Subcellular distribution of free and ester-bound triterpene triols in Calendula officinalis flowers

In cellular subfractions obtained from Calendula officinalis ligulate flowers, the contents of individual free and ester-bound triterpene triols, as well as fatty acid components of the ester form, were determined. It was shown that triterpene triols are localized only in the chromoplast fraction, almost exclusively in a free form and in a very small amount as monoesters. The compositions of fatty acids esterifying triols were similar to those esterifying diols in chromoplasts.     

Ent-norlabdane triols from Austroeupatorium inulaefolium

Two new ent-norlabdane triols were isolated from the above-ground parts of Austroeupatorium inulaefolium.     

From d-xylose to terminal polyols: a simple synthetic route

A simple and efficient synthetic approach toward different terminal alkyl tetraols and triols, starting from d-xylose, is described. The opening of the oxetane ring in a suitably protected 3,5-anhydro-d-xylose derivative with Grignard reagents leads to d-xylose-derived 5-deoxy-5-C-alkyl derivatives, which are suitable for reduction to terminal polyols after protecting group hydrolysis.     

Synthesis and investigation of antimicrobial activity of 8-hydroxyquinoline glucosaminides

Synthesis of the fully acetylated 8-hydroxyquinoline O-??-D-glucosaminides and its 2-methyl- and 5-chloro-derivatives was conducted in the phase transfer catalytic system of solid potassium carbonateanhydrous acetonitrile. The respective triols were obtained by deacetylation according to Zemplen. The structure of all synthesized compounds was proven by ¹H NMR spectroscopy. Antimicrobial activity of the non-protected glycosides was investigated using the luminescence inhibition test with marine luminous bacteria Vibrio fischeri F1 as well as by the serial dilution method with Escherichia coli, Agrobacterium tumefaciens, Bacillus cereus, and Micrococcus luteus strains from culture collection. It was found that the coupling of N-acetyl-??-D-glucosamidine residue decreased antimicrobial activity in comparison with non-glycosylated forms of quinoline.     

Synthesis of Novel Acyclic Nucleoside Analogues with Anti-Retroviral Activity

A series of novel acyclic thymine nucleoside analogues were prepared by the Mitsunobu reaction from appropriately protected chiral triols. The enantiomeric triols were obtained from substituted γ-lactone acids, prepared by asymmetric oxidation of 3-substituted-1,2-cyclopentanediones. The cytotoxic activity of new analogues was evaluated on MCF-7 human breast cancer and HeLa cells, and antiviral activities on human immunodeficiency virus type 1 and hepatitis C virus models. The synthesized compounds revealed specific anti-retroviral activity and no cytotoxic side effects.     

Environmentally induced variation in diterpene composition of the marine sponge Rhopaloeides odorabile

A common Great Barrier Reef sponge, previously attributed to the genus Spongia, is described as new and placed in a new genus Rhopaloeides. This genus includes Spongiidae otherwise identical to Spongia in which the cored primary fibres form simple fascicles. The genus is also characterized by its form (massive, thick broad-based lamellae or multiple fused thick clubs). The chemistry is distinctive, characterised by possession of a rare group of C ₂₀ diterpene furanodiols, triols and their peracetates. Considerable variation in the total yield and composition of the diterpenes for different collections of R. odorabile was confusing and led to a suggestion that more than one species was represented. Field experiments in which fragments of one individual sponge were transplanted to different conditions of illumination and depth, demonstrate that the chemical variability reflects the range of environmental conditions under which R. odorabile lives rather than any genetic differences.     

Synthesis of 2-amino-2-deoxy- and 3-amino-3-deoxy-α-d-mannopyranosyl α-d-mannopyranoside by sequential osmylations of a dienic disaccharide

