Ruizgenin,a new steroidal sapogenin diol from AgaveLecheguilla

From the leaves of Agavelecheguilla Torrey, two steroidal sapogenin diols have been isolated. Mass spectral, infra-red and nuclear magnetic resonance data of these two compounds showed them to be (25R) spirost-5-ene-2α, 3β-diol (yuccagenin) and (25R)-5β-spirostane-3β,6α-diol. The latter is a new compound to which the trivial name ruizgenin has been given.     

Dinoflagellate sterols IV: Isolation and structure of 4α,23ξ,24ξ-trimethylcholestanol from the dinoflagellate Glenodiniumhallii

The dinoflagellate $\text{Glenodinium}$$\text{hallii}$ was investigated for its sterol composition. Five of the six sterols were isolated and identified as cholest-5-en-3β-ol, (24ξ)-24-methylcholest-5-en-3β-ol, stigmasta-5,22-dien-3β-ol, (22E,24R)-4α,23,24-trimethyl-5α-cholest-22-en-3β-ol, and 4α,23ξ,24ξ-trimethyl-5α-cholestan-3β-ol.     

1β-Hydroxyneotigogenin,a sapogenin from Solanum polyadenium leaves

A new sapogenin has been isolated from leaves of Solanum polyadenium P.I. 161728, a clone that is highly resistant to Colorado potato beetle and potato leaf hopper. The structure of this compound has been established as 1β-hydroxyneotigogenin, 5α-spirostan-1β,3β-diol.     

Minor and trace sterols from marine invertebrates 28. A novel polyhydroxylated sterol from the soft coral Anthelia glauca

A novel sterol containing four hydroxy groups has been isolated from the soft coral $\text{Anthelia glauca.}$ Its structure, 5α-ergostane-3β, 5,6β,7β-tetrol ($\text{1}$), has been deduced by spectroscopic methods and confirmed by comparison with a synthetic analog.     

Marine sterols. XIII.★ Isolation and synthesis of 1β,3β,5,6β-tetrahydroxy-5α-androstan-17-one from the soft coral Sarcophyton glaucum

A new polyhydroxysterol 1β,3β,5,6β-tetrahydroxy-5α-androstan-17-one ($\text{1}$) was isolated from the soft coral $\text{Sarcophyton glaucum}$. The structure of $\text{1}$ was deduced from comparison of the spectral data with those of known 1β,3β,5α,6β-tetrahydroxysterols and confirmed by the synthesis starting from 1β,3β-dihydroxy-5,16-pregnadien-20-one ($\text{6a}$)     

Two new triterpenoids from Rhodomyrtus tomentosa

Repetition of an investigation of the petrol extracts of Rhodomyrtus tomentosa has led to the isolation of two new triterpenoids, R₄ from the leaves and R₅ from the stems besides R₁, R₂, R₃ and the other known compounds already reported. R₁ and R₄ were proved to be 21α$\text{H}$-hop-22(29)en-3β,30-diol and 3β-hydroxy-21α$\text{H}$-hop-22(29)-en-30-al respectively, and R₂, R₃ and R₅ are 3β-acetoxy-11α,12α-epoxyoleanan-28,13β-olide, 3β-acetoxy-12α-hydroxyoleanan-28, 13β-olide and 3β-acetoxy-12-oxo-oleanan-28,13β- olide respectively. The ethanol extract of the leaves contained betulinic, ursolic and aliphitolic acids and that of the stems betulonic, betulinic and oleanolic acids.     

Marine natural products: 5alpha-cholestane-3beta,5,6beta,9-tetrol: a polyhydroxylated steroid from the gorgonian Pseudopterogorgia elisabethae.

A tetrahydroxylated steroid isolated from a gorgonian, $\text{Pseudopterogorgia elisabethae}$, has been shown by spectral analyses and degradative studies to be 5α-cholestane-3β,5,6β,9-tetrol.     

Solanolide,a steroid lactone sapogenin from Solanum hispidum

Solanolide, a new C₂₂ steroid lactone sapogenin isolated from the leaves of Solanum hispidum Pers., has been characterized as 3β, 6α, 16β-trihydroxy-5α-pregnane-20S-carboxylic acid (22, 16)-lactone from ¹H and ¹³C NMR analyses and correlation with neochlorogenin.     

