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

• -phase HPLC [70:30 H2O (0.1% TFA)/MeCN (0.1% TFA), v/v] to get a mixture of 3 and 15 (3.5 mg) as well as 4 (3.0 mg). Biological activity test The antimicrobial activities of isolated compounds were evaluated against five microorganisms [Gram-positive: Straptococcus aureus (MRSA and MSSA) and Micrococcus

The marine sponge Agelas citrina as a source of the new pyrrole–imidazole alkaloids citrinamines A–D and N-methylagelongine

• Christine Cychon,
• Ellen Lichte and
• Matthias Köck

Beilstein J. Org. Chem. 2015, 11, 2029–2037, doi:10.3762/bjoc.11.220

• mice fibroblasts. Only minor antimicrobial activities were obtained for citrinamines B–D (2–4) whereas no activities were found in the cytotoxicity assay for citrinamines A–D (1–4). Experimental General experimental procedures 1H, 13C, and 15N NMR spectra were conducted on Bruker Avance I 400 MHz

• . Antimicrobial assay As already described in [18] the antimicrobial activities were determined by agar diffusion tests using paper disks of 6 mm diameter soaked with 20 µL of the test compound in MeOH (1 mg/mL). The microorganisms were obtained from the HZI collection, grown on standard media, and cultured in

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

• . Keywords: antimicrobial activities; D-glucosamine; diosgenin glycosylation; N-alkylation; Introduction Saponins are a group of steroid or triterpenoid glycosides, widely distributed in the plant kingdom [1]. Saponins are characteristic by their foaming properties in aqueous solution, causing them to be

Aspergiloid I, an unprecedented spirolactone norditerpenoid from the plant-derived endophytic fungus Aspergillus sp. YXf3

• Zhi Kai Guo,
• Rong Wang,
• Wei Huang,
• Xiao Nian Li,
• Rong Jiang,
• Ren Xiang Tan and
• Hui Ming Ge

Beilstein J. Org. Chem. 2014, 10, 2677–2682, doi:10.3762/bjoc.10.282

• anti-oxidant, and acetylcholinesterase (AChE), α-glucosidase, and topoisomerase IIα inhibitory activities at a concentration of 50 μg/mL. Antimicrobial activities against a variety of plant pathogenic bacteria (Xanthomonas oryzae pv. oryzae Swings, Xanthomonas oryzae pv. oryzicola Swings, Acidovorax

• colorectal cancer, were evaluated with the MTT assay [16][17]. Antimicrobial activities against a variety of plant pathogenic bacteria (Xanthomonas oryzae pv. oryzae Swings, Xanthomonas oryzae pv. oryzicola Swings, Acidovorax avenae subsp. Citrulli, Erwinia amylovora, Pseudomonas syringae pv. Lachrymans

Cuevaenes C–E: Three new triene carboxylic derivatives from Streptomyces sp. LZ35ΔgdmAI

• Jing-Jing Deng,
• Chun-Hua Lu,
• Yao-Yao Li,
• Shan-Ren Li and
• Yue-Mao Shen

Beilstein J. Org. Chem. 2014, 10, 858–862, doi:10.3762/bjoc.10.82

• A and B (1 and 2) from the metabolites of the strain LZ35ΔgdmAI (Figure 1). The antimicrobial activities of cuevaenes A–E (1–5) were evaluated. Results and Discussion The strain Streptomyces sp. LZ35ΔgdmAI was cultured on oatmeal medium for 11 days at 28 °C and extracted with EtOAc/MeOH/AcOH (80:15

• compounds 4 and 5 due to the rotation around the C-5/C-6 single bond (Figure 2). The antimicrobial activities of cuevaenes A–E (1–5) were investigated by paper disc diffusion assay. Cuevaenes A–C (1–3) displayed moderate activity against Gram-positive bacteria such as Bacillus subtilis strain ATCC 11060

New sesquiterpene hydroquinones from the Caribbean sponge Aka coralliphagum

• Qun Göthel and
• Matthias Köck

Beilstein J. Org. Chem. 2014, 10, 613–621, doi:10.3762/bjoc.10.52

• :17, 60 min 80:20). The fraction C was also further purified by HPLC using the same RP-18 column yielding 3 (2.5 mg, HPLC gradient flow: H2O (5 mM NH4OAc)/MeCN: 0 min 76:24, 40 min 74:26, 45 min 70:30) Antimicrobial assay Determination of antimicrobial activities was carried out by the Helmholtz

