N-Propargylamines: versatile building blocks in the construction of thiazole cores

• S. Arshadi,
• E. Vessally,
• L. Edjlali,
• R. Hosseinzadeh-Khanmiri and
• E. Ghorbani-Kalhor

Beilstein J. Org. Chem. 2017, 13, 625–638, doi:10.3762/bjoc.13.61

• ], antimicrobial [57][58][59], and specially antibiotic [60][61][62][63][64] agents. Despite their great relevance in drug design, only very few synthetic methods towards these compounds have been reported to date [44]. N-Propargylamines are one of the most specific class of alkynes having diverse reaction

Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

• allowed the synthesis of 60 in yields ranged from 31 to 56%. 1-Indanones exhibit a broad spectrum of biological activity including anti-inflammatory [41], analgesic [42], antimicrobial [43], antiviral [5], anticancer [44] and antimalarial [45] activity. A combination of two or more biologically active

• moieties may increase or decrease the biological activity. A series of isoxazole fused 1-indanones 64 with increased anti-inflammatory and antimicrobial activity has been synthesized by Giles et al. [46]. In this synthesis, diethyl phthalate (61) was reacted with ethyl acetate to obtain indane-1,3-dione

Biosynthetic origin of butyrolactol A, an antifungal polyketide produced by a marine-derived Streptomyces

• Enjuro Harunari,
• Hisayuki Komaki and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2017, 13, 441–450, doi:10.3762/bjoc.13.47

• recently, isolation of butyrolactols C and D was presented but the details are not available in public domains [10]. 1 has a broad antimicrobial activity against fungi ranging from Candida albicans to Trichophyton mentagrophytes with comparative activity to nystatin [9]. Despite the uniqueness of the

Synthesis and evaluation of anti-oxidant and cytotoxic activities of novel 10-undecenoic acid methyl ester based lipoconjugates of phenolic acids

• Naganna Narra,
• Shiva Shanker Kaki,
• Rachapudi Badari Narayana Prasad,
• Sunil Misra,
• Koude Dhevendar,
• Venkateshwarlu Kontham and
• Padmaja V. Korlipara

Beilstein J. Org. Chem. 2017, 13, 26–32, doi:10.3762/bjoc.13.4

• are a class of natural compounds which are found ubiquitously in the plant kingdom. They are reported to possess a wide range of biological properties like anti-oxidant, antimicrobial, anti-inflammatory, anticarcinogenic and antiviral activities [1]. The phenolic acids are also reported to show in

• transesterified with different oils or triglycerides [6]. Apart from these structured phenolipids, different fatty acids were esterified with phenolic compounds to produce novel esters which were evaluated for anti-oxidant and antimicrobial activities [7][8]. However, there are very few reports where the phenolic

First DMAP-mediated direct conversion of Morita–Baylis–Hillman alcohols into γ-ketoallylphosphonates: Synthesis of γ-aminoallylphosphonates

• Marwa Ayadi,
• Haitham Elleuch,
• Emmanuel Vrancken and
• Farhat Rezgui

Beilstein J. Org. Chem. 2016, 12, 2906–2915, doi:10.3762/bjoc.12.290

• interesting antimicrobial and antimalarial properties [8][9], as well as useful substrates for the synthesis of valuable organic compounds [10][11][12]. Historically, the Michaelis−Arbuzov rearrangement [13] is the most widely and generally high yielding strategy for phosphonate synthesis. The current three

Synthesis of acylhydrazino-peptomers, a new class of peptidomimetics, by consecutive Ugi and hydrazino-Ugi reactions

• Angélica de Fátima S. Barreto,
• Veronica Alves dos Santos and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2016, 12, 2865–2872, doi:10.3762/bjoc.12.285

• one of the CONH links is replaced by a hydrazido fragment CONHNH, Figure 1) represent another class of peptidomimetics with promising conformational and biological activities, such as protease inhibition [37] and antimicrobial activity [38]. There are some natural peptides that contain such an α

Facile synthesis of indolo[3,2-a]carbazoles via Pd-catalyzed twofold oxidative cyclization

