A new cyclic polyketide and other constituents from Ononis spinosa growing wildly in Jordan and their antioxidant activity.

The new cyclic polyketide 7,9,11-trihydroxytetracos-2-eneoic acid δ-lactone (1), together with other eleven known compounds, were isolated from Ononis spinosa, growing wildly in Jordan. All isolated compounds were identified by thorough investigation of their spectral data including NMR and HRESIMS. Antioxidant activity testing of puerol B, specionin and the new cyclic polyketide revealed that puerol B had the highest DPPH radical scavenging activity (IC50 0.09 ± 0.006 mg/ml) as compared to α-tocopherol (IC50 0.039 ± 0.0006 mg/ml), while specionin had the highest ABTS radical scavenging power (IC50 0.013 ± 0.0008 mg/ml) as compared to α-tocopherol and ascorbic acid (IC50 0.042 ± 0.0004; 0.026 ± 0 .0007 mg/ml; respectively).

Therapeutic Potential of Agonists and Antagonists of A1, A2a, A2b and A3 Adenosine Receptors.

Adenosine is a naturally occurring nucleoside and an essential component of the energy production and utilization systems of the body. Adenosine is formed by the degradation of adenosine-triphosphate (ATP) during energy-consuming processes. Adenosine regulates numerous physiological processes through activation of four subtypes of G-protein coupled membrane receptors viz. A1, A2A, A2B and A3. Its physiological importance depends on the affinity of these receptors and the extracellular concentrations reached. ATP acts as a neurotransmitter in both peripheral and central nervous systems. In the peripheral nervous system, ATP is involved in chemical transmission in sensory and autonomic ganglia, whereas in central nervous system, ATP, released from synaptic terminals, induces fast excitatory postsynaptic currents. ATP provides the energetics for all muscle movements, heart beats, nerve signals and chemical reactions inside the body. Adenosine has been traditionally considered an inhibitor of neuronal activity and a regulator of cerebral blood flow. Since adenosine is neuroprotective against excitotoxic and metabolic dysfunctions observed in neurological and ocular diseases, the search for adenosinerelated drugs regulating adenosine transporters and receptors can be important for advancement of therapeutic strategies against these diseases. This review will summarize the therapeutic potential and recent SAR and pharmacology of adenosine and its receptor agonists and antagonists.

Coumarin derivatives as acetyl- and butyrylcholinestrase inhibitors: An in vitro, molecular docking, and molecular dynamics simulations study.

Alzheimer's disease is an irreversible and progressive brain disease that can cause problems with memory and thinking skills. It is characterized by loss of cognitive ability and severe behavioral abnormalities, and could lead to death. Cholinesterases (ChEs) play a crucial role in the control of cholinergic transmission, and subsequently, the acetylcholine level in the brain is upgraded by inhibition of ChEs. Coumarins have been shown to display potential cholinesterase inhibitory action, where the aromatic moiety has led to the design of new candidates that could inhibit Aß aggregation. Accordingly, the present work is an in vitro activity, along with docking and molecular dynamics (MD) simulation studies of synthesized coumarin derivatives, to explore the plausible binding mode of these compounds inside the cholinesterase enzymes. For this purpose, a series of previously prepared N1-(coumarin-7-yl) derivatives were screened in vitro for acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities. The assayed compounds exhibited moderate inhibitory activity against AChE, with IC50 values ranging from 42.5 ± 2.68 to 442 ± 3.30 µM. On the other hand, the studied compounds showed remarkable activity against BChE with IC50 values ranging from 2.0 ± 1.4 nM to 442 ± 3.30 µM. In order to better understand the ligand binding site interaction of compounds and the stability of protein-ligand complexes, a molecular docking with molecular dynamics simulation of 5000 ps in an explicit solvent system was carried out for both cholinesterases. We concluded that the tested coumarin derivatives are potential candidates as leads for potent and efficacious ChEs inhibitors.

Recent Advances in the In-silico Structure-based and Ligand-based Approaches for the Design and Discovery of Agonists and Antagonists of A2A Adenosine Receptor.

A2A receptor belongs to the family of GPCRs, which are the most abundant membrane protein family. Studies in the last few decades have shown the therapeutic applications of A2A receptor in various diseases. In the present mini-review, we have discussed the recent progress in the in-silico studies of the A2A receptor. Herein, we described the different structures of A2A receptor, the discovery of new agonists and antagonists using virtualscreening/ docking, pharmacophore modeling, and QSAR based pharmacophore modeling. We have also discussed various molecular dynamics (MD) simulations studies of A2A receptor in complex with ligands.

Fungal biotransformation of diuretic and antihypertensive drug spironolactone with Gibberella fujikuroi, Curvularia lunata, Fusarium lini, and Aspergillus alliaceus.

