Archangelolide: A sesquiterpene lactone with immunobiological potential from Laserpitium archangelica

• Silvie Rimpelová,
• Michal Jurášek,
• Lucie Peterková,
• Jiří Bejček,
• Vojtěch Spiwok,
• Miloš Majdl,
• Michal Jirásko,
• Miloš Buděšínský,
• Juraj Harmatha,
• Eva Kmoníčková,
• Pavel Drašar and
• Tomáš Ruml

Beilstein J. Org. Chem. 2019, 15, 1933–1944, doi:10.3762/bjoc.15.189

• biological effects. In plants, they are synthesized, among others, for pesticidal and antimicrobial effects. Two such compounds, archangelolide and trilobolide of the guaianolide type, are structurally similar to the well-known and clinically tested lactone thapsigargin. While trilobolide has already been

N-(1-Phenylethyl)aziridine-2-carboxylate esters in the synthesis of biologically relevant compounds

• Iwona E. Głowacka,
• Aleksandra Trocha,
• Andrzej E. Wróblewski and
• Dorota G. Piotrowska

Beilstein J. Org. Chem. 2019, 15, 1722–1757, doi:10.3762/bjoc.15.168

• as components of a variety of plants and exhibit a wide range of biological properties including inhibition of glucosidases [102]. When the aziridine epoxide 162 was treated with acetic acid the aziridine ring cleavage was observed to give the epoxyaldehyde 178 (Scheme 45) [94]. Catalytic

Phylogenomic analyses and distribution of terpene synthases among Streptomyces

• Lara Martín-Sánchez,
• Kumar Saurabh Singh,
• Mariana Avalos,
• Gilles P. van Wezel,
• Jeroen S. Dickschat and
• Paolina Garbeva

Beilstein J. Org. Chem. 2019, 15, 1181–1193, doi:10.3762/bjoc.15.115

• depends on the precursors that these synthases can accommodate: geranyl diphosphate (monoterpenes, C10), farnesyl diphosphate (sesquiterpenes, C15) and geranylgeranyl diphosphate (diterpenes, C20). The biological function of terpenes is best studied for plants where they play important roles in

• played by terpenoids in plants [11]. However, although geosmin was discovered more than 50 years ago [14], its biological or ecological function still remains unclear. Streptomyces pactum KLBMP 5084 (the only species included in this study that does not carry geosmin synthases) is an endophytic plant

• evolution of terpenes synthases among Streptomyces species. It would be interesting in follow-up studies to assess the distribution and evolution of these genes among other bacteria, fungi, protists and plants. In addition, a deeper knowledge of the ecological function of terpenes in bacteria and in the

Mechanistic investigations on multiproduct β-himachalene synthase from Cryptosporangium arvum

• Jan Rinkel and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2019, 15, 1008–1019, doi:10.3762/bjoc.15.99

• occur frequently in plants [11]. Whether the reduced selectivity of TSs both for substrates and for products can be attributed to imperfect catalysis, or if this function is even beneficial for the producing organism, remains elusive in most cases. Also the structural basis of promiscuous catalysis by

Chemical structure of cichorinotoxin, a cyclic lipodepsipeptide that is produced by Pseudomonas cichorii and causes varnish spots on lettuce

• Hidekazu Komatsu,
• Takashi Shirakawa,
• Takeo Uchiyama and
• Tsutomu Hoshino

Beilstein J. Org. Chem. 2019, 15, 299–309, doi:10.3762/bjoc.15.27

• Pseudomonas cichorii causes varnish spots on lettuce. Varnish spots, also called midrib rot or bacterial rot [1][2][3][4], are dark brown and can induce necrotic lesions [1][2][3][4][5][6][7]. P. cichorii, isolated by us, infects a wide range of host plants, including monocot and dicot species (e.g

• ., Asteraceae, Solanaceae, Apiaceae, and Liliaceae; 54 species in 17 families) [5], but necrotic lesions most commonly occur in lettuce plants and seriously hurt lettuce production in the highland areas of Japan (e.g., Nagano and Iwate prefectures) in the summer season [5]. Effective ways of inhibiting the

