Abstract: The invention relates to a method for preparing 5-hydroxymethylfurfural (HMF) by reacting hexose in water and in the presence of carboxylic acid. The present invention further relates to the preparation of 5-hydroxymethylfurfural (HMF) by reacting hexose in water and in the presence of carboxylic acid and of a heterogenous acid catalyst. The invention also relates to an HMF-rich carboxylic acid solution.

Abstract: The subject of the invention is process for the preparation of the prostaglandin amides of the general formula I, —where in the formula the bonds marked with dotted lines may be single or double bonds, in the case of double bounds at positions 5,6 and 13,14 they may be in cis or in trans orientation, Q stands for a hydroxyl-group and Z stands for a hydroxyl- or oxo-group, R1 and R2 independently represent hydrogen atom or a straight or branched C1-10 alkyl- or aralkyl-group, optionally substituted with —ONO2 group, or an aralkyl- or aryl-group, which contains heteroatom, R3 represents a straight or branched, saturated or unsaturated C4-6 hydrocarbon group, or a C4-10 alkylcycloalkyl- or cycloalkyl-group, or an optionally with alkyl group or halogen atom substituted phenyl-, C7-10 alkylaryl- or hetaryl-group, Y represents (CH2)n group or 0 atom or S atom, and where n=0-3.

Abstract: Discloses is a process for preparation of a compound of formula 7, or a derivative thereof, wherein PG1 is an alcohol protecting group. Also, disclosed are intermediates and processes for their preparation. The compound of formula 7 can be useful in the preparation of halinchondrin analogs such as Eribulin.

Abstract: A photoacid generator includes those of formula (I): wherein each Ra in formula 1 is independently H, F, a C1-10 nonfluorinated organic group, C1-10 fluorinated organic group, or a combination comprising at least one of the foregoing, provided at least one Ra is F or a C1-10 fluorinated organic group, the C1-10 fluorinated and nonfluorinated organic groups each optionally comprising O, S, N, or a combination comprising at least one of the foregoing heteroatoms; L1 is a linking group comprising a heteroatom comprising O, S, N, F, or a combination comprising at least one of the foregoing; G+ is an onium salt of the formula (II): wherein in formula (II), X is S or I, each R0 is independently C1-30 alkyl group; a polycyclic or monocyclic C3-30 cycloalkyl group; a polycyclic or monocyclic C4-30 aryl group; or a combination comprising at least one of the foregoing, provided at least one R0 is substituted where each R0 is a C6 monocyclic aryl group, and wherein when X is I, a is 2, and where X is S, a is 3,

Abstract: A substance includes diamond particles having a maximum linear dimension of less than about 1 ?m and an organic compound attached to surfaces of the diamond particles. The organic compound may include a surfactant or a polymer. A method of forming a substance includes exposing diamond particles to an organic compound, and exposing the diamond particles in the presence of the organic compound to ultrasonic energy. The diamond particles may have a maximum linear dimension of less than about 1 ?m. A composition includes a liquid, a plurality of diamond nanoparticles dispersed within the liquid, and an organic compound attached to surfaces of the diamond nanoparticles. A method includes mixing a plurality of diamond particles with a solution comprising a liquid solvent and an organic compound, and exposing the mixture including the plurality of diamond nanoparticles and the solution to ultrasonic energy.

Abstract: The present invention provides methylene beta-ketoester monomers, methods for producing the same, and compositions and products formed therefrom. In the method for producing the methylene beta-ketoesters of the invention, a beta-ketoester is reacted with a source of formaldehyde in a modified Knoevenagel reaction optionally in the presence of an acidic or basic catalyst, and optionally in the presence of an acidic or non-acidic solvent, to form reaction complex. The reaction complex may be an oligomeric complex. The reaction complex is subjected to further processing, which may be vaporization by contact with an energy transfer means in order to isolate the beta-ketoester monomer. The present invention further compositions and products formed from methylene beta-ketoester monomers of the invention, including monomer-based products (e.g., inks, adhesives, coatings, sealants or reactive molding) and polymer-based products (e.g., fibers, films, sheets, medical polymers, composite polymers and surfactants).

