Il17A Autoantibody Induced by Recombinant Protein Ag85A-Il17A

IL17A is a widely studied cytokine which plays an important role in autoimmune diseases as well as asthma. In this study, murine IL17a gene fragment was inserted into pET28a-Ag85A and it was expressed as a fusion protein named Ag85A-IL17A. Recombinant protein Ag85A-IL17A was expressed as an open reading frame of 1,287 bp, encoding a polypeptide of 429 amino acid residues with a predicted molecular mass of 50 kDa. It was expressed in Escherichia coli. BL21 and purified by metal affinity chromatography using a nickel–nitrilotriacetic acid column. Bioinformatics revealed that Ag85A-IL17A contained B cell epitopes of IL17A. Purified proteins Ag85A-IL17A and Ag85A were injected with adjuvants into mice then antibody responses in sera were measured by enzyme-linked immunosorbent assay and western blot assay. Experiments showed that purified protein Ag85-IL17A could bind to a standard IL17A antibody and could induce IL17A autoantibody in mice.     

The revised structure, total synthesis, and absolute configuration of streptophenazine A

A total synthesis of both diastereomers of the originally proposed structure for streptophenazine A (1) has been achieved. However, both synthetic compounds are different from the natural product. Re-examination of NMR data reported for streptophenazine A and a concise total synthesis of both diastereomers of 17 (17a and 17b) led to the structural revision of streptophenazine A to 17b. Asymmetric synthesis of (-)-streptophenazine A was also conducted, and its absolute configuration was determined to be 1'S,2'R.     

Self-assembly of Aβ-based peptide amphiphiles with double hydrophobic chains

Two peptide-amphiphiles (PAs), 2C(12)-Lys-Aβ(12-17) and C(12)-Aβ(11-17)-C(12), were constructed with two alkyl chains attached to a key fragment of amyloid β-peptide (Aβ(11-17)) at different positions. The two alkyl chains of 2C(12)-Lys-Aβ(12-17) were attached to the same terminus of Aβ(12-17), while the two alkyl chains of C(12)-Aβ(11-17)-C(12) were separately attached to each terminus of Aβ(11-17). The self-assembly behavior of both the PAs in aqueous solutions was studied at 25 °C and at pHs 3.0, 4.5, 8.5, and 11.0, focusing on the effects of the attached positions of hydrophobic chains to Aβ(11-17) and the net charge quantity of the Aβ(11-17) headgroup. Cryogenic transmission electron microscopy and atomic force microscopy show that 2C(12)-Lys-Aβ(12-17) self-assembles into long stable fibrils over the entire pH range, while C(12)-Aβ(11-17)-C(12) forms short twisted ribbons and lamellae by adjusting pHs. The above fibrils, ribbons, and lamellae are generated by the lateral association of nanofibrils. Circular dichroism spectroscopy suggests the formation of β-sheet structure with twist and disorder to different extents in the aggregates of both the PAs. Some of the C(12)-Aβ(11-17)-C(12) molecules adopt turn conformation with the weakly charged peptide sequence, and the Fourier transform infrared spectroscopy indicates that the turn content increases with the pH increase. This work provides additional basis for the manipulations of the PA's nanostructures and will lead to the development of tunable nanostructure materials.     

Studies on topical antiinflammatory agents. III. Synthesis of 17 alpha-acyloxy-9 alpha-fluoro-11 beta-hydroxy-16 beta-methyl-1,4-pregnadiene-3,20-dione 21-thio derivatives and related compounds

A series of 21-thio derivatives of 9 alpha-fluoro-11 beta,17 alpha-dihydroxy-16 beta-methyl-1,4-pregnadiene-3, 20-dione 17-esters and related compounds were synthesized and evaluated as topical antiinflammatory agents. These compounds were prepared by the reaction of 9 alpha-fluoro-11 beta,17 alpha,21-trihydroxy-16 beta-methyl-1,4-pregnadiene-3, 20-dione (betamethasone, I) 17-ester derivatives and various mercapto compounds. A structure-activity relationship study revealed that the structural combination of a thio group at the 21-position and an ester group at the 17-position contributed to vasoconstrictive activity. Among these compounds, the 21-methylthio 17-propanoate compound (6) was found to have the most potent activity, being more potent than betamethasone 17-valerate (BV).     

Studies on topical antiinflammatory agents. I. Synthesis and vasoconstrictive activity of corticosteroid 17-succinyl esters

A series of 17-succinyl derivatives of four corticosteroids was prepared. They were tested for vasoconstrictive activity in humans, using 9 alpha-fluoro-11 beta, 21-dihydroxy-16 beta-methyl-17 alpha-valeryloxy-1,4-pregnadiene-3,20-dione (betamethasone 17-valerate, BV) as a standard. The activities of the 21-chloro 17-methylsuccinate compounds (6A, 6C and 6D) were greater than that of BV. A structure-activity relationship study showed that the activities of the 21-chloro 17-methylsuccinates were more potent than those of the corresponding 21-esters.     