Partial oxyamination of 4,6-di-O-acetyl-2,3-dideoxy-α-d-erythro-hex-2-enopyranosyl 4,6-di-O-acetyl-2,3-dideoxy-α-d-erythro-hex-2-enopyranoside with chloramine-T and osmium tetraoxide gave 4,6-di-O-acetyl-2-deoxy-2-(p-toluene-sulfonamido)-α-d-mannopyranosyl 4,6-di-O-acetyl-2,3-dideoxy-α-d-erythro-hex-2-enopyranoside and its 3-deoxy-3-(p-toluenesulfonamido) regioisomer, each in 18–19% isolated yield. Osmium tetraoxide-catalyzed cis-hydroxylation of the remaining alkenic residue in these products led in high yields to the corresponding triols having the α-d-manno, α-d-manno configuration. These were N-desulfonylated (and simultaneously O-deacetylated) by the action of sodium in liquid ammonia to furnish 2-amino-2-deoxy-α-d-mannopyranosyl α-d-mannopyranoside and 3-amino-3-deoxy-α-d-mannopyranosyl α-d-mannopyranoside as new, trehalose-type amino sugars.     

Chemical synthesis of 7- and 8-dehydro derivatives of pregnane-3,17alpha,20-triols,potential steroid metabolites in Smith-Lemli-Opitz syndrome

Pregnane-3,17 alpha,20-triols bearing unsaturation at delta(7), delta(8), delta(5,7), or delta(5,8) have been tentatively identified as steroid metabolites in Smith-Lemli-Opitz syndrome (SLOS). Starting with 17 alpha-hydroxypregnenolone diacetate, we have synthesized 13 unsaturated C(21) triols by four different routes in one to four steps. These multifunctional steroids were prepared by a series of regio- and stereoselective transformations chosen to minimize facile olefin isomerization and 17-deoxygenation. The results include a study of stereoselectivity in the reduction of 17 alpha-hydroxy-20-ketosteroids, an alternative method for reducing diethyl azodicarboxylate adducts of delta(5,7) steroids, and an efficient oxidation-isomerization of a delta(5,7) steroid using cholesterol oxidase. The 13 triols and their synthetic precursors were fully characterized by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. The NMR data, together with molecular modeling, indicated unanticipated conformational heterogeneity for two synthetic intermediates, 17 alpha-hydroxypregna-4,7-diene-3,20-dione and 17 alpha-hydroxy-5 beta-pregn-7-ene-3,20-dione. The unsaturated C(21) triols are useful as reference standards to study adrenal steroid production in SLOS and to develop methods for pre- and postnatal diagnosis of this congenital disorder.     

Intracellular localization of metabolism of lupeol and its palmitate in Calendula officinalis flowers

In the non-fractionated flowers and in the chromoplast and extra-chromoplast fractions obtained from Calendula officinalis flowers the incorporation of radioactivity after incubation with [3-³H]lupeol and [3-³H]lupeyl[¹⁴C]palmitate were determined. It was shown that both precursors were metabolized. Monol esters are the main precursors of diol 3-monoesters, whereas free monols are hydroxylated to the diols and triols. The shape and course of the dynamic curves suggest that the process of hydroxylation of free monols, free diols and monol esters is situated only inside chromoplasts. On the other hand the hydrolysis of monol esters and esterification of free monols proceeds both outside and inside the chromoplasts.     

Regio- and stereospecific synthesis of rac-carbasugar-based cyclohexane pentols; Investigations of their α- and β-glucosidase inhibitions

In the present study, (3aR,7aS)-1,3,3a,4,7,7a-hexahydroisobenzofuran was submitted to photooxygenation and two isomeric hydroperoxides were successfully obtained. Without any further purification, reduction of the hydroperoxides with titanium tetraisopropoxide catalyzed by dimethyl sulfide gave two alcohol isomers in high yields. After acetylation of alcohol with Ac₂O in pyridine, epoxidation reaction of formed monoacetates with m-CPBA, then chromatographed and followed by hydrolysis of the acetate groups with NH₃ in CH₃OH resulted in the formation of epoxy alcohol isomers respectively. These epoxy alcohol isomers were subjected to trans-dihydroxylation reaction with acid (H₂SO₄) in the presence of water to afford triols. Acetylation of the free hydroxyl groups produced benzofuran triacetates in high yields. Ring-opening reaction of furan triacetates with sulfamic acid catalyzed in the presence of acetic acid/acetic anhydrate and subsequently hydrolysis of the acetate groups with ammonia gave the targeted cyclohexane carbasugar-based pentols. All products were separated and purified by chromatographic and crystallographic methods. Structural analyses of all compounds were conducted by spectral techniques including NMR and X-ray analyses. The biological inhibition activity of the target compounds was tested against glycosidase enzymes, α- and β-glucosidase.     

