Abstract: Systems and methods for the extraction of carbon nanotubes (CNTs) by continuous and/or batch processing are disclosed. Generally, a carbon nanotube material including carbon nanotubes (CNTs), carbon nanoparticles (CNPs), and carboxylated carbon (CC) is provided and agitated to produce a well-dispersed mixture. The well-dispersed mixture can be allowed to stand in a vessel having a lower end and an upper end. In some cases, the CNPs settle at the lower end. In some cases, at least some of the CNTs and CC are disposed at the upper end and can be removed in a dispersion, which can be pH adjusted and/or filtered to extract the CNTs from the CC.

Abstract: The invention provides a fuel composition comprising a ring-hydrogenated alkyl furfuryl ether of the general formula (I): (I) R?-TF-CH2-O—R wherein TF represents a 2,5-disubstituted tetrahydrofuran ring, wherein each R independently represents a hydrocarbyl group having from 1 to 20 carbon atoms and wherein each R? independently represents a methyl group, a hydroxymethyl group, the product of an aldol condensation reaction or an alkoxymethyl group of the general formula (II): (II) —CH2-O—R? wherein each R? independently represents a hydrocarbyl group having from 1 to 20 carbon atoms. The invention also provides novel and useful ring-hydrogenated alkoxymethyltetrahydrofuran ethers of the general formula (I) above. Moreover, these ring-hydrogenated alkoxymethyltetrahydrofuran ethers disclosed herein have never been used as fuel component, and therefore the use of these ethers has also been claimed as an invention. A further embodiment of the current invention is the process for preparing these components.

Abstract: The present invention relates to methods and compositions for increasing telomerase activity in cells. Such compositions include pharmaceutical, including topical, and nutraceutical formulations. The methods and compositions are useful for treating diseases subject to treatment by an increase in telomerase activity in cells or tissue of a patient, such as, for example, HIV infection, various degenerative diseases, and acute or chronic skin ailments. They are also useful for enhancing replicative capacity of cells in culture, as in ex vivo cell therapy and proliferation of stem cells.

Abstract: The present invention is directed to ester derivatives of levulinic acid that are useful as plasticizers and/or coalescent solvents in polymer compositions, compositions comprising the ester derivatives, methods of making the derivatives and the compositions, and the use of the derivatives as additives in polymer compositions.

Abstract: An object of the present invention is to provide organic solvent extracts of red algae laurencia sp., compounds isolated and identified therefrom, and an agent for preventing attachment of barnacles comprising them. The present invention relates to a barnacle attachment preventive agent consisting of at least one selected from the group consisting of Laurencin, Thyrsiferol, Magireol A, Omaezallene, Hachijojimallene A and organic solvent extracts of red algae laurencia sp.

Abstract: The present invention provides stock solutions for production of nonlinear-optical materials using a wet coating method. In particular, the invention provides a stock solution containing a nonlinear-optically active organic compound, which is a push-pull ?-conjugated compound having a particular chemical structure, having one or more cross-linkable functional groups. In addition, the invention provides a stock solution comprising a nonlinear-optically active organic compound having at least a certain chemical structure and a matrix-forming compound having one or more cross-linkable functional groups. Further, the invention provides a nonlinear-optical material and a nonlinear-optical device, both prepared by using the stock solutions.

Abstract: Silicon compounds having fluorinated hemiacetal structure are provided. Silicone resins having the same structure have an appropriate acidity to enable formation of a finer pattern by minimizing the pattern collapse by swelling, exhibit improved resistance to the etching used in the pattern transfer to an organic film, and are thus suited for use in resist compositions for the bilayer process.

Abstract: This application relates to a substituted hydroxyphenyl ketone compound of formula I, or a pharmaceutically acceptable salt thereof, a pharmaceutical composition thereof and its use in treating migraine. This application also relates to processes for preparing a compound of formula I, and intermediate compounds useful therein.

Abstract: A method of preparing 2,5-bis(hydroxymethyl)tetrahydrofuran comprises heating a reaction mixture comprising 2,5-(hydroxymethyl)furaldehyde, an organic solvent, and a catalyst system comprising nickel and zirconium at a temperature, for a time, and at a pressure sufficient to promote reduction of the 2,5-(hydroxymethyl)furaldehyde to 2,5-bis(hydroxymethyl)tetrahydrofuran to produce a product mixture comprising 2,5-bis(hydroxymethyl)tetrahydrofuran.