Tanzawaic acids I–L: Four new polyketides from Penicillium sp. IBWF104-06

• Louis P. Sandjo,
• Eckhard Thines,
• Till Opatz and
• Anja Schüffler

Beilstein J. Org. Chem. 2014, 10, 251–258, doi:10.3762/bjoc.10.20

• preparative HPLC (Waters SunFire, Prep C18 OBD, 5 µm, 19 × 250 mm, 16 mL/min, isocratic conditions, 2:3 acetonitrile/0.1% formic acid) to yield tanzawaic acid I (1, 7.7 mg, tR 9 min) and tanzawaic acid J (2, 12.6 mg, tR 10.5 min). Bioactivity assays. Antimicrobial activities against bacteria and fungi were

Multivalent display of the antimicrobial peptides BP100 and BP143

• Imma Güell,
• Rafael Ferre,
• Kasper K. Sørensen,
• Esther Badosa,
• Iteng Ng-Choi,
• Emilio Montesinos,
• Eduard Bardají,
• Lidia Feliu,
• Knud J. Jensen and
• Marta Planas

Beilstein J. Org. Chem. 2012, 8, 2106–2117, doi:10.3762/bjoc.8.237

• potential alternative to traditional antibiotics. To date, a very large number of antimicrobial peptides have been produced based on naturally occurring products or by de novo design, and most of them display a broad spectrum of antimicrobial activities [3][4]. Despite their remarkable structural diversity

Partial thioamide scan on the lipopeptaibiotic trichogin GA IV. Effects on folding and bioactivity

• Marta De Zotti,
• Barbara Biondi,
• Cristina Peggion,
• Matteo De Poli,
• Haleh Fathi,
• Simona Oancea,
• Claudio Toniolo and
• Fernando Formaggio

Beilstein J. Org. Chem. 2012, 8, 1161–1171, doi:10.3762/bjoc.8.129

• -dioleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (DOPG) model membrane was exploited. The extent of permeation induced by the three analogues is similar, although 30–40% lower than that of the parent peptaibiotic. The antimicrobial activities were assessed on a large set of Gram-positive and Gram-negative

Synthesis and characterization of new diiodocoumarin derivatives with promising antimicrobial activities

• Hany M. Mohamed,
• Ashraf H. F. Abd EL-Wahab,
• Ahmed M. EL-Agrody,
• Ahmed H. Bedair,
• Fathy A. Eid,
• Mostafa M. Khafagy and
• Kamal A. Abd-EL-Rehem

Beilstein J. Org. Chem. 2011, 7, 1688–1696, doi:10.3762/bjoc.7.199

• Hz, 2H, CH2(d)), 7.66 (d, 1H, Ar-H-9), 7.95 (d, J = 1.8 Hz, 1H, Ar-H-7); MS m/z (% relative intensity): 541 (M+, 3.4), 196 (59.2), 150 (27.6), 56 (100). Antimicrobial assays The newly synthesized compounds were screened for their antimicrobial activities in vitro against two species of Gram-positive

Natural product biosyntheses in cyanobacteria: A treasure trove of unique enzymes

• Jan-Christoph Kehr,
• Douglas Gatte Picchi and
• Elke Dittmann

Beilstein J. Org. Chem. 2011, 7, 1622–1635, doi:10.3762/bjoc.7.191

• antimicrobial activities (lantibiotics) [68]. Cyanobacteria were shown to frequently encode LanM type enzymes, i.e., bifunctional enzymes catalyzing both dehydration and cyclization reactions [68]. An interesting phenomenon was observed for the strain Prochlorococcus MIT9313, which is a single-celled planktonic

Advances in synthetic approach to and antifungal activity of triazoles

• Kumari Shalini,
• Nitin Kumar,
• Sushma Drabu and
• Pramod Kumar Sharma

Beilstein J. Org. Chem. 2011, 7, 668–677, doi:10.3762/bjoc.7.79

• scaffolds possessing potent activities or enhancing biological activities [24]. Additionally, many investigations have shown that the addition of alkyl chains and/or various aromatic substituents, especially containing halogen atoms, has an important effect on the antimicrobial activities. The antifungal

An asymmetric synthesis of all stereoisomers of piclavines A1-4 using an iterative asymmetric dihydroxylation

• Yukako Saito,
• Naoki Okamoto and
• Hiroki Takahata

Beilstein J. Org. Chem. 2007, 3, No. 37, doi:10.1186/1860-5397-3-37

• marine biosphere, exhibit interesting antimicrobial activities. [2] However, very little effort has been made to synthesize the piclavines. So far, among the four isomers shown in Figure 1, the synthesis of piclavine A4 [3] and a mixture of piclavines A1 and A2 [4] has been reported, but the synthesis of