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

• display antibacterial, antiviral, antifungal, anti-inflammatory and anticancer properties [4][5][6][7][8][9][10]. Their polyphenolic structure also gives them excellent anti-oxidant and cardioprotective properties [11][12]. Our research group has recently reported the antibacterial properties of a new

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

• strain Na a174, is supposed to be a result of degradation processes due to long-time cultivation. Additionally, the known compound 1,6-dihydroxyphenazin (19) and its arabinofuranoside 20 were obtained. To date, 14 has shown marginal antifungal activity towards Mucor hiemalis (DSM 2656, MIC: 33.3 μg/mL

• flava (DSM 14601) as their closest relative (16S rDNA sequence identity lower than 95%). The GC content of H. ochraceum and H. tepidum is 67 and 69 mol %, respectively. H. ochraceum was found by Fudou et al. [51] to be a producer of secondary metabolites with antibacterial and antifungal activities

• niger (AJ117374, MIC: 12.5 μg mL−1) and Fusarium sp. (AJ177167, MIC: 6.3 μg mL−1). These MIC values were in a similar range as those of known antifungal compounds such as amphotericin B or nystatin against the same fungi (MIC: 3.1 μg mL−1 for both compounds). Recently, the 9.4 Mb genome of H. ochraceum

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

• ]. 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

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

• , respectively. In contrast, the tripeptidic cystobactamid 507 seems to be either a biosynthetic byproduct or a degradation fragment of its larger congeners. All cystobactamids lack antifungal and cytotoxic properties, but they exhibit significant antibacterial activities. Especially derivative 919-2 (19

Biosynthesis of α-pyrones

• Till F. Schäberle

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

• (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

• kill their prey [45][46]. Fusapyrone (32) and the derivative deoxyfusapyrone (33) had been isolated from Fusarium semitectum [39]. These compounds show considerable antifungal activity, e.g., a minimum inhibitory concentration against Botrytis cinerea, Aspergillus parasiticus, and Penicillium brevi

• been used against skin diseases due to its mutagenic effect [71]. Bacterial monobenzo-α-pyrones were isolated from the myxobacterium Stigmatella aurantiaca MYX-030. Myxocoumarins A (65) and B (66) were identified, and 65 was tested for antifungal activity [72]. It showed a promising activity against

Regiodefined synthesis of brominated hydroxyanthraquinones related to proisocrinins

• Joyeeta Roy,
• Tanushree Mal,
• Supriti Jana and
• Dipakranjan Mal

Beilstein J. Org. Chem. 2016, 12, 531–536, doi:10.3762/bjoc.12.52

• condensation; Hauser annulation; proisocrinins; Introduction Anthraquinones constitute the largest group of naturally occurring quinones [1][2][3][4][5]. Isolated mainly from fungal sources, they display a wide range of biological activities which include anti-inflammatory, antifungal, antiparasidal, and

Copper-mediated arylation with arylboronic acids: Facile and modular synthesis of triarylmethanes

• H. Surya Prakash Rao and
• A. Veera Bhadra Rao

Beilstein J. Org. Chem. 2016, 12, 496–504, doi:10.3762/bjoc.12.49

• binding affinity [21], inhibition of hepatic cholesterol [22], inhibition of aldose reductase [23], antiproliferative [24], antiviral, cytotoxic [25], antifungal [26], anti-HIV [27][28][29] and antibacterial activity [30]. Although rare, there are a few natural products, for example, melanervin (5), a

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

• derivatives have been shown to possess a variety of biological activities, such as antibiotic, antifungal and antiproliferative activity [47]. The combination of the antibiotic properties of piericidins and streptochlorin is most likely the reason for the effective inhibition of various entomopathogenic

• an additional chlorine and/or hydroxy substituent. In contrast to dentigerumycin, gerumycins do not exhibit significant antifungal activity in vitro against dentigerumycin-sensitive Escovopsis strains. A detailed biosynthetic analysis of gerumycins revealed that the biosynthetic gene clusters are

• microtermolides A (16) and B (17) (Figure 6), products by an unusual hybrid non-ribosomal–polyketide pathway [95]. In a follow-up study, a Streptomyces isolate with exceptional high antifungal activity was investigated, and an unusual geldanamycin-derived natalamycin A (18), 19-S-methylgeldanamycin (19), and a