Abstract: The present invention relates to a process for preparing a compound of formula (Ia), (Ib), (Ic) or (Id), or a pharmaceutically acceptable salt, hydrate, solvate, complex or prodrug thereof, said process comprising the steps of: (A) (i) treating a compound of formula (IVa), where R48 is alkyl or tosyl, with an oxidising agent to form a compound of formula (Va); and (ii) converting said compound of formula (Va) to a compound of formula (Ia) or (Ic); or (B) (i) treating a compound of formula (IVb), where R48 is alkyl or tosyl, with an oxidising agent to form a compound of formula (Vb); and (ii) converting said compound of formula (Vb) to a compound of formula (Ib) or (Id).

Abstract: Versatile Group VIII metathesis catalysts, as can be used in a range of polymerization reactions and other chemical methodologies.

Abstract: The invention relates to vitamin D derivatives and their uses, particularly in the pharmaceutical industry. The invention discloses compounds having different interesting biological properties, including vitamin D nuclear receptor (VDR) agonist activity, as well as therapeutics methods by administering said compounds, in particular for treating cancer, psoriasis, autoimmune diseases, osteodistrophy and osteoporosis. It further relates to pharmaceutical compositions comprising said compounds and methods for preparing the same.

Abstract: Acceptor compounds useful for making hyperpolarizable organic chromophores having a ?-donor conjugated to a ?-acceptor through a ?-bridge.

Abstract: A method of preparing 2,5-bis(hydroxymethyl)tetrahydrofuran comprises heating a reaction mixture comprising 2,5-(hydroxymethyl)furaldehyde, an organic solvent, and a catalyst system comprising nickel and zirconium at a temperature, for a time, and at a pressure sufficient to promote reduction of the 2,5-(hydroxymethyl)furaldehyde to 2,5-bis(hydroxymethyl)tetrahydrofuran to produce a product mixture comprising 2,5-bis(hydroxymethyl)tetrahydrofuran.

Abstract: Triphenylethylene compounds of formula (I) are provided. The compounds are particularly useful for selective estrogen receptor modulation.

Abstract: A process to obtain synthetic and semi-synthetic derivatives of lignans, especially dibenzylbutyrolactonic, tetrahydrofuranic, aryltetralynic, furofuranic and dibenzocyclooctanic lignans obtained by means of partial synthesis and/or full synthesis or also by isolation from plant extracts. It refers to a process to obtain synthetic and semi-synthetic derivatives of (?)-cubebin, such as: (?)-O-acetylcubebin; (?)-O-methylcubebin; (?)-O—N,N-(dimethylamino-ethyl)-cubebin; (?)-hinokinin; (?)-6,6?-dinitroinokinine; (?)-O-benzylcubebin; (?)-6,6?-diaminoinokinin, (?)-6,6?-dinitroinokinin, as well as to obtain dibenzocyclooctanic lignans from dibenzylbutyrolactoinic lignans by means of structural modifications in the positions 7, 7?, 8, 8?, 9? and in the aromatic rings (introduction and/or substitution of functional groups such as: —OH, —CO2H, —CO2CH3, —NO2, —NH2, —OCH3, —OAc, —SO2CH3, —SO2NH2, prenyl and halogens) is provided. A therapeutic method using the derivatives is also provided.

Abstract: A non-metallocene organometallic complex comprising a tridentate ligand and a metal bonded to a tridentate ligand, wherein two substituted aryl groups in the tridentate ligand are connected to a cyclic group at the ortho position via semi-rigid ring-ring linkages, and selected so to provide the resulting non-metallocene organometallic complex with a CS geometry, a C1 geometry, a C2 geometry or a C2v geometry.

Abstract: Novel compounds of the formula I in which R, X, n and m are as defined herein are inhibitors of tyrosine kinase and can be employed for the treatment of tumours, for neuroprotection and for protection of the stress proteins of the skin.

Abstract: The present invention provides a therapeutic agent or prophylactic agent for a disease that requires enhancement of nerve growth factor production, an enhancer for nerve growth factor production, or a food, beverage or feed for enhancing nerve growth factor production, each comprising as an effective ingredient a specified compound or a salt thereof having enhancing activity for nerve growth factor production; a method for enhancing nerve growth factor production, comprising administering to a mammal the above-mentioned compound or a salt thereof; and use of the above-mentioned compound or a salt thereof in the preparation of a therapeutic agent or prophylactic agent for a disease that requires enhancement of nerve growth factor production, an enhancer for nerve growth factor production, or a food, beverage or feed for enhancing nerve growth factor production. In addition, the present invention provides novel compounds having enhancing activity for nerve growth factor production.