Abstract: Methods of making reduced derivatives of hydroxymethyl furfural using metal catalysts are described. The derivatives may have tetrahydrofuran or furan nucleus with alkoxymethyl ether or ester moieties on the 5? carbon and methanol on the 2? carbon. Suitable metal catalyst include Raney nickel, a nickel catalyst with a zirconium promoter, a chromite catalyst with a barium, a palladium catalyst, such as palladium on carbon, or a ruthenium catalyst. Also provided are a new class of compounds, which are n-alkoxy hexane diols (i.e., 1,2 or 1,5 hexane diol ethers) and methods of making the same by reduction of furan or tetrahydrofuran derivatives.

Abstract: A process for preparing a prostaglandin analogue comprising a step of converting a compound of formula (8?): to the prostaglandin analogue, wherein R3 represents hydrogen or a hydroxyl protecting group.

Abstract: Methods of making reduced derivatives of hydroxymethyl furfural using metal catalysts are described. The derivatives may have tetrahydrofuran or furan nucleus with alkoxymethyl ether or ester moieties on the 5? carbon and methanol on the 2? carbon. Suitable metal catalyst include Raney nickel, a nickel catalyst with a zirconium promoter, a chromite catalyst with a barium, a palladium catalyst, such as palladium on carbon, or a ruthenium catalyst. Also provided are a new class of compounds, which are n-alkoxy hexane diols (i.e., 1,2 or 1,5 hexane diol ethers) and methods of making the same by reduction of furan or tetrahydrofuran derivatives.

Abstract: Embodiments of the present disclosure present systems and methods for the synthesis of carbon nanotubes (CNTs) functionalized with mono-terminated, protected polyethylene glycol (PEG). As compared with bi-functional PEG, mono-terminated PEG the PEG-THFF oligomer has only one reaction site. The use of mono-terminated PEG may enhance the solubility of CNTs functionalized with mono-terminated PEG by inhibiting cross-linking between nanotubes and leads to a dramatic increase in aqueous solubility. In an example, single-walled carbon nanotubes functionalized with PEG having a tetrahydrofurfuryl (THFF) terminal group (SWNT-PEG-THFF) is found to disperse in water by ultrasonication and forms stable viscous dispersions at concentrations as high as about 9 g/L. This result exceeds the solubility of a previously reported SWNT-PEG graft copolymer, approximately 6 g/L, by more than 30%.

Abstract: Cyclohexanedione compounds of Formula (I) wherein R1 is methyl, ethyl, n-propyl, iso-propyl, cyclopropyl, halomethyl, haloethyl, halogen, vinyl, ethynyl, methoxy, ethoxy, halomethoxy or haloethoxy, R2 and R3 are, independently hydrogen, halogen, C1-C6alkyl, C1-C6haloalkyl, C1-C6alkoxy, C1-C6haloalkoxy, C2-C6alkenyl, C2-C6haloalkenyl, C2-C6alkynyl, C3-C6alkenyloxy, C3-C6haloalkenyloxy, C3-C6alkynyloxy, C3-C6cycloalkyl, C1-C6alkylthio, C1-C6alkylsulfinyl, C1-C6alkylsulfonyl, C1-C6alkylsulfonyloxy, C1-C6haloalkylsulfonyloxy, cyano, nitro, phenyl, phenyl substituted by C1-C4alkyl, C1-C3Cahaloalkyl, C1-C3alkoxy, C1-C3haloalkoxy, cyano, nitro, halogen, C1-C3alkylthio, C1-C3alkylsulfinyl or C1-C3alkylsulfonyl, or heteroaryl or heteroaryl substituted by C1-C3Calkyl, d.

Abstract: The present application provides intermediates for preparing prostaglandin analogues and processes for preparing prostaglandin analogues and intermediates thereof. The intermediates include: A compound of formula (6): R1 represents H, C1-C5-alkyl, or benzyl, in particular isopropyl.