Synthesis of cyclic N¹-pentylinosine phosphate, a new structurally reduced cADPR analogue with calcium-mobilizing activity on PC12 cells

• Ahmed Mahal,
• Stefano D’Errico,
• Nicola Borbone,
• Brunella Pinto,
• Agnese Secondo,
• Valeria Costantino,
• Valentina Tedeschi,
• Giorgia Oliviero,
• Vincenzo Piccialli and
• Gennaro Piccialli

Beilstein J. Org. Chem. 2015, 11, 2689–2695, doi:10.3762/bjoc.11.289

• synthetic building blocks towards the synthesis of biologically relevant compounds such as antiviral and antineoplastic drugs [3][4][5][6][7][8], antibiotics and antifungal agents [9][10][11]. Furthermore, several NNs act as potent second messengers involved in the regulation of key metabolic pathways [12

Versatile synthesis and biological evaluation of novel 3’-fluorinated purine nucleosides

• Hang Ren,
• Haoyun An,
• Paul J. Hatala,
• William C. Stevens Jr,
• Jingchao Tao and
• Baicheng He

Beilstein J. Org. Chem. 2015, 11, 2509–2520, doi:10.3762/bjoc.11.272

• -D-riboside (6-β-D-MPR) is an isolated antibiotic agent that possesses potent antifungal, antiviral, and antitumor activities [44]. In order to explore the effect of fluorine on the biological activity of this pharmacophore, we synthesized 6-methylpurine-3’-deoxy-3’-fluoro-β-D-riboside (4) (Scheme 2

Recent highlights in biosynthesis research using stable isotopes

• Jan Rinkel and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2015, 11, 2493–2508, doi:10.3762/bjoc.11.271

• reductase [16], aflatoxin B1 (2) [17] and the potent antifungal agent amphotericin B (3) [18], which affects membrane integrity. The products of polyketide synthases (PKS) belong to the first secondary metabolites that were investigated using isotopically labeled compounds [19]. Feeding experiments using

Diversity-oriented synthesis of analogues of the novel macrocyclic peptide FR-225497 through late stage functionalization

• Jyotiprasad Mukherjee,
• Suman Sil and
• Shital Kumar Chattopadhyay

Beilstein J. Org. Chem. 2015, 11, 2487–2492, doi:10.3762/bjoc.11.270

• peptides of the general structure 1 (Figure 1) displays important histone deacetylase inhibition property relevant to drug design against a number of diseases ranging from antifungal, antimicrobial to arrest of proliferation of several cell types of epithelial and hematological origin [13]. The compounds

Bromotyrosine-derived alkaloids from the Caribbean sponge Aplysina lacunosa

• Qun Göthel,
• Thanchanok Sirirak and
• Matthias Köck

Beilstein J. Org. Chem. 2015, 11, 2334–2342, doi:10.3762/bjoc.11.254

• activities, including antiviral [2], antibiotic [3][4][5], Na+/K+ ATPase inhibition [6][7][8], anti-HIV [9][10], antifungal [11], histidine-H3 antagonist [12], cytotoxic [13][14], and antimalarial activities [15][16][17]. During our investigation of the chemical constituents of Aplysina lacunosa (Aplysinidae

• luteus; Gram-negative: Peumonia aruginosa and Klebsiella pneumonia] and antifungal Candida albicans using microdilution technique. The MIC was defined as lowest concentration that shows 50% growth inhibition after 24 hour incubation. Cytotoxicity assay The cytotoxicity was determined using WST-1 cell

Syntheses of 2-substituted 1-amino-4-bromoanthraquinones (bromaminic acid analogues) – precursors for dyes and drugs

• Enas M. Malik,
• Younis Baqi and
• Christa E. Müller

Beilstein J. Org. Chem. 2015, 11, 2326–2333, doi:10.3762/bjoc.11.253

• ][18][19]. AQ derivatives can also exert a variety of pharmacological activities including laxative, anti-inflammatory [20][21], antitumor [22][23], antifungal [24], antiviral [25], and blood platelet inhibitory effects [26][27][28]. Reactive Blue 2 (RB-2), a chlorotriazinyl-containing AQ dye, defined

