11, 15, 19-trihydroxy-9-ketoprost-13-enoic acid and 11, 15, 19-trihydroxy-9-ketoprosta-5, 13-dienoic acid in human seminal fluid.

Two novel prostaglandins (PG) have been found in human seminal fluid which had been frozen immediately after collection. They were characterized by combined gas-liquid chromatography-mass spectrometry of various derivatives as 19-hydroxy prostaglandin E1 (11, 15, 19-trihydroxy-9-ketoprost-13-enoic acid) and 19-hydroxy prostaglandin E2 (11, 15, 19-trihydroxy-9-ketoprosta-5, 13-dienoic acid). They were present in three to five times the quantity of prostaglandins E1 and E2. Incubation of seminal fluid for 3 hr at 25 degrees C reduced levels of 190H-PGEs2.5-fold and PGE22-fold, while increasing levels of PGAs and PGBs 2-fold. No 190H PGA or 190H PGB was detected in extracts of unincubated fluid. The PGAs, PGBs and their 19-hydroxy analogs are probably artifacts arising metabolically or as a result of classical isolation techniques.     

Stereoselective Synthesis of a Promising Flower-Inducing KODA Analog, (9R,12S,13R,15Z)-9-Hydroxy-12,13-methylene-10-oxooctadec-15-enoic Acid

Stereoselective synthesis of a promising flower-inducing 9,10-ketol octadecadienoic acid (KODA) analog, (9R,12S,13R,15Z)-9-hydroxy-12,13-methylene-10-oxooctadec-15-enoic acid, was designed to obtain the desired stereoisomer via coupling between chiral sulfone and aldehyde segments. A known chiral cyclopropane derivative was converted to the sulfone segment via carbon-chain elongation and sulfonylation. Dec-9-en-1-ol was converted to the aldehyde segment, whose C-9 configuration was introduced by Sharpless asymmetric dihydroxylation. Coupling of the both segments and subsequent assembly gave the desired (9R,12S,13R,15Z)-analog. The (9S,12S,13R,15Z)-analog was also synthesized by using the enatiomeric aldehyde segment. This strategy made it possible to synthesize the remaining stereoisomeric analogs.     

Concerning the biosynthesis of prostaglandin I2

Two diastereoisomers, 5R,6R-5-hydroxy-6(9α)-oxido-11α,15S-dihydroxyprost-13-enoic acid (7) and 5S,6S-5-hydroxy-6(9α)-oxido-11α,15S-dihydroxyprost-13-enoic acid (10) were synthesized for evaluation as possible biosynthetic intermediates in the enzymatic transformation of PGH₂ or PGG₂ into PGI₂. The synthetic sequence entails the stereospecific reduction of the 9-keto function in PGE₂ methyl ester after protecting the C-11 and C-15 hydroxyls as tbutyldimethylsilyl ethers. The resulting PGF_2α derivative was epoxidized exclusively at the C-5 (6) double bond to yield a mixture of epoxides, which underwent facile rearrangement with SiO₂ to yield the 5S,6S and 5R,6R-5-hydroxy-6(9α)-oxido cyclic ethers. It was found that dog aortic microsomes were unable to transform radioactive 9β-5S,6S[³H] or 9β-5R,6R[³H]-5-hydroxy-6(9α)-oxido cyclic ethers into PGI₂. Also, when either diastereoisomer was included in the incubation mixture, neither isomer diluted the conversion of [1-¹⁴C]arachidonic acid into [1-¹⁴C]PGI₂.     

Method for quantitative analysis of 16, 16-dimethyl-prostaglandin E2 from plasma using deuterated carrier and gas chromatography-mass spectrometry.

The preparation of 3,3,4,4-²H₄16,16-dimethyl-prostaglandin E₂ (PGE₂), 16,16-dimethyl-5,6-didehydro-PGE₂, and 5,6-³H₂16,16-dimethyl-PGE₂ is described. These compounds have been used for development of a gas-liquid chromatography-mass spectrometry method for quantitative determination of corresponding nondeuterated prostaglandin. The method is based on addition of a known amount of carrier to the sample and after purification and derivation the ratio between the protium and deuterium form is measured in the mass spectrometer. With this technique 40 pg of 16,16-dimethyl-PGE₂ can be determined with a precision of ±2.6%.     