Polyurethane networks from fatty-acid-based aromatic triols: synthesis and characterization

Novel biobased aromatic triols (1,3,5-(9-hydroxynonyl)benzene and 1,3,5-(8-hydroxyoctyl)-2,4,6-octylbenzene) were synthesized through the transition-metal-catalyzed cyclotrimerization of two alkyne fatty acid methyl esters (methyl 10-undecynoate and methyl 9-octadecynoate) followed by the reduction of the ester groups to give terminal primary hydroxyl groups. A series of biobased segmented polyurethanes based on these triols, 1,4-butanediol as a chain extender and 4,4'-methylenebis(phenyl isocyanate) as a coupling agent, were synthesized. Samples were prepared with hard-segment contents up to 50%. The morphologies and thermal properties of these polyurethanes were studied by Fourier transform infrared spectroscopy, wide-angle X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical thermal analysis. Partial crystallinity and phase separation were detected in samples with hard-segment content of 50%.     

Hydroxy functional acrylate and methacrylate monomers prepared via lipase—catalyzed transacylation reactions

Candida antarctica lipase B (CAL-B, Novozyme 435) catalyzes the transacylation of methyl acrylate and methyl methacrylate with diols and triols in 2-methyl-2-butanol at 50 °C. Under the experimental conditions, up to 70 mol% of the acyl donor methyl acrylate was converted. Methyl methacrylate is the less efficient acyl donor (up to 60 mol%) due to the higher sterical hindrance in the enzymatic transacylation. Under the reaction conditions high yields of the mono-acylated products are obtained, which contain minor amounts of bis(meth)acrylates. In addition it was observed that Novozyme 435 catalyzes regioselectively the acylation of the primary hydroxyl groups. In comparison with the chemical catalyzed route no selectivity was observed for unsubstituted diols. For substituted diols more mono-acylated product was formed in the lipase-catalyzed reaction than in the chemical catalyzed reaction.     

Purification and properties of a polyvinyl alcohol-degrading enzyme produced by a strain of Pseudomonas

An enzyme which degraded polyvinyl alcohol, a water-soluble synthetic polymer, was isolated as a single protein from a culture of a strain of Pseudomonas. The pink-colored enzyme had absorption maxima at 280, 370, and 480 nm, a molecular weight of about 30,000, and an isoelectric point at about pH 10.3. The enzyme was most active at pH values from 7 to 9 and at 40 dgC and was stable at pH values from 3.5 to 9.5 and at temperatures below 45 dgC. The viscosity of the reaction mixture decreased and the pH dropped when the enzyme acted on polyvinyl alcohol as a substrate. Furthermore, the enzyme required O₂ for the reaction and produced 1 mol of H₂O₂, per 1 mol of O₂ consumed. The molecules of polyvinyl alcohol were cleaved into small fragments with a wide distribution of molecular weights. Inorganic Hg ions markedly inactivated the enzyme, and the activity was immediately recovered by glutathione. Enzyme inhibitors tested, which included p-chloromercuribenzoic acid, KCN, o-phenanthroline, and H₂O₂, showed no effect on the activity. Polyvinyl alcohol oxidized by periodic acid was similarly oxidized by the enzyme. The enzyme did not oxidize most of a variety of low molecular weight hydroxy compounds examined, such as primary alcohols, secondary alcohols, tertiary alcohols, diols, triols, and polyols, except for some secondary alcohols, such as 4-heptanol.     