Synthesis of D-fructose-derived spirocyclic 2-substituted-2-oxazoline ribosides

• Madhuri Vangala and
• Ganesh P. Shinde

Beilstein J. Org. Chem. 2015, 11, 2289–2296, doi:10.3762/bjoc.11.249

• compounds with a wide range of applications spanning different chemistry disciplines. 2-Oxazoline derivatives are extensively studied due to their presence in numerous bioactive natural products [1][2][3] and synthetic drugs with anticancer, antibiotic, antidiabetic, and antifungal properties (Figure 1, 1–4

2-Hetaryl-1,3-tropolones based on five-membered nitrogen heterocycles: synthesis, structure and properties

• Yury A. Sayapin,
• Inna O. Tupaeva,
• Alexandra A. Kolodina,
• Eugeny A. Gusakov,
• Vitaly N. Komissarov,
• Igor V. Dorogan,
• Nadezhda I. Makarova,
• Anatoly V. Metelitsa,
• Valery V. Tkachev,
• Sergey M. Aldoshin and
• Vladimir I. Minkin

Beilstein J. Org. Chem. 2015, 11, 2179–2188, doi:10.3762/bjoc.11.236

• -1,2-tropolone) isolated from Chamacyparis taiwanensis possesses antimicrobial and antifungal activity [4][5][6], pronounced insecticidal properties [7][8], and the capability of inhibiting the growth of plants [9]. It also exerts a cytotoxic effect on tumor cells [10] and serves as a potent inhibitor

Synthesis, antimicrobial and cytotoxicity evaluation of new cholesterol congeners

• Mohamed Ramadan El Sayed Aly,
• Hosam Ali Saad and
• Shams Hashim Abdel-Hafez

Beilstein J. Org. Chem. 2015, 11, 1922–1932, doi:10.3762/bjoc.11.208

• antifungal activities against the filamentous fungal strain Aspergillus flavus (Link) and the yeast forming fungal strain Candida albicans (ATCC 7102) were moderate compared with amphotericin B in vitro. In the cytotoxicity study, this derivative was the most cytotoxic one against the prostate cancer PC3

• that were as active as ampicillin. However, conjugate VI from the previous investigation was still more active than these conjugates [24]. The antifungal activity of selected newly synthesized chalcone conjugates was evaluated in vitro against A. flavus (Link) and Candida albicans (ATCC 7102) similarly

• according to the Kirby–Bauer disc diffusion method (Figure 2). Although, the series was inactive against A. flavus, they showed some promising antifungal results against C. albicans. As shown in Figure 2, only chalcone 6c was as active as the control (amphotericin B). Cholesterols 6a,b, 7a,b, 11b, 13 and 20

Pyridinoacridine alkaloids of marine origin: NMR and MS spectral data, synthesis, biosynthesis and biological activity

• Louis P. Sandjo,
• Victor Kuete and
• Maique W. Biavatti

Beilstein J. Org. Chem. 2015, 11, 1667–1699, doi:10.3762/bjoc.11.183

• synthetic compounds, has been widely investigated. Many of them displayed cytotoxic activity in addition to other bioactivities such as antiviral, antifungal, antibacterial, antitumor and antiparasitic potential [41]. Several reviews on pyridoacridine alkaloids have been published between 1983–2015 [35][43

• alkaloids such as meridine (56) that are found to exert its antifungal activity via the inhibition of nucleic acid biosynthesis [87]. Petrosamine B (99), isolated from the sponge Oceanapia sp., inhibited the Helicobacter pylori enzyme aspartyl semialdehyde dehydrogenase explaining it as an antibacterial

Structure and conformational analysis of spiroketals from 6-O-methyl-9(E)-hydroxyiminoerythronolide A

• Ana Čikoš,
• Irena Ćaleta,
• Dinko Žiher,
• Mark B. Vine,
• Ivaylo J. Elenkov,
• Marko Dukši,
• Dubravka Gembarovski,
• Marina Ilijaš,
• Snježana Dragojević,
• Ivica Malnar and
• Sulejman Alihodžić

Beilstein J. Org. Chem. 2015, 11, 1447–1457, doi:10.3762/bjoc.11.157

• example, in cases of calyculin and okadaic acid it has been proposed [18][19] that the spiroketal unit acts as a β-turn mimic. Naturally occurring spiroketals exhibit a wide spectrum of biological activity: anticancer [20][21][22], antibiotic [23][24], antifungal [25], anthelmintic [26] and anti-HIV [27

New depsidones and isoindolinones from the mangrove endophytic fungus Meyerozyma guilliermondii (HZ-Y₂) isolated from the South China Sea