Method for quantitative analysis of PGA2 from plasma using deuterated carrier and gas-liquid chromatography-mass spectrometry

The preparation of [3,3,4,4,-²H₄, 17, 18-³H₂]prostaglandin A₂ (PGA₂) and [17, 18-³H₂]PGA₂ is described. These compounds have been prepared for use in quantitative determination of corresponding nondeuterated prostaglandin by gas-liquid chromatography-mass spectrometry. The method is based on addition of a known amount of carrier to the sample. After purification and derivatization, the ratio between the protium and deuterium form is measured in the mass spectrometer. Ions originating from deuterated and nondeuterated moleeules are focused intermittently on the electron multiplier using an accelerating voltage alternator. With this technique, 60 pg of PGA₂ can be determined with a precision of ±8.4%. The recoveries from plasma of added PGA₂ were about 97%. Basal levels of PGA₂ in human plasma were lower than 10 pg/ml.     

Synthesis,and In Vitro and In Silico α-Glucosidase Inhibitory Studies of 5-Chloro-2-Aryl Benzo[d]thiazoles

Twenty-five derivatives of 5-chloro-2-aryl benzo[d]thiazole (1–25) were synthesized and evaluated for their α-glucosidase (S. cerevisiae EC 3.2.1.20) inhibitory activity in vitro. Among them eight compounds showed potent activity with IC₅₀ values between 22.1 ± 0.9 and 136.2 ± 5.7 μM, when compared with standard acarbose (IC₅₀ = 840 ± 1.73 μM). The most potent compounds 4, 9, and 10 showed IC₅₀ values in the range of 22.1 ± 0.9 to 25.6 ± 1.5 μM. Compounds 2, 5, 11, and 19 showed IC₅₀ values within the range of 40.2 ± 0.5 to 60.9 ± 2.0 μM. Compounds 1 and 3 were also found to be good inhibitors with IC₅₀ values 136.2 ± 5.7 and 104.8 ± 9.9 μM, respectively. Their activities were compared with α-glucosidase inhibitor drug acarbose (standard) (IC₅₀ = 840 ± 1.73 μM). The remaining compounds were inactive. Structure-activity relationships (SAR) have also been established. Kinetics studies indicated compounds 2, 3, 10, 19, and 25 to be non-competitive, while 1, 5, 9, and 11 as competitive inhibitors of α-glucosidase enzyme. All the active compounds (1–5, 9–11, and 19) were also found to be non-cytotoxic, in comparison to the standard drug i.e., doxorubicin (IC₅₀ = 0.80 ± 0.12 μM) in MTT assay. Furthermore, molecular interactions of active compounds with the enzyme binding sites were predicted through molecular modeling studies.     

The absolute configuration of the new amino acid 2-amino-4-methyl-hex-5-enoic acid from a new guinea Boletus

The absolute configuration of the 2-amino-4-methyl-hex-5-enoic acid isolated from Boletus was shown to be 2S, 4S, by an unambiguous synthesis of its dihydro derivative from 2S-(?)-2-methylbutan-1-ol.     

A radioimmunoassay for the initial metabolites of the F prostaglandins

Antibodies to the F metabolite 9α, 11α-dihydro-15-keto-prostanoic acid (I), produced in the rabbit, do not cross react with any of the primary PGs. There is a 50% cross reaction with the metabolite 9α, 11α-dihydroxy-15-keto-prost-5-enoic acid (III), and a 23% cross reaction with 9α,11α,15-trihydroxy prostanoic acid (F₀α). No cross reactivity resulted with this antiserum when tested against 9α,11α,15-trihydroxy-5-enoic acid (VII) or with 9α,11α-dihydroxy-15-ketoprost-5,13-dienoic acid (VIII). Utilizing this antibody in a radioimmunoassay, some preliminary data are presented on levels of these F metabolites (I and III) for human adult male samples of plasma, urine and seminal plasma.     