Oxazoline derivatives of [17(20)<Emphasis Type="Italic">E</Emphasis>]-21-norpregnene – inhibitors of CYP17A1 activity and proliferation of prostate carcinoma cells

Nine new oxazolinyl derivatives of [17(20)E]-21-norpregnene, differing in the structure of steroid moiety, were investigated for their potency to inhibit the CYP17A1 catalytic activity, as well as growth and proliferation of LNCaP and PC-3 prostate carcinoma cell lines. The activity of one of the investigated compounds, 2´-{[(E)3β-hydroxyandrost-5-en-17-ylidene]methyl}-4´,5´-dihydro-1´,3´-oxazole (1), was found to be comparable with that of Abiraterone, a known inhibitor of CYP17A1 used for treatment of prostate cancer. A model of the interaction of oxazoline 1 with the active site of CYP17A1 was constructed by the molecular dynamics method. A correlation was found between the structure and the biological activity in the series of [17(20)E]-21-norpregnene oxazolinyl derivatives.     

若干17β-乙酰氧基甾族化合物用节杆菌芳构化时的水解

具有17β-乙酰氧基的不同甾族化合物8～12用节杆菌芳构化时,生成17β-羟基、17-酮基或未被水解的17β-乙酰氧基芳构化产物13～18.17-酮基化合物14或17是先由节杆菌将17β-乙酰氧基水解成羟基后再氧化而成的.17β-乙酰氧基水解与否与底物的取代基有关.     

Altered extracellular striatal in vivo biotransformation of the opioid neuropeptide dynorphin A(1-17) in the unilateral 6-OHDA rat model of Parkinson's disease

The in vivo biotransformation of dynorphin A(1-17) (Dyn A) was studied in the striatum of hemiparkinsonian rats by using microdialysis in combination with nanoflow reversed-phase liquid chromatography/electrospray time-of-flight mass spectrometry. The microdialysis probes were implanted into both hemispheres of unilaterally 6-hydroxydopamine (6-OHDA) lesioned rats. Dyn A (10 pmol microl(-1)) was infused through the probes at 0.4 microl min(-1) for 2 h. Samples were collected every 30 min and analyzed by mass spectrometry. The results showed for the first time that there was a difference in the Dyn A biotransformation when comparing the two corresponding sides of the brain. Dyn A metabolites 1-8, 1-16, 5-17, 10-17, 7-10 and 8-10 were detected in the dopamine-depleted striatum but not in the untreated striatum. Dyn A biotransformed fragments found in both hemispheres were N-terminal fragments 1-4, 1-5, 1-6, 1-11, 1-12 and 1-13, C-terminal fragments 2-17, 3-17, 4-17, 7-17 and 8-17 and internal fragments 2-5, 2-10, 2-11, 2-12, and 8-15. The relative levels of these fragments were lower in the dopamine-depleted striatum. The results imply that the extracellular in vivo processing of the dynorphin system is being disturbed in the 6-OHDA-lesion animal model of Parkinson's disease.     

Solid phase analytical derivatization of anthropogenic and natural phenolic estrogen mimics with pentafluoropyridine for gas chromatography-mass spectrometry

A simple, low cost, fast and sensitive method is reported for the determination of the four endocrine disrupting chemicals (EDCs) 4-tert-butylphenol, 4-tert-octylphenol, bisphenol A and 17β-estradiol using pentafluoropyridine as the derivatizing reagent. These EDCs were determined by simultaneous extraction and derivatization in a solid phase analytical derivatization (SPAD) technique without the aid of any phase transfer catalyst (PTC) or an ion-pair mechanism. Recoveries of analytes as their tetrafluoropyridyl derivatives from water ranged from 71% for 4-tert-butylphenol to 106% for 17β-estradiol; from urine they ranged from 61% for 17β-estradiol to 91% for 4-tert-octylphenol; and from humic acids solution the ranged from 59% for 17β-estradiol to 104% for 4-tert-octylphenol in humic acid solutions. Calibration curves were constructed from a matrix of human male urine in the range 1-40 ng/mL and had coefficients of correlation greater than 0.99. For 4-tert-butylphenol, bisphenol A and 17β-estradiol the limits of quantitation were 5 ng/mL and for 4-tert-octylphenol it was 1 ng/mL. This method was applied to determine EDCs and detected 4-tert-octylphenol, bisphenol A and 17β-estradiol in concentrations comparable to those found in the literature. The method offers advantages in speed of analysis, reduced reagent and specificity of derivatization.     

