Chemical constituents of the brown alga Dictyopteris divaricata

A novel sesquiterpene-substituted benzoic acid, named dictyvaric acid (1), together with nine known compounds (2–10), have been isolated from the brown alga Dictyopteris divaricata Okam. The structure of 1 was elucidated as 3-[(decahydro-2-hydroxy-2,5,5,8a-tetramethyl-1-naphthalenyl)-methyl]-4-hydroxybenzoic acid by spectroscopic methods, including IR, FABMS, HR-FABMS, 1D and 2D NMR techniques. All compounds were obtained from this species for the first time.     

Synthesis of N3-fumaramoyl-L-2,3-diaminopropanoic acid analogues,the irreversible inhibitors of glucosamine synthetase

Several analogues of N³-fumaramoyl-L-2,3-diaminopropanoic acid were synthesized and evaluated for inhibition of glucosamine-6-phosphate synthetase activity. The syntheses were accomplished by acylation reaction of N²-tert.-butoxycarbonyl-L-2,3-diaminopropanoic acid (Boc-A₂pr) or N²-tert.-butoxy-carbonyl-L-2,4-diaminobutanoic acid (Boc-A₂-bu) with the N-succinimidoyl esters of several derivatives of α, β-unsaturated acids 2a-d followed by deprotection of the Boc groups. The obtained compounds were tested for inhibition of glucosamine synthetase isolated from Salmonella typhimurium and Saccharomyces cerevisiae. The results indicated that among the synthesized compounds, N³-4-methoxyfumaroyl-L-2,3-diaminopropanoic acid (FMDP) was the most powerful inhibitor of glucosamine synthetase.     

吡啶丙烯酰氨基酸衍生物的设计、合成及其对离体HeLa-S3细胞的放射增敏作用

本文设计、合成了一类新型的放射增敏剂—吡啶丙烯酰氨基酸衍生物,并测定了对HeLa-Sa细胞的增敏作用和细胞毒性。3-吡啶丙烯酰甲基甘氨酸(3A)和4-吡啶丙烯酰甲基甘氨酸(4A)的主要作用分别为减小细胞存活曲线的肩宽和Do值。这类化合物,尤其是3A和4A,或其结构类似物,如果体内实验证明有明显增敏作用,将有重要的潜在临床应用价值。     

Synthesis and pp60c‐Src Tyrosine Kinase Inhibitory Activities of Novel Indole‐3‐Imine and Amine Derivatives Substituted at N1 and C5

A series of novel 1,3,5‐trisubstituted indole derivatives, namely, N‐benzyl 5‐phenyl indole‐3‐imine, N‐benzyl‐5‐(p‐fluorophenyl)indole‐3‐imine and their corresponding amine congeners, were designed and synthesized as pp60^c‐Src tyrosine kinase inhibitors, and their inhibitory activities toward pp60^c‐Src tyrosine kinase were evaluated by in‐vitro kinase assay. Pre‐screening at two doses of compounds against kinase target revealed that, except for the N‐benzyl‐5‐phenyl indole imine derivatives 7a – 7d , all indole derivatives show the target inhibition at varying levels. Consequently, the compounds, 8c , 8f , 8g , and 8h , were selected for prescreening tests. The dose‐response curves for up to six concentrations (250 to 7.8 μM) of the active compounds were obtained by tyrosine kinase assay and the four‐parameter logistic analysis of these data resulted in the IC₅₀s of 4.69, 74.79, 75.06, and 84.23 μM for compounds 8c , 8f , 8g , and 8h , respectively. Therefore, compound 8c , 1‐(1‐benzyl‐5‐phenyl‐1H‐indole‐3‐yl)‐N‐(4‐fluorobenzyl)methanamine·HCl, was the promising inhibitor for pp60^c‐Src, followed by compounds 8g and 8h . Under the same conditions, compound 8f did not provide any reasonable inhibition pattern to be considered as active compound. Therefore, among all four active compounds, compound 8f was not found suitable for further analysis.     