• Chao Yang,
• Kai Lin,
• Lan Huang,
• Wei-dong Pan and
• Sheng Liu

Beilstein J. Org. Chem. 2016, 12, 2490–2494, doi:10.3762/bjoc.12.243

• in 2002 [1]. Up to now, four members of this family were isolated from marine organisms (Figure 1) [1][2][3]. Preliminary results of the antimicrobial and cytotoxicity assays indicated that these compounds have medicinal potentiality to target neurological and psychiatric disorders [1][2]. Several

Enduracididine, a rare amino acid component of peptide antibiotics: Natural products and synthesis

• Darcy J. Atkinson,
• Briar J. Naysmith,
• Daniel P. Furkert and
• Margaret A. Brimble

Beilstein J. Org. Chem. 2016, 12, 2325–2342, doi:10.3762/bjoc.12.226

• B Enduracidin A (7) and B (8) were first isolated from Streptomyces fungicidicus B 5477 from a soil sample collected in Nishinomiya, Japan (Figure 2) [1]. Detailed reports of the isolation procedures, in vivo and in vitro antimicrobial activity, physical properties and structure elucidation have

• using traditional techniques. Teixobactin (17) exhibits bactericidal activity through binding of Lipid II, a precursor of peptidoglycan, and therefore shows great potential as the foundation for discovery of a new generation of antibiotics to overcome the development of antimicrobial resistance

An effective one-pot access to polynuclear dispiroheterocyclic structures comprising pyrrolidinyloxindole and imidazothiazolotriazine moieties via a 1,3-dipolar cycloaddition strategy

• Alexei N. Izmest’ev,
• Galina A. Gazieva,
• Natalya V. Sigay,
• Sergei A. Serkov,
• Valentina A. Karnoukhova,
• Vadim V. Kachala,
• Alexander S. Shashkov,
• Igor E. Zanin,
• Angelina N. Kravchenko and
• Nina N. Makhova

Beilstein J. Org. Chem. 2016, 12, 2240–2249, doi:10.3762/bjoc.12.216

• viruses [35], anti-HIV and anticancer [36][37], antimicrobial and antifungal activities as well as cytotoxicity to MCF-7 cells [38][39]. Based on these observations we therefore aimed at combining the spiropyrrolidinyloxindole motif with hetero-annelated 1,2,4-triazine scaffolds. Recently, we have already

Varioloid A, a new indolyl-6,10b-dihydro-5aH-[1]benzofuro[2,3-b]indole derivative from the marine alga-derived endophytic fungus Paecilomyces variotii EN-291

• Peng Zhang,
• Xiao-Ming Li,
• Xin-Xin Mao,
• Attila Mándi,
• Tibor Kurtán and
• Bin-Gui Wang

Beilstein J. Org. Chem. 2016, 12, 2012–2018, doi:10.3762/bjoc.12.188

• search for structurally unique and bioactive secondary metabolites from marine fungi, especially from marine alga-derived fungi [6][7][8], we discovered evident DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity and diverse antimicrobial activities in the EtOAc extract from Paecilomyces

• variotii EN-291, an endophytic fungus isolated from the red alga Grateloupia turuturu. The investigation of the chemical constituents of this fungal strain had been performed and as a result, three new oxepine-containing alkaloids with antimicrobial activities [9][10], two new butenolide derivatives with

Total synthesis of leopolic acid A, a natural 2,3-pyrrolidinedione with antimicrobial activity

• Atul A. Dhavan,
• Rahul D. Kaduskar,
• Loana Musso,
• Leonardo Scaglioni,
• Piera Anna Martino and
• Sabrina Dallavalle

Beilstein J. Org. Chem. 2016, 12, 1624–1628, doi:10.3762/bjoc.12.159

• suggests that they could be considered as promising candidates for future developments. Keywords: antimicrobial; heterocyclic compounds; natural products; pyrrolidinedione; total synthesis; Introduction Great concern has recently been expressed about the diminishing efficacy of current antibiotic

• 17 in 50% yield. Compounds 1 and 17 were subjected to a preliminary study of the antimicrobial activity against Staphylococcus and Escherichia coli (Staphylococcus pseudintermedius [25], 25 strains; Escherichia coli, 20 strains. QC: S. aureus ATCC 25923 and Escherichia coli ATCC 25922 were also used