Abstract: In the presence invention, a (2R)-2-fluoro-2-C-methyl-D-ribono-?-lactone precursor is produced in the form of a ring-opened fluorinated compound by reaction of a 1,2-diol with sulfuryl fluoride (SO2F2) in the presence of an organic base and, optionally, a fluoride ion source. The production method of the present invention secures less number of process steps as compared to the conventional production method (shortening of three steps: cyclic sulfurous esterification, oxidation and ring-opening fluorination to one step) and satisfies the requirements for industrial production (high yield and high reproductivity). The thus-obtained (2R)-2-fluoro-2-C-methyl-D-ribono-?-lactone precursor is useful as an important intermediate for the synthesis of 2?-deoxy-2?-fluoro-2?-C-methylcytidine with antivirus activity.

Abstract: The invention provides sulphone compounds and their use in treating medical disorders, such as obesity. Pharmaceutical compositions and methods of making various sulphone compounds are provided. The compounds are contemplated to have activity against methionyl aminopeptidase 2.

Abstract: The present invention relates to a pharmaceutical composition for stimulating angiogenesis and/or the treatment or prevention of hypovascularity and/or the prevention and/or treatment of an angiogenic disorder/disease, whereby the composition comprises specific compounds which may be obtained from Leontopodium alpinum Cass, (Edelweiss). These compounds relate to lignan compounds as shown in herein disclosed formula I. A preferred compound in this context is leologin—IUPAC name [(2S,3R,4R)-4-(3,4-dimethoxybenzyl)-2-(3,4-dimethoxyphenyl)tetxahydrofuran-3-yl]methyl (2Z)-2-methylbut-2-enoat], and even more particularly 5-methoxy-leoligin (IUPAC name: [(25,3R,4R)-4-(3,4-dimethoxybenzyl)-2-(3,4,5-trimethoxyphenyl)tetrahydrofuran-3-yl]methyl-(2Z)-2-methylbut-2-enoat) and derivatives thereof. Corresponding means and methods in respect of medical uses of these compounds are described.

Abstract: Methods of making reduced derivatives of hydroxymethyl furfural using metal catalysts are described. The derivatives may have tetrahydrofuran or furan nucleus with alkoxymethyl ether or ester moieties on the 5? carbon and methanol on the 2? carbon. Suitable metal catalyst include Raney nickel, a nickel catalyst with a zirconium promoter, a chromite catalyst with a barium, a palladium catalyst, such as palladium on carbon, or a ruthenium catalyst. Also provided are a new class of compounds, which are n-alkoxy hexane diols (i.e., 1,2 or 1,5 hexane diol ethers) and methods of making the same by reduction of furan or tetrahydrofuran deivatives.

Abstract: Method for the manufacture of organic acid esters of 5-hydroxymethylfurfural by reacting a fructose or glucose-containing starting material with an organic acid or its anhydride in the presence of a catalytic or sub-stoechiometric amount of solid acid catalyst. The catalysts are heterogeneous and may be employed in a continuous flow fixed bed reactor. The esters can be applied as a fuel or fuel additive.

Abstract: The instant invention involves a process for enhancing molecular mass of biomass reactants. The process comprises first forming a substituted or unsubstituted furfural from a biomass. The substituted or unsubstituted furfural is then reacted with an activated methylene compound in the presence of a catalyst and, if desired, a solvent to form a Knoevenagel product. The product may then be hydrogenated to products containing an alcohol, ether, aldehyde, or ketone functional groups or to an olefinic or aliphatic species wherein as much as all of the oxygen and/or nitrogen has been removed.

Abstract: Antimicrobial compounds, such as silanol or alcohol, include a protecting or leaving group that can protect the compound from degradation during the process of preparing a medical device containing the compound or reduce the volatility of the compound relative to its counterpart without the leaving group. Nearly any hydrolysable leaving group may be employed. The leaving group may be an agent that may serve a therapeutic function in addition to protecting or retaining the antimicrobial agents.

Abstract: Compounds of the formula (I) wherein the substituents are as defined in claim 1, are suitable for use as herbicides.