Derivatives of spironolactone (1), a diuretic and antihypertensive drug, were synthesized by using fungal cells for the first time. Ten different fungi were screened for their ability to biotransform 1, four of which were able to produce metabolites 2-8. Gibberella fujikuroi produced canrenone (2), 1-dehydrocanrenone (3), Curvularia lunuta provided compound 2, and 7α-thio-spironolactone (4), Fusarium lini yielded compounds 2, 3, 1ß-hydroxycanrenone (5), 1α-hydroxycanrenone (6), 1-dehydro-15α-hydroxycanrenone (7), and 15α-hydroxycanrenone (8), while Aspergillus alliaceus was able to produce all the seven metabolites. Metabolites 5, 6, and 7 were identified as new compounds. Their structures were elucidated by using different spectroscopic techniques. Substrate 1 and its metabolites 2, 3, and 5-8 were also evaluated for α-glucosidase inhibitory activity in vitro. Substrate 1 was found to be strongly active with IC50 = 335 ±â€¯4.3 µM as compared to the standard drug acarbose IC50 = 840 ±â€¯1.73 µM, whereas all of resulting metabolites were found to be inactive.

In-silico identification of the binding mode of synthesized adamantyl derivatives inside cholinesterase enzymes.

AIM: To investigate the binding mode of synthesized adamantly derivatives inside of cholinesterase enzymes using molecular docking simulations. METHODS: A series of hybrid compounds containing adamantane and hydrazide moieties was designed and synthesized. Their inhibitory activities against acetylcholinesterase (AChE) and (butyrylcholinesterase) BChE were assessed in vitro. The binding mode of the compounds inside cholinesterase enzymes was investigated using Surflex-Dock package of Sybyl7.3 software. RESULTS: A total of 26 adamantyl derivatives were synthesized. Among them, adamantane-1-carboxylic acid hydrazide had an almost equal inhibitory activity towards both enzymes, whereas 10 other compounds exhibited moderate inhibitory activity against BChE. The molecular docking studies demonstrated that hydrophobic interactions between the compounds and their surrounding residues in the active site played predominant roles, while hydrophilic interactions were also found. When the compounds were docked inside each enzyme, they exhibited stronger interactions with BChE over AChE, possibly due to the larger active site of BChE. The binding affinities of the compounds for BChE and AChE estimated were in agreement with the experimental data. CONCLUSION: The new adamantly derivatives selectively inhibit BChE with respect to AChE, thus making them good candidates for testing the hypothesis that BChE inhibitors would be more efficient and better tolerated than AChE inhibitors in the treatment of Alzheimer's disease.

Three new seco-ursadiene triterpenoids from Salvia syriaca.

Three new seco-ursadiene triterpenoids 1-3 together with 11 known compounds were isolated from Salvia syriaca of Jordanian origin. The compounds were identified by using NMR spectroscopy including extensive 2D NMR experiments and mass spectrometry. The structure of compound 3 was confirmed by X-ray crystallography, and the information thus obtained was used to confirm the stereochemistry of compounds 1 and 2. This is the second report of 17,22-seco-17(28),12-ursadien-22-oic acids.

Selective phytotoxic activity of 2,3,11ß,13-tetrahydroaromaticin and ilicic acid isolated from Inula graveolens.

Inula graveolens is a poisonous annual plant of Mediterranean origin. The invasive nature of the plant suggests that it may possess phytotoxic activity. The aim of this study was to assess the ability of I. graveolens to inhibit the growth of different plants in Petri dish and to identify the main bioactive compounds. Bio-guided fractionation of the plant extracts led to the isolation of 2,3,11ß,13-tetrahydroaromaticin (THA) and ilicic acid. Both compounds showed selective and significant phytotoxic activity at 25 ppm. Root length of barley, oat, millet, tuberous canary grass and lentils were significantly reduced by 25 ppm of THA, while the root of cauliflower, cress and radish were similarly reduced by ilicic acid at 25 ppm. The structure of each compound was elucidated by using NMR and HR-MS. X-ray crystallography of THA is reported for the first time to confirm the relative stereochemistry of the compound.

Synthesis and antibacterial activity of some novel 4-oxopyrido[2,3-a]phenothiazines.

A series of substituted 4-oxopyrido[2,3-a]phenothiazine-3-carboxylic acids (6a-d) were prepared via cyclization of the corresponding ethyl 7-(arylthioxy)-8-nitro(or azido)-4-oxoquinoline-3-carboxylates (3a-d/4a-d), followed by hydrolysis of the resultant esters (5a-d). Among these tetracyclics, compound 6a with unsubstituted terminal benzo-ring D was the most active against representative Gram-positive and Gram-negative bacterial strains. These compounds were also active against methicillin-resistant Staphylococcus aureus (MRSA), with very low toxicity to normal cells. Virtual screening using ligand-protein docking modeling predicted that the compounds 6a-d are potential inhibitors of the topoisomerase IV enzyme and that hydrophobic interactions and hydrogen bonds are the major molecular interactions between these compounds and the residues of the active site of topoisomerase IV.

Plants used for the treatment of diabetes in Jordan: a review of scientific evidence.

