Diterpenes of Podocarpus ferrugineus bark

The following oxygenated diterpenes have been isolated from the bark of Podocarpus ferrugineus D. Don: isopimarol, isopimaric acid, sandaracopimaric acid, ferruginol, sugiol, sugiyl methyl ether, xanthoperol, royleanone, 6-dehydroroyleanone, cryptojaponol, 5β-hydroxy-6-oxasugiyl methyl ether, 2-ketoferruginol and 2β-acetoxysugiyl methyl ether.     

Phenols and lignans from Chenopodium album

Cinnamic acid, 4-hydroxy-cinnamic acid, ferulic acid, methyl ferulate, sinapic acid, methyl 3-(4-hydroxy-3-methoxyphenyl)propanoate, 4-(1-hydroxyethyl)-2-methoxyphenol, vanillyl alcohol, 4-(hydroxymethyl)-2-methoxyphenol, 4-hydroxy-3-methoxybenzoic acid, 4-vinylphenol, 4-methylbenzaldehyde, N-[2-(1H-indol-3-yl)ethyl]acetamide, pinoresinol, syringaresinol, lariciresinol, 5,5'-dimethoxy-lariciresinol, threo-guaiacylglycerol-3-beta-4-syringaresinol ether and two new sesquilignans, namely, threo-guaiacylglycerol-alpha-O-methyl-beta-O-4-syringaresinol ether and threo-syringylglycerol-alpha-O-methyl-beta-O-4-syringaresinol ether, were isolated and identified as components of Chenopodium album. Constitutions were established on the basis of spectroscopic data, including two-dimensional NMR analyses.     

Identification of 3 beta, 7 beta-dihydroxy-5 beta-cholan-24-oic acid in serum from patients treated with ursodeoxycholic acid

An unknown bile acid was found by gas-liquid chromatography in the serum of patients who were administered ursodeoxycholic acid for the treatment of cholesterol gallstones. Identification of the chemical structure of the unknown bile acid was performed by the use of gas-liquid chromatography-mass spectrometry. Mass spectrum analysis of the methyl ester trimethylsilyl ether of the bile acid showed explicitly that this is dihydroxy-5 beta-cholanoic acid, since peaks at m/e 460 and 370 characteristic of methyl ester trimethylsilyl ether of dihydroxy bile acid were clearly exhibited. Sites of the two hydroxyl groups on the steroid nucleus were determined to be at the 3- and 7-positions by conversion of the bile acid to the corresponding dioxo-cholanoic acid and by comparison of the gas-liquid chromatographic behavior with those of authentic dioxo bile acids. Four authentic 3,7-dihydroxy-5 beta-cholan-24-oic acids were chemically synthesized and retention times and mass spectra of their methyl ester trimethylsilyl ether derivatives compared precisely with that of the unknown bile acid. The results indicate that the unknown bile acid is 3 beta, 7 beta-dihydroxy-5 beta-cholan-24-oic acid. Preliminary experiments suggest that 3 beta, 7 beta-dihydroxy-5 beta-cholan-24-oic acid is absent as amino acid-conjugated forms in serum. It is also suggested that the bile acid is excreted into urine but not into bile.     

Metabolism of symmetrical dialkyl ethers by Acinetobacter sp. HO1-N

The growth of Acinetobacter species HO1-N on a homologous series of dialkyl ethers yielded characteristic cellular and extracellular ether fatty acids. Microbial growth on diheptyl ether resulted in the appearance of 7-n-heptoxy-1-n-heptanoic acid as a cellular fatty acid and 2-n-heptoxy-1-acetic acid as the sole extracellular fatty acid. The oxidation of dinonyl ether and didecyl ether by Acinetobacter resulted in the extracellular accumulation of 2-n-nonoxy-acetic acid and 2-n-decoxy-1-acetic acid, respectively. The 16-carbon ether fatty acid, 6-n-decoxy-1-n-hexanoic acid, was identified as a major cellular fatty acid in didecyl ether-grown cells. The extracellular ether fatty acids accumulated in an inverse relationship to the disappearance of the dialkyl ether and appeared to represent end products of metabolism. The carbon and energy required for cellular growth and metabolism resided in the terminal 5-carbons of diheptyl ether, 7-carbons of dinonyl ether and 8-carbons of didecyl ether. Glutarate, adipate, pimelate and suberate were identified from cells grown at the expense of diheptyl, dioctyl, dinonyl and didecyl ether, respectively, suggesting a role for dibasic acids as metabolic intermediates. A new and novel mechanism for the metabolism of symmetrical dialkyl ethers is suggested. Terminal methyl group oxidation of the dialkyl ether results in the formation of an alkoxy-fatty acid followed by an internal carbon-carbon scission reaction 2-carbons removed from the oxygen atom. The resulting endproducts are alkoxyacetic acid and the corresponding dibasic acid.Non-Standard Abbreviations TLC Thin Layer Chromatography - PS-DEGS · PS Diethylene glycol succinate - DHE Diheptyl ether - DOE Dioctyl ether - DNE Dionyl ether - DDE Didecyl ether     