Synthesis of 3-(3-pyridyl)- and 3-(3-benzo[b]thienyl)-D-alanine

The DL-arylamino acid ethyl ester derivatives of β-(3-pyridyl)-DL-alanine, and β-(3-benzo[b]thienyl)-DL-alanine were synthesized by diethyl acetamidomalonate condensation with the respective arylmethyl halides followed by partial hydrolysis to the monoethyl ester and decarboxylation. Each derivative was enzymatically resolved to a separable mixture of the corresponding N-acetyl-L-amino acid and the unchanged D amino acid derivative. Acidic hydrolysis of the latter gave the corresponding D-amino acid, the optical purity of which was established by HPLC analysis of the 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl isothiocyanate (GITC) derivative. The free D amino acids were converted to D-BOC derivatives by reaction with di-tert-butyldicarbonate in tert-butyl alcohol, water and sodium hydroxide.     

Practical preparation and deblocking conditions for N-α-(2-(P-biphenylyl)-2-propyloxycarbonyl)-amino acid (N-α-Bpoc-Xxx-OH) derivatives

Reproducible preparations are given for salts of the following L-amino acid derivatives: Bpoc-Ala-OH, Bpoc-Arg(Mtr)-OH, Bpoc-Asn-OH, Bpoc-Asp(OtBu)-OH, Bpoc-Cys(Acm)-OH, Bpoc-Cys(S-tBu)-OH, Bpoc-Gln-OH, Bpoc-Glu(OtBu)-OH, Bpoc-Gly-OH, Bpoc-Ile-OH, Bpoc-Leu-OH, N-α-Bpoc-Lys(ε-Boc)-OH, Bpoc-Met-OH, Bpoc-Phe-OH, Bpoc-Pro-OH, Bpoc-Ser(OtBu)-OH, Bpoc-Thr(OtBu)-OH, Bpoc-Tyr-OH, Bpoc-Val-OH. A study of the deblocking of N-α-Bpoc peptides in dichloromethane containing 0.5% trifluoroacetic acid revealed that a rapid equilb-rium is established between the first-formed monomeric alkene 2-p-biphenylylpropene and the hindered dimer 2,4-bis(p-biphenylyl)-4-methyl-l-pentene. Thioethers were found to be inefficient carbocation scavengers for the deblocking reaction. The most efficient scavengers were found to be thiophenol and benzyl mercaptan, and the following approximate reactivity order was established: benzyl mercaptan ～ thiophenol 〉 indole 1,3-dimethoxybenzene ～ resorcinol 〉1,3,5-trimethoxybenzene ～ dimethyl sulfide ～ thioanisole.     

Synthesis,Toxicological, and Pharmacological Assessment of Derivatives of 2-Aryl-4-(3-arylpropyl)morpholines

The synthesis of nine original morpholine derivatives, i.e. 2-aryl-4-(3-arylpropyl)morpholines, is described. The structure of all synthesised derivatives was proved by IR and ¹H-NMR, and some of them by ¹³C-NMR. Acute toxicity studies of the compounds were performed on mice. A comparative pharmacological study of the in vivo effects on the central nervous system was undertaken using the screening tests: hexobarbital induced sleeping time; locomotor activity; and behaviour despair (for antidepressive activity). The most active compound 4-(2-benzoylethyl)-2-phenyl-3-methyl) morpholine 4e was studied for MAO-A and MAO-B inhibition in vitro in rat brain mitochondria preparations.     

Design,synthesis, molecular modeling,and antimicrobial potential of novel 3-[(1H-pyrazol-3-yl)imino]indolin-2-one derivatives as DNA gyrase inhibitors

A series of 3-[(1H-pyrazol-3-yl)imino]indolin-2-one derivatives were designed using the molecular hybridization method, characterized using different spectroscopic techniques, and evaluated for their in vitro antimicrobial activity. Most of the target compounds demonstrated good to moderate antimicrobial activity compared with ciprofloxacin and fluconazole. Four compounds ( 8b , 9a , 9c , and 10a ) showed encouraging results, with minimal inhibitory concentration (MIC) values (53.45–258.32 µM) comparable to those of norfloxacin (100.31–200.63 µM) and ciprofloxacin (48.33–96.68 µM). Noticeably, the four derivatives revealed excellent bactericidal and fungicidal activities, except for the bacteriostatic potential of compounds 8b and 9a against Escherichia coli and Staphylococcus aureus, respectively. The time-killing kinetic study against S. aureus confirmed the efficacy of these derivatives. Furthermore, two of the four promising derivatives, 9a and 10a , could prevent the formation of biofilms of S. aureus without affecting the bacterial growth at low concentrations. A combination study with seven commercial antibiotics against the multidrug-resistant bacterium P. aeruginosa showed a notable reduction in the antibiotic MIC values, represented mainly through a synergistic or additive effect. The enzymatic assay implied that the most active derivatives had inhibition potency against DNA gyrase comparable to that of ciprofloxacin. Molecular docking and density functional theory calculations were performed to explore the binding mode and study the reactivity of the promising compounds.     