• unusual 2,3-pyrrolidinedione system and developed a synthetic strategy towards new lead compounds with antimicrobial activity. Efforts to synthesize analogues to build a structure–activity relationship (SAR) profile and optimize the activity are underway. Structure of leopolic acid A. Synthesis of

Biosynthesis of oxygen and nitrogen-containing heterocycles in polyketides

• Franziska Hemmerling and
• Frank Hahn

Beilstein J. Org. Chem. 2016, 12, 1512–1550, doi:10.3762/bjoc.12.148

• spontaneously in the absence of the enzyme. Acridones. The acridones are pyridin-4(1H)-one-containing metabolites of Rutaceae, which serve for UV protection and antimicrobial defense [169][170]. They are produced by various acridone synthases (ACSs), which are expressed depending on external triggers like

Mutagenic activity of quaternary ammonium salt derivatives of carbohydrates

• Barbara Dmochowska,
• Karol Sikora,
• Anna Woziwodzka,
• Jacek Piosik and
• Beata Podgórska

Beilstein J. Org. Chem. 2016, 12, 1434–1439, doi:10.3762/bjoc.12.138

• and sugar moieties were described before [22][25][26]. It was shown that quaternization of chitosan increases its antimicrobial activity; such polymer is proposed to be used as a wound dressing after surgeries to eliminate infections and to improve the healing process [27][28][29]. Moreover, the

Cyclisation mechanisms in the biosynthesis of ribosomally synthesised and post-translationally modified peptides

• Andrew W. Truman

Beilstein J. Org. Chem. 2016, 12, 1250–1268, doi:10.3762/bjoc.12.120

• antimicrobial peptides (AMPs) that have important roles in the mammalian immune system [143], including in humans [144], and these AMPs often exist as a cocktail of compounds. Many of these are unmodified linear peptides, such as the human peptide cathelicidin LL-37 [145], or are cyclised by disulphide bonds

• formed by the head-to-tail cyclisation of two nonapeptides that are themselves derived from the C-terminal region of precursor peptides, and both heterodimers or homodimers can be formed in this process [84][144]. Along with their antimicrobial activity, these peptides can inhibit fusion of HIV-1 to host

• human-tissue cultures leads to the production of properly cyclised θ-defensins that possess antimicrobial activity [148], indicating that humans have retained the proteins required for processing and cyclisation. The identity of these genes in either humans or monkeys has not been found, although a

Synthesis, fluorescence properties and the promising cytotoxicity of pyrene–derived aminophosphonates

• Jarosław Lewkowski,
• Maria Rodriguez Moya,
• Anna Wrona-Piotrowicz,
• Janusz Zakrzewski,
• Renata Kontek and
• Gabriela Gajek

Beilstein J. Org. Chem. 2016, 12, 1229–1235, doi:10.3762/bjoc.12.117

• properties. This expectation is supported by the biological activity of azomethine derivatives of pyrene-1-carboxaldehyde. They show antimicrobial action, e.g., 1-phenytoinylacetic acid hydrazone of pyrene-1-carboxaldehyde demonstrated a moderate antimicrobial activity towards Escherichia coli and

Antibacterial structure–activity relationship studies of several tricyclic sulfur-containing flavonoids

• Lucian G. Bahrin,
• Henning Hopf,
• Peter G. Jones,
• Laura G. Sarbu,
• Cornelia Babii,
• Alina C. Mihai,
• Marius Stefan and
• Lucian M. Birsa

Beilstein J. Org. Chem. 2016, 12, 1065–1071, doi:10.3762/bjoc.12.100

• different halogen substituents on the antibacterial properties has been tested against Staphylococcus aureus and Escherichia coli. Amongst the N,N-dialkylamino-substituted flavonoids, those having an N,N-diethylamino moiety exhibited good to excellent antimicrobial properties against both pathogens

• also established that dithiocarbamic flavanones of type 4 display no such activity. Therefore, only flavonoids 5a–m were tested against Staphylococus aureus (Gram positive) and Escherichia coli (Gram negative) in an attempt to establish an antimicrobial structure–activity relationship. Minimum

• indicated that the newly synthesized tricyclic flavanoids exhibit similar or even better antimicrobial properties. However, due to the lack of cytotoxicity results one may assume that the investigated structures represent a promising class of compounds. In summary, the newly synthesized compounds exhibit