New Withanolides from Nicandra physaloides (Solanaceae)

Two new withanolides, named nicandrenone methyl ether (1), 26S nicandrenone methyl ether (2), together with ten known compounds were isolated from the whole plants of Nicandra physaloides (Solanaceae). Their chemical structures were deduced on the basis of spectroscopic analysis. Ten known compounds were identified as nicandrenone (3), Nic-7 (4), nicaphysalin E (5), pinosylvin monomethyl ether (6), 2S-pinocembrin (7), (1S, 2R)-1, 2-bis (4-hydroxy-3-methoxyphenyl)-1, 3-propanediol (8), vanillin (9), indole-3-carboxylic acid (10), vanillic acid (11) and drummondol (12).     

Pyranocoumarins as chemotaxonomic markers in Eriostemon coccineus and Philotheca citrina

Examination of the aerial parts of Eriostemon coccineus and Philotheca citrina has shown both to contain the unusual pyranocoumarins avicennol, avicennin and cis-avicennol. Three minor coumarins isolated from P. citrina have been identified as avicennol methyl ether, cis-avicennol methyl ether and avicennol ethyl ether. Philotheca citrina also yielded another pyranocoumarin, dipetalolactone, and the common lignan sesamin. Eriostemon coccineus, in addition to coumarins, gave the furoquinoline alkaloids maculosidine and γ-fagarine and two dihydrocinnanic acid derivatives, eriostoic acid and a new compound with a substitution pattern comparable to cis-avicennin and which has been assigned the trivial name cis-avicennic acid. The co-occurrence of these rare pyranocoumarins supports the contention that Philotheca is closely allied to certain taxa currently placed in Eriostemon sect. Nigrostipulae.     

假酸浆中新的醉茄内酯类化合物

从假酸浆（Nicandra physaloides）全草中分离得到12个化合物,其中两个为新的醉茄内酯类化合物,经波谱学方法将其结构鉴定为nicandrenone methyl ether （1） 和26S-nicandrenone methyl ether （2）;已知化合物为三个醉茄内酯,nicandrenone （3）,Nic-7 （4）,nicaphysalin E （5）,以及pinosylvin monomethyl ether （6）,2S-pinocembrin （7）,（1S, 2R）-1, 2-bis （4-hydroxy-3-methoxyphenyl）-1, 3-propanediol （8）,vanillin （9）,indole-3-carboxylic acid （10）,vanillic acid （11） 和drummondol （12）。     

Synthesis and antiestrogenic activity of 2,4-bis(bromomethyl)-estrone methyl ether1: A bifunctional alkylating steroid

The synthesis of 2,4-bis(bromomethyl)estrone methyl ether was accomplished by reacting estrone methyl ether with formaldehyde and hydrogen bromide in s-tetrachloroethane. The compound readily reacts with cysteine, tryptophan and histidine in 0.05 $\text{M}$ phosphate buffer pH 7.0. It also reacts with compounds containing sulfhydryl groups, such as 2-mercaptoethanol and the reduced form of 5,5'dithiobis(2-nitrobenzoic acid). Structural analysis and stoichiometry of the reaction of the bromomethylsteroid with cysteine indicates that the title compound contains two reactive bromomethyl groups. The biological activity of the bromomethylsteroid was evaluated by analysis of its effect on uterine glucose-6-phosphate dehydrogenase activity after administration into the uterine lumen of ovariectomized rats. While it lacked estrogenic activity, the compound did display an antiestrogenic effect that was both greater and more persistent than that of an equimolar quantity of estrone methyl ether.     

Synthesis of disaccharide fragments of the AT-III binding domain of heparin and their sulfonatomethyl analogues

d-Glucuronate and l-iduronate-containing disaccharides related to the antithrombin-binding domain of heparin were prepared. The carboxylic function of the uronic acid unit was formed on a disaccharide level in the case of the glucuronate, while on a monosaccharide level in the case of the iduronate derivatives. Synthesis of their sulfonic acid analogues was carried out analoguosly applying sulfonatomethyl-containing acceptors in the form of either salts or methyl esters. Significant difference could be observed in the methyl ether formation reactions of the sulfonatomethyl-containing uronate disaccharides and the non-sulfonic acid uronates.     

