Phenethyl Derivatives Research Articles

Design, synthesis, and biological evaluation of novel EGFR inhibitors containing 5-chloro-3-hydroxymethyl-indole-2-carboxamide scaffold with apoptotic antiproliferative activity

New EGFR inhibitor series of fifteen 5-chloro-3-hydroxymethyl-indole-2-carboxamide derivatives has been designed, synthesized, and tested for antiproliferative activity against a panel of cancer cell lines. The results showed that p-substituted phenethyl derivatives 10, 11, 13, 15 and 17–19 showed superior antiproliferative activity compared to their m-substituted counterparts 12, 14, 16 and 20. Compounds 15, 16, 19 and 20 displayed promising EGFR inhibitory activity as well as an increase in caspase 3 levels. Compounds 15 and 19 increased caspase-8 and 9 levels, as well as inducing Bax and decreasing Bcl-2 protein levels. Compound 19 demonstrated cell cycle arrest at pre-G1 and G2/M phases. The results of the docking study into the active site of EGFR revealed strong fitting of the new compounds with higher binding affinities compared to erlotinib.

Metabolite Profiling of Christia vespertilionis Leaf Metabolome via Molecular Network Approach

Christia vespertilionis (L.f.) Bakh. f. is an ornamental plant with unique butterfly-shaped leaves, hence its vernacular name “butterfly wing” or “rerama” in Malay. In Malaysia, the green-leafed variety of this plant has gained popularity in recent years due to testimonial reports by local consumers of its medicinal uses, which include treatment for cancer. Despite these popular uses, there is very limited information on the phytochemistry of the leaf of this plant, presenting a significant gap in the cheminformatics of the plant species. Herein, we report a substantially detailed phytochemical profile of the leaf metabolome of the green-leafed variety of C. vespertilionis, obtained by deploying an untargeted tandem mass spectrometry-based molecular networking approach. The detailed inspection of the molecular network map generated for the leaf metabolome enabled the putative identification of 60 metabolites, comprising 13 phenolic acids, 20 flavonoids, 2 benzyltetrahydroisoquinoline-type alkaloids, 4 hydroxyjasmonic acid derivatives, 2 phenethyl derivatives, 3 monoacylglycerols, 4 fatty acid amides, 2 chlorophyll derivatives, 4 carotenoids, 2 organic acids, 1 nucleoside, and 3 amino acids. Flavonoids are the major class of metabolites that characterize the plant leaves. Employing a mass-targeted isolation approach, two new derivatives of apigenin-6-C-β-glucoside, the major constituents of the plant leaf, were successfully purified and spectroscopically characterized as apigenin-6-C-β-glucoside 4′-O-α-apiofuranoside (28) and apigenin-6-C-β-[(4″,6″-O-dimalonyl)-glucoside] 4′-O-α-apiofuranoside (47). This work provides further information on the chemical space of the plant leaf, which is a prerequisite to further research towards its valorization as a potential phytopharmaceutical product.

4-Aryl-1-oxa-4,9-diazaspiro[5.5]undecane Derivatives as Dual μ-Opioid Receptor Agonists and σ1 Receptor Antagonists for the Treatment of Pain.

The synthesis and pharmacological activity of a new series of 1-oxa-4,9-diazaspiro[5.5]undecane derivatives as potent dual ligands for the sigma-1 receptor (σ1R) and the μ-opioid receptor (MOR) are reported. The different positions of the central scaffold, designed using a merging strategy of both target pharmacophores, were explored using a versatile synthetic approach. Phenethyl derivatives in position 9, substituted pyridyl moieties in position 4 and small alkyl groups in position 2 provided the best profiles. One of the best compounds, 15au, showed a balanced dual profile (i.e., MOR agonism and sigma antagonism) and a potent analgesic activity, comparable to the MOR agonist oxycodone in the paw pressure test in mice. Contrary to oxycodone, as expected from the addition of σ1R antagonism, 15au showed local, peripheral activity in this test, which was reversed by the σ1R agonist PRE-084. At equianalgesic doses, 15au showed less constipation than oxycodone, providing evidence that dual MOR agonism and σ1R antagonism may be a useful strategy for obtaining potent and safer analgesics.