CONTEXT: Diabetes is a serious disease which has reached epidemic proportions in many parts of the world. Despite the tremendous developments in medicinal chemistry, traditional medicine is still a common practice for the treatment of diabetes. OBJECTIVES: In Jordanian traditional medicine, 69 plant species are used by diabetic patients to reduce glucose levels in blood. The aim of the present study is to report these plants and link their traditional use with scientific evidence confirming their claimed activity. The plant part(s) used, method(s) of preparation, common Arabic names, and other ethnopharmacological uses are also listed. MATERIALS AND METHODS: The literature and databases (SciFinder, PubMed, ScienceDirect and Scirus) have been thoroughly investigated and the plants used have been grouped according to the reported scientific evidence. RESULTS: Results showed that 40 plants have been reported to possess hypoglycemic activities in in vivo/in vitro experiments. Five plant species did not exhibit in vivo hypoglycemic activity, while 24 plants had not been studied for such an activity. Twenty plants had been screened for their α-amylase/α-glucosidase inhibitory activities. DISCUSSION: The reported in vivo and in vitro hypoglycemic as well as α-amylase/α-glucosidase inhibitory activities of these plants are discussed. CONCLUSION: Additional in vitro and in vivo studies are needed to test the hypoglycemic activity of the plants with claimed antidiabetic activity which has not yet been evaluated. Identification of the active ingredients of potent plants might generate lead compounds in drug discovery and development.

Synthesis and antimicrobial activity of cholic acid hydrazone analogues.

Synthesis and antimicrobial activity of cholic acid analogues 4a-t are reported. The synthesis of 4a-t was accomplished from ethylcholate 2. The hydrazone moiety was introduced via coupling of the cholic acid hydrazide (3) with appropriately functionalized aldehyde utilizing acetic acid as a catalyst. Quiet of interest in relation to the synthesized hydrazones is the formation of two rotamers s-cis.E and s-trans.E. Most compounds showed stronger antimicrobial activity against Gram-positive bacteria than Cefaclor and Cefixime. Compounds 4d, 4i and 4j indicated 15-fold stronger antimicrobial activities against Enterobacter faecalis compared to Cefaclor and Cefixime. Some of the synthesized compounds (e.g. 4a, 4c, 4d, 4i, and 4l) reflected two-folds less activity against Escherichia coli relative to Cefixime.

Rational design and synthesis of potent dibenzazepine motifs as beta-secretase inhibitors.

We have identified small-molecule dibenzazepine inhibitors of beta-secretase (BACE1). These BACE1 inhibitors possess two key salient features. The first is a seven-membered heterocyclic ring fused to two aromatic rings representing the P3-P2 residues. The second is an amide and/or amide bioisostere representing the P1' residue. Rational optimization led to the identification of potent analogues, such as 10 (K(I) = 211 nM).

New oxandrolone derivatives by biotransformation using Rhizopus stolonifer.

Structural transformation of the steroidal lactone, oxandrolone (1), by suspended-cell cultures of the plant pathogen fungus Rhizopus stolonifer, resulted in the production of three new metabolites. These metabolites were identified as 11alpha-hydroxyoxandrolone (2), 6alpha-hydroxyoxandrolone (3) and 9alpha-hydroxyoxandrolone (4), by different spectroscopic methods and single-crystal X-ray diffraction analysis for metabolite 2. Compounds 1 and 3 showed a significant beta-glucuronidase inhibitory activity.

Biotransformation of methyl cholate by Aspergillus niger.

Biotransformation of methyl cholate using Aspergillus niger was investigated. This led to the isolation of two derivatives: methyl 3alpha,7alpha,12alpha,15beta-tetrahydroxy-5beta-cholan-24-oate identified as a new compound, and a known compound methyl 3alpha,12alpha-dihydroxy-7-oxo-5beta-cholan-24-oate. The structure elucidation of the new compound was achieved using 1D and 2D NMR, MS and X-ray diffraction.

Butyrylcholinesterase inhibitory activity of testosterone and some of its metabolites.

Testosterone and ten of its metabolites were examined as inhibitors of butyrylcholinesterase. A significant enzyme inhibition activity (IC(50) = 1.55 microM) was observed for androst-4-en-3,7-dione. The kinetic parameters of butyrylcholinesterase inhibition were determined and molecular docking was carried out in order to develop a better understanding of the inhibitor-enzyme interactions. The results showed that the inhibition was non-competitive, stabilized mainly by hydrogen bonds and hydrophobic interactions between the inhibitor and butyrylcholinesterase.

Microbial transformation of testosterone by Rhizopus stolonifer and Fusarium lini.

The microbial transformation of testosterone by the fungi Rhizopus stolonifer and Fusarium lini has been investigated for the first time. The bioconversion reactions observed from R. stolonifer included oxidation of a 17beta-hydroxyl group, a hydroxylation at equatorial 11alpha position, reduction of the double bond at C-4 with oxidation of the methylene at C-6 to the corresponding keto group, and lactonisation of ring D; the latter is the first report of this reaction by a Rhizopus species. Fusarium lini promoted 1-dehydrogenation of the steroid, which has been rarely observed in fungi cultures. The other routes of biotransformations included oxidation of the 17beta-hydroxyl group and the hydroxylation at 11alpha position. These reactions are not common for Fusarium species.