D-isomeric replacements within the 6-9 core sequence of Ac-[Nle4]-alpha-MSH4-11-NH2: a topological model for the solution conformation of alpha-melanotropin

Analogs of Ac-[Nle⁴]-α-MSH_4–11-NH₂ and Ac-[Nle⁴, D -Phe⁷]-α-MSH_4–11-NH₂ were prepared with D -isomeric replacements at the His⁶, Arg⁸, and Trp⁹ residues. The requirement for an indole moiety at position 9 also was evaluated by replacement with L -leucine in both parent fragment analogs. D -isomeric replacements at positions 6 and 8 in either series were detrimental to biological potency in frog (Rana pipiens) and lizard skin (Anolis carolinensis) in vitro melanotropic assays. However, Ac-[Nle⁴, D -Trp⁹]-α-MSH_4–11-NH₂ and Ac-[Nle⁴, D -Phe⁷, D -Trp⁹]-α-MSH_4–11-NH₂ were equipotent and 10 × more potent than Ac-[Nle⁴]-α-MSH_4–11-NH₂, respectively, in the lizard skin bioassay, and 30 and 1900 times more potent in the frog skin bioassay. Ac-[Nle⁴, D -Phe⁷, D -Trp⁹]-α-MSH_4–11-NH₂ was 3 × more potent than α-MSH in the frog skin bioassay. Proton nmr studies in aqueous solution revealed a marked preservation of the backbone conformation of these linear analogs. Chemical-shift variations due to the through-space anisotropic influence of the core aromatic amino acid residues permitted evaluation of side-chain topology. The observed topology was consistent with nonhydrogen-bonded β-like structure (? = ?139°, ψ = +135° for L -amino acids; ? = +139°, ψ = ?135° for D -amino acids) as the predominant solution conformation. The biological and conformational data suggest that high melanotropic potency requires a close spatial arrangement of the His⁶, Phe⁷, and Arg⁸ side chains.     

The synthesis of (Z)-4-oxo-4-(arylamino)but-2-enoic acids derivatives and determination of their inhibition properties against human carbonic anhydrase I and II isoenzymes

The synthesis of (Z)-4-oxo-4-(arylamino)but-2-enoic acid (4) derivatives containing structural characteristics that can be used for the synthesis of several active molecules, is presented. Some of the butenoic acid derivatives (4a, 4c, 4e, 4i, 4j, 4k) are synthesized following literature procedures and at the end of the reaction. In addition, structures of all synthesized derivatives (4a–4m) were determined by ¹H-NMR, ¹³C-NMR and IR spectroscopy. Carbonic anhydrase is a metalloenzyme involved in many crucial physiologic processes as it catalyzes a simple but fundamental reaction, the reversible hydration of carbon dioxide to bicarbonate and protons. Significant results were obtained by evaluating the enzyme inhibitory activities of these derivatives against human carbonic anhydrase hCA I and II isoenzymes (hCA I and II). Butenoic acid derivatives (4a–4m) strongly inhibited hCA I and II with K_is in the low nanomolar range of 1.85?±?0.58 to 5.04?±?1.46?nM against hCA I and in the range of 2.01?±?0.52 to 2.94?±?1.31?nM against hCA II.     

Inhibition of prostaglandin E2-induced cyclic AMP accumulation in the rat anterior pituitary by 11-deoxyprostaglandin E analogs (9-ketoprostynoic acids)

The effects of various 11-deoxyprostaglandin E analogs on the basal and prostaglandin E₂ (PGE₂)-induced cyclic AMP accumulation in the rat anterior pitutiary were studied . 13-Hydroxy-9-oxoprost-14-ynoic acid at 5 × 10⁻⁴M, but not 5 × 10⁻⁵M, decreased (45%) the induced accumulation and did not alter the basal accumulation; 15-hydroxy-9-oxoprost-13-ynoic acid at 5 × 10⁻⁴M caused less of a decrease (29%) in the induced and also did not alter the basal accumulation. (14Z)-13-Hydroxy-9-oxoprost-14-enoic acid at 5 × 10⁻⁴M did not alter the induced and caused a slight increase (5 fold) in the basal accumulation. 7-Oxa-13-prostynoic acid increased slightly the basal accumulation at 5 × 10⁻⁵M (2 fold) and 2.33 × 10⁻⁴M (6 fold) and did not antagonize the induced accumulation. Thus, the 9-ketoprostynoic acids are effective PGE₂ antagonists in this system.     

