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

• elimination step. Macrolactam and macrolactone formation A diverse array of macrolactams are found in RiPPs from bacteria [31], plants [83] and mammals [84]. These can arise from a variety of routes: (i) head-to-tail cyclisation by attack of the N-terminal amine of the core peptide onto the C-terminus [85

• concept and early studies showed that peptide bond formation could be achieved by modulating protease reaction conditions accordingly [106]. This has since been found to happen in the biosynthesis of cyclic RiPPs from a wide range of hosts, including cyclic peptides from both plants [105] and bacteria

Efficient syntheses of climate relevant isoprene nitrates and (1R,5S)-(−)-myrtenol nitrate

• Sean P. Bew,
• Glyn D. Hiatt-Gipson,
• Graham P. Mills and
• Claire E. Reeves

Beilstein J. Org. Chem. 2016, 12, 1081–1095, doi:10.3762/bjoc.12.103

• this topic a whole issue of Chemical Reviews was dedicated to the ‘Role of Chemistry in the Earth’s Climate’ [1]. Plants emit into the biosphere a substantial amount (0.5–2%) of their assimilated carbon as small organic molecules. In this context isoprene is one of the most important compounds emitted

• its derivatives is largely based on chemical theory and modeling with very little verified measurements. Therefore, the impact of isoprene on air quality and climate change remains highly uncertain. Isoprene or 2-methylbuta-1,3-diene is a volatile C5-organic compound generated by plants to help

Three new trixane glycosides obtained from the leaves of Jungia sellowii Less. using centrifugal partition chromatography

• Luíse Azevedo,
• Larissa Faqueti,
• Marina Kritsanida,
• Antonia Efstathiou,
• Despina Smirlis,
• Gilberto C. Franchi Jr,
• Grégory Genta-Jouve,
• Sylvie Michel,
• Louis P. Sandjo,
• Raphaël Grougnet and
• Maique W. Biavatti

Beilstein J. Org. Chem. 2016, 12, 674–683, doi:10.3762/bjoc.12.68

• for the prevention of Leishmania diseases exist, whereas current chemotherapy is ineffective due to the high toxicity, the emergence of drug resistance, and the high cost of treatment, among others [15][16][17]. Consequently, infected people betake of medicinal plants as an alternative to provide

• treatment. Plants also have an important role as a source of antitumoral agents, and several anticancer drugs currently in use are derived from natural sources. Natural products often have selective biological actions due to binding affinities for specific proteins, and have superior chemical diversity and

Elucidation of a masked repeating structure of the O-specific polysaccharide of the halotolerant soil bacteria Azospirillum halopraeferens Au4

• Elena N. Sigida,
• Yuliya P. Fedonenko,
• Alexander S. Shashkov,
• Nikolay P. Arbatsky,
• Evelina L. Zdorovenko,
• Svetlana A. Konnova,
• Vladimir V. Ignatov and
• Yuriy A. Knirel

Beilstein J. Org. Chem. 2016, 12, 636–642, doi:10.3762/bjoc.12.62

• Elena N. Sigida Yuliya P. Fedonenko Alexander S. Shashkov Nikolay P. Arbatsky Evelina L. Zdorovenko Svetlana A. Konnova Vladimir V. Ignatov Yuriy A. Knirel Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Prospekt Entuziastov 13, Saratov 410049

• environments. Their ubiquitous distribution in nature is evidently due to the extraordinary plasticity of their genomes and the ability to form beneficial associations with plants owing to plant-growth promoting activities [1]. The plant–microbe symbiosis increases the tolerance of both partners to various

• stimulates the growth of halophyte forage and oilseed crops in seawater irrigated agriculture [7]. The successful use of Azospirillum inoculants requires understanding the mechanisms regulating their interactions with plants at a molecular level. A lipopolysaccharide (LPS) having an O-specific polysaccharide

Biosynthesis of α-pyrones

• Till F. Schäberle

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

• ], and graphislactone A (21) from Cephalosporium acremonium IFB-E007 (Figure 3) [19]. These compounds show toxic effects in plants and animals. In addition, Alternaria spp. have been involved in the contamination of food, even in refrigerated stocks, since the fungi is able to grow also at low

• ]. These toxic fungi-derived metabolites are often pathogenic to plants, and are therefore called phytotoxins. Phytotoxins are divided into host-specific and host non-specific toxins, whereby the here named Alternaria-derived dibenzo-α-pyrones 17, 18, and 19 represent host-specific phytotoxins [26