Intramolecular catalysis. VII: The nature of side chain shielding of the 12alpha-hydroxyl group of steroids

A series of 12α-hydroxy steroids with varying side chains was prepared, and their 24-hour acetylation yields were compared, l2α-Hydroxy-5β-pregnan-20-one ($\text{lb}$) was prepared from 3α, 12α-diacetoxy-5β~pregnan-20-one ($\text{2}$) and also by side chain degradation of 12α-acetoxy-5β-cholanoic acid ($\text{5d}$). 21-Benzyl-5β-pregnan-12α-ol ($\text{1g}$) was synthesized by hydrogenation of the 21-benzylidine derivative of ketone $\text{1b}$. 23-Pheny1-5β-norcholan-12α-ol ($\text{1k}$) was obtained by the Grignard reaction of 2-phenyl-ethylmagnesium bromide and ketone $\text{1b}$, dehydration, hydrogenation and hydride reduction; a similar sequence produced 20-methyl-5β-pregnan-12α-ol ($\text{lm}$). The acetylation results (Table 11) imply that branching at C-20 may be more significant for 12α-hydroxyl reactivity than side chain length or type. An additional compound with an unbranched side chain, 21-nor-5β-cholan-12α-ol ($\text{14}$), was synthesized by a Grignard reaction on the 21-bromo intermediate $\text{11b}$. Acetylation rates determined by glc indicate (Table 111) That compounds with unbranched side chains have 12α-hydroxyl groups about ten times as reactive as their analogs with 20-methyl groups.     

Reactions of 4β,5-epoxy-5β-androstan-3-ones with hydrogen fluoride in pyridine

4β,5-Epoxy-5β-androstane-3,17-dione ($\text{1a}$), 17β-hydroxy-4β,5-epoxy-5β-androstan-3-one ($\text{1b}$) and 17β-acetoxy-4β,5-epoxy-5β-androstan-3-one ($\text{1c}$) were treated with anhydrous hydrogen fluoride in pyridine (70% solution) at 55° and yielded the corresponding 4-en-4-ols e.g. 4-hydroxy-4-androstene-3, 17-dione ($\text{2a}$).As the reaction temperature was lowered each epoxide formed a second product which, at ?75°, was the major component of the reaction mixture and was identified as the 5α-fluoro-4α-ol derivative of the parent enone, e.g. 4α-hydroxy-5-fluoro-5α-androstane-3,17-dione ($\text{3a}$). These fluorohydrins are thermally unstable, losing hydrogen fluoride.The acetates of the fluorohydrins were also prepared, characterized, and shown to be more stable than the parent alcohols.     

A rapid,sensitive method for simultaneous measurements of tissue levels of oxygenated derivatives of cholesterol

A mass spectrometric procedure which utilizes multiple selected ion monitoring (SIM) for measuring the tissue levels of cholest-5-en-3β,7α-diol, cholest-5-en-3β,7β-diol, cholest-5-en-3β,25-diol, and cholest-5-en-3β-ol-7-one is described. Trimethylsilyl ethers (TMS) of sterols in a lipid extract are analyzed directly by focusing the ions at $\text{m}\text{e}$ 546, 472, and 443. Endogenous cholesterol serves as an internal standard and its concentration is determined by gas chromatography. The sensitivity of this method has allowed measurement of 2 ng of oxygenated sterol which corresponded to the amount present in 1 mg of rat liver.     

Minor and trace sterols in marine invertebrates 39.1 24ξ,25ξ-24,26-cyclocholest-5-en-3β-ol,a novel cyclopropyl sterol.

The novel cyclopropyl sterol, 24ξ, 25ξ-24, 26-cyclocholest-5-en-3β-ol (24, 26-cyclocholesterol), has been isolated from the sponge $\text{Spheciospongia sp}$. ($\text{Spirastrella vagabunda}$ Ridley) and its structure established by spectral analysis and by correlation with papakusterol.     

A-nor steroids. 1. The stereochemistry of A 2-carbomethoxy-A-nor-cholestan-3-one obtained via the Dieckmann condensation

The Dieckmann condensation of dimethyl 3, 4-$\text{seco}$-5α-cholestan-3, 4-dioate ($\text{1}$), using sodium methoxide in benzene under reflux for two hours, is shown to give 2α-carbomethoxy-A-nor-5α-cholestan-3-one ($\text{2}$). Confirmation of the stereochemistry of the β-keto ester $\text{2}$ was obtained through its sodium borohydride reduction product, 2α-carbomethoxy-A-nor-5α-cholestan-3β-ol ($\text{4}$).     