Abstract: Benzocycloheptenes of formula (I), in which R1, R2 and Y have the meanings that indicated herein, exhibit selective estrogenic activity on bones and are suitable for the production of pharmaceutical agents, especially for prophylaxis and therapy of osteoporosis:

Abstract: A method for the preparation of lariciresinol, cyclolariciresinol or secoisolariciresinol, which method includes the steps of a) reducing hydroxymatairesinol to give 7-hydroxy-secoisolariciresinol, and b) subjecting the 7-hydroxy-secoisolariciresinol obtained in step a) to i) cyclization to give lariciresinol, or ii) cyclization to give cyclolariciresinol, or iii) catalytic hydrogenolysis to give secoisolariciresinol.

Abstract: A class of 3,4-diaryl substituted thiophene, furan and pyrrole derivatives and analogs thereof, pharmaceutical compositions containing them and methods of using them to treat inflammation and inflammation-related disorders. Compounds of particular interest are defined by Formula I: wherein Y is selected from O, S and NR1; wherein R1 is selected from hydrido and lower alkyl; wherein X is one or two substituent selected from hydrido, halo, lower alkoxycarbonyl and carboxyl; wherein R2 and R3 are independently aryl or heteroaryl; and wherein R2 and R3 are optionally substituted at a substitutable position with one or more radicals selected from sulfamyl, alkylsulfonyl, halo, lower alkoxy and lower alkyl; or a pharmaceutically-acceptable salt thereof.

Abstract: The present invention relates to novel ether compounds, compositions comprising ether compounds, and methods useful for treating and preventing cardiovascular diseases, dyslipidemias, dysproteinemias, and glucose metabolism disorders comprising administering a composition comprising an ether compound. The compounds, compositions, and methods of the invention are also useful for treating and preventing Alzheimer's Disease, Syndrome X, peroxisome proliferator activated receptor-related disorders, septicemia, thrombotic disorders, obesity, pancreatitis, hypertension, renal disease, cancer, inflammation, and impotence. In certain embodiments, the compounds, compositions, and methods of the invention are useful in combination therapy with other therapeutics, such as hypocholesterolemic and hypoglycemic agents.

Abstract: The object of the invention are p-aminophenol derivatives of general formula (I) or physiologically tolerated, water-soluble salts thereof and oxidative coloring preparations based on a developer-coupler combination containing at least one p-aminophenol derivative of formula (I).

Abstract: The present invention relates to novel triaromatic compounds having the general formula (I): as well as to a method for preparing them and to their use in pharmaceutical compositions intended for use in human or veterinary medicine (in dermatology, in carcinology and in the field of autoimmune diseases and that of organ or tissue transplants in particular), or alternatively in cosmetic compositions.

Abstract: Compounds that are effective lipoxygenase inhibitors, and methods and pharmaceutical compositions for inhibiting lipoxygenases and for treatment of lipoxygenase-mediated conditions in humans and other subjects. The compounds, methods and pharmaceutical compositions utilize subersic terpenoids, jaspic terpenoids, igernellic terpenoids, hippospongic terpenoids, halicondric terpenoids, dictyodendric terpenoids, and/or heteronemic terpenoids, and synthetic derivatives or analogs thereof. Exemplary compounds include (−)-subersic acid, (+)-subersin, jaspaquinol, (−)-jaspic acid, igernellin, halisufate 7, and hipposulfate C and D, and derivatives thereof.

Abstract: The present invention relates to novel ether compounds, compositions comprising ether compounds, and methods useful for treating and preventing cardiovascular diseases, dyslipidemias, dysproteinemias, and glucose metabolism disorders comprising administering a composition comprising an ether compound. The compounds, compositions, and methods of the invention are also useful for treating and preventing Alzheimer's Disease, Syndrome X, peroxisome proliferator activated receptor-related disorders, septicemia, thrombotic disorders, obesity, pancreatitis, hypertension, renal disease, cancer, inflammation, and impotence. In certain embodiments, the compounds, compositions, and methods of the invention are useful in combination therapy with other therapeutics, such as hypocholesterolemic and hypoglycemic agents.