Differential metabolism of L–phenylalanine in the formation of aromatic volatiles in melon (Cucumis melo L.) fruit

Studies on the active pathways and the genes involved in the biosynthesis of L-phenylalanine-derived volatiles in fleshy fruits are sparse. Melon fruit rinds converted stable-isotope labeled L-phe into more than 20 volatiles. Phenylpropanes, phenylpropenes and benzenoids are apparently produced via the well-known phenylpropanoid pathway involving phenylalanine ammonia lyase (PAL) and being (E)-cinnamic acid a key intermediate. Phenethyl derivatives seemed to be derived from L-phe via a separate biosynthetic route not involving (E)-cinnamic acid and PAL. To explore for a biosynthetic route to (E)-cinnamaldehyde in melon rinds, soluble protein cell-free extracts were assayed with (E)-cinnamic acid, CoA, ATP, NADPH and MgSO4, producing (E)-cinnamaldehyde in vitro. In this context, we characterized CmCNL, a gene encoding for (E)-cinnamic acid:coenzyme A ligase, inferred to be involved in the biosynthesis of (E)-cinnamaldehyde. Additionally we describe CmBAMT, a SABATH gene family member encoding a benzoic acid:S-adenosyl-L-methionine carboxyl methyltransferase having a role in the accumulation of methyl benzoate. Our approach leads to a more comprehensive understanding of L-phe metabolism into aromatic volatiles in melon fruit.

Synthesis of novel 13α-estrone derivatives by Sonogashira coupling as potential 17β-HSD1 inhibitors.

Novel 13α-estrone derivatives were synthesized by Sonogashira coupling. Transformations of 2- or 4-iodo regioisomers of 13α-estrone and its 3-methyl ether were carried out under different conditions in a microwave reactor. The 2-iodo isomers were reacted with para-substituted phenylacetylenes using Pd(PPh3)4 as catalyst and CuI as a cocatalyst. Coupling reactions of 4-iodo derivatives could be achieved by changing the catalyst to Pd(PPh3)2Cl2. The product phenethynyl derivatives were partially or fully saturated. Compounds bearing a phenolic OH group furnished benzofurans under the conditions used for the partial saturation. The inhibitory effects of the compounds on human placental 17β-hydroxysteroid dehydrogenase type 1 isozyme (17β-HSD1) were investigated by an in vitro radiosubstrate incubation method. Certain 3-hydroxy-2-phenethynyl or -phenethyl derivatives proved to be potent 17β-HSD1 inhibitors, displaying submicromolar IC50 values.

3D-QSAR and docking studies of pentacycloundecylamines at the sigma-1 (σ1) receptor

Pentacycloundecylamine (PCU) derived compounds have been shown to be promising lead structures for the development of novel drug candidates aimed at a variety of neurodegenerative and psychiatric diseases. Here we show for the first time a 3D quantitative structure–activity relationship (3D-QSAR) for a series of aza-PCU-derived compounds with activity at the sigma-1 (σ1) receptor. A comparative molecular field analysis (CoMFA) model was developed with a partial least squares cross validated (q2) regression value of 0.6, and a non-cross validated r2 of 0.9. The CoMFA model was effective at predicting the sigma-1 activities of a test set with an r2 >0.7. We also describe here the docking of the PCU-derived compounds into a homology model of the sigma-1 (σ1) receptor, which was developed to gain insight into binding of these cage compounds to the receptor. Based on docking studies we evaluated in a [3H]pentazocine binding assay an oxa-PCU, NGP1-01 (IC50=1.78μM) and its phenethyl derivative (IC50=1.54μM). Results from these studies can be used to develop new compounds with specific affinity for the sigma-1(σ1) receptor.

Antimicrobial phenylpropanoids from the Argentinean highland plant Parastrephia lucida (Meyen) Cabrera

Ethnopharmacological relevanceThe Argentinean highland plant Parastrephia lucida (Meyen) Cabrera is used in traditional medicine as an antiseptic and anti-inflammatory crude drug. Aim of the studyTo relate the antimicrobial effect of the crude drug with the constituents of the active fractions and traditional use. Materials and methodsAssay-guided isolation of the methanol (MeOH) plant extract was carried out using bacteria and yeasts as target organisms. Both ATCC and local strains were included in the study. The antimicrobial fractions and compounds were detected by bioautographic assays. Minimum inhibitory concentrations (MIC) of each extract and fraction were determined and compared with reference antibiotics. Fractions were analyzed by HPLC–DAD, GC–MS, 1H NMR and 13C NMR. ResultsFrom the MeOH extract of the plant, assay-guided isolation of the antimicrobial constituents led to 12 phenylpropanoids and two simple phenolics. Most of the compounds occurring in the active fractions were E-caffeoyl or E-cinnamoyl esters including prenyl and phenethyl derivatives. The MIC values of the most active fractions ranged between 12.5 and 200μg/mL against reference strains and local isolates of Staphylococcus aureus and Enterococcus faecalis. ConclusionsThe antimicrobial effect found in the crude drug was associated with mixtures of phenylpropanoids, including prenyl and phenethyl esters of caffeic and cinnamic acids. The results support at least in part the traditional use of the plant as local antiseptic.