• , production by a fungus and modification of the metabolites by plant enzymes is also possible. Further α-pyrone plant secondary metabolites are ellagitannins and ellagic acid (22) [27] (Figure 4). These metabolites are important constituents of different foods, e.g., berries, nuts, medicinal plants and

A selective and mild glycosylation method of natural phenolic alcohols

• Mária Mastihubová and
• Monika Poláková

Beilstein J. Org. Chem. 2016, 12, 524–530, doi:10.3762/bjoc.12.51

• phenylpropenyl) glycosides having a free phenolic function at the para-position of the aglycone are substances widely occurring in plants. They exhibit numerous biological activities which are in many cases related to their structure–antioxidant activity relationship. 4-Hydroxy-3-methoxybenzyl β-D

• activities [2][3][4][5][6][7][8][9][10][11][12][13] are reported for 4-hydroxyphenethyl β-D-glucopyranoside (salidroside, 2) which is known to be the main bioactive component of plants of the genus Rhodiola. 4-Hydroxy-3-methoxycinnamyl β-D-glucopyranoside (isoconiferin or citrusin D, 3) has been shown to

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

• advance to the many researchers whose research might not be covered. Review Insects as host systems Insects, the most diverse groups of animals on Earth [12][13][14][15][16][17], originated about 480 million years ago, at about the same time period when terrestrial plants evolved [33]. Since their initial

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

• : cyclodextrins; DOSY-NMR; formation constant; molecular modeling; solubility; Introduction Carvacrol (2-methyl-5-(1-methylethyl)phenol, 1) and thymol (5-methyl-2-(1-methylethyl)phenol, 2) are monoterpenic phenol isomers (Figure 1) produced by several aromatic plants (oregano, thyme, savory, marjoram, etc.) [1

Genicunolide A, B and C: three new triterpenoids from Euphorbia geniculata

• Alia Farozi,
• Javid A. Banday and
• Shakeel A. Shah

Beilstein J. Org. Chem. 2015, 11, 2707–2712, doi:10.3762/bjoc.11.291

• . Keywords: Euphorbiaceae; Euphorbia geniculata; friedelin; friedelinol; genicunolide A; B; C; pentacyclic triterpenoids; Introduction Euphorbia (Euphorbiaceae) is a very large and diverse genus of flowering plants comprising of about 2,000 members and is found all over the world, ranging from short annual

• plants to well developed tall trees [1]. The plants of the family Euphorbiaceae contain well-known skin irritating and tumor-promoting diterpenoids with tigliane, ingenane and daphnane skeletons [2]. Some of the species are used in folk medicine to cure skin diseases, gonorrhea, migraines, intestinal

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

• ]. Among these NNs there is the cyclic ADP-ribose (cADPR 1, Figure 1), a metabolite strictly involved in the homeostasis of cellular calcium ions. cADPR is a second messenger that activates the ryanodine receptors of the sarcoplasmic reticulum and mobilizes Ca2+ ions in many cell types of protozoa, plants

Biocatalysis for the application of CO₂ as a chemical feedstock

• Apostolos Alissandratos and
• Christopher J. Easton

Beilstein J. Org. Chem. 2015, 11, 2370–2387, doi:10.3762/bjoc.11.259

• generation biofuel production processes. In this way, the carbon fixed by plants (biomass) is further transformed into a wide array of products through microbial processing [16]. Genetically engineered plants and algae have been employed to divert carbon flux in planta towards other metabolic products of

• , ranging from the use of carboxylated cofactors [28][32] to complex extended metabolic pathways in C4 and CAM plants [17][33][34] and substrate channelling. In addition, a number of enzymes accept HCO3− as a substrate, which is converted to CO2 close to the active site before the reductive step [26][28

• ]. Carboxysomes have been the subject of studies on increasing the efficiency of C3 carbon fixation in plants [38][39][40]. The recent production of a transgenic tobacco plant, expressing bacterial carboxysome proteins and able to photosynthesise at an increased rate, was a significant breakthrough in this field

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

• ; Introduction Anthraquinones (AQs, anthracene-9,10-diones) represent an important class of organic compounds. They may be produced synthetically, but many derivatives can also be found in nature, e.g., in medicinal plants, as well as in bacteria, fungi and some insects [1][2][3][4][5][6]. Both, natural and

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

SmI₂-mediated dimerization of indolylbutenones and synthesis of the myxobacterial natural product indiacen B

• Nils Marsch,
• Peter G. Jones and
• Thomas Lindel

Beilstein J. Org. Chem. 2015, 11, 1700–1706, doi:10.3762/bjoc.11.184

• plants [1][2][3] and also in fungi [4] and myxobacteria [5][6]. One example is raputindole A (1), isolated in 2010 from the Rutaceous tree Raputia simulans Kallunki [1], which exhibits a unique tetrahydrocyclopenta[f]indole partial structure (Figure 1) probably formed by dimerization of (E)-6-(3