Synthesis,biological evaluation and docking study of 1,3,4-thiadiazole-thiazolidinone hybrids as anti-inflammatory agents with dual inhibition of COX-2 and 15-LOX

Selective inhibition of both cyclooxygenase-2 (COX-2) and 15-lipooxygenase (15-LOX) may provide good strategy for alleviation of inflammatory disorders while minimizing side effects associated with current anti-inflammatory drugs. The present study describes the synthesis, full characterization and biological evaluation of a series of thiadiazole-thiazolidinone hybrids bearing 5-alk/arylidene as dual inhibitors of these enzymes. Our design was based on merging pharmacophores that exhibit portent anti-inflammatory activities in one molecular frame. 5-(4-hydroxyphenyl)-1,3,4-thiadiazol-2-amine (3) was efficiently synthesized, chloroacetylated and cyclized to give the key 4-thiazolidinone (5). Knovenagel condensation of 5 with different aldehydes afforded the final compounds 6a-m, 7, 8 and 9. These compounds were subjected to in vitro COX-1/COX-2, 15-LOX inhibition assays. Compounds (6a, 6f, 6i, 6l, 6m and 9) with promising potency (IC₅₀ = 70–100 nM) and selectivity index (SI = 220-55) were further tested for in vivo anti-inflammatory activity and effect on gastric mucosa. The most promising compound (6l) inhibits COX-2 enzyme at a nanomolar concentration (IC₅₀ = 70 nM, SI = 220) with simultaneous inhibition of 15-LOX (IC₅₀ = 11 µM). These results are comparable to the potency and selectivity of the standard drugs of both enzymes; celecoxib (COX-2 IC₅₀ = 49 nM, SI = 308) and zileuton (15-LOX IC₅₀ = 15 µM) in one construct. Interestingly three compounds (6a, 6l and 9) exhibited equivalent to or even higher than that of celecoxib in vivo anti-inflammatory activity at 3 h interval with good GIT safety profile. Molecular docking study conferred binding sites of these compounds on COX-2 and 15-LOX. Such type of compounds would represent valuable leads for further investigation and derivatization.     

Microbial conversion of 5-sulfoisophthalic acid into 5-hydroxyisophthalic acid by Ochrobactrum anthropi S9

5-Hydroxyisophthalic acid-producing microorganisms were isolated from enrichment cultures using 5-sulfoisophthalic acid as a sulfur source. One bacterium, Ochrobactrum anthropi S9, had the highest 5-sulfoisophthalic acid-degrading activity, and stoichiometrically formed 5-hydroxyisophthalic acid, a raw material for polymer synthesis. Under optimum culture conditions, 1.3 mM 5-hydroxyisophthalic acid accumulated in the medium by 60 h. The addition of Na₂SO₄, l-methionine or l-cysteine at 2 mM inhibited the conversion of 5-sulfoisophthalic acid. O. anthropi S9 cells converted 5-sulfoisophthalic acid, benzenesulfonic acid, 3-sulfobenzoic acid, 4-aminobenzenesulfonic acid, naphthalene-1-sulfonic acid and naphthalene-2-sulfonic acid into the corresponding hydroxylated compounds.     

Synthesis,ADME, docking studies and in vivo anti-hyperglycaemic potential estimation of novel Schiff base derivatives from octadec-9-enoic acid

A new series of octadec-9-enoic acid schiff base entities (S1-S30) were designed and synthesized targeting peroxisome proliferator activated receptor-gamma for agonist action. Molinspiration software (online) was used to estimate drug like molecular properties of the metabolites. Docking disquisition on co-crystallized protein of PPAR-γ (PDB ID 1FM9) was carried out which showed S21, S10 and S7 as best situated in the vital sites of receptor having docking scores −9.19, −8.68 and −8.64 respectively. Free binding energy measured using model of Maestro 9.0 and was in range of from −40.01 and −80.54 kcal/mol, significant when compared with pioglitazone (−51.58 Kcal/mol). Seven best docked derivatives were assessed for in-vivo oral glucose tolerance on normal rats and anti-hyperglycaemic activity by streptozotocin induced diabetes model. S21 unveiled to be the best measured analogue among all the synthesized entities. Encouraging outcomes motivates fatty acids for further development of more effective and safer compounds.     