Oxo-bridged isomers of aza-trishomocubane sigma (σ) receptor ligands: Synthesis, in vitro binding, and molecular modeling

Isomeric oxo-bridged analogs of aza-trishomocubane sigma (sigma) receptor ligands were synthesized and shown to display a reduced affinity for the sigma receptor. In the case of phenethyl derivative 4, there was a concomitant introduction of high-affinity for the alpha(2C) adrenergic receptor, and moderate affinity for the dopamine transporter. Molecular modeling was undertaken to rationalize these results.

Synthesis, QSAR and Calcium Channel Antagonist Activity of New 1,4‐Dihydropyridine Derivatives Containing 1‐Methyl‐4,5‐dichloroimidazolyl Substituents

A group of dialkyl and diarylester analogues of nifedipine, in which the ortho-nitrophenyl group at position 4 was replaced by a 1-methyl-4,5-dichloroimidazolyl substituent, were synthesized and evaluated as calcium-channel antagonists using the high K(+)concentration of guinea-pig ileum longitudinal smooth muscle. The structure of all compounds was confirmed by IR,(1)H-NMR, and mass spectra. The calcium-channel antagonist activity of compounds 10a-f demonstrated that compound 10b was the most active and 10f the least active one. With unsymmetrical diesters 12a-k, the most active compound was the ethyl, phenethyl derivative. Structural parameters on the calcium-channel antagonist activity were evaluated by QSAR analysis and a linear correlation was found between the -log IC(50) values of these compounds and their constitutional and topological properties.

The novel primaquine derivatives of N-alkyl, cycloalkyl or aryl urea: Synthesis, cytostatic and antiviral activity evaluations

The novel urea primaquine derivatives 3a– i were prepared by aminolysis of benzotriazolide 2 with the corresponding amine in the presence or absence of triethylamine. Compound 2 was prepared by acylation of primaquine with 1-benzotriazole carboxylic acid chloride. Among all compounds evaluated, the pyridine derivative 3h exhibited the best cytostatic activities against colon carcinoma, human T-lymphocyte and murine leukemia. However, this compound showed also rather marked cytotoxicity towards human normal fibroblasts. The highest selectivity in the inhibitory effects on human malignant tumor cell lines vs. normal fibroblasts was found for ureas 3c, 3d and 3g. Results of broad antiviral evaluation showed that pyridine and phenethyl derivatives of urea 3h and 3g exhibited some selective inhibition against cytomegalovirus.

Phenylethyl-substituted pyrimido[2,1- f]purinediones and related compounds: Structure–activity relationships as adenosine A 1 and A 2A receptor ligands

The synthesis of N-(un)substituted-phenylalkylpyrimido[2,1- f]purinediones was performed starting with 7-(3-chloropropyl)-8-bromotheophylline and 7-(3-chloropropyl)-8-bromo-1,3-dipropylxanthine. Compounds with unsubstituted or substituted ethylene spacer to an aromatic ring were synthesized. Additionally variations in the spacer—elongation of the linker containing more than two atoms, introduction of a double bond or heteroatoms were performed. Physicochemical properties of the synthesized compounds were described. The obtained compounds envisaged as sterically fixed and configurationally stable analogs of 8-styrylxanthines, were evaluated for their affinity to adenosine A 1 and A 2A receptors, the receptor subtypes that are predominant in the brain. Selected compounds were also investigated for the affinity to the A 2B and A 3 receptor subtypes. It was stated that phenylethyl pyrimido[2,1- f]purinediones and their analogs with variations of the ethylene spacer (substituted or extended) exhibit micromolar or submicromolar affinity for A 2A ARs (adenosine receptors); for example compound 2Ac with p-hydroxy substituent displayed a K i value of 0.23 μM at the rat A 2A receptor. In comparison to the previously obtained phenyl and benzyl pyrimido[2,1- f]purinediones compounds with a shorter spacer, phenethyl derivatives were optimal for A 2A AR. The kind of substituent at the aromatic ring was important for the affinity. Oxygen and nitrogen atoms in the spacer resulted frequently in a slight decrease of the A 2A AR affinity, introduction of more heteroatoms into the spacer—in carbamates—caused distinctly negative effect on the activity. In this series of compounds more frequently the adenosine A 1 activity was observed, also in submicromolar range as for dipropyl derivative 2Ba with K i value of 0.62 μM at the rat A 2A AR. 3D-QSAR models were developed for the compounds presented in this paper as well as in the previous publications showing activity at adenosine A 1 and A 2A ARs. It was concluded that for the activity at adenosine A 1 and A 2A receptors lipophilicity, steric effects along with the molecule’s electrostatic surface properties had greatest value. Chosen compounds were evaluated in vivo as anticonvulsants in MES, scMet tests and examined for neurotoxicity. Contrary to previously obtained phenyl and benzyl pyrimido[2,1- f]purinediones, all tested compounds were inactive as anticonvulsants.