Abstract: A substance includes diamond particles having a maximum linear dimension of less than about 1 ?m and an organic compound attached to surfaces of the diamond particles. The organic compound may include a surfactant or a polymer. A method of forming a substance includes exposing diamond particles to an organic compound, and exposing the diamond particles in the presence of the organic compound to ultrasonic energy. The diamond particles may have a maximum linear dimension of less than about 1 ?m. A composition includes a liquid, a plurality of diamond nanoparticles dispersed within the liquid, and an organic compound attached to surfaces of the diamond nanoparticles. A method includes mixing a plurality of diamond particles with a solution comprising a liquid solvent and an organic compound, and exposing the mixture including the plurality of diamond nanoparticles and the solution to ultrasonic energy.

Abstract: Intermediates and methods of their use in the synthesis of analogs of halichondrin B are provided.

Abstract: The present invention relates to a compound represented by wherein each symbol is as defined in the specification, a salt thereof and the like.

Abstract: The present application provides intermediates for preparing prostaglandin analogues and processes for preparing prostaglandin analogues and intermediates thereof. The intermediates include: A compound of formula (6): R1 represents H, C1-C5-alkyl, or benzyl, in particular isopropyl.

Abstract: The present application relates to novel substituted furan derivatives, to processes for their preparation, to their use for the treatment and/or prophylaxis of diseases and to their use for preparing medicaments for the treatment and/or prophylaxis of diseases, in particular for the treatment and/or prophylaxis of cardiovascular diseases.

Abstract: The present application provides intermediates for preparing prostaglandin analogues and processes for preparing prostaglandin analogues and intermediates thereof. The intermediates include: A compound of formula (6): R1 represents H, C1-C5-alkyl, or benzyl, in particular isopropyl.

Abstract: The present invention aims to provide a compound having superior pharmacological action, physicochemical properties and the like and useful as an sGC activation drug, or an agent for the prophylaxis and/or treatment of diseases such as hypertension, ischemic cardiac disease, cardiac failure, kidney disease, arteriosclerotic disease, atrial fibrillation, pulmonary hypertension, diabetes, diabetic complications, metabolic syndrome, peripheral arterial obstruction, erectile dysfunction and the like. An sGC activation drug containing a compound represented by the formula (II): wherein each symbol is as defined in the specification, or a salt thereof, as an active ingredient.

Abstract: Polyglycerol ethers of sorbitan carboxylic acid, particularly C8 to C22 carboxylic acid, esters are new surfactant compounds, useful as emulsifiers. Desirable compounds are of the formula (I): Sor(R1)(R2)(R3)(R4) where R1, R2, R3, R4 have defined meanings such that at least one group is of the formula (II): -G2CR5, where R5 is a C7 to C21 hydrocarbyl group, and at least one is of the formula (III): -[Gly]-[AO]m-H where Gly is a glycerol residue, AO is an alkyleneoxy residue of a corresponding diol cyclic carbonate, in any order; n is an average of from 0 to 100; and m is an average of from 0 to 75; such that the total of all the indices n is at least 1.

Abstract: The present invention relates to compounds derived from substituted 3-phenyl-1-(thien-2-yl)propan-1-ones, pharmaceutical compositions comprising them as well as their therapeutic applications, notably in the field of human and animal health.

Abstract: The invention generally relates to compositions and methods for treatment of disease caused by Yersinia spp. infection. More specifically, the invention relates to protein tyrosine phosphatase inhibitors and derivatives and analogs thereof, pharmaceutical compositions containing the protein tyrosine phosphatase inhibitors and analogs, methods of making the protein tyrosine phosphatase inhibitors and analogs and methods of use thereof.

Abstract: Method for the manufacture of organic acid esters of 5-hydroxymethylfurfural by reacting a fructose or glucose-containing starting material with an organic acid or its anhydride in the presence of a catalytic or sub-stoechiometric amount of solid acid catalyst. The catalysts are heterogeneous and may be employed in a continuous flow fixed bed reactor. The esters can be applied as a fuel or fuel additive.

Abstract: The present application provides intermediates for preparing prostaglandin analogues and processes for preparing prostaglandin analogues and intermediates thereof. The intermediates include: A compound of formula (6): R1 represents H, C1-C5-alkyl, or benzyl, in particular isopropyl.

Abstract: Disclosed herein are novel compounds with activity at RAR? 2 receptors. Further disclosed are the use of such compounds for treatment of or to alleviate symptoms of cancer, neurological disorders such as memory deficits and schizophrenia, neurodegenerative disorders such as Parkinson's and Alzheimer's diseases, inflammatory disorders such as psoriasis and rheumatoid arthritis, eye disorders and depression.

