http://www.orgmedchemlett.com The latest research articles published by Organic and Medicinal Chemistry Letters 2013-03-04T00:00:00Z Background: Glycosmis is a genus of evergreen glabrous shrub and distributed all over India. It possesses various medicinal properties and is used in indigenous medicine for cough, rheumatism, anemia, and jaundice. Glycosmis arborea is a rich source of alkaloids, terpenoids, coumarins, as well as flavonoids. Results: The chemical investigation of methanol fraction of the leaves of G. arborea led to the isolation of one new flavone C-glycoside along with three known flavanoids, named as 5,7-dihydroxy-2-[4-hydroxy-3-(methoxy methyl) phenyl]-6-C-β-d-glucopyranosyl flavone (4), 5,7,4′-trihydroxy-3′-methoxy flavone (1), 5,4′-dihydroxy-3′-methoxy-7-O-β-d-glucupyranosyl flavanone (2), and 5,4′-dihydroxy-3′-methoxy-7-O-(α-l-rhamnosyl-(1‴→6‴)-β-d-glucopyranosyl) flavanone (3), respectively. The structures of all compounds were elucidated with the help of nuclear magnetic resonance spectrometry. Pure compounds and fractions were evaluated for pest antifeedant and antimicrobial activity. Conclusion: Four compounds were isolated from the leaves of G. arborea. Among them, compound 4 showed significant antimicrobial activity. http://www.orgmedchemlett.com/content/3/1/4 Mohammad Khan Nisha Negi Rajnikant Sharma Devendra Negi Organic and Medicinal Chemistry Letters 2013, null:4 2013-03-04T00:00:00Z doi:10.1186/2191-2858-3-4 /content/figures/2191-2858-3-4-toc.gif Organic and Medicinal Chemistry Letters 2191-2858 ${item.volume} 4 2013-03-04T00:00:00Z XML Background: The combretastatins are a class of natural stilbenoids. These molecules generally share three common structural features: a trimethoxy "A"-ring, a "B"-ring containing substituent often at C3′ and C4′, and an ethene bridge between the two rings, which provides necessary structural rigidity. Members of the combretastatin family possess varying ability to cause vascular disruption in tumors. Combretastatin binds to the colchicine binding site of β-subunit of tubulin. Despite having a similar name, combretastatin is unrelated to statins, a family of cholesterol-lowering drugs. Results: New combretastatin 2-(1-acetyl-1H-indole-3-yl)-3-(phenyl) propenoic analogues (2a to 2y), bearing indole moiety at the place of ring A of combretastatin (CA4), were synthesized and evaluated for anticancer activity against various cancer cell lines such as THP-1 (leukemia), A-549 (lung), IGROV-1 (ovary), HEP-2 (liver), MCF-7 (breast), and DU-145 (prostate). Compound 2d showed anti-cancer activity against THP-1 and MCF-7 with IC50 0.80 and 0.37 μM, respectively, and 2y showed against MCF-7 with IC50 3.60 μM comparable to paclitaxel. Conclusions: The target compounds bind to the colchicine binding site which is situated at α and β interface of tubulin and prevent polymerization as it was confirmed by immunofluorescence technique. The molecular docking further confirmed the binding of the potent compound 2d to the colchicine binding site at α and β interface of tubulin. http://www.orgmedchemlett.com/content/3/1/3 Sunil Kumar Samir Mehndiratta Kunal Nepali Manish Gupta Surrinder Koul Parduman Sharma Ajit Saxena Kanaya Dhar Organic and Medicinal Chemistry Letters 2013, null:3 2013-03-03T00:00:00Z doi:10.1186/2191-2858-3-3 /content/figures/2191-2858-3-3-toc.gif Organic and Medicinal Chemistry Letters 2191-2858 ${item.volume} 3 2013-03-03T00:00:00Z XML Background: Synthesized arylidene derivatives of rhodanine and 2,4-thiazolidiendione have potent pharmacological activities, and these are also key substrates for the preparation of clinically used antidiabetics.FindingsSome 1,1,3,3-tetramethylguanidine-based task-specific ionic liquids (TSILs) 1a-1e were prepared and employed to the catalyzed solvent-free Knoevenagel condensation of 2,4-thiazolidinedione 3a and rhodanine 3b with a variety of aldehydes. Conclusions: Best results were obtained with 1,1,3,3-tetramethylguanidine lactate ([TMG][Lac]) 1c. The TSIL used can be easily recovered and recycled, yielding products 4–5 in excellent yields under ultrasonic environment without the formation of any side products or toxic waste. http://www.orgmedchemlett.com/content/3/1/2 Suresh Jagir Singh Sandhu Organic and Medicinal Chemistry Letters 2013, null:2 2013-03-03T00:00:00Z doi:10.1186/2191-2858-3-2 /content/figures/2191-2858-3-2-toc.gif Organic and Medicinal Chemistry Letters 2191-2858 ${item.volume} 2 2013-03-03T00:00:00Z XML Background: The benzhydryl ether moiety is