Biochemical effects of the hypoglycaemic compound pent-4-enoic acid and related non-hypoglycaemic fatty acids. Carbohydrate metabolism

1. The effects of the hypoglycaemic compound, pent-4-enoic acid, and of four structurally related non-hypoglycaemic compounds (pent-2-enoic acid, pentanoic acid, cyclopropanecarboxylic acid and cyclobutanecarboxylic acid), on glycolysis, glucose oxidation and gluconeogenesis in some rat tissues were determined. 2. None of the compounds at low concentrations inhibited glycolysis by particle-free supernatant fractions from rat liver, skeletal muscle and intestinal mucosa, though there was inhibition by cyclopropanecarboxylic acid and cyclobutanecarboxylic acid at 3mm concentration. 3. Pent-4-enoic inhibited the oxidation of [1-(14)C]palmitate by rat liver slices, but did not increase the oxidation of [U-(14)C]glucose. 4. Pent-4-enoic acid (0.01mm) strongly inhibited gluconeogenesis by rat kidney slices from pyruvate or succinate, but none of the other compounds inhibited significantly at low concentrations. 5. There was also some inhibition of gluconeogenesis in kidney slices from rats injected with pent-4-enoic acid. 6. The mechanism of the hypoglycaemic effect of pent-4-enoic acid is discussed; it is suggested that there is an inhibition of fatty acid and ketone-body oxidation and of gluconeogenesis so that glucose reserves become exhausted, leading to hypoglycaemia. 7. The mechanism of the hypoglycaemic action of pent-4-enoic acid appears to be similar to that of hypoglycin.     

Regioselectivity of an arachidonate 9S-lipoxygenase from Sphingopyxis macrogoltabida that biosynthesizes 9S,15S- and 11S,17S-dihydroxy fatty acids from C20 and C22 polyunsaturated fatty acids

Lipoxygenases (LOXs) biosynthesize lipid mediators (LMs) as human signaling molecules. Among LMs, specialized pro-resolving mediators (SPMs) are involved in the resolution of inflammation and infection in humans. Here, the putative LOX from the bacterium Sphingopyxis macrogoltabida was identified as arachidonate 9S-LOX. The enzyme catalyzed oxygenation at the n-12 position of C20 and C22 polyunsaturated fatty acids (PUFAs) to form 9S- and 11S-hydroperoxy fatty acids, which were reduced to 9S- and 11S-hydroxy fatty acids (HFAs) by cysteine, respectively, and it catalyzed again oxygenation at the n-6 position of HFAs to form 9S,15S- and 11S,17S-DiHFAs, respectively. The regioselective residues of 9S-LOX were determined as lle395 and Val569 based on the amino acid alignment and homology models. The regioselectivity of the I395F variant was changed from the n-12 position on C20 PUFA to the n-6 position to form 15S-HFAs. This may be due to the reduction of the substrate-binding pocket by replacing the smaller Ile with a larger Phe. The V569W variant had a significantly lower second?oxygenating activity compared to wild-type 9S-LOX because the insertion of the hydroxyl group of the first?oxygenating products at the active site was seemed to be hindered by substituting a larger Trp for a smaller Val. The compounds, 11S-hydroxydocosapentaenoic acid, 9S,15S-dihydroxyeicosatetraenoic acid, 9S,15S-dihydroxyeicosapentaenoic acid, 11S,17S-hydroxydocosapentaenoic acid, and 11S,17S-dihydroxydocosahexaenoic acid, were newly identified by polarimeter, LC-MS/MS, and NMR. 11S,17S-DiHFAs as SPM isomers biosynthesized from C22 PUFAs showed anti-inflammatory activities in mouse and human cells. Our study contributes may stimulate physiological studies by providing new LMs.     

Facile synthesis of (Z)-tetracos-5-enoic acid and racemic cis-4-(2-octadecylcyclopropane-1-yl)-butanoic acid

(Z)-tetracos-5-enoic acid and racemic cis-4-(2-octadecylcyclopropane-1-yl)-butanoic acid have been prepared from 1-eicosene by a new facile route. Periodic acid cleavage of the epoxide of 1-eicosene gave nonadecanal which was condensed with 4-carboxybutyltriphenylphosphonium bromide to give predominately (Z)-tetracos-5-enoic acid. Simmons-Smith type cyclopropanation of (Z)-tetracos-5-enoic acid gave a minor proportion of racemic cis-4-(2-octadecylcyclopropane-1-yl)-butanoic acid accompanied by major amounts of its methyl ester.     