• not effect any reaction, as we learned when trying to dimerize the natural product verticillatine B (20) from the Brazilian plants Borreria verticillata and Raputia simulans [2][3]. We had speculated on the participation of the benzenoid double bond in dimerization reactions which would have

Synthesis and spectroscopic properties of β-triazoloporphyrin–xanthone dyads

• Dileep Kumar Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2015, 11, 1434–1440, doi:10.3762/bjoc.11.155

• diporphyrin analogues [20][28][29][30]. Xanthene-9H-ones are an important class of oxygen-containing heterocycles and are mainly found as secondary metabolites in higher plants and microorganisms. The naturally occurring and synthetic xanthones possess diverse pharmacological activities [31][32][33][34

Antioxidant potential of curcumin-related compounds studied by chemiluminescence kinetics, chain-breaking efficiencies, scavenging activity (ORAC) and DFT calculations

• Adriana K. Slavova-Kazakova,
• Silvia E. Angelova,
• Timur L. Veprintsev,
• Petko Denev,
• Davide Fabbri,
• Maria Antonietta Dettori,
• Maria Kratchanova,
• Vladimir V. Naumov,
• Aleksei V. Trofimov,
• Rostislav F. Vasil’ev,
• Giovanna Delogu and
• Vessela D. Kancheva

Beilstein J. Org. Chem. 2015, 11, 1398–1411, doi:10.3762/bjoc.11.151

• Utilization: From Plants to Pharmacy Shelf, 3–6 November 2013, Bansko, Bulgaria, is gratefully acknowledged. The calculations were performed on the computer system installed at IOCCP–BAS with the financial support of the Bulgarian Scientific Fund under Project “MADARA” (RNF01/0110, contract no. DO02-52/2008).

Synthesis of icariin from kaempferol through regioselective methylation and para-Claisen–Cope rearrangement

• Qinggang Mei,
• Chun Wang,
• Zhigang Zhao,
• Weicheng Yuan and
• Guolin Zhang

Beilstein J. Org. Chem. 2015, 11, 1220–1225, doi:10.3762/bjoc.11.135

• ; Introduction The plants of the Genus Epimedium, also known as “Yin-Yang-Huo”, were used in traditional Chinese medicine and are believed to invigorate the kidney and enhance the “Yang”. For more than one thousand years, some plants of Epimedium have been widely used in China to treat cardiovascular diseases

• , amnesia, arthritis, asthenia, impotence, infertility, lumbago and other chronic illnesses [1][2]. Icariin (1), a 3,7-diglycosylflavone (Figure 1), is recognized as the major pharmacologically active ingredient of these plants [3][4], and has been used as the index for quality control of the herbs and

Adsorption mechanism and valency of catechol-functionalized hyperbranched polyglycerols

• Stefanie Krysiak,
• Qiang Wei,
• Klaus Rischka,
• Andreas Hartwig,
• Rainer Haag and
• Thorsten Hugel

Beilstein J. Org. Chem. 2015, 11, 828–836, doi:10.3762/bjoc.11.92

• development, mussels, barnacles and numerous other animals and plants have found a way for strong, long-term adhesion to wet surfaces [1]. Wet hydrophilic surfaces are difficult to be wetted by glues since the adhesive competes with the surface water layer [2]. Mussels can easily adhere to hydrophilic metal

Selective methylation of kaempferol via benzylation and deacetylation of kaempferol acetates

• Qinggang Mei,
• Chun Wang,
• Weicheng Yuan and
• Guolin Zhang

Beilstein J. Org. Chem. 2015, 11, 288–293, doi:10.3762/bjoc.11.33

• . Keywords: benzylation; deacetylation; kaempferol; methylation; regioselectivity; Introduction Kaempferol [2-(4-hydroxyphenyl)-3,5,7-trihydroxychromen-4-one] (Figure 1) and its derivatives are widely distributed in plants such as beans, broccoli, strawberries, teas, and propolis [1][2]. They are well known

• -methylkaempferol exhibits modest cytotoxicity [17]. These methylated derivatives of flavonols are found as natural products in relative low quantity, whereas kaempferol is relatively rich in plants. Therefore, it is quite worthwhile to develop procedures for the preparation of methylated derivatives of kaempferol

