- 7-Dehydrocholesterol reductase activity is independent of cytochrome P450 reductase
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7-Dehydrocholesterol reductase (DHCR7) catalyzes the final step in cholesterol synthesis. The enzyme utilizes NADPH as a source of electrons and has been reported to require NADPH-cytochrome P450 reductase (POR) as its redox partner. To test this hypothes
- Zou, Ling,Li, Li,Porter, Todd D.
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experimental part
p. 435 - 438
(2012/04/23)
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- PROCESS FOR RECOVERING STEROLS FROM A CRUDE SOURCE CONTAINING STEROL ESTERS
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A process of obtaining sterols suitable for human consumption from a crude wood pulping source containing sterol esters is disclosed. The sterols are obtained at high yield and purity. In particular, a process of obtaining sterols at high yield and purity from tall oil pitch (TOP) is disclosed. The sterols obtained can be esterified to sterol esters for use in dietary supplements and as additives for food and beverage products.
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Page/Page column 3
(2008/12/06)
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- Process for recovery of plant sterols from by-product of vegetable oil refining
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The process for recovery of plant sterols and tocopherols from deodorization distillates formed during chemical or physical refining of vegetable oils consists of the following steps: free fatty acids are removed from the deodorization distillate by vacuum distillation or by continuation solvent saponification, after the removal of free fatty acids, the received material is reacted with an aromatic carboxylic acid anhydride at a temperature of 50-150° C., under reduced pressure, after the treatment with anhydride, tocopherols are removed from the mixture, and crystalline free sterols are recovered from the distillation residue containing sterol esters, di- and triglycerides by transesterification.
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Page/Page column 5-6
(2008/06/13)
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- Method of producing a vitamin product
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A process for producing a nutrient supplement powder is provided. The process forms a powder into a plastic mass which is not completely molten. The plastic mass is then formed into an elongated shape and allowed to cool to set to a solid state. The solid is then comminuted to obtain a powder having a desirable particle size, e.g. not more than 5% by weight through a 120-mesh sieve and not more than 5% by weight retained on a 14-mesh sieve.
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- A NEW SYNTHESIS OF BRASSICASTEROL
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A new method has been developed for obtaining brassicasterol - the initial compound for the synthesis of the natural brassinosteroid epibrassinolide.
- Khripach, V. A.,Zhabinskii, V. N.,Zhernosek, E. V.
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- Biosynthetic Studies of Marine Lipids. 33. Biosynthesis of Dinosterol, Perdinosterol, and Gorgosterol: Unusual Patterns of Bioalkylation in Dinoflagellate Sterols
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The biosynthesis of the 23-methylated dinoflagellate sterols gorgosterol (1-N), dinosterol (2-K), and peridinosterol (3-K) was demonstrated experimentally using cell-free extracts of the dinoflagellates Cryptothecodinium cohnii, Peridinium foliaceum, and the cultured zooxanthella symbiont of Cassiopea xamachana.In assays of sterol methyltransferases using 3H>-S-adenosylmethionine, radiochemical conversions were demonstrated by reverse phase HPLC of the Δ24 sterol side chain (5) to the 24-methylene side chain (4); of the sequence 24(R)-4α-methylergost-22-enol (9-K) to dinosterol (2-K) to 4α-methylgorgostanol (1-K); and, in P. foliaceum, of 24(R)-4α-methylergost-22-enol (9-K) to peridinosterol (3-K).Methylation of the 24(R)-methyl Δ22 side chain (9) in P. foliaceum is believed to involve more than one SAM-sterol methyltransferase based on changes in the ratios of the products (2 and 3) with changes in the conditions of the assay.Furthermore, deuterium substitution of the sterol substrate (9-K) at C-23 did not significantly alter the product ratio.A hypothesis is put forward that the attenuation of gorgosterol (1-N) production in aposymbiotic zooxanthellae is linked to an increase in dimethylpropiothetin biosynthesis via a decrease in S-adenosylmethionine concentration.