Abstract: The present invention generally relates to novel compounds HNP-98701A (epi-manassantin A), HNP-98701B and HNP-98701C (manassantin A), or mixture thereof (HNP-98701) as carcinostatis substance, preparation method thereof and carcinostatis pharmaceutical composition containing them as effective constituents and, more specifically, to novel compounds HNP-98701A and HNP-98701B, known compounds HNP-98701C, or mixture thereof and derivatives thereof obtained by extracting saururus with methanol, fractionating this with various organic solvents, separating ethyl acetate fraction with highest anticancer activity through thin-layer chromatography or column chromatography and purifying it, preparation method thereof and carcinostatis pharmaceutical composition containing them as effective constituents. The carcinostatis substances HNP-98701A, HNP-98701B and HNP-98701C of the present invention selectively affect cancer cell line cells and cause apoptosis-type cell death.

Abstract: The present invention refers to a new procedure for obtaining and purifying 2-bromo-5-(2-bromo-2-nitrovinyl)-furan in one reaction step starting with 2-nitrovinylfuran, and maintains high indexes of purity and an appropriate yield. The process involves the direct bromination of 2-nitrovinylfuran using charcoal from the beginning of the reaction, followed by the neutralization and dehydrobromination using pyridine, and finally crystallizing and purifying the product obtained with ethanol and charcoal. With the new procedure it is possible to reduce the time of obtaining the final product, the reaction becomes endothermic instead of exothermic, which facilitates the work of the operators and allows for the scaling up of the reaction to superior levels. The process significantly decreases the amount of chemicals in the reaction, some of them with toxic properties.

Abstract: 2,5-Diaryl tetrahydrofurans, 2,5-diaryl tetrahydrothiophenes, 1,3-diaryl cyclopentanes are disclosed that reduce the chemotaxis and respiratory burst leading to the formation of damaging oxygen radicals of polymorphonuclear leukocytes during an inflammatory or immune response. The compounds exhibit this biological activity by acting as PAF receptor antagonists, by inhibiting the enzyme 5-lipoxygenase, or by exhibiting dual activity, i.e., by acting as both a PAF receptor antagonist and inhibitor of 5-lipoxygenase. Also disclosed is a method to treat disorders mediated by PAF and/or leukotrienes that includes administering an effective amount of one or more of the above-identified compounds or a pharmaceutically acceptable salt thereof, optionally in a pharmaceutically acceptable carrier, to a patient in need of such therapy.

Abstract: The present invention relates to a process for the production of (−)3,4-divanillyl tetrahydrofiran of formula (2) which comprises (a) isolating) (−) secoisolariciresinol of formula (1) from the heartwood and roots of Taxus wallichiana by an improved process which consists of partitioning of the alcoholic extract of the heartwood and roots of T. wallichiana between water and chlorinated solvent, (b) extracting the chlorinated solvent extract with alkali and (c) isolating (−) secoisolariciresinol from the alkali extract upon neutralization with mineral acid and extracting with organic solvent and (d) crystallizing it from suitable organic solvent, (e) dissolving the isolated (−) secoisolariciresinol in suitable organic solvent and (f) reacting with triphenyl phosphine halide at 0-80° C. for 1-10 hours and (g) isolating (−) 3,4-divanillyl tetrahydrofuran by column chromatography.

Abstract: Substituted tetrahydrofuran analogs of prostaglandins and methods of their use in treating glaucoma and ocular hypertension are disclosed.

Abstract: Compositions that comprise at least one compound that corresponds to general formula (I): in which n is a number from 0 to 20; R1, R2, R3 and R4 each represent a hydrogen atom or a hydrocarbon radical, for example alkyl, with 1 to 30 carbon atoms, whereby at least one of R1, R2, R3, and R4 is a hydrocarbon radical; and m is a number from 1 to 30, can be prepared by a process that comprises the reaction of a hydroxymethylated derivative of tetrahydrofuran with ethylene oxide, then with one or more other epoxidized compounds. These compositions can be used as detergent additives for gasoline-type fuels.

Abstract: Substituted triols are prepared by reducing appropriately substituted carboxylic esters. The substituted triols can be used as active substances in medicaments.

Abstract: Novel tubulin binding compounds having potent tubulin depolymerization activity and inhibitory activity against tubulin polymerization. The compounds are effective agents for inhibiting cellular proliferation, for example, in cancer cells. The compounds are adapted to interact favorably with a novel tubulin binding pocket, which pocket is useful for screening of anti-tubulin, anti-proliferation, and anti-cancer drugs.

Abstract: The invention relates to the use of cyclopentane heptan(ene)oic acid, 2-heteroarylalk(en)yl derivatives as ocular hypotensives.