Isolation and catalytic activity of cytochrome P-450 from ventral prostate of control rats

5 alpha-Androstane-3 beta, 17 beta-diol hydroxylase (3 beta-diol hydroxylase), a form of cytochrome P-450, was purified from rat ventral prostate, and its regulation as a function of age and 5 alpha-dihydrotestosterone (DHT) treatment was examined. Cytochrome P-450 could be quantitated by its CO difference spectrum only after partial purification from the microsomal membrane, and this was achieved by chromatography on p-chloroamphetamine-coupled Sepharose. Further purification of prostate microsomal P-450 by anion exchange chromatography yielded a preparation with a P-450 content of 8-10 nmol/mg of protein, which upon sodium dodecyl sulfate electrophoresis showed, in the molecular weight region between 50,000 and 60,000 where P-450 is expected to migrate, a single protein band of Mr 54,000. This preparation upon reconstitution with cytochrome P-450 reductase and microsomal lipid catalyzed the formation of three triols, 5 alpha-androstane-3 beta, 7 beta, 17 beta-triol, 5 alpha-androstane-3 beta, 6 alpha, 17 beta-triol, and 5 alpha-androstane-3 beta, 7 alpha, 17 beta-triol from 3 beta-diol in the ratio 1:7:3. Both turnover number and the ratio of the three products in the reconstituted system were similar to that found in prostate microsomes. These data indicate that a single form of P-450 catalyzes the formation of all three triols and that 3 beta-diol hydroxylase is the major, if not the only, form of P-450 in the prostate microsomes of untreated rats. The yield of P-450 from prostate microsomes varied as a function of age from a high level of 0.05 nmol/mg of microsomal protein in 6-week-old rats to 0.002 nmol/mg of microsomal protein in rats 11 weeks or older. 3 beta-Diol hydroxylase activity followed a similar age-related pattern varying between 2,000 and 4,000 nmol of triols formed/g of tissue/h in 6-week-old rats to 100 nmol of triols formed/g of tissue/h in 11-week-old rats. Treatment of 6-week-old rats with DHT did not prevent the age-related decrease in 3 beta-diol hydroxylase activity. However, DHT does play a role in the regulation of this enzyme since castration resulted in a loss of catalytic activity from the prostate and treatment of castrated rats with DHT caused an induction of the enzyme.     

SAR studies of gymnasterkoreayne derivatives with cancer chemopreventive activities

We synthesized diyne triols based on gymnasterkoreayne and evaluated their cancer chemopreventive activities in terms of the chemopreventive index (CI) to reveal the structure-activity relationship, and discovered more active compounds than natural diynes.     

Lipoprotein lipase releases esterified oxylipins from very low-density lipoproteins

We previously demonstrated that defects in lipoprotein metabolism alter the distribution of oxygenated polyunsaturated fatty acids (PUFAs) in lipoprotein particles. If these oxidation products are released by lipoprotein lipase (LpL), then their delivery to peripheral tissues with bulk lipids could influence cellular function. Using 26-week-old normolipidemic and hyperlipidemic Zucker rats, we measured PUFA alcohols, epoxides, diols, ketones, and triols (i.e. oxylipins) in esterified and non-esterified fractions of whole plasma, VLDL, and LpL-generated VLDL-lipolysates. Whole plasma, VLDL, and lipolysate oxylipin profiles were distinct and altered by hyperlipidemia. While >90% of the whole plasma oxylipins were esterified, the fraction of each oxylipin class in the VLDL varied: 46% of alcohols, 30% of epoxides, 19% of diols, <10% of ketones, and <1% triols. Whole plasma was dominated by arachidonate alcohols, while the linoleate alcohols, epoxides, and ketones showed an increased prevalence in VLDL. LpL-mediated VLDL lipolysis of PUFA alcohols, diols and ketones was detected and the relative abundance of oxygenated linoleates was enhanced in the lipolysates, relative to their corresponding VLDL. In summary esterified oxylipins were seen to be LpL substrates with heterogeneous distributions among lipoprotein classes. Moreover, oxylipin distributions are changes within the context of obesity-associated dyslipidemia. These results support the notion that the VLDL–LpL axis may facilitate the delivery of plasma oxylipins to the periphery. The physiological implications of these findings are yet to be elucidated; however, these molecules are plausible indicators of systemic oxidative stress, and could report this status to the peripheral tissues.     