不同溶剂对海边月见草种子油脂肪酸萃取的比较

分别用乙醚、石油醚及氯仿一甲醇等三种溶剂萃取海边月见草种子油,经KOH-Me0H室温酯化法或BF₃-Me0H酯化法将其脂肪酸转化成甲酯,而后采用毛细管气相色谱外标法进行定量测定,结果表明:三种溶剂萃取所获得的种子油脂肪酸中亚油酸、γ-亚麻酸的含量无显著差异。但若考虑到溶剂的残留,选择石油醚为溶剂更合适。此外,采用上述两种酯化法,γ-亚麻酸均能与其它脂肪酸,尤其是亚油酸较好分离。     

2-O-Methylconfluentinsäure: Ein neues depsid aus Lecidea fuscoatra

The lichen, Lecidea fuscoatra contains the new depside 2-O-methylconfluentinic acid. The structure of this compound follows front spectroscopical data and hydrolysis of its methyl ester to give olivetonic acid dimethyl ether and 2-O-methyl olivetol carboxylic acid.     

Biocatalytic potential of lipase from Staphylococcus sp. MS1 for transesterification of jatropha oil into fatty acid methyl esters

An extracellular lipase producing isolate Staphylococcus sp. MS1 was optimized for lipase production and its biocatalytic potential was assessed. Medium with tributyrin (0.25 %) and without any exogenous inorganic nitrogen source was found to be optimum for lipase production from Staphylococcus sp. MS1. The optimum pH and temperature for lipase production were found to be pH 7 and 37 °C respectively, showing lipase activity of 37.91 U. It showed good lipase production at pH 6–8. The lipase was found to be stable in organic solvents like hexane and petroleum ether, showing 98 and 88 % residual activity respectively. The biotransformation using the concentrated enzyme in petroleum ether resulted in the synthesis of fatty acid methyl esters like methyl oleate, methyl palmitate and methyl stearate. Thus, the lipase under study has got the potential to bring about transesterification of oils into methyl esters which can be exploited for various biotechnological applications.     

Metabolism of 4,7,10,13,16-docosapentaenoic acid by human platelet cyclooxygenase and lipoxygenase

Washed human platelets are shown to metabolize 4,7,10,13,16-docosapentaenoic acid into three major metabolites which were purified by reverse-phase HPLC. The mass spectra of the methyl ester-trimethylsilyl ether and ethyl ester-trimethylsilyl ether of compound A established it as delta 4-dihomo-thromboxane B2. Compound B was shown to be 14-hydroxy-4,7,10,12-nonadecatetraenoic acid, which is analogous to 12-hydroxy-5,8,10-heptadecatrienoic acid from arachidonic acid. Compound C was produced via an indomethacin-insensitive pathway and was identified as 14-hydroxy-4,7,10,12,16-docosapentaenoic acid. Time- and substrate-dependent studies showed that compounds A,B and C were produced approximately 10,15 and 65% of the extent to which thromboxane B2, 12-hydroxy-5,8,10-heptadecatrienoic acid and 12-hydroxy-5,8,10,14-eicosatetraenoic acid were produced, respectively, from arachidonic acid.     

Dimeric epoxy fatty acid methyl esters: formation,chromatography and mass spectrometry

The formation of dimers is reported from the thermal treatment of a series of epoxy fatty acid methyl esters. These compounds were isolated from the reaction mixture by steric exclusion chromatography and were subsequently characterised by their high resolution electron impact and ammonia chemical ionisation mass spectra. The spectra were consistent in each case with the presence of a mixture of four possible positional isomers each containing an ether bridge linking a pair of fatty acid methyl esters across the carbon chains, with a keto group on a carbon adjacent to the bridge on one of the esters.     

The metabolism of retinyl methyl ether in the rat in vivo

1. Retinyl methyl ether was converted into vitamin A in vitamin A-deficient rats regardless of whether administered by oral, intraperitoneal, intramuscular or subcutaneous route; intramuscular administration seemed to be the best for conversion as well as storage. 2. Significantly, unchanged retinyl methyl ether was also found in the liver after oral administration but not after administration by other routes. 3. Oral administration of 1mg of retinyl methyl ether led to a progressive increase in liver vitamin A with time reaching a value of 16% of administered dose after 24h. No retinyl methyl ether was detectable in liver at any time-interval in this experiment. 4. Conversely, oral administration of 4mg of retinyl methyl ether/day for 4 days led to the accumulation of 25% of the dose as unchanged retinyl methyl ether in the liver 1 day after the last dose; however, it was gradually but completely converted into vitamin A over a period of 18 days. 5. The significance of these findings with special reference to the fundamental metabolism of vitamin A, the site of conversion of retinyl methyl ether into vitamin A, the relative efficiency of various routes of administration and its biological activity are discussed.     