widely distributed in nature and constitutes a key structural motif in numerous molecules of significant biological potential and of prospective clinical uses. Solvent-free and cost-effective facile synthesis of symmetrical bis(benzhydryl)ethers is, thus, much desirable. Results: A simple and efficient method for the facile synthesis of symmetrical bis(benzhydryl)ethers directly from the corresponding benzhydrols has been developed using a catalytic amount of p-toluenesulfonyl chloride (5 mol%) at an oil bath temperature of 110°C under solvent-free conditions. Conclusions: Operational simplicity, low reagent loading, high product yields, short reaction time, and solvent-free conditions are the notable advantages of the present method. http://www.orgmedchemlett.com/content/3/1/1 Goutam Brahmachari Bubun Banerjee Organic and Medicinal Chemistry Letters 2013, null:1 2013-02-18T00:00:00Z doi:10.1186/2191-2858-3-1 /content/figures/2191-2858-3-1-toc.gif Organic and Medicinal Chemistry Letters 2191-2858 ${item.volume} 1 2013-02-18T00:00:00Z XML Free radicals are well known for playing a dual role in our body- deleterious as well as beneficial. It includes a metabolic pathway for its generation. Oxidative stress in our body occurs due to excessive generation of free radicals and reduced level of antioxidants, but at low concentrations, these radicals help to perform normal physiological functions of the body. Scientific evidence suggests that antioxidants reduce the risk for chronic diseases including cancer and heart disease. This review shows current tendency in the pyrimidine synthesis and reveals the pyrimidine core to be a very potent moiety which can be a rich source for the synthesis of new compounds having desirable antioxidant activity. http://www.orgmedchemlett.com/content/2/1/34 Tabassum Bano Nitin Kumar Rupesh Dudhe Organic and Medicinal Chemistry Letters 2012, null:34 2012-11-14T00:00:00Z doi:10.1186/2191-2858-2-34 /content/figures/2191-2858-2-34-toc.gif Organic and Medicinal Chemistry Letters 2191-2858 ${item.volume} 34 2012-11-14T00:00:00Z XML Background: This experiment was conducted to evaluate the effect of different amounts of fertilizers on the polysaccharides of Aloe vera plant. There were four different treatments, viz. T1 = 150% N, T2 = 150% P, T3 = 150% K, and T4 = 150% NPK (50% N + 50% P + 50% K) soil. Crude water-soluble polysaccharides were isolated from the gel juice, skin juice, and flowers of A. vera planted in these soils. Results: Result indicates that skin juice contained 2.4 times the level of polysaccharides in gel juice from one plant, suggesting the potential industrial application of A. vera skin rather than discarding it. After anion-exchange chromatography, neutral polysaccharides accounted for 58.1% and 78.5% of the total recovered neutral and acidic polysaccharide preparations from the gel juice and skin juice, respectively, whereas the crude flower polysaccharides were largely composed of weakly acidic polysaccharides (84.2%). Sugar analysis of the polysaccharides after gel permeation chromatography revealed that glucose and galactose were the most abundant monosaccharide in the neutral polysaccharides from the gel juice and skin juice, respectively. The acidic polysaccharides from the two juices consisted of glucuronic acid, galactose, glucose, mannose, and xylose with variable proportions. Conclusions: Except glucuronic acid (15.4%) in flower acidic polysaccharide, the flower neutral and acidic polysaccharides contained galactose, glucose, and mannose as the main sugar components. Glucuronic acid was the major uronic acid in all acidic polysaccharides from different tissues. http://www.orgmedchemlett.com/content/2/1/33 Fatemeh Nejatzadeh-Barandozi Sattar Tahmasebi Enferadi Organic and Medicinal Chemistry Letters 2012, null:33 2012-10-24T00:00:00Z doi:10.1186/2191-2858-2-33 /content/figures/2191-2858-2-33-toc.gif Organic and Medicinal Chemistry Letters 2191-2858 ${item.volume} 33 2012-10-24T00:00:00Z XML Background: The endocannabinoid system is involved in many physiological and pathological processes. Two receptors (cannabinoid receptor type 1 (CB1) and type 2 (CB2)) are known so far. Many unwanted psychotic side effects of inhibitors of this system can be addressed to the interaction with CB1. While CB1 is one of the most abundant neuroreceptors, CB2 is expressed in the brain only at very low levels. Thus, highly potent and selective compounds for CB2 are desired. N-aryl-((hetero)aromatic)-oxadiazolyl-propionamides represent a