A New Diterpenoid Dimer from Annona Glabra

A new diterpenoid dimer annonebinide A has been isolated from the stems of Annona glabra.Its structure was determined to be ent-16α-hydroxykauran-17-yl ent-16β-kauran-17-oate on the basis of spectroscopic and chemical evidence.     

3-Formylcyclopent-3-enyl- and 3-carboxycyclopentylglycine derivatives: a new stereocontrolled approach via retro-aldol or retro-Claisen reactions

A new synthetic approach to diastereomeric cyclopent-3-enylglycines 19/20, functionalized on the ring with a formyl group, and to cyclopentylglycine, substituted with a carboxy group (compounds 21/22), was devised by applying retro-aldol and retro-Claisen reactions, respectively, to diastereomeric 2-amino-3-ethoxycarbonyloxynorbornene-2-carboxylic acid derivatives 5, 6 and to diastereomeric 2-amino-3-oxo-norbornane-2-carboxylic acid derivatives 17, 18. The goal of controlling the cis stereochemistry of the cyclopentyl substituents was reached using compounds 17, 18. A partial control of the stereochemistry of the amino acidic carbon was achieved starting from 17 and using sodium hydrogen carbonate in acetone/DMF. From exo-17, the acid 22 was obtained as the major diastereomer.     

Exploring the inter-molecular interactions in amyloid-β protofibril with molecular dynamics simulations and molecular mechanics Poisson-Boltzmann surface area free energy calculations

Aggregation of amyloid-β (Aβ) peptides correlates with the pathology of Alzheimer's disease. However, the inter-molecular interactions between Aβ protofibril remain elusive. Herein, molecular mechanics Poisson-Boltzmann surface area analysis based on all-atom molecular dynamics simulations was performed to study the inter-molecular interactions in Aβ(17-42) protofibril. It is found that the nonpolar interactions are the important forces to stabilize the Aβ(17-42) protofibril, while electrostatic interactions play a minor role. Through free energy decomposition, 18 residues of the Aβ(17-42) are identified to provide interaction energy lower than -2.5 kcal/mol. The nonpolar interactions are mainly provided by the main chain of the peptide and the side chains of nine hydrophobic residues (Leu17, Phe19, Phe20, Leu32, Leu34, Met35, Val36, Val40, and Ile41). However, the electrostatic interactions are mainly supplied by the main chains of six hydrophobic residues (Phe19, Phe20, Val24, Met35, Val36, and Val40) and the side chains of the charged residues (Glu22, Asp23, and Lys28). In the electrostatic interactions, the overwhelming majority of hydrogen bonds involve the main chains of Aβ as well as the guanidinium group of the charged side chain of Lys28. The work has thus elucidated the molecular mechanism of the inter-molecular interactions between Aβ monomers in Aβ(17-42) protofibril, and the findings are considered critical for exploring effective agents for the inhibition of Aβ aggregation.     

Stereospecific Synthesis of Steroidal 20,16-γ-Carbolactones

Two strategies have been explored for the synthesis of steroidal 20,16-γ-carbolactones from the corresponding 17-ketoandrostane. A highly efficient, stereospecific protocol has been developed for the β-oriented cis-γ-lactone, based on a Michael addition of cyanide to a conjugated ketone. A different approach, involving prior attachment of a 3-carbon side chain on C-17 of a 17-oxo-16β-acetoxy-androstane led to the epimeric, α-oriented lactone.     

Structure and reactivity of steroids—VI : Long range effects in a series of Δ1,3,5(10)-estratriene compounds

The kinetics of the oxidation of 17β-hydroxy-Δ^1,3,5(10)-estratrienes which differ in D ring size, in C₃, substituent and in the character of fusion of the B and C rings by CrO₃ in AcOH has been studied. An increase in size of the D ring in the substrate diminishes reactivity of the 17β-hydroxy group in the oxidation. It has been found that the reactivities of the 17β and 17β-hydroxy groups of the Δ^1,3,5(10)-estratriene derivatives depend upon the electronic nature of the substituent at C³, explained by a long range effect operating from the A to D ring. The pK'a's of phenolic steroids have been measured and it was shown that introduction of the Δ⁸⁽⁹⁾ double bond increases the degree of dissociation of the phenolic hydroxyl. Expansion of the D ring and also reduction of the 17(17a)-keto group to 17β (17aβ) hydroxy group decreases the degree of dissociation of the phenolic hydroxyl as a result of the long range effect from the D to A ring. A linear correlation has been established between the oxidation and dissociation rate constants, confirming the existence of an interaction between C₃ and C_17(17a) at the expense of the long range effects from the A to D ring and vice versa. The long range effect apparently arises from a combination of inductive and conformational effects of the substituent. The kinetics of enzymic oxidation of 17β-hydroxy-Δ^1,3,5(10)-estratrienes by soluble 17β-estradiol dehydrogenase from human placenta has been investigated. In the case of 17β-hydroxy-Δ^1,3,5(10)-estratrienes of natural configuration, a linear correlation has been established between the values of the maximum rate constant and the oxidation rate constant. An assumption can thus be made about the major role of the contribution of the specific reactivity of the substrate to that of the enzyme-substrate complex, involving the size of the D ring and the long range effect of the substituent at C₃ upon the reaction center at C_17(17a). For 17β-hydroxy-Δ^1,3,5,(10)-estratrienes of the 8-isoconfiguration it is the specific reactivity of the substrate that makes the major contribution to the maximum rate values; this specific activity is a result of the substrate's configuration, which is responsible for the stability of the enzyme-substrate complex.     