Three new phenolic acid derivatives from Oenothera biennis

Three new phenolic acid derivatives, 1-methyl glyceric acid-2-vanillic acid ether (1), methyl 2-hydroxy-6-(3-methoxy-3-oxoprop-1-en-2-yloxy) benzoate (2), methyl 2-hydroxy-6-(1-Carboxyvinyloxy) benzoate (3) and five known compounds namely 4-hydroxymellein (4), mellein methyl ether (5), 2-methyl-5,7-dihydroxychromone (6), latifolicinin C (7) and oresbiusin A (8) were isolated from Oenothera biennis L. The structures of these secondary metabolites were elucidated using different spectroscopic techniques, including ¹H, ¹³C NMR, HR-ESI-MS, ECD and comparison with published data.     

On the role of the sterol hydroxyl group in membranes.

The adequacy of sterol derivatives containing a blocked 3-hydroxyl group for sustaining the growth of two sterol auxotrophs has been investigated. Mycoplasma capricolum, a cholesterol-requiring bacterium, grows nearly as well on media supplemented with cholesteryl methyl ether or cholesteryl acetate as on free cholesterol. The two derivatives are recovered unchanged from the bacterial cells. Similarly, cholesteryl methyl ether or ergosteryl methyl ether replace cholesterol or ergosterol as sterol sources for a yeast mutant, strain GL7, defective in 2,3-oxidosqualene-lanosterol cyclization. During aerobic or semianaerobic growth, yeast cells demethylate some of the cholesteryl methyl ether to free cholesterol. However, cells growing on cholesterol methyl ether under strict anaerobic conditions do not produce free sterol. The bearing of these results on the postulated requirement of a free sterol hydroxyl group for membrane function is discussed. Sterol esterification does not appear to be essential for the two microbial systems.     

A new chromone from the stems of Cneorum tricoccum

From the stems of Cneorum tricoccum L. 3,3-dimethylallylspatheliachromene, spatheliabischromene and alloptaeroxylin methyl ether have been isolated as well as the new natural product ptaerochromenol methyl ether, which was chemically interconverted to isoheteropeucenin methyl ether.     

Evaluation of alternariol and alternariol methyl ether for mutagenic activity in Salmonella typhimurium.

Alternariol and alternariol methyl ether were tested in the Ames Salmonella typhimurium assay, and both were shown, with and without metabolic activation, to be nonmutagenic to strains TA98 and TA100. The finding of other investigators that alternariol methyl ether is weakly mutagenic to TA98 without metabolic activation could have resulted from the presence of a small amount of one of the highly mutagenic altertoxins in the alternariol methyl ether originally tested.     

The effect of the sterol oxygen function on the interaction with phospholipids

The effect of cholesteryl ethers (namely cholesteryl methyl ether, cholesteryl ethyl ether, cholesteryl n-propyl ether, cholesteryl isopropyl ether, cholesteryl butyl ether, cholesteryl methoxymethyl ether, cholesteryl (2'-hydroxy)-3-ethyl ether) and cholesteryl ester (namely cholesteryl acetate) is tested on the interaction with phosphatidylcholines in liquid-crystalline and crystalline state. The interfacial properties of sterols are tested at the air-water interface. The cholesteryl ethers show a reduced interfacial stability with increasing hydrophobicity of the ether-linked moiety. The interaction between the sterol derivatives and phospholipids in mixed monolayers is indicated by measuring the deviation from the simple addivity rule (condensing effect). An interaction is found only for cholesteryl (2'-hydroxy)-3-ethyl ether, cholesteryl methyl ether and cholesteryl ethyl ether. These sterols also reduce the glucose permeability of liposomal membranes in this order. In this respect cholesteryl (2'-hydroxy)-3-ethyl ether is as effective as cholesterol. Cholesteryl methyl ether and cholesteryl ethyl ether show 62 and 33 percent of the effect observed with cholesterol. The effect of the sterol derivatives on the gel-to-liquid-crystalline phase transition of dipalmitoylphosphatidylcholine is measured by differential scanning calorimetry. Cholesteryl methyl ether, cholesteryl ethyl ether, and cholesteryl (2'-hydroxy)-3-ethyl ether reduce the energy content of the phase transition nearly as effective as cholesterol, cholesteryl n-propyl ether has only a small effect. Although cholesteryl acetate, and cholesteryl methoxymethyl ether have no condensing or permeability-reducing effect, they have a considerable effect on the gel-to-liquid-crystalline phase transition. Cholesteryl isopropyl ether and cholesteryl butyl ether have no effect. It is concluded that a free 3 beta-hydroxy group is not a prerequisite to observe a sterol-like effect in membranes. However, the interfacial stability and the orientation of the sterol and oxygen moiety at the sterol 3-position are important.