promising class of such selective ligands for the human CB2. Here, a library of various derivatives is studied for suitable routes for labelling with 18F. Such 18F-labelled compounds can then be employed as CB2-selective radiotracers for molecular imaging studies employing positron emission tomography (PET). Results: By varying the N-arylamide substructure, we explored the binding pocket of the human CB2 receptor and identified 9-ethyl-9H-carbazole amide as the group with optimal size. Radioligand replacement experiments revealed that the modification of the (hetero)aromatic moiety in 3-position of the 1,2,4-oxadiazoles shows only moderate impact on affinity to CB2 but high impact on selectivity towards CB2 with respect to CB1. Further, we could show by autoradiography studies that the most promising compounds bind selectively on CB2 receptors in mouse spleen tissue. Molecular docking studies based on a novel three-dimensional structural model of the human CB2 receptor in its activated form indicate that the compounds bind with the N-arylamide substructure in the binding pocket. 18F labelling at the (hetero)aromatic moiety at the opposite site of the compounds via radiochemistry was carried out. Conclusions: The synthesized CB2-selective compounds have high affinity towards CB2 and good selectivity against CB1. The introduction of labelling groups at the (hetero)aromatic moiety shows only moderate impact on CB2 affinity, indicating the introduction of potential labelling groups at this position as a promising approach to develop CB2-selective ligands suitable for molecular imaging with PET. The high affinity for human CB2 and selectivity against human CB1 of the herein presented compounds renders them as suitable candidates for molecular imaging studies. http://www.orgmedchemlett.com/content/2/1/32 Thomas Rühl Winnie Deuther-Conrad Steffen Fischer Robert Günther Lothar Hennig Harald Krautscheid Peter Brust Organic and Medicinal Chemistry Letters 2012, null:32 2012-10-15T00:00:00Z doi:10.1186/2191-2858-2-32 /content/figures/2191-2858-2-32-toc.gif Organic and Medicinal Chemistry Letters 2191-2858 ${item.volume} 32 2012-10-15T00:00:00Z XML AbstractBackgroundThe biological importance of members of genus Ferula promoted us to investigate the leaves of Ferula vesceritensis Coss et Dur. (endemic plant) previously not investigated. This study presents the chemical composition and antibacterial activities of the hydrodistilled oils.ResultsVolatile components of the leaves of F. vesceritensis have been studied by gas chromatography–mass spectrometry to afford 23 compounds. The major components were found to be 5,9-tetradecadiyne (24.72%), germacrene D (24.51%), farnesene (8.57%), and α-bisabolene (8.57%). The antimicrobial activities of the essential oils were evaluated by disk diffusion method and tested against Gram-positive and Gram-negative bacteria. The volatile oil showed a strong antibacterial activity against Staphylococcus aureus, Escherichia coli, and Klebsiella pneumonia.ConclusionsThese results reinforce the previous studies showing that the genus Ferula is considered as a good source of essential oils. The results presented here can be considered as the first information on the antimicrobial properties of F. vesceritensis. http://www.orgmedchemlett.com/content/2/1/31 Amar Zellagui Noueddine Gherraf Salah Rhouati Organic and Medicinal Chemistry Letters 2012, null:31 2012-09-03T00:00:00Z doi:10.1186/2191-2858-2-31 /content/figures/2191-2858-2-31-toc.gif Organic and Medicinal Chemistry Letters 2191-2858 ${item.volume} 31 2012-09-03T00:00:00Z XML Background: More than 15,000 marine products have been described up to now; Sponges are champion producers, concerning the diversity of products that have been found. Most bioactive compounds from sponges were classified into anti-inflammatory, antitumor, immuno- or neurosurpressive, antiviral, antimalarial, antibiotic, or antifouling. Evaluation of in vitro inhibitory effects of different extracts from four marine sponges versus some antioxidants indices and carbohydrate hydrolyzing enzymes concerned with diabetes mellitus was studied. The chemical characterizations for the extracts of the predominating sponges; SP1 and SP3 were discussed. Methods: All chemicals served in the biological study were of analytical grade and purchased from Sigma, Merck and Aldrich. All kits were the products of Biosystems (Spain), Sigma Chemical Company (USA), Biodiagnostic (Egypt). Carbohydrate metabolizing enzymes; α-amylase, α-glucosidase, and