Synthesis of 16α-bromoacetoxy androgens and 17 β-bromoacetylamino-4-androsten-3-one: Potential affinity labels of human placental aromatase

A novel synthesis of 16α-hydroxy-4-androstene-3,17-dione ($\text{3}$), 16α-hydroxy-4-androstene-3, 6,17-trione ($\text{4}$), 17β-amino-5-androsten-3β-ol ($\text{10}$) and 17β-amino-4-androsten-3-one (14) is described. 16α-Bromoacetoxy-4-androstene-3, 17-dione ($\text{5}$), 16α-bromoacetoxy-4-androstene-3, 6,17-trione ($\text{6}$) and 17β-bromoacetylamino-4-androsten-3-one ($\text{15}$) were synthesized as potentially selective irreversible inhibitors of androgen aromatases. 16α-Bromo-4-androstene-3,17-dione ($\text{1}$) and 16α-bromo-4-androstene-3, 6,17-trione ($\text{2}$) were converted to compounds $\text{3}$ and $\text{4}$ in 80–90% yield by controlled stereospecific hydrolysis using sodium hydroxide in aqueous pyridine. Reductive amination of 3β-hydroxy-5-androsten-17-one and 3-methoxy-3,5-androstadien-17-one ($\text{11}$) using ammonium acetate and sodium cyanohydridoborate (NaBH₃CN) and a subsequent treatment with acid gave the amines $\text{10}$ and $\text{14}$ respectively, as a salt. The corresponding 17-imino compounds $\text{9}$ and $\text{13}$ were also isolated from the reaction mixtures when methanol was used as a solvent for the reaction. The 16α-hydroxyl compounds $\text{3}$ and $\text{4}$ and the 17β-amino compound $\text{14}$ were con- verted to the corresponding bromoacetyl derivatives, $\text{5}$, $\text{6}$, and $\text{15}$, with bromoacetic acid and N,N'-dicyclohexylcarbodiimide.     

Androgen metabolism by rat epididymis. 1. Metabolic conversion of 3 H-testosterone in vivo

The epididymis of adult rats metabolize ³H-testosterone by experiments $\text{in vivo}$. Thirty minutes after the injection of 100 μCi ³H-testosterone, some 10 per cent of the total radioactivity of the epididymis was found in the water-soluble fraction, whereas 90 per cent was found in the ether soluble fraction (free steroids). The free steroids were examined further and the following androgenic metabolites identified: $\text{testosterone}$ (17β-hydroxy-4-androsten-3-one) 8, 9%, $\text{androstendipne}$ (4-androstene-3, 17-dione, 2,7%,$\text{5α-A-dione}$ (5α-androstane-3, 17-dione) 6,5%, $\text{DHT}$ (17β-hydroxy-5α-androstan-3-one) 47, 2%, $\text{3β-diol}$ (5α-androstane-3β, 17β-diol) 4, 4%, $\text{3α-diol}$ (5α-androstane-3α,17β-diol) 20, 8% and $\text{androsterone}$ (3α-hydroxy-5α-androstan-3-one) 3,4%. The relative amount of each metabolite is given in per cent of total radioactivity in the ether soluble fraction.     

Specificity in the enzymic transfer of sialic acid to the oligosaccharide branches of BI- and triantennary glycopeptides of α1-acid glycoprotein

Partial $\text{in}\text{vitro}$ sialylation of biantennary and triantennary glycopeptides of α₁-acid glycoprotein using colostrum β-galactosideα(2→6) sialyltransferase followed by high resolution ¹H-NMR spectroscopic analysis of the isolated products enabled the assignment of the $\text{Galβ(1→4)GlcNAcβ(1→2)Man}\text{α(1→3)}\text{Man}$ branch as the most preferred substrate site for sialic acid attachment. The $\text{Galβ(1→4)GlcNAcβ(1→2)Man}\text{α(1→6)}\text{Man}$ branch appeared to be much less preferred and the Galβ(1→4)GlcNAcβ(1→4)Manα(1→3)Man sequence of triantennary structures was of intermediate preference for the sialyltransferase. The specificity of the β-galactoside α(2→6) sialyltransferase is thus shown to extend to structural features beyond the terminal $\text{N}$-acetyllactosamine units on the oligosaccharide chains of serum glycoproteins.     