Novel Steroidal 1,4-Diketones and Pyridazine Derivatives as Potential Antiestrogens

A series of steroidal 1,4-diketone derivatives was synthesized by acid-catalyzed condensation of 2-acetylestradiol-17β-acetate with substituted phenylglyoxals. Conversion of the products into the corresponding pyridazine derivatives was achieved by reaction with hydrazine hydrate. The synthesized compounds were evaluated for their uterotrophic, antiuterotrophic, and antifertility activities in mature female albino rats. Among the compounds tested, the phenyl 2 , p-bromophenyl 3 , and p-methoxyphenyl 5 diketone derivatives displayed uterotrophic activity of 72%, 72%, and 91%, respectively. The gradation of antiestrogenic activity was assessed in vivo by the inhibition of the estrone-stimulated uterine growth. Compounds 2–5 showed moderate antiestrogenic activity of 53–56%. None of the tested compounds elicited antifertility activity as assessed by the post-coital antiimplantation activity test.     

Comparative effect of chemical structure of chlorinated N-hydroxy-N-acyl-aminobiphenyl ethers and their related compounds on rat liver cytosol-catalyzed transacylation

Studies of structure-transacylation relationships for a series of acylhydroxamic acids of chlorinated biphenyl ethers and their related compounds by rat liver N-arylacylhydroxamic acid-dependent N-acyltransferase (AHNAT) are described. In the transacylation of 4-aminoazobenzene catalyzed by AHNAT, 4-substituents (chloro, phenoxy, and mono-, di-, and trichlorophenoxy groups) of N-phenylacetohydroxamic acid enhanced the ability of the unsubstituted hydroxamic acid to serve as acetyl donors. As to the number of chlorines in the phenoxy group, the activity increased with decreasing number from three to zero. Of the monochlorophenoxy compounds, the 4'-chloro compound was the most effective acetyl donor. In 3-substituents (chloro and phenoxy groups) of N-phenylacetohydroxamic acid, the 3-chloro compound was an effective acetyl donor similarly to the 4-chloro compound, whereas the 3-phenoxy compound was 48% as active as the 4-phenoxy compound. None of 2-substituted N-phenylacetohydroxamic acids examined showed transacetylation activity. As to the effect of acyl group structure on the activity, N-propionyl, N-glycoloyl, and N-formyl derivatives of the 4-(4'-chlorophenoxy) compound were only 4, 2, and 0% as active as the corresponding acetyl compound, respectively. Esterification of the N-arylacetohydroxamic acid decreased the activity; O-acetyl, O-methyl, O-glucosyl, and O-glucuronosyl derivatives of the 4-(4'-chlorophenoxy) compound were 35, 7, 0, and 0% as active as the corresponding N-hydroxy compound, respectively.     

A novel indole alkaloid from deep-sea sediment metagenomic clone-derived Escherichia coli fermentation broth

To explore secondary metabolites in deep-sea sediment metagenomic clone-derived Escherichia coli fermentation broth, different kinds of chromatography methods were used in the isolation procedures, while the structures of the isolated compounds were assigned based on the MS analysis and their ¹H and ¹³C NMR spectra including 2D NMR techniques such as COSY, HMQC, and HMBC experiments. As a result, a novel compound was isolated and characterized as N-{1-[4-(acetylamino)phenyl]-3-hydroxy-1-(1H-indol-3-yl)propan-2-yl}-2,2-dichloroacetamide (1). In addition, eight known compounds were also obtained. Fatty acid amide hydrolase and monoacylglycerol lipase were used to screen analgesic activity, and the new compound showed analgesic activity to some extent in pharmacological test.     