Abstract: The invention provides surfactant compounds of formulas I-IX, which can be used in methods for aiding the solubilization, digestion, preparation, analysis, and/or characterization of biological material, for example, proteins or cell membranes. The compounds can also aid in the recovery of peptides generated during protein digestion, particularly for in-gel digestion protocol. Additionally, the compounds can improve enzymatic protein deglycosylation without interfering with downstream sample preparation steps and mass spectrometric analysis. The compounds can be specifically useful as digestion aids that can be decomposed by an acid, by heat, or a combination thereof. Decomposition of the surfactants allows for facile separation from isolated samples, and/or allows for analysis of the sample without interfering with the sensitivity of various analytical techniques.

Abstract: The present invention relates to a 2-phenyl-3-heteroarylpropionic acid derivative or a salt thereof, and also relates to a pharmaceutical agent and a VLA-4 and/or LPAM-1 antagonist each of which contains the same as an active ingredient.

Abstract: A checker which comprises potassium iodide, thiosulfate ion, and starch, wherein a weight ratio of the potassium iodide and the thiosulfate ion (potassium iodide/thiosulfate ion) is 0.70 to 0.3; and a kit comprising two or more of the aforementioned checkers, wherein the aforementioned weight ratio is different between said checkers are provided. The checker or the kit easily and precisely determines whether or not the concentration of an organic carboxylic acid peroxide such as peracetic acid in an aqueous composition for sterilization comprising the organic carboxylic acid peroxide as an active ingredient is an effective concentration.

Abstract: Compounds of formula (I): wherein: R2 is H or an optionally substituted C1-4 alkyl group; Y is either —(CH2)n—X—, where n is 1 or 2 and X is O, S, S(?O), S(?O)2, or NRN1, where RN1 is selected from H or optionally substituted C1-4 alkyl, or Y is —C(?O)NRN2—, where RN2 is selected from H, and optionally substituted C1-7 alkyl or C5-20 aryl; R3 is an optionally substituted C6 aryl group linked to a further optionally substituted C6 aryl group, wherein if both C6 aryl groups are benzene rings, there may be an oxygen bridge between the two rings, bound adjacent the link on both rings; A is a single bond or a C1-3 alkylene group; and R5 is either: (i) carboxy; (ii) a group of formula (II): or (iii) a group of formula (III): ?wherein R is optionally substituted C1-7 alkyl, C5-20 aryl or NRN3RN4, where RN3 and RN4 are independently selected from optionally substituted C1-4 alkyl; (iv) tetrazol-5-yl.

Abstract: An acrylate compound of formula (4): is produced by allowing an acrylic acid compound of formula (1): to react with an unsaturated compound of formula (2) or (3): In formulae (1) through (4), R1 and R2 are H or F, R3 is H, F, or an alkyl, alkenyl, fluoroalkyl or fluoroalkenyl group, R4 and R5 are H, halogen, or an alkyl, alkenyl, halogenated alkyl or halogenated alkenyl group; and X and Y are an unsubstituted or substituted hydrocarbon group, and dashed line - - - means that X and Y may be bonded together to form a cyclic structure.

Abstract: Novel compounds of the general formula (I), wherein Ar, R1, R2, X1, X2, Y1, Y, and Z are as defined in the specification, the use of these compounds as pharmaceutical compositions, pharmaceutical compositions comprising the compounds and methods of treatment employing these compounds and compositions. The present compounds may be useful in the treatment and/or prevention of conditions mediated by Peroxisome Proliferator-Activated Receptors (PPAR), in particular the PPAR? subtype.

Abstract: An acrylate compound of formula (4): is produced by allowing an acrylic acid compound of formula (1): to react with an unsaturated compound of formula (2) or (3): In formulae (1) through (4), R1 and R2 are H or F, R3 is H, F, or an alkyl, alkenyl, fluoroalkyl or fluoroalkenyl group, R4 and R5 are H, halogen, or an alkyl, alkenyl, halogenated alkyl or halogenated alkenyl group; and X and Y are an unsubstituted or substituted hydrocarbon group, and dashed line - - - means that X and Y may be bonded together to form a cyclic structure.