Abstract: An acetal, wherein the acetal is 2,2-di(tetrahydrofurfuryloxy)propane as well as processed for producing the acetal and methods of using the acetal.

Abstract: The invention relates to precursors of the A-ring of vitamin D, of the formula (I): in which A, R, R1 and R2 are as defined in the specification. The invention also relates to a method of preparing compounds (I) comprising the enzymatic asymmetrization of 3,5-dihydroxybenzoic acid derivatives, as well as intermediates of preparation of said compounds.

Abstract: The invention relates to the use of derivatives of F-type prostaglandins as ocular hypotensives. The compounds used in accordance with the invention are represented by the following formula I: ##STR1## wherein wavy line attachments indicate either the alpha (.alpha.) or beta (.beta.) configuration; hatched segments indicate .alpha. configuration; the solid triangle is used to indicate .beta. configuration; dashed bonds represent a double bond, or a single bond; R is a substituted heteroaryl radical having at least two pendant substituents selected from the group consisting of C.sub.1 to C.sub.6 alkyl; halogen; trifluoromethyl; COR.sup.1 ; COCF.sub.3 ; SO.sub.2 NR.sup.1 ; NO.sub.2 and CN or at least one cyano group; R.sup.1 is hydrogen or a lower alkyl radical having up to six carbon atoms, X is selected from the group consisting of --OR.sup.1 and --N(R.sup.1).sub.2 ; Y is .dbd.

Abstract: A tetrahydrofuran (THF) epoxide and method of its preparation according to a novel stereoselective synthetic method. The compounds of the invention are used to prepare therapeutically active mono-THF and bis-THF containing Annonaceous Acetogenins.

Abstract: The invention relates to the use of derivatives of F-type prostaglandins as ocular hypotensives. The compounds used in accordance with the invention are represented by the following formula I: ##STR1## wherein wavy line attachments indicate either the alpha (.alpha.) or beta (.beta.) configuration; hatched segments indicate a configuration; the solid triangle is used to indicate .beta. configuration; dashed bonds represent a double bond, or a single bond; R is a substituted heteroaryl radical having at least two pendant substituents selected from the group consisting of C.sub.1 to C.sub.6 alkyl; halogen; trifluoromethyl; COR.sup.1 ; COCF.sub.3 ; SO.sub.2 NR.sup.1 ; NO.sub.2 and CN or at least one cyano group; R.sup.1 is hydrogen or a lower alkyl radical having up to six carbon atoms, X is selected from the group consisting of --OR.sup.1 and --N(R.sup.1).sub.2 ; Y is .dbd.

Abstract: The present application describes amidinophenyl-pyrrolidines, -pyrrolines, and -isoxazolidines and derivatives thereof of formula I: ##STR1## or pharmaceutically acceptable salt forms thereof, wherein one of D and D' may be C(.dbd.NH)NH.sub.2 and the other H, and J.sup.1 and J.sup.2 may be O or CH.sub.2, which are useful as inhibitors of factor Xa.

Abstract: Unsaturated or polyunsaturated, conjugated or nonconjugated hydrocarbons are reacted with an oxidizing agent including hydroperoxides and monopersulfate compounds in the presence of phase-transfer catalysts. Suitable hydrocarbons include ricinic compounds such as castor oil and dehydrated castor oil. The phase-transfer catalysts include novel tungsten peroxo complexes, such as quaternary ammonium tetrakis (diperoxotungsto) phosphates, and crown ethers. Other additives opionally utilized include pH buffers, alkaline compounds, and solvents.

Abstract: The invention encompasses the novel compound of Formula I useful in the treatment of diseases, including asthma, by raising the level of cyclic adenosine-3',5'-monophosphate (cAMP) through the inhibition of phosphodiesterase IV (PDE IV). ##STR1## The invention also encompasses certain pharmaceutical compositions and methods for treatment of diseases by inhibition of PDE IV, resulting in an elevation of cAMP, comprising the use of compounds of Formula I.

Abstract: The invention relates to the use of derivatives of F-type prostaglandins as ocular hypotensives. The PGF derivatives used in accordance with the invention are represented by the following formula I: ##STR1## wherein wavy line attachments indicate either the alpha (.alpha.) or beta (.beta.) configuration; hatched segments indicate .alpha. configuration, solid triangles are used to indicate .beta. configuration, dashed bonds represent a double bond, or a single bond, R is a substituted heteroaryl radical, R.sup.1 is hydrogen or a lower alkyl radical having up to six carbon atoms, X is selected from the group consisting of --OR.sup.1 and --N(R.sup.1).sub.2, Y is =O or represents 2 hydrogen radicals. Certain of the compounds represented by Formula I comprise another aspect of the present invention.