Synthesis of N-acetyl-l-aspartyl-l-glutamic acid; [3H]NAAG

[³H]NAAG, N-acetyl-l -aspartyl-l -glutamic acid, has been widely used as a substrate in glutamate carboxypeptidase II (GCPII) reactions, either to determine the inhibitory constants at 50% inhibition (IC₅₀) of novel compounds or to measure GCPII activities in different tissues harvested from various disease models. The importance of [³H]NAAG, combined with its current commercial unavailability, prompted the development of a reliable eight-step synthetic procedure towards [³H₂]NAAG starting from commercially available pyroglutamate. Pure [³H]NAAG of high molar activity (49.8 Ci/mmol) and desired stereochemistry was isolated in high radiochemical yield (67 mCi) and radiochemical purity (>99%). The identity was confirmed by mass spectrometry and co-injection with unlabeled reference.     

血吸虫病化学治疗的研究 ⅩⅩⅩⅥ.4-苯基(或烯丙基)-5-(吡嗪-2)-1,2,4-三唑-3-硫酮衍生物的合成

本文报导28个4-苯基(或烯丙基)-5-(吡嗪-2)-1,2,4-三唑-3-硫酮衍生物的合成。这类化合物的合成是以吡嗪甲酸乙酯与水合肼反应得2-吡嗪甲酰肼,再与不同的异硫氰酸酯作用后,在2N氢氧化钠溶液中环合而得Ⅱ或Ⅲ,然后经烷化、酰化及Mannich反应,分别制得相应的化合物。其中Ⅲ₁和Ⅲ₂对感染日本血吸虫小白鼠有明显肝移作用。     

Pharmacokinetics and Antiepileptic Activity of Valproyl Hydroxamic Acid Derivatives

Purpose. To explore the utilization of seven novel hydroxamic acid derivatives of valproic acid (VPA) as new antiepileptics. Methods. The study was carried out by investigating the pharmacokinetics of two active compounds in dogs and pharmacodynamics (anti-convulsant activity and neurotoxicity) of valproyl hydroxamic acid and six of its derivatives. Results. Three valproyl hydroxamic acid derivatives: valproyl hydroxamic acid—VPA-HA, N-(l-hydroxyethyl)-valpromide—HEV and N-methoxy valpromide, showed better anticonvulsant activity than VPA at the maximal electroshock (MES) test. The remaining four compounds, O-valproyl-VPA-HA, N-valproyl-O-valproyl-VPA-HA, N-(l-methoxyethyl) valpromide and N-( 1,2-dihydroxylpropyl)-valpromide were found to be inactive. Therefore, only the pharmacokinetics of the active compounds VPA-HA and HEV was studied. Conclusions. In contrast to valpromide (VPD) which is biotransformed to VPA, VPA-HA and HEV were found to be stable in vivo to the biotransformation of the amide to its corresponding acid. VPA-HA and HEV showed improved anticonvulsant activity over VPA because of their greater intrinsic activity and not due to better pharmacokinetic characteristics. This paper discusses the structural requirements for active anticonvulsant valproyl hydroxamic acid derivatives.     

Aromatic acid derivatives from the lateral roots of Aconitum carmichaelii

Seven new aromatic acid derivatives (1–7), together with five known analogs, were isolated from the lateral roots of Aconitum carmichaelii. Structures of the new compounds were determined by spectroscopic and chemical methods as 4-methyl ( ? )-(R)-hydroxyeucomate (1), 4-butyl ( ? )-(R)-hydroxyeucomate (2), 4-butyl-1-methyl (+)-(R)-2-O-(4′-hydroxy-3′-methoxybenzoyl)malate (3), 1-butyl-4-methyl (+)-(R)-2-O-(4′-hydroxy-3′-methoxybenzoyl)malate (4), dimethyl (+)-(R)-2-O-(4′-hydroxy-3′-methoxybenzoyl)malate (5), dimethyl (+)-(R)-2-O-(4′-hydroxybenzoyl)malate (6), and methyl ( ± )-3-(4′-hydroxy-3′-methoxyphenyl)-3-sulfopropionate (7), respectively. Compounds 1 and 2 are 2-benzylmalates (eucomate derivatives), 3–6 belong to 2-O-benzoylmalates, and 7 is a rare phenylpropionate containing a sulfonic acid group. The absolute configurations of eucomate derivatives were confirmed by X-ray crystallographic analysis of 4-methyl eucomate (11).     