Abstract: The invention relates to novel heterocycle substituted diphenyl leukotriene B4 (LTB4) antagonists, to compositions containing such compounds, and to methods of using such compounds for treatment of inflammatory diseases.

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: wherein wavy line attachments indicate either the alpha (&agr;) or beta (&bgr;) configuration; dashed bonds represent a double bond, or a single bond, R is a substituted heteroaryl radical, R1 is hydrogen or a lower alkyl radical having up to six carbon atoms, X is selected from the group consisting of —OR1, —N(R1)2, R1 is hydrogen or a lower alkyl radical having up to six carbon atoms, X is selected from the group consisting of —OR1, —N(R1)2 and —N(R5)SO2R6, wherein R5 represents hydrogen or CH2OR6 and R6 represents hydrogen or a lower alkyl radical having up to six carbon atoms and halogen substituted derivatives of said lower alkyl radical, e.g. a fluoro substituted lower alkyl radical; Y is ═O or represents 2 hydrogen radicals.

Abstract: The present invention provides cyclopentane heptanoic acid, 2 heteroaryl alkyl or alkenyl derivatives which may be substituted in the 1-position with hydroxyl, alkyloxy, amino and amido groups, e.g. 1-OH cyclopentane heptanoic acid, 2 heteroarylalkenyl derivatives. In particular, these derivatives are 7-[5-hydroxy-2-(heteroatom-substituted hydroxyhydrocarbyl)-3-hydroxycyclopentyl]heptanoic or heptenoic acids and amine, amide, ether, ester and alchohol derivatives of said acids wherein one or more of said hydroxy groups are replaced with an ether group. These compounds are potent ocular hypotensive and are particularly suited for the management of glaucoma.

Abstract: The present invention relates to compounds of the general formula (I) The compounds are useful in the treatment and/or prevention of conditions mediated by nuclear receptors, in particular the Peroxisome Proliferator-Activated Receptors (PPAR).

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: Compounds represented by formula I: as well as pharmaceutically acceptable salts, esters and hydrates thereof are disclosed along with pharmaceutical compositions and methods of treatment. The compounds are useful as inhibitors of caspase-3, which is implicated in modulating apoptosis.

Abstract: Compounds of formula I, ##STR1## and the physiologically tolerable salts thereof, wherein the substituents R.sub.1 -R.sub.4 have the meanings given in the specifications and show an activity against inflammatory conditions.

Abstract: The present invention relates to a pharmaceutical composition comprising, as active principle, a compound of formula: ##STR1## in which the groups A and B are chosen, independently of each other, from: a mono-, bi- or tricyclic aryl group having from 6 to 14 carbon atoms;a heteroaromatic group chosen from pyridyl, pyrimidyl, pyrrolyl, furyl and thienyl groups;an alkyl group having from 1 to 14 carbon atoms;a cycloalkyl group having from 5 to 8 carbon atoms;a saturated heterocyclic group chosen from tetrahydrofuryl, tetrahydropyranyl, piperidyl and pyrrolidinyl groups;to its solvate or to a salt of this acid with a pharmaceutically acceptable base.Figures: none.

Abstract: The present invention provides cyclopentane heptanoic acid, 2 heteroaryl alkyl or alkenyl derivatives which may be substituted in the 1-position with hydroxyl, alkyloxy, amino and amido groups, e.g. 1-OH cyclopentane heptanoic acid, 2 heteroarylalkenyl derivatives. In particular, these derivatives are 7-[5-hydroxy-2-(heteroatom-substituted hydroxyhydrocarbyl)-3-hydroxycyclopentyl] heptanoic or heptenoic acids and amine, amide, ether, ester and alchohol derivatives of said acids wherein one or more of said hydroxy groups are replaced with an ether group. These compounds are potent ocular hypotensive and are particularly suited for the management of glaucoma.

Abstract: ?- and ?-amino acid hydroxyethylamino sulfonamide compounds are effective as retroviral protease inhibitors, and in particular as inhibitors of HIV protease.