Browsing by Author "Wilson, William K."
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Item Are Isoursenol and γ-Amyrin Rare Triterpenes in Nature or Simply Overlooked by Usual Analytical Methods?(American Chemical Society, 2015) Shan, Hui; Wilson, William K.; Castillo, Dorianne A.; Matsuda, Seiichi P.T.Among pentacyclic triterpenes commonly found in plants, γ-amyrin and isoursenol are seldom reported and considered rare in nature. It was hypothesized that these triterpenes are instead routinely overlooked due to inadequate spectral characterization. γ-Amyrin was prepared by HCOOH isomerization of α-amyrin, and isoursenol was isolated from products of a heterologously expressed oxidosqualene cyclase. With precise NMR and GC-MS data, a metabolomics strategy was used to identify isoursenol and γ-amyrin in a wide range of plants.Item Dehydro-estriol (8-DHE3) and dehydro-pregnanetriol (7-DHPT)- methods of their synthesis(2006-09-12) Shackleton, Cedric; Guo, Li-Wei; Wilson, William K.; Rice University; Children's Hospital & Research Center at Oakland; United States Patent and Trademark OfficeThe invention provides isolated dehydro-estriol (8-DHE3) and dehydro-pregnanetriol (7-DHPT), and methods of their synthesis. These compounds are useful in diagnosis of Smith-Lemli-Optiz syndrome (SLOS).Item Process for synthesis of 5.alpha.-cholest-8(14)-en-3.beta.-ol-15-one and other 15-oxygenated sterols(1990-01-30) Schroepfer, George J., Jr.; Wilson, William K.; Wang, Ker-shi; Kisic, Alemka; Rice University; United States Patent and Trademark OfficeA process for preparing 15-oxygenated sterols, such as 3β-hydroxy-5α-cholest-8(14)-ene-15 one, comprising converting 7-dehydrocholesterol to 3β-benzoyloxycholesta-5,7-diene, converting the 3β-benzoyloxycholesta-5,7-diene to a 3β-benzoyloxy-5-cholesta-7,14-diene, converting the 3β-benzoyloxy-5-cholesta-7,14-diene to a 3β-benzoyloxy-14α, 15α-epoxy-5-cholest-7-ene and converting the 3β-benzoyloxy-14α, 15α-epoxy-5-cholest-7-ene to a 15-oxygenated sterol. Preferably, the 3β-benzoyloxy-cholesta-5,7-diene is converted to a 3β-benzoyloxy-5-cholesta-7,14-diene by (i) contacting 3β-benzoyloxy-cholesta-5,7-diene, in a solvent at a temperature of at most about -55° C., with HCl at a concentration of at least about 2.0 M for a time sufficient to convert the 3β-benzoyloxycholesta-5,7-diene to a 3β-benzoyloxy-5-cholesta-7,14-diene; (ii) neutralizing the resultant reaction mixture with a base to prevent formation of a significant amount of 3β-benzoyloxy-5-cholesta-8,14-diene; and (iii) recovering the 3β-benzoyloxy-5-cholesta-7,14-diene.Item Side chain derivatized 15-oxygenated sterols- methods of using them and a process for preparing them(1994-12-06) Schroepfer, George J., Jr.; Herz, Josef E.; Swaminathan, Shankar; Wilson, William K.; Rice University; United States Patent and Trademark OfficePharmaceutical compositions are provided for lowering the activity of HMG-CoA reductase and/or lowering serum cholesterol, comprising an amount effective to lower the activity of HMG-CoA reductase and/or lower serum cholesterol of a side chain derivatized 15-oxygenated sterol having the formula (I): ##STR1## the basic ring structure being saturated or unsaturated, wherein R1 is --OH, O, --OR7, ##STR2## a sulfate group, a sugar moiety, or a Mg, Na, or K salt of a sulfate group; R2 is --H, --OH, O, mono- or di-halogen, or a C1 to C6 alkyl group, which may be unsaturated or substituted with halogen; R3 is --H, --OH, halogen, or a C1 to C6 alkyl group, which may be unsaturated or substituted with halogen; R4 is nonexistent when there is a double bond between the 8 and 14 carbons or αH, βH, or an αC1 to C6 alkyl group; R5 is --OH, O, NOH, or ##STR3## R6 is --CH2 CH(CH3)2 or CH2 N(CH3)2, in which one or more of the hydrogen atoms is replaced by OH or halogen; R7 is a C1 to C6 alkyl group; R8 is a C1 to C20 aliphatic group, which may be substituted or unsubstituted, or a phenyl group; and n is an integer of from 2 to 6; andoptionally a pharmaceutically acceptable carrier or excipient, with the proviso that R6 is not --CH2 CH(CH3)(CH2 OH). Methods of using the pharmaceutical compositions containing the side chain derivatized 15-oxygenated sterols are also provided.A new process is also provided for preparing side chain derivatized 15-oxygenated sterols. This process includes oxidative cleavage of the saturated side chain of the sterol with trifluoroperacetic acid to give a side chain trifluoroacetate and subsequent hydrolysis of this ester. The resultant side chain alcohol is a valuable and advanced intermediate for the preparation of side chain derivatives of 15-oxygenated sterols.