Marine-derived myxobacteria of the suborder Nannocystineae: An underexplored source of structurally intriguing and biologically active metabolites

• Antonio Dávila-Céspedes,
• Peter Hufendiek,
• Max Crüsemann,
• Till F. Schäberle and
• Gabriele M. König

Beilstein J. Org. Chem. 2016, 12, 969–984, doi:10.3762/bjoc.12.96

• ample amount of them was shown to work as antimicrobial agents, above all corallopyronin A. This is probably a reflection of their predatory habits [27][28]. A comprehensive description of antibiotics obtained from myxobacteria can be found in a previous review [21]. One outstanding example of a

• molecules. Additionally, the siderophore nannochelin A (23) also from other myxobacteria was isolated [50]. All three compounds were tested against a broad range of microorganisms and mammalian cell lines. The most relevant antimicrobial activity was shown by 21 towards Mycobacterium diernhoferi (DSM 43542

A cross-metathesis approach to novel pantothenamide derivatives

• Jinming Guan,
• Matthew Hachey,
• Lekha Puri,
• Vanessa Howieson,
• Kevin J. Saliba and
• Karine Auclair

Beilstein J. Org. Chem. 2016, 12, 963–968, doi:10.3762/bjoc.12.95

• , Canberra, Australian Capital Territory, 2601, Australia Medical School, College of Medicine, Biology and Environment, The Australian National University, Canberra, Australian Capital Territory, 2601, Australia 10.3762/bjoc.12.95 Abstract Pantothenamides are known for their in vitro antimicrobial activity

• currently applied antimicrobials and as a result, our ability to treat infections effectively is diminishing. Efforts to control infections in this resistance era have taken a variety of paths from a renewed push for novel antimicrobial agents to a fresh understanding of antibiotic resistance mechanisms [1

• ]. One successful research direction has been to revisit “older” unexploited structural classes of antimicrobials [2][3][4][5]. As first demonstrated in the 1970s [6], many pantothenamides show antimicrobial activity [7][8][9][10][11][12], including antibacterial, antifungal and/or antiplasmodial

Muraymycin nucleoside-peptide antibiotics: uridine-derived natural products as lead structures for the development of novel antibacterial agents

• Daniel Wiegmann,
• Stefan Koppermann,
• Marius Wirth,
• Giuliana Niro,
• Kristin Leyerer and
• Christian Ducho

Beilstein J. Org. Chem. 2016, 12, 769–795, doi:10.3762/bjoc.12.77

• Daniel Wiegmann Stefan Koppermann Marius Wirth Giuliana Niro Kristin Leyerer Christian Ducho Department of Pharmacy, Pharmaceutical and Medicinal Chemistry, Saarland University, Campus C2 3, 66123 Saarbruecken, Germany 10.3762/bjoc.12.77 Abstract Muraymycins are a promising class of antimicrobial

• ; natural products; nucleosides; peptides; structure–activity relationship; Introduction The treatment of infectious diseases caused by bacteria is a severe issue. With multiresistant bacterial strains rendering well-established therapeutic procedures ineffective, the exploration of novel antimicrobial

• nucleoside antibiotics which address the same biological target, thereby inhibiting peptidoglycan biosynthesis. Figure 2 shows the structures of selected other classes of nucleoside antibiotics, with structural similarities being highlighted. A broad overview of antimicrobial nucleoside antibiotics blocking

Unconventional application of the Mitsunobu reaction: Selective flavonolignan dehydration yielding hydnocarpins

• Guozheng Huang,
• Simon Schramm,
• Jörg Heilmann,
• David Biedermann,
• Vladimír Křen and
• Michael Decker

Beilstein J. Org. Chem. 2016, 12, 662–669, doi:10.3762/bjoc.12.66

• -methoxyhydnocarpin has been described to enhance the antimicrobial activity of berberine [19]. In the light of steadily growing antibiotic resistance any potent and nontoxic MDR inhibitor is of utmost importance. Hydnocarpin has also antineoplastic activity due to sensitizing multidrug-resistant cancer cell lines