Synthesis of nonracemic hydroxyglutamic acids

• Dorota G. Piotrowska,
• Iwona E. Głowacka,
• Andrzej E. Wróblewski and
• Liwia Lubowiecka

Beilstein J. Org. Chem. 2019, 15, 236–255, doi:10.3762/bjoc.15.22

• giant neurons of the African giant snail appeared to be sensitive to various extents to all stereoisomers of 2 [21][22][23]. Hydroxyglutamic acids are widely spread in nature, especially in plants but they were also found in other species or as components of more complex molecules of interesting

• [(2S,4S)-3] was found in several plants, e.g., Phlox decussata [29] and other Phlox species [30], as well as in Linaria vulgaris [31]. It has also been discovered in mammalian cells as an intermediate in the degradation of hydroxyproline [32][33]. Its various amides have been identified in numerous

• plants [34][35][36][37][38][39] as well as components of complex molecules produced by different species [40][41][42]. 3,4-Dihydroxyglutamic acid (4) of unknown stereochemistry was identified as a constituent of seeds of Lepidum sativum and leaves of Rheum rhaponticum and later on in other species [43

Synthesis and biological activity of methylated derivatives of the Pseudomonas metabolites HHQ, HQNO and PQS

• Sven Thierbach,
• Max Wienhold,
• Susanne Fetzner and
• Ulrich Hennecke

Beilstein J. Org. Chem. 2019, 15, 187–193, doi:10.3762/bjoc.15.18

• )-quinolones (AQs) have been identified as natural products produced by higher plants of the Rutaceae family as well as by some microorganisms including Alteromonas, Burkholderia and Pseudomonas species [1][2][3][4][5][6][7][8][9]. Plant-derived AQs occur with alkyl chains of different lengths, branches and

• cytochromes in Mycobacteria than HQNO and therefore the methylation of HQNO can be seen as detoxification strategy [16]. Considering the natural occurrence of N- as well as O-methylated AQs in plants and the use of methylation of HQNO in Mycobacteria as detoxification reaction, we decided to investigate the

Lectins of Mycobacterium tuberculosis – rarely studied proteins

• Katharina Kolbe,
• Sri Kumar Veleti,
• Norbert Reiling and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2019, 15, 1–15, doi:10.3762/bjoc.15.1

• containing a carbohydrate-recognition domain similar to the CRD in ricin, a toxin of the poisonous plant Ricinus communis. R-type lectins have been detected in plants, animals, and bacteria. Plant R-type lectins often contain a separate subunit functioning as a toxin. Furthermore, ricin-type lectin domains

A simple and effective preparation of quercetin pentamethyl ether from quercetin

• Jin Tatsuzaki,
• Tomohiko Ohwada,
• Yuko Otani,
• Reiko Inagi and
• Tsutomu Ishikawa

Beilstein J. Org. Chem. 2018, 14, 3112–3121, doi:10.3762/bjoc.14.291

• results. Keywords: computational calculation; per-O-methylation; quercetin; quercetin pentamethyl ether; reactivity; Introduction Flavonoids are distributed widely in plants, and exhibit various biological activities [1]. Polymethoxyflavones (PMFs) in particular have attracted much attention due to

Ring-closing-metathesis-based synthesis of annellated coumarins from 8-allylcoumarins

• Christiane Schultze and
• Bernd Schmidt

Beilstein J. Org. Chem. 2018, 14, 2991–2998, doi:10.3762/bjoc.14.278

• to antineurodegenerative activities [2][3]. The majority of natural coumarins are secondary metabolites isolated from plants [5][6][7]. A commonly used taxonomy for these natural products (which has been extended to the non-natural analogues) is based on the coumarin structure (Figure 1) [4][8]. It

• ]. This consideration has, for example, led to the development of substituted angelicins rather than psoralens as potential anti-influenza drugs [16]. Seselin (4) is an example of an angular pyranocoumarin found in various plants, e.g., from the family of Rutaceae [17]. Among other bioactivities, the

Volatiles from the hypoxylaceous fungi Hypoxylon griseobrunneum and Hypoxylon macrocarpum