Synthesis of the furo[2,3-b]chromene ring system of hyperaspindols A and B

• Danielle L. Paterson and
• David Barker

Beilstein J. Org. Chem. 2015, 11, 265–270, doi:10.3762/bjoc.11.29

• Two novel racemic acylphoroglucinols, hyperaspidinols A (1) and B (2) (Figure 1) were recently isolated from the leaves of Hypericum chinense, a member of the St John’s Wort plants, which contains 490 flowering plants [1]. These plants have been used medicinally for treating illnesses such as

• hepatitis and depression, and as topical antimicrobials for wounds and snake bites [2][3][4][5]. There is great interest in secondary metabolites produced by plants from the Hypericum genus due to the bioactivity of many compounds that have been isolated from this source. A wide variety of compounds have

Natural phenolic metabolites with anti-angiogenic properties – a review from the chemical point of view

• Qiu Sun,
• Jörg Heilmann and
• Burkhard König

Beilstein J. Org. Chem. 2015, 11, 249–264, doi:10.3762/bjoc.11.28

• natural metabolites available from plants, phenolic compounds play a particularly important role in human health as they occur in significant amounts in many fruits, vegetables and medicinal plants. In this review natural phenolic compounds of plant origin with significant anti-angiogenic properties are

• compound found in plants and has been isolated from, for example, the flowers of carrot (Daucus carrota L., Apiaceae). In 2007, Park and co-workers [15] found no change in the vascular density in the chick chorioallantoic membrane (CAM) assay in the presence of HBA, indicating that HBA had no influence on

• . Resveratrol Resveratrol (8) is a natural polyphenol that belongs to the stilbene-type compounds and exists in a large number of plants. It has been primarily extracted from grape (Vitis vinifera L., Vitaceae) and mulberry (Morus L., Moraceae) fruits (Figure 4) [34]. It has antioxidant effects, anti-estrogenic

Cathodic reductive coupling of methyl cinnamate on boron-doped diamond electrodes and synthesis of new neolignan-type products

• Taiki Kojima,
• Rika Obata,
• Tsuyoshi Saito,
• Yasuaki Einaga and
• Shigeru Nishiyama

Beilstein J. Org. Chem. 2015, 11, 200–203, doi:10.3762/bjoc.11.21

• interesting biological activities [1]. Due to their plausible roles as defense substances of plants, lignans, neolignans, and their congeners are promising candidates for agricultural chemicals, and some of their antioxidant and/or anti-inflammatory properties may be utilized for biological research and as

Effects of RAMEA-complexed polyunsaturated fatty acids on the response of human dendritic cells to inflammatory signals

• Éva Rajnavölgyi,
• Renáta Laczik,
• Viktor Kun,
• Lajos Szente and
• Éva Fenyvesi

Beilstein J. Org. Chem. 2014, 10, 3152–3160, doi:10.3762/bjoc.10.332

• , C22:6), which can be found in plants (flaxseed, walnut) and fish oil, respectively. ALA and linoleic acid (LA, C18:3 n−6 having the first double bond at the 6th carbon atom from the chain end, therefore classified as n−6 PUFA) are essential fatty acids, because they cannot be synthesized by the human

Trogopterins A–C: Three new neolignans from feces of Trogopterus xanthipes

• Soyoon Baek,
• Xuikui Xia,
• Byung Sun Min,
• Chanil Park and
• Sang Hee Shim

Beilstein J. Org. Chem. 2014, 10, 2955–2962, doi:10.3762/bjoc.10.313

• with IC50 values of 34.77–45.68 μM. Keywords: cytotoxic activity; neolignans; Trogopterus xanthipes; Introduction Chemical studies of natural products including ones derived from plants and microorganisms have led to the isolation of numerous novel metabolites with biological activities [1][2]. As a

Thermal and oxidative stability of the Ocimum basilicum L. essential oil/β-cyclodextrin supramolecular system

• Daniel I. Hădărugă,
• Nicoleta G. Hădărugă,
• Corina I. Costescu,
• Ioan David and
• Alexandra T. Gruia

Beilstein J. Org. Chem. 2014, 10, 2809–2820, doi:10.3762/bjoc.10.298

• oxidative stability; Introduction Aromatic and pharmaceutical plants have been used in both food and medicinal fields since ancient time. These valuable plants have been used directly as raw materials (such as teas/infusions, ground spices, dressings, sauces, etc.) [1][2][3], or indirectly by isolation of

• flavonolignan silybin from Silybum marianum L. or its disuccinate derivative, with hepatoprotective properties [4][5]. Ocimum genus (Lamiaceae family) is comprised of more than fifty species of herbs and shrubs growing in tropical and warm temperate regions [6][7][8][9]. All of these plants contain various