Abstract: Disclosed is a process for the recovery of formyltetrahydrofurans (FTHF's) produced by the rhodium-catalyzed hydroformylation of 2,5-dihydrofuran (2,5-DHF) wherein the FTHF's are recovered as an equilibrium mixture of 2- & 3-FTHF and their hydrates, 2- and 3-?di(hydroxy)methyl!tetrahydrofuran from a hydroformylation product solution comprising a rhodium catalyst, 2- and 3-FTHF and an organic hydroformylation solvent obtained as a liquid product take-off from a hydroformylation process wherein 3-FTHF is produced by the hydro-formylation of 2,5-DHF 3-FTHF is a valuable organic intermediate useful, for example, in the preparation of 3-methyltetrahydrofuran and 3-amino-methyltetrahydorfuran.

Abstract: A phosphorus ester oligomer having the structure: ##STR1## wherein A can be the same or different in each monomeric unit and each is independently selected from the group consisting of oxygen, sulfur, lower alkyl, alkyl- or aryl-substituted amino and aminoalkyl; B.sub.1 and B.sub.2 can be the same or different and each is independently selected from hydrogen, lower alkyl, a labelling group, a protecting group, a phosphoramidate or a phosphomonoester; R.sub.1 can be the same or different in each monomeric unit, and in at least one of the non-nucleotide monomeric units, R.sub.

Abstract: Novel tetrahydrofuran-epoxide compounds are described as intermediates for the preparation of non-adjacent bis-THF-acetogenins of pharmaceutical interest. Also described is a novel stereocontrolled synthesis for preparing such intermediates starting with commercially available enantiomers of glycidyl benzylether.

Abstract: Compounds of the formula ##STR1## where W is (CH.sub.2).sub.n where n is 1 or 2, or n is 0 and W represents lower alkyl groups attached to each oxygen;m is an integer between 1 and 8;R.sub.1 is COOH or a pharmaceutically acceptable salt thereof, COOR.sub.4, CONR.sub.5 R.sub.6, CONR.sub.5 SO.sub.2 R.sub.7, CH.sub.2 OH, CH.sub.2 OR.sub.7, CH.sub.2 O--COR.sub.7, CH.sub.2 O--CONR.sub.5,R.sub.7, CH.sub.2 OCOOR.sub.7, CH.sub.2 NH.sub.2, CH.sub.2 NR.sub.5 R.sub.6, etc. where R.sub.4 is an alkyl group, or a cycloalkyl group, or R.sub.4 is phenyl or lower alkylphenyl, R.sub.5 and R.sub.6 independently are hydrogen, an alkyl group, etc., R.sub.7 is alkyl of 1 to 10 carbons, phenyl or lower alkylphenyl, R.sub.8 is lower alkyl, and R.sub.9 is divalent alkyl radical of 2-5 carbons, R.sub.10 is an alkyl OR cycloalkyl containing 1 to 5 carbons;R.sub.2 is H, COR.sub.7, R.sub.7, CO--OR.sub.7, CO--NR.sub.5,R.sub.7, PO(OH)OR.sub.7, PO(OR.sub.7).sub.2, POR.sub.7 OH, or POR.sub.7 (OR.sub.7) ;R.sub.

Abstract: 2,5-Diaryl tetrahydrofurans, 2,5-diaryl tetrahydrothiophenes, 2,4-diaryl tetrahydrofurans, 2,4-diaryl tetrahydrothiophenes, 1,3-diaryl cyclopentanes, 2,4-diaryl pyrrolidines, and 2,5-diaryl pyrrolidines are disclosed that reduce the chemotaxis and respiratory burst leading to the formation of damaging oxygen radicals of polymorphonuclear leukocytes during an inflammatory or immune response. The compounds exhibit this biological activity by acting as PAF receptor antagonists, by inhibiting the enzyme 5-lipoxygenase, or by exhibiting dual activity, i. e., by acting as both a PAF receptor antagonist and inhibitor of 5-lipoxygenase.A method to treat disorders mediated by PAF or leukotrienes is also disclosed, that includes administering an effective amount of one or more of the above-identified compounds or a pharmaceutically acceptable salt thereof, optionally in a pharmaceutically acceptable carrier.