• Senhua Chen,
• Zhaoming Liu,
• Yayue Liu,
• Yongjun Lu,
• Lei He and
• Zhigang She

Beilstein J. Org. Chem. 2015, 11, 1187–1193, doi:10.3762/bjoc.11.133

• of bioactivities including antibacterial [10], antifungal [6], antiviral [12], antioxidant [5], and cytotoxic [9]. In the last decade, our research group has been focused on isolating novel compounds from endophytic fungi growing on mangroves in the South China Sea and investigating their bioactivity

Thiazole formation through a modified Gewald reaction

• Carl J. Mallia,
• Lukas Englert,
• Gary C. Walter and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2015, 11, 875–883, doi:10.3762/bjoc.11.98

• number of therapeutic areas including anticancer, antifungal, antibacterial, anti-inflammatory and as antidepressants (Figure 1) [1]. Several protocols have already been described for the synthesis of substituted thiazoles and benzothiazoles [2][3][4][5][6][7][8][9][10][11]. The current first choice

N-Alkyl derivatives of diosgenyl 2-amino-2-deoxy-β-D-glucopyranoside; synthesis and antimicrobial activity

• Agata Walczewska,
• Daria Grzywacz,
• Dorota Bednarczyk,
• Małgorzata Dawgul,
• Andrzej Nowacki,
• Wojciech Kamysz,
• Beata Liberek and
• Henryk Myszka

Beilstein J. Org. Chem. 2015, 11, 869–874, doi:10.3762/bjoc.11.97

• glucopyranoside is presented. Evaluation of antibacterial and antifungal activities of these derivatives indicates that they have no inhibitory activity against Gram-negative bacteria, whereas many of the tested N-alkyl saponins were found to inhibit the growth of Gram-positive bacteria and human pathogenic fungi

• used as detergents, surfactants and emulsifiers. Moreover, they display a wide range of pharmacological activities, including antifungal, antiparasitic, antiinflammatory, antibacterial, and antitumor activities [2][3][4][5]. No wonder, saponins have been evaluated as vaccine adjuvants [6]. Despite the

• their cardiovascular, antifungal, anticancer [33][34][35][36] and antithrombotic activities [37] have been investigated. Gelation ability of the pentose derivatized diosgenyl saponins have also been reported [38]. In the family of diosgenyl β-glycosides D-glucopyranose is the first sugar attached to the

Novel biphenyl-substituted 1,2,4-oxadiazole ferroelectric liquid crystals: synthesis and characterization

• Mahabaleshwara Subrao,
• Dakshina Murthy Potukuchi,
• Girish Sharada Ramachandra,
• Poornima Bhagavath,
• Sangeetha G. Bhat and
• Srinivasulu Maddasani

Beilstein J. Org. Chem. 2015, 11, 233–241, doi:10.3762/bjoc.11.26

• ; SmC* phase; spontaneous polarization; Suzuki coupling; Introduction The 1,2,4-oxadiazole derivatives are prevalently reported compounds with promising biological [1][2][3][4][5] and physiological [6][7][8] activity such as antiinflammatory, antibacterial, antimicrobial, antifungal, anticancer

Electrochemical selenium- and iodonium-initiated cyclisation of hydroxy-functionalised 1,4-dienes

• Philipp Röse,
• Steffen Emge,
• Jun-ichi Yoshida and
• Gerhard Hilt

Beilstein J. Org. Chem. 2015, 11, 174–183, doi:10.3762/bjoc.11.18

• are in turn potential substrates for the synthesis of functionalised heterocycles. Particularly, we were interested in the synthesis of tetrahydrofuran and pyran derivatives. Those heterocycles are prevalent substructures in many natural compounds, pesticides and drugs with antifungal and

Come-back of phenanthridine and phenanthridinium derivatives in the 21st century

• Lidija-Marija Tumir,
• Marijana Radić Stojković and
• Ivo Piantanida

Beilstein J. Org. Chem. 2014, 10, 2930–2954, doi:10.3762/bjoc.10.312

• bioactivity-guided fractionation, the bioactive compound chelerythrine (21, a quaternary benzo[c]phenanthridine alkaloid) was isolated from Chelidonium majus L. [103]. In addition to strong antihelmintic activity (against D. intermedius), chelerythrine also showed antimicrobial, antifungal and anti