Diels–Alder reactions of myrcene using intensified continuous-flow reactors

• Christian H. Hornung,
• Miguel Á. Álvarez-Diéguez,
• Thomas M. Kohl and
• John Tsanaktsidis

Beilstein J. Org. Chem. 2017, 13, 120–126, doi:10.3762/bjoc.13.15

• referred to in the following only as “myrcene” (1), see Scheme 1, vide infra). It can be found in significant quantities (up to 39%) in the essential oils of several plants, such as wild thyme [4], ylang-ylang [5], bay leaf [6], juniper berries [7], lemongrass [8], or parsley [9], and in smaller

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

• biological potentials. Aminophosphonates and their derivatives [22][23][24][25][26] are thus recognized as promising compounds and a new class of drugs that are widely used in a variety of commercial applications. Indeed, they are known to influence various biochemical processes in plants, modifying or

O-Alkylated heavy atom carbohydrate probes for protein X-ray crystallography: Studies towards the synthesis of methyl 2-O-methyl-L-selenofucopyranoside

• Roman Sommer,
• Dirk Hauck,
• Annabelle Varrot,
• Anne Imberty,
• Markus Künzler and
• Alexander Titz

Beilstein J. Org. Chem. 2016, 12, 2828–2833, doi:10.3762/bjoc.12.282

• -methylated carbohydrate ligands was demonstrated (e.g., 2, Figure 1). O-Methylation of carbohydrates is a rare modification, but widespread in nature as it has been observed in bacteria, protozoa, animals and plants but not in mammals [29][30]. Besides fungal and animal tectonins that recognize O-methylated

Interactions between cyclodextrins and cellular components: Towards greener medical applications?

• Loïc Leclercq

Beilstein J. Org. Chem. 2016, 12, 2644–2662, doi:10.3762/bjoc.12.261

• are, with proteins and lipids, essential constituents of living organisms because they are key biological intermediates for energy storage. In autotrophs, such as plants, sugars are converted into starch whereas for heterotrophic organisms, such as animals, they are stored as glycogen. However

• , polysaccharides serve also as structural components: cellulose for plants and chitin for arthropods. Moreover, saccharides and their derivatives play key roles in the immune system, fertilization, blood clotting, information transfer, etc. For instance, the 5-carbon monosaccharide ribose forms the backbone of the

A detailed view on 1,8-cineol biosynthesis by Streptomyces clavuligerus

• Jan Rinkel,
• Patrick Rabe,
• Laura zur Horst and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2016, 12, 2317–2324, doi:10.3762/bjoc.12.225

• complexity is reached within the largest, the terpenoids. An estimated number of 75,000 different compounds are known from all kinds of organisms including plants [1], bacteria [2][3][4][5], fungi [6] and, as recently shown, even social amoebae [7]. These molecules are all made from only a handful of linear

• conserved motifs including the aspartate-rich motif (DDXXD) and the NSE triad (ND(L,I,V)XSXXXE, modified in plants to a DTE triad: DD(L,I,V)XTXXXE) [8]. Their substrates bind with the diphosphate portion to the (Mg2+)3 cluster and via hydrogen bridges to a highly conserved arginine (diphosphate sensor) and

Robust C–C bonded porous networks with chemically designed functionalities for improved CO₂ capture from flue gas

• Damien Thirion,
• Joo S. Lee,
• Ercan Özdemir and
• Cafer T. Yavuz

Beilstein J. Org. Chem. 2016, 12, 2274–2279, doi:10.3762/bjoc.12.220

• high regeneration energy and raises the overall cost of the carbon capture operations [12][25]. Dry CO2 uptake is not always meaningful, especially with amine functionalities, as flue gas from power plants contains moisture [26]. When binding to CO2, amines go through either carbamate or carbamic acid

New furoisocoumarins and isocoumarins from the mangrove endophytic fungus Aspergillus sp. 085242

• Ze’en Xiao,
• Senhua Chen,
• Runlin Cai,
• Shao’e Lin,
• Kui Hong and
• Zhigang She

Beilstein J. Org. Chem. 2016, 12, 2077–2085, doi:10.3762/bjoc.12.196

• features and interesting biological activities. They have been widely isolated from fungi, lichens, bacteria, plants, and insects [1][2]. Furoisocoumarins combining a furan ring and an isocoumarin moiety are divided into two subclasses depending on their fusion type: linear furo[2,3-g]isocoumarins and

Mechanistic investigations on six bacterial terpene cyclases

• Patrick Rabe,
• Thomas Schmitz and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2016, 12, 1839–1850, doi:10.3762/bjoc.12.173

• interesting molecular properties. Particularly obvious is their often characteristic aroma that contributes to the typical flavour of many essential oils from plants. This is exemplified by the monoterpene α-pinene that occurs in form of both enantiomers in pine trees, while (R)-(+)-limonene is found in

• WP_003956090) [19], but the two enzymes show only a sequence homology of 32% and are phylogenetically distant. The (−)-enantiomer is known from plants including Taiwania cryptomerioides ([α]D23 = −102.9 (c 1.0, CHCl3)) [42], while the (+)-enantiomer has also been isolated from the liverwort Scapania undulata

• strict stereochemical course for the FPP cyclisation, as is reported for most, but not all other terpene cyclases that were investigated for this aspect. It is interesting to note that the bacterial sesquiterpenes identified in this study are in most cases the opposite enantiomers as known from plants

Cross-linked cyclodextrin-based material for treatment of metals and organic substances present in industrial discharge waters

• Élise Euvrard,
• Nadia Morin-Crini,
• Coline Druart,
• Justine Bugnet,
• Bernard Martel,
• Cesare Cosentino,
• Virginie Moutarlier and
• Grégorio Crini

Beilstein J. Org. Chem. 2016, 12, 1826–1838, doi:10.3762/bjoc.12.172

• their own treatment plants, generally physicochemical decontamination steps, the DWs still contain non-negligible amounts of pollutants. Among them, metals (in particular chromium, nickel and zinc) are commonly found at concentrations in the range of milligrams per liter, and organic molecules, such as

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

Organic chemistry meets polymers, nanoscience, therapeutics and diagnostics

• Vincent M. Rotello

Beilstein J. Org. Chem. 2016, 12, 1638–1646, doi:10.3762/bjoc.12.161

• stuff found in cells [68]. This was the start of a collaboration that continues to this day, where we have used laser desorption ionization (LDI) to characterize ligands on particles [69][70], supramolecular chemistry in cells [71], track NPs in fish [72] and plants [73], and to image NPs in animal

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

• mutagenicity test; quaternary ammonium salt; Introduction Carbohydrates and alditols occur broadly in nature and possess many biological functions essential to living organisms. Sugars not only contribute as energetic substances, but also serve as building materials for fungi, microbes, plants, and animals

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