alkane (RH) on heating with tri-n-butyltin hydride in the presence of a radical initiator, whereas under photolytic conditions the corresponding aldehyde (RCHO) is the major product. Yields of decarboxylated product from various steroidal acids are high, but the conditions must be carefully controlled. The same degradation can be... 

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