Minor sterols of marine invertebrates 37. Isolation of novel coprostanols and 4α-methyl sterols from the tunicate Ascidia nigra

The complex sterol mixture isolated from $\text{A, nigra}$ was found to contain a low level of Δ⁴-3-keto steroids, 5β-stanols and 4α-methyl sterols in addition to regular (4-demethyl) sterols. The following new marine sterols were isolated and identified using MS and 360 MHz NMR: 5β-cholest-22E-en-3β-ol, 24S-methyl-5β-cholest-22E-en-3β-ol, 24-methylene-5β-cholestan-3β-ol, both epimers at C-24 of 4α-methyl-24-ethyl-5α-cholest-22E-en-3β-ol, 4α, 22ξ, 23ξ-(or 24ξ-)trimethyl-5α-cholest-8(14)-en-3β-ol and (22S, 23S, 24S)-4α-24-dimethyl-22, 23-methylene-5α-cholestan-3β-ol. The latter sterol and 23-demethylgorqosterol have opposite configurations at C-22, C-23, and C-24; the Δ⁸⁽¹⁴⁾ sterol has an unprecedented side chain.     

Structure of the ceramide octadekahexoside isolated from gastric mucosa

A fucose-containingceramide octadekahexoside exhibiting blood-group (A+H) activity has been isolated from hog gastric mucosa. Based on the results of partial acid hydrolysis, sequential degradation with specific glycosidases, oxidation with periodate and chromium trioxide, and permethylation analysis, we propose that the carbohydrate chain of this fucolipid contains four branches. Two of the branches are terminated by βGall→4βGlcNAc, one by $\text{αFucl→2βGall→}\text{3}\text{4}\text{βGlcNAc}$ and one by $\text{αGalNAcl→3(αFucl→2)βGall→}\text{3}\text{4}\text{βGlcNAc}$.     

Sterols of a diatomaceous ooze from walvis bay

Almost an of the solvent-extractable sterols and their nuclearsaturated analogues in a sample of Walvis Bay surface sediment have been analysed by capillary GLC and GC-MS, and by coinjection with a variety of standards. The presence in sediments of 22-$\text{trans}$-24-nor-5α-cholest-22-en-3β-ol, 24-methylene-5α-cholestan-3β-ol, and components tentatively assigned as 23,24-dimethylcholesta-5,22-dien-3β-ol and 23,24-dimethyl-5α-cholest-22-en-3β-ol has been demonstrated for the first time. A novel sterol and its saturated analogue have also been found. The sterol distribution cannot be related solely to the reported major input of phytoplankton; the presence of 22,23-methylene-23,24-dimethylcholest-5-en-3β-ol and its saturated analogue indicates a coelenterate contribution. The analysis emphasises the necessity of glass capillary columns and coinjection of standards.     

Sterol biosynthesis: Establishment of the structure of 3β-p-bromobenzoyloxy-5α-cholest-8(14)-en-15β-ol

Previous studies have established that hydride reduction of 3β-benzoyloxy-5α-cholest-8(14)-en-15-one yields two epimers (at C-15) of 5α-cholest-8(14)-en-3β,15-diol which were designated as diol A and B. Efficient enzymatic conversion of both compounds to cholesterol was observed. To determine the absolute configuration of the 15-OH function in the two compounds, the 3β-p-bromobenzoyl ester of diol B was prepared from 3β-p-bromobenzoyloxy-5α-cholest-8(14)-en-15-one by reduction with sodium borohydride. Crystals of the derivative were found to belong to the space group P1, with unit cell parameters; $\text{a = 9.24}\text{A}\text{?}$, $\text{b = 12.61}\text{A}\text{?}$, $\text{c = 7.03}\text{A}\text{?}$, α = 93.05°, β = 100.27°, γ = 90.82°, and one molecule per unit cell. Least-squares refinement of the structure was carried out to final R value of 0.14. The configuration of the hydroxyl group at the 15 position of diol B has been determined to be β.