Antibiotics from predatory bacteria

• Juliane Korp,
• María S. Vela Gurovic and
• Markus Nett

Beilstein J. Org. Chem. 2016, 12, 594–607, doi:10.3762/bjoc.12.58

• further characterized by their large genome sizes and their striking potential for the production of structurally diverse natural products with antimicrobial activities [12][30][31][32][33][34][35]. For many years, it has been speculated whether antibiotic biosynthesis is functionally linked to the

• specific enzymatic targets for these natural products [60][68], which are not due to their iron affinity [69]. Myxalamids [70][71][72][73] and myxovirescins [74][75][76][77][78][79] are distinguished by their potent antimicrobial activities. The former are inhibitors of electron transport in the

• consumed the prey bacterium Bacillus subtilis, but not Escherichia coli. Further tests revealed that P. fallax HKI 727 exhibits a prey range that is restricted to Gram-positive bacteria. Culture extracts of strain HKI 727 showed a consistent antimicrobial profile, i.e., they were highly active against Gram

Biosynthesis of α-pyrones

• Till F. Schäberle

Beilstein J. Org. Chem. 2016, 12, 571–588, doi:10.3762/bjoc.12.56

• are applied for defense against competitors and predators. The biological activities these compounds exhibit is immense, including antimicrobial [2], antitumor [3][4], and cytotoxic activities [5]. Aflatoxins, produced by several Aspergillus species, are known to cause food poisoning due to their

• (29) showed antifungal activity against Rhizoctonia cerealis, Gaeumannomyces graminis and Botrytis cinerea (Figure 6) [34]. The structural related trichopyrone (30) instead showed no antimicrobial activity [35]. For compound 29 it was further revealed that it represents the prominent headspace

• -pyrone derivatives for their antimicrobial and cytotoxic properties [2]. The volatile α-pyrone 5-(2,4-dimethylheptyl)-3-methyl-2H-pyran-2-one (7, Figure 1), also named supellapyrone) is used by female brownbanded cockroaches to attract males [13]. It is known that cockroaches use pheromones in many

Natural products from microbes associated with insects

• Christine Beemelmanns,
• Huijuan Guo,
• Maja Rischer and
• Michael Poulsen

Beilstein J. Org. Chem. 2016, 12, 314–327, doi:10.3762/bjoc.12.34

• challenged by invading fungal species such as Escovopsis, Fusarium, and Trichoderma (Ascomycota). To clean the garden, ants apply mechanical grooming [71] and secrete antimicrobial compounds, such as 3-hydroxydecanoic acid, from their metapleural glands [72]. As a second line of defense, the ants are

• associated with protective Actinobacteria belonging in most attine ant genera to the genus Pseudonocardia, which grow on species-specific areas of the cuticle [73][74][75][76]. In vitro bioassay-guided screening of one of the Pseudonocardia symbionts afforded the antimicrobial cyclic depsipeptide

• isolation and identification of many, including known, antimicrobial compounds. Among the reported structures are candicidin derivatives (e.g., candicidin D (8)) [79][80][81], actinomycin derivatives (e.g., actinomycin D (9)) [82], antimycin derivatives (e.g., antimycin A1 (10)), and novel quinones (e.g

Enabling technologies and green processes in cyclodextrin chemistry

• Giancarlo Cravotto,
• Marina Caporaso,
• Laszlo Jicsinszky and
• Katia Martina

Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30

• -assisted click cluster synthesis. An example of the MW-promoted ‘cooperative’ click reaction of azido-CDs has recently been reported and offers useful synthetic insights into a specific labelling strategy [54]. The aforementioned reaction afforded a new series of antimicrobial γ-CD derivatives that

Determination of formation constants and structural characterization of cyclodextrin inclusion complexes with two phenolic isomers: carvacrol and thymol

• Miriana Kfoury,
• David Landy,
• Steven Ruellan,
• Lizette Auezova,
• Hélène Greige-Gerges and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2016, 12, 29–42, doi:10.3762/bjoc.12.5

• Environnementale et Interactions sur le Vivant (UCEIV, EA 4492), ULCO, F-59140 Dunkerque, France 10.3762/bjoc.12.5 Abstract Carvacrol and thymol have been widely studied for their ability to control food spoilage and to extend shelf-life of food products due to their antimicrobial and antioxidant activities