抗高血压药物2-亚氨基-3-(β-羟基苯乙基)-噻唑烷衍生物的合成

2-Imino-3-(β-hydroxyphenethyl)thiazolidine showed hypotensive activity. In order to find more active derivatives, a series of compounds has been synthesized.In preliminary screening tests, Compounds (Ⅱ-2) and (Ⅳ-1) showed considerable hypotensive effect.     

Synthesis of some biologically active substituted thiazole and thiazoline-amino acid derivatives

Synthesis of a series of N-(2-acetylaminothiazole-5-sulphonyl) amino acids (II–VI) and some of their corresponding methyl esters (VII–XI) is described. Coupling of N-tosyl- or N-phthalylamino acid with 2-amino-2-thiazoline using the DCC method furnishes 2-(N-tosyl- or N-phthalylamino acyl)amino-2-thiazolines (XII–XXI). Hydrazinolysis of 2-(N-Pht-L-Phe or N-Pht-L-Ala)amino-2-thiazoline in ethanol afforded 2-(L-Phe or L-Ala) amino-2-thiazoline (XXII and XXIII) respectively. Synthesis of the dipeptide 2-(N-Tos-L-Val-L-Leu) amino-2-thiazoline (XXIV) has been achieved employing the azide method. Sixteen thiazole- and thiazoline-amino acid derivatives were found to be active against a number of microorganisms.     

(E)-3-苯基丙烯酸衍生物的合成及抗炎活性考察

目的设计合成(E)-3-苯基丙烯酸衍生物,寻找具有较强抗炎活性的化合物。方法对先导化合物(E)-3-[3-甲氧基-4-(3-苯基)丙烯酰氧基]苯基丙烯酸(1)进行结构修饰,将其分别与脂肪(环)醇、芳香醇、芳杂环醇成酯,与脂肪(环)胺、芳香胺、芳杂环胺成酰胺;以二甲苯致小鼠耳肿胀模型考察不同类型的酯和酰胺的抗炎活性。结果合成了8个未见文献报道的(E)-3-苯基丙烯酸衍生物,经红外光谱和核磁共振氢谱确证其结构;目标化合物3a、3b、3c具有一定的抗炎活性,抑制率分别为31.3%、40.3%、31.7%。结论所设计的合成方法可应用于较大分子酯类和酰胺类的合成;在本实验条件下,(E)-3-苯基丙烯酰胺类目标化合物3a、3b、3c具有抗炎作用,高于先导化合物1,(E)-3-苯基丙烯酸酯类目标化合物几乎无抗炎活性。     

阿哌沙班中3个杂质的合成研究

目的设计并合成阿哌沙班中的3个杂质。方法以2-氯-2-[2-(4-甲氧基苯基)亚肼基]乙酸乙酯和5,6-二氢-3-(4-吗啉基)-1-[4-(2-氧代-1-哌啶基)苯基]-2(1H)-吡啶酮为起始原料,经过环合和水解反应得到目标化合物1,化合物1分别经过水解和取代反应得到目标化合物2和3。结果合成了目标化合物,并利用MS、~1H-NMR和~(13)C-NMR确证了结构:目标化合物1~3的质量分数分别为99.3%、99.1%、99.2%。结论 3个杂质的合成和纯化为阿哌沙班的杂质研究奠定了物质基础。     

吡啶丙烯酰氨基酸衍生物的设计、合成及其对离体HeLa-S_3细胞的放射增敏作用

本文设计、合成了一类新型的放射增敏剂—吡啶丙烯酰氨基酸衍生物,并测定了对HeLa-Sa细胞的增敏作用和细胞毒性。3-吡啶丙烯酰甲基甘氨酸(3A)和4-吡啶丙烯酰甲基甘氨酸(4A)的主要作用分别为减小细胞存活曲线的肩宽和Do值。这类化合物,尤其是3A和4A,或其结构类似物,如果体内实验证明有明显增敏作用,将有重要的潜在临床应用价值。