- Giner, Jose-Luis,Djerassi, Carl
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p. 2357 - 2363
(2007/10/02)
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- 24-EPIBRASSINOLIDE UPTAKE IN GROWING MAIZE ROOT SEGMENTS EVALUATED BY MULTIPLE-SELECTED ION MONITORING
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The evaluation of the uptake of 24-epibrassinolide (BR) in growing maize root segments by means of multiple-selected ion monitoring showed that BR is accumulated into the fresh tissue independently of energy supply, while the experiments performed with fr
- Allevi, Pietro,Anastasia, Mario,Cerana, Raffaella,Ciuffreda, Pierangela,Lado, Piera
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p. 1309 - 1314
(2007/10/02)
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- Studies on the Constituents of Orchidaceous Plants. III. Isolation of Non-conventional Side Chain Sterols from Nervilia purpurea SCHLECHTER and Structure Determination of Nervisterol
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From the neutral fraction of the ether extract of Nervilia purpurea SCHLECHTER (Orchidaceae), unusual side chain sterols (5a, 6a, and 7a), previously reported as the constituents of marine invertebrates, were isolated along with 24-epibrassicasterol, 24ξ-methylcholesterol, ergosterol, and stigmasterol.A new non-conventional side chain sterol, named nervisterol (8a), was also isolated and its structure was elucidated.Keywords- Nervilia purpurea; Orchidacea; non-conventional side chain sterol; nervisterol; 22-dehydro-24-isopropylcholesterol; 24-isopropylcholesterol; 24ξ-isopropenylcholesterol; 24-epibrassicasterol; GC-MS;1H-NMR
- Kikuchi, Tohru,Kadota, Shigetoshi,Suehara, Hisashi,Namba, Tsuneo
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p. 2235 - 2242
(2007/10/02)
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- Selective Reduction of the 7(8)-Double Bond in Ergosterol
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Reduction of ergosterol alkoxide derivatives with lithium metal gives better yields of the 7(8)-reduced product brassicasterol than previous procedures; the mixed products of the reduction are easily converted into ergosta-2,22-dien-6-one, a convenient in
- Barton, Derek H. R.,Lusinchi, Xavier,Magdzinski, Leon,Ramirez, Jesus Sandoval
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p. 1236 - 1238
(2007/10/02)
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- Side Chain Structural Requirement for Utilization of Sterols by the Silkworm for Growth and Development. Non-stereoselective Utilization of the 24-Stereoisomeric Pairs of 24-Alkylsterols
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Four C-24 epimeric pairs of 24-alkylsterols 1-8 were stereoselectively synthesized via orthoester Claisen rearrangement of the (22)R or (22S)-Δ23Z steroid derivatives (11 and 12).These compounds were tested on the silkworm larvae, Bombyx mori, in order to examine the relationship of the C-24 stereochemical arrangement and utilizability as a nutrient sterol.All of the tested sterols effectively supported the growth and development of the insect and were converted into cholesterol regardless of the C-24 configuration.Keywords - 24-alkylcholesterol; 24-alkyl-22-dehydrocholesterol; orthoester Claisen rearrangement; stereoselective synthesis; insect sterol; silkworm
- Fujimoto, Yoshinori,Kimura, Miki,Khalifa, Fathy A. M.,Ikekawa, Nobuo
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p. 4372 - 4381
(2007/10/02)
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- Stereoselective Synthesis of Crinosterol
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A stereoselective synthesis of crinosterol, (22E,24S)-ergosta-5,22-dien-3β-ol, was developed from (20S)-6β-acetoxy-3α,5-cyclo-5α-pregnane-20-carbaldehyde using the Claisen rearrangement of an appropriate precursor of established absolute configuration.
- Anastasia, Mario,Allevi, Pietro,Ciuffreda, Pierangela,Fiecchi, Alberto
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p. 2365 - 2367
(2007/10/02)
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- A New Synthesis of Brassino Steroids: Plant Growth Promoting Steroids
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(22R,23R)- and (22S,23S)-2α,3α,22,23-Tetrahydroxy-B-homo-7-oxa-5α-ergostan-6-one, two physiologically active brassino steroids, have been synthesized via key intermediate brassicasterol obtained in a very simple way by reduction with lithium dissolved in ethylamine of the 1,4-cycloadduct of ergosterol and 4-phenyl-1,2,4-triazoline-3,5-dione.
- Anastasia, Mario,Ciuffreda, Pierangela,Fiecchi, Alberto
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p. 379 - 382
(2007/10/02)
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- Sterochemical Aspects of Acid-Catalyzed Cyclopropane Ring-Opening Reactions. A Stereospecific Pathway to Crinosterol and Brassicasterol
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It is shown that the acid-catalyzed ring-opening of the two diastereoisomeric 23,24-methylenecholosterols 3 and 5 on treatment with gaseous HCl in acetic acid leads sterospecifically to the naturally occuring crinosterol (4) and brassicasterol (6), respectively (Scheme 1).This isomerization can be viewed as a biomimetic model of an in vivo methylation process of the type already known in plant sterol metabolism (cf. cycloeucalenol --> obtusifoliol, 1-->2).The synthetic application of this method provides a convenient labelling of sterol side chain for tracer experiments.The mechanistic features of the reaction with respect to its particular stereospecificity are discussed.
- Lang, Robert W.,Djerassi, Carl
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p. 407 - 418
(2007/10/02)
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- A Simple Method for the Reduction of the 7,8-Double Bond of Steroidal 5,7-Dienes
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1,4-Cycloadducts of various steroidal 5,7-dienes and 4-phenyl-1,2,4-triazoline-3,5-dione gave a separable mixture (3 : 2) of the corresponding Δ5- and Δ7-sterols in good yield when treated with lithium dissolved in refluxing ethylamine.
- Anastasia, Mario,Ciuffreda, Pierangela,Fiecchi, Alberto
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p. 1169 - 1170
(2007/10/02)
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