A further study of the substrate specificity in the reduction of 20-oxosteroids with a culture ofActinomyces roseochromogenus

Chemistry of Natural Compounds - A culture ofActinomyces roseochromogenus ATCC 3347 reduces 17-hydroxy- and 16α, 17α-epoxy-20-oxopregnenes to the corresponding 20α-alcohols, but is...     

Combined high-performance liquid chromatography and radioimmunoassay for the screening of 19-nortestosterone and methyltestosterone residues in meat samples

A procedure is described for the detection of 17 beta-19-nortestosterone (17 beta-19-NT) and 17 alpha-methyltestosterone (17 alpha-MT) in muscle tissue by a combination of high-performance liquid chromatography and radioimmunoassay. The steroids were released from the muscle tissue by enzyme digestion, and the extracts were purified by solid-phase extraction. A meat sample from the retail trade, which was proved to contain 17 beta-19-NT and 17 alpha-MT residues by gas chromatography-mass spectrometry, and blank meat samples obtained from non-treated experimental animals were purified and the extracts injected into the liquid chromatograph. With an automatic fraction collector, fifteen fractions of 1 ml each were obtained, which after evaporation were subjected to a radioimmunoassay for the steroid concerned. It was demonstrated that none of the fractions from the blank meat samples contains any substance that interfered with the immunochemical detection system. In addition, a good qualitative agreement between the two sets of results was obtained. Although the sample preparation step is rather labour-intensive, the method can be successfully applied as a reliable confirmation method for positive radioimmunoassay screening results in circumstances where no gas chromatography-mass spectrometry facilities are available.     

A novel derivative of geldanamycin and its antitumor activity

A new derivative of geldanamycin was synthesized by introducing the 6-cinnamamido-hexyl-amino group into the 17-site of geldanamycin,a heat shock protein 90(Hsp90)inhibitor,to obtain 17-(6-cinnamamido-hexylamino)-17-demethoxygel-danamycin (CNDG).Its in vitro and in vivo anfitumor effects were evaluated by MTT assay and xenografl in nude mice.     

Transformed steroids. 193. Synthesis of 16α,17α-isopropylidene derivatives of pregn-4-ene-9α,16α,17α,21-tetraol-3,20-dione and its 17α-thioanalog

A study was carried out on the pathways for the transformation of 16α,17α-epoxypregn-4-ene-9α,21-diol-3,20-dione to give 16α,17α-isopropylidene derivatives of pregn-4-ene-9α,16α,17α,21-tetraol-3,20-dione and its 17α-thioanalog. The key step in this pathway is thecis-cleavage of the 20-carboethoxyhydrazone of this epoxide by acetic and thioacetic acids and subsequent condensation of the products formed with acetone. This pathway is an efficient approach to the synthesis of the 16α,17α-dioxolane derivative and is equally efficient for preparation of the thioanalog, namely, 16α,17α-isopropylidenepregn-4-ene-9α,16α,21-triol-17α-thiol-3,20-dione, which has already been synthesized by an alternative method.     

Three steroids with unique structural feature of 5β-Spirostan-1β,3β,17α-trihydroxyl from Reineckia carnea

A new spirostanol sapogenin and two spirostanol saponins, tentatively named reineckiagenin A (1), reineckiagenoside A (2), and reineckiagenoside B (3), were isolated from the whole plant of Reineckia carnea. By detailed analysis of their 1D and 2D NMR spectra, chemical methods, and by comparison with spectra data of known compounds, the structures of the new steroids were determined to be 25(S)-5β-spirostan-1β,3β,17α-triol (1), 25(S)-5β-spirostan-1β,3β,17α-triol 1-O-β-D-xylopyranoside (2), 25(S)-5β-spirostan-1β,3β,17α-triol 1-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranoside (3). Compounds 1, 2, and 3 are the first naturally occurring steroids with unique structural feature of 5β-spirostan-1β,3β,17α-trihydroxyl.