Alkamides and phenethyl derivatives from Aristolochia gehrtii

From the stems of Aristolochia gehrtii, the cis-N-feruloyl-3-O-methyldopamine and a hemiacetal derivative of 5-hydroxymethylfurfural were isolated, together with twenty-two known compounds. These compounds include five lignans, three terpenes, six alkaloids (five alkamides), two benzoic acid derivatives, and six phenethyl derivatives. The structures of the isolated compounds were determined by means of spectroscopic methods and comparison with literature data.

Anti-Helicobacter pylori agents. 4. 2-(Substituted guanidino)-4-phenylthiazoles and some structurally rigid derivatives.

In order to find a new class of anti-Helicobacter pylori (H. pylori) agents, a series of 4-[(3-acetamido)phenyl]-2-(substituted guanidino)thiazoles and some structurally rigid analoges were synthesized and evaluated for antimicrobial activity against H. pylori. Among the compounds obtained, high anti-H. pyrori activities were observed in benzyl derivative 34 (MIC = 0.025 microg/mL) and phenethyl derivatives 35 and 36 (MIC = 0.037 microg/mL and 0.017 microg/mL). Though alkyl derivatives generally showed lower activity, the 2-methoxyethyl derivative 28 preserved significant activity (MIC = 0.32 microg/mL) and also exhibited more potent gastric antisecretory activity than ranitidine. Structural restriction by bridging between the thiazole and the phenyl rings with an alkyl chain did not improve the activity in this series.

3-Benzisothiazolylpiperazine derivatives as potential atypical antipsychotic agents.

A series of substituted phenethyl derivatives of 3-benzisothiazolylpiperazine incorporating potent D2 and 5-HT2A antagonist activity was investigated as an approach to a novel atypical antipsychotic agent. The in vitro profile of 8e from this series is a combination of D2 receptor affinity comparable to the typical antipsychotic agent haloperidol and a 5-HT2A/D2 ratio comparable to the atypical agent clozapine. In vivo 8e possesses activity consistent with an efficacious antipsychotic agent with less tendency to induce extrapyramidal side effects in man.

FPL 64176: The effect of the chain length separating the two aryl groups on calcium agonist activity

Analogs of the L-type calcium channel agonist FPL 64176 ( 5) were prepared in which the chain length separating the two aryl moieties was varied between zero and four. FPL 64176 ( 5) and phenethyl derivative 19 were the most potent compounds tested, displaying EC 50 values for enhancing calcium influx into GH 3 cells of 1−2×10 −7 M.

Opioid agonist and antagonist activities of morphindoles related to naltrindole.

A series of naltrindole-related ligands (4-10) with an N-methyl,N-phenethyl,N-cinnamyl, or an unsubstituted basic nitrogen were synthesized and tested for opioid agonist and antagonist activity in smooth muscle preparations and in mice. The nor compounds (4 and 6) and the phenethyl derivatives (5 and 8) displayed full agonist activity (IC50 = 85-179 nM) in the mouse vas deferens preparation (MVD) while the other members of the series exhibited partial agonist or weak antagonist activity. In the guinea pig ileum preparation (GPI), all compounds except 8 were partial agonists. The ligands that were evaluated in mice were found to produce antinociception that was not selectively mediated via delta opioid receptors. However, two of these ligands (4 and 5) appeared to be delta-selective opioid receptor antagonists at subthreshold doses for antinociception. The finding that all of the compounds bind selectively to delta opioid receptors in guinea pig brain membranes together with the in vitro pharmacology and in vivo antagonist studies suggests that the lack of delta agonist selectivity in vivo may be due to a number of factors, including a basic difference between the delta receptor system in the MVD and in the mouse brain. Further, it is suggested that the constellation of message and address components in the morphindole nucleus may tend to stabilize delta receptors in the brain in antagonist state.