• Jan Rinkel,
• Alexander Babczyk,
• Tao Wang,
• Marc Stadler and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2018, 14, 2974–2990, doi:10.3762/bjoc.14.277

• also important in the interaction between different species, e.g., between ophiostomatoid fungi and conifer bark beetles that show different behavioural responses to fungal volatiles [9]. Fungal volatiles can also be of importance in the interaction between plants and fungi. In some cases, fungal

• germination and to cause necrotic lesions in the plant tissue. In other cases, fungal volatiles can have beneficial effects and may even be involved in the induction of systemic resistance in plants, as can be assumed for 6-pentyl-2H-pyran-2-one (5) that is produced by many fungi from the genus Trichoderma

• spectrometry in plants from the genus Asarum [45], but never from fungi before. However, it remains unclear how 45 was distinguished from 44 or other possible isomers in the earlier study. Conclusion Both investigated ascomycetes, Hypoxylon griseobrunneum and Hypoxylon macrocarpum, were found to emit complex

Studies towards the synthesis of hyperireflexolide A

• G. Hari Mangeswara Rao

Beilstein J. Org. Chem. 2018, 14, 2106–2111, doi:10.3762/bjoc.14.185

• hyperireflexolide A. Keywords: alkylation; allylation; cross metathesis; hyperireflexolide A; spiroterpene; Introduction Hyperireflexolide A (1) [1] is a spiroterpenoid, isolated from hypericum reflexum, plants of the genus hypericum (Figure 1). Hyperireflexolide A is widely used in folk medicine, displays

Assessing the possibilities of designing a unified multistep continuous flow synthesis platform

• Mrityunjay K. Sharma,
• Roopashri B. Acharya,
• Chinmay A. Shukla and
• Amol A. Kulkarni

Beilstein J. Org. Chem. 2018, 14, 1917–1936, doi:10.3762/bjoc.14.166

• plants [66]. The entire platform has separate tanks for storing the feed, product, solvent/buffer solution for extraction and waste collection. The feed storage tanks will be equipped with temperature control for preheating or precooling of any reagent before mixing. Moreover, the unified platform can be

Two new 2-alkylquinolones, inhibitory to the fish skin ulcer pathogen Tenacibaculum maritimum, produced by a rhizobacterium of the genus Burkholderia sp.

• Dandan Li,
• Naoya Oku,
• Atsumi Hasada,
• Masafumi Shimizu and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2018, 14, 1446–1451, doi:10.3762/bjoc.14.122

• association with animals or plants as pathogens or symbionts and exhibit a variety of catabolic and metabolic activities [1][7]. One hundred ten secondary metabolites have been reported from Burkholderia (data retrieved from the Dictionary of Natural Products, as of March 20, 2018). However, it is likely that

• )-one [17], 6 was identified as PSC-D or (E)-3-methyl-2-(non-2-en-1-yl)quinolin-4(1H)-one) [17], 7 was identified as pyrrolnitrin [18], and 8 was identified as BN-227 [19] (Figure 1). 4-Quinolone is a common core in synthetic antibactericides [20] and in bioactive metabolites produced by Rutaceae plants

• NBRC16015, Trichophyton rubrum NBRC5467, Candida albicans NBRC0197 (human opportunistic pathogen), R. oryzae NBRC4705, Glomerella cingulata NBRC5907 (pathogen of anthracnose), Ralstonia solanacearum SUPP1541 (pathogen of bacterial wilt of Solanaceous plants), Rhizobium radiobacter NBRC14554 (pathogen of

Recyclable hypervalent-iodine-mediated solid-phase peptide synthesis and cyclic peptide synthesis

• Dan Liu,
• Ya-Li Guo,
• Jin Qu and
• Chi Zhang

Beilstein J. Org. Chem. 2018, 14, 1112–1119, doi:10.3762/bjoc.14.97

• FPID/(4-MeOC6H4)3P will be described in the following part. Moreover, angiotensin I converting enzyme (ACE) inhibitory peptides, widely exist in plants and animals, can serve as