(10E,12Z,15Z)-9-Hydroxy-10,12,15-octadecatrienoic Acid Methyl Ester as an Anti-inflammatory Compound from Ehretia dicksonii

The methanol extract of Ehretia dicksonii provided (10E,12Z,15Z)-9-hydroxy-10,12,15-octadecatrienoic acid methyl ester (1) which was isolated as an anti-inflammatory compound. Compound 1 suppressed 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced inflammation on mouse ears at a dose of 500 μg (the inhibitory effect (IE) was 43%). Linolenic acid methyl ester did not inhibit this inflammation at the same dose. However, the related compounds of 1, (9Z,11E)-13-hydroxy-9,11-octadecadienoic acid (5) and (9Z,11E)- 13-oxo-9,11-octadecadienoic acid (6), showed potent activity (IE_{500 μg} of 63% and 79%, respectively). Compounds 1, 4 ((9Z,12Z,14E)-16-hydroxy-9,12,14-octadecatrienoic acid), 5 and 6 also showed inhibitory activity toward soybean lipoxygenase at a concentration of 10 μg/ml.     

Biochemical effects of the hypoglycaemic compound pent-4-enoic acid and related non-hypoglycaemic fatty acids. Fatty acid oxidation

1. The effects of the hypoglycaemic compound, pent-4-enoic acid, and of four structurally related non-hypoglycaemic compounds (pentanoic acid, pent-2-enoic acid, cyclopropanecarboxylic acid and cyclobutanecarboxylic acid), on the oxidation of saturated fatty acids by rat liver mitochondria were determined. 2. The formation of (14)CO(2) from [1-(14)C]palmitate was strongly inhibited by 0.01mm-pent-4-enoic acid. 3. The inhibition of oxygen uptake was less than that of (14)CO(2) formation, presumably because fumarate was used as a sparker. 4. The oxidation of [1-(14)C]-butyrate, -octanoate or -laurate was not strongly inhibited by 0.01mm-pent-4-enoic acid. 5. The other four non-hypoglycaemic compounds did not inhibit the oxidation of any saturated fatty acid when tested at 0.01mm concentration, though they all inhibited strongly at 10mm. 6. The oxidation of [1-(14)C]-myristate and -stearate, but not of [1-(14)C]decanoate, was strongly inhibited by 0.01mm-pent-4-enoic acid. 7. The oxidation of [1-(14)C]palmitate was about 50% carnitine-dependent under the experimental conditions used. 8. The percentage inhibition of [1-(14)C]palmitate oxidation by pent-4-enoic acid was the same whether carnitine was present or not. 9. Acetoacetate formation from saturated fatty acids was inhibited by 0.1mm-cyclopropanecarboxylic acid to a greater extent than their oxidation. 10. The other compounds tested inhibited acetoacetate formation from saturated fatty acids proportionately to the inhibition of oxidation. 11. Possible mechanisms for the inhibition of long-chain fatty acid oxidation by pent-4-enoic acid are discussed. 12. There was a correlation between the ability to inhibit long-chain fatty acid oxidation and hypoglycaemic activity in this series of compounds.     

Cytotoxic and anti-angiogenic effects of lanostane triterpenoids from Ganoderma lucidum

Two new lanostane triterpenes, 3α,12β,15α-triacetoxy-5α-lanosta-7,9(11),24-trien-26-oic acid (1) and 5α-lanosta-8,24-diene-26,27-dihydroxy-3,7-dione (2), together with sixteen known compounds (3–18) were isolated from the fruiting bodies of the Vietnamese mushroom Ganoderma lucidum. Their chemical structures were determined by extensive spectroscopic (IR, HR-EI-MS, 1D and 2D NMR) analyses. Potential cytotoxic activities of these compounds were evaluated against human non-small cell lung adenocarcinoma (A549), breast adenocarcinoma (MCF-7), and prostatic small cell carcinoma (PC-3). Among the compounds, 3α,12β,15α-triacetoxy-5α-lanosta-7,9(11),24-trien-26-oic acid (1) showed significant cytotoxic activity against PC-3 cells with an IC₅₀ of 11.5 μM. In studies of anti-angiogenesis activity, ganoderic acid F (17) was found to have the most potent inhibitory effect on the formation of capillary-like structures of human umbilical vein endothelial cells.