Effect of chirality at C-20 of methyl 11beta,17alpha,20-trihydroxy-3-oxo-1,4-pregnadien-21-oate derivatives on antiinflammatory activity

In an effort to determine the C-20 chirality effect on the antiinflammatory activity of 17beta-glycolate esters, methyl 11beta,17alpha,20-trihydroxy-3-oxo-1,4-pregnadien-21-oate and its 9alpha-fluoro analog, their acetonide and their carbonate derivatives were synthesized and evaluated. The agents were tested for their binding potency to the macrophage glucocorticoid receptor, and their effect on LPS-induced nitric oxide generation in RAW 264.7 cells. The acetonide derivatives showed the highest binding affinity while the triols and carbonates bound rather poorly to the receptors. With the exception of the triols, the alpha-isomer in each pair of the agents exhibited higher binding affinity to the receptor than its corresponding beta-isomer, clearly indicating that C-20 chirality has a significant effect on antiinflammatory activity. In addition, the alpha-isomers of the acetonides showed substantially higher binding affinity than the parent compound, prednisolone. In contrast to the high binding activity exhibited by some of the acetonides, all of the agents showed weak inhibitory effect on NO generation. Metabolic inactivation during assessment of NO inhibition may play a role in the divergence noted between receptor affinity and the measured biologic activity resulting from the binding.     

Synthesis of aromatic triols and triacids from oleic and erucic acid: separation and characterization of the asymmetric and symmetric isomers

Hexasubstituted benzene derivatives, aromatic triols 4, 9 and triacids 5, 10 have been synthesized from oleic and erucic acid derivatives followed by a cyclotrimerization step catalyzed by palladium-on-carbon (Pd/C) and chlorotrimethylsilane (TMSCl). The asymmetric isomer, which is the main product, was isolated from its symmetric isomer by flash chromatography. All the products were fully characterized by IR, (1)H NMR, (13)C NMR and mass spectrometry. The products are suitable monomers for the production of polyurethanes, polyesters and polyamides.     

Alpha-pinene-type monoterpenes and other constituents from Artemisia suksdorfii

Two alpha-pinene-type monoterpenes, 7-hydroxymyrtenol (1) and 7-hydroxymyrtenal (2), a inositol derivative, (+)-quebrachitol (3) and two p-menthene triols (4 and 5), in addition to two known compounds were isolated from the aerial parts of Artemisia suksdorfii. The structures of the isolated compounds were established by analysis of spectroscopic data (IR, HR-MS, (1)H and (13)C NMR), including high-field 2D NMR techniques ((1)H-(1)H COSY, HMQC, HMBC and NOE) and in case of 3 was confirmed by X-ray analysis.     

Analogs of natural lipids. I. Synthesis and properties of tris-homoacyl derivatives of cyclopentane- 1,2,3-triols.

A new series of analogs of triglycerides has been synthesized, in which the glycerol moiety is replaced by each of the three isomeric cyclopentanetriols. For each of the isomeric cyclopentane-1,2,3-triols (1,2,3/0; DL-1,2/3; and 1,3/2), the tris-homoacyl derivatives of octanoic, decanoic, lauric, myristic, palmitic, stearic, and dihydrosterculic acids were prepared by treatment of the respective triols with the appropriate acyl chloride in pyridine. The dihydrosterculates were prepared by fusing the triols with a mixture of the acyl anhydride and the corresponding potassium salt. It is proposed that because of restricted rotation of the carbon-carbon bonds the cyclopentanoid compounds are analogs of specific rotamers of triglycerides. Infrared spectra (KBr discs) obtained at room temperature show differences in crystal structure from series to series. A band near 720 cm-minus 1 (CH2 rock) is doubled in the 1,2,3/0 and 1,2/3 series and is single in the 1,3/2 series and the triglycerides. In each spectrum with a doublet at 720 cm-minus 1, a band near 1470 cm-minus 1 (CH2 bend) is doubled also. A strong band at 890 cm-minus 1 present in the triglyceride spectra is weak or missing from the spectra of the analogs. A band at 1418 cm-minus 1 (bending of CH2 adjacent to C equal to 0) present in the triglyceride spectra is demonstrable only in the 1,2,3/0 derivatives in comparison with the other three series. In all series the dihydrosterculates show a decrease in apparent polarity, relative to the stearates, significantly greater than expected from the introduction of an additional carbon atom. The potential utility of the analogs as probes of the effects of conformation on the physical properties and enzymatic susceptibility of glycerides is discussed.