β-galactosidase (EC3.2.1.1, EC3.2.1.20, and EC3.2.1.23, respectively) were obtained from Sigma Chemical Company (USA). Results: Four marine sponges; Smenospongia (SP1), Callyspongia (SP2), Niphates (SP3), and Stylissa (SP4), were collected from the Red Sea at Egyptian coasts, and taxonomically characterized. The sponges' extracts exhibited diverse inhibitory effects on oxidative stress indices and carbohydrate hydrolyzing enzymes in linear relationships to some extent with concentration of inhibitors (dose dependant). The extracts of sponges (3, 1, and 2) showed, respectively, potent-reducing power. Purification and Chemical characterization of sponge 1 using NMR and mass spectroscopy, recognized the existence of di-isobutyl phthalate (1), di-n-butyl phthalate (2), linoleic acid (3), β-sitosterol (4), and cholesterol (5). Sponge 3 produced bis-[2-ethyl]-hexyl-phthylester (6) and triglyceride fatty acid ester (7). Conclusion: Marine sponges are promising sources for delivering of bioactive compounds. Four marine sponges, collected from Red Sea at Egyptian coasts, were identified as Smenospongia (SP1), Callyspongia (SP2), Niphates (SP3), and Stylissa (SP4). The results demonstrated that different sponges extracts exhibited inhibitory effects on oxidative stress indices and carbohydrate hydrolyzing enzymes in linear relationships to some extent with concentration of inhibitors (dose dependant). The extracts of sponges (3, 1, and 2) showed, respectively, potent-reducing power. Chemical characterizations of sponges SP1 and SP3 were discussed. Based on this study, marine sponges are considered as talented sources for production of diverse and multiple biologically active compounds. http://www.orgmedchemlett.com/content/2/1/30 Mohamed Shaaban Howaida Abd-Alla Amal Hassan Hanan Aly Mohamed Ghani Organic and Medicinal Chemistry Letters 2012, null:30 2012-08-16T00:00:00Z doi:10.1186/2191-2858-2-30 /content/figures/2191-2858-2-30-toc.gif Organic and Medicinal Chemistry Letters 2191-2858 ${item.volume} 30 2012-08-16T00:00:00Z XML Background: An antibacterial is a substance that either kills bacteria or slows their growth. Antifungal are the agents that use drugs for treatment of fungal infections. 5-Chloro-1,3-benzoxazol-2(3 H)-one (5-Chloro Benzoxazolinone) contains an azole ring structure. Numbers of azole compounds are reported as antibacterial and antifungal agents. Benzoxazolinones naturally occur in plants. They play a role as defense compounds against bacteria, fungi, and insects. Results: In this article, synthesis of six Benzoxazolinone derivatives with various substituents is presented. Benzoxazolinone substituted with p-aminobenzoic acids and sulphanilamide derivatives. The above both substituents are reported as potent antimicrobial agents. Attachment with azole leads to increase its potency. The other substituents are 2,4-dichlorobezylchloride. The same rings are found in miconazole and this may lead to increase its antifungal activity. Fluconazole also contains triazole moiety and triazole is having other numbers of activity like antimicrobial, anti-inflammatory, local anesthetic, antiviral, anticancer, antimalarial, etc. Here, there is a substitution for azole ring at 5-Chloro position which might increase antibacterial and antifungal activity. The synthesis and interpretation of six final compounds and three intermediates are presented in this article. Synthesis of 5-Chloro Benzoxazolinone derivatives substituted with Halogenated rings, sulfonated and benzylated derivatives and azole derivatives. There is a synthesis of P2A, P2B, P4A, P4B, P5A, and P6A compounds and their structures were characterized by UV–Visible, IR, MASS spectroscopy, and NMR spectroscopy. Conclusions: The antibacterial activity of all six compounds is measured against various Gram-positive and Gram-negative bacteria and against fungi. Compounds P4A and P4B have good antibacterial and antifungal activity, half of the Ampicillin and Cephalexin. P4A, P4B, P6A have good activity against Staphylococcus aureus and Escherichia coli. Compound P2B has good antifungal activity, half of the Miconazole against Candida albicans. P2A, P2B, P5A, P6A have almost equal antibacterial activity. http://www.orgmedchemlett.com/content/2/1/29 Priya Modiya Chhaganbhai Patel Organic and Medicinal Chemistry Letters 2012, null:29 2012-08-01T00:00:00Z doi:10.1186/2191-2858-2-29 /content/figures/2191-2858-2-29-toc.gif Organic and Medicinal Chemistry Letters 2191-2858 ${item.volume} 29 2012-08-01T00:00:00Z XML