Vacuum vapor deposited thin films of a perylene dicarboximide derivative: Microstructure versus deposition parameters

The microscopic physical structure in thin films of vapor deposited, large heterocyclic organic molecules is strongly dependent on the deposition parameters. The scale of the microstructure can vary enormously compared to inorganic systems, strongly affecting the macroscopic properties. Multiple polymorphs frequently characterize these systems. We have extended our previous work with the perylene dicarboximides to include a phenethyl derivative. Films in the 300–1000 Å thickness range, deposited on metal and transparent substrates at varying rates and substrate temperatures from −165 to 155 °C, with and without vacuum annealing, have been characterized by scanning electron microscopy, ultraviolet/visible, and infrared (IR) spectroscopies, and polarization modulation reflectivity changes. Evidence is presented for a critical substrate temperature between −22 and −32 °C. Also a polymorphic phase sensitivity to deposition substrate temperature and rate is demonstrated, consistent with an exothermic peak observed by differential scanning calorimetry of the vapor deposited material, and an annealing induced molecular reorientation observed by reflection absorption IR.

High performance liquid chromatographic determination of aclacinomycin a and its related compounds. II. Reverse phase HPLC determination of aclacinomycin A and its metabolites in biological fluids using fluorescence detection.

A sensitive, simple and selective reverse phase high performance liquid chromatographic method was applied to the determination of aclacinomycin A (ACM) and its metabolites in plasma. The chromatography was performed on a microparticulate phenethyl derivative of silica using a mobile phase of acetonitrile-0.03 M ammonium formate buffer (pH 5.0), (50:50, v/v) and monitoring with fluorescence detector (excitation 435 nm-emission 505 nm). High reproducibility and linear calibration curves were obtained from 20 ng/ml to 100 ng/ml of ACM and its metabolites in plasma by use of internal standard methods.

ChemInform Abstract: THE REVISED STRUCTURE OF DISPERMOL AND TOTAL SYNTHESIS OF MAYTENOQUINONE, DISPERMOL, AND DISPERMONE

AbstractKondensation von β‐Cyclocitral (I) mit dem Benzylchlorid (II) ergibt die Alkohole (±)‐(III), von denen (±)‐(IIIa) zu dem Keton (±)‐(IV) oxidiert wird, aus dem durch intramolekulare Cyclisierung gefolgt von Methylierung das Totaratrienon (±)‐(V) gebildet wird, Demethylierung von (±)‐(V) ergibt (±)‐Maytenochinon (±)‐(VI).

The Revised Structure of Dispermol and Total Synthesis of Maytenoquinone, Dispermol, and Dispermone

Abstract Condensation of β-cyclocitral with 2-isopropyl-3,4-dimethoxybenzyl chloride afforded an alcohol (15) which was converted into (±)-12,13-dimethoxytotara-8,11,13-trien-6-one (18). Demethylation of (±)-18 followed by air oxidation gave (±)-maytenoquinone. Reductive cleavage of the hydroxyl group in (±)-15 produced a phenethyl derivative which was cyclized to give (±)-12,13-dimethoxytotara-8,11,13-triene (23) and its cis-isomer (24). Oxidation of (±)-23 with chromium trioxide, followed by demethylation of the resulting 7-oxo compound (25), afforded (±)-dispermone. The Wittig reaction of (R)-(−)-α-cyclocitral with 2-isopropyl-3,4-dimethoxybenzyltriphenylphosphonium chloride yielded a styrene derivative. This was partially hydrogenated and then cyclized to give (+)-23 and (−)-24. The trans-isomer (23) was converted into (−)-dispermone (3) via (−)-25 and also partially demethylated to (+)-12-methoxytotara-8,11,13-trien-13-ol (2), the proposed structure for dispermol. Since the synthetic (+)-2 was not identical with the natural compound, (−)-3 was then converted into (+)-13-methoxytotara-8,11,13-trien-12-ol, which was identical with natural dispermol. (−)-25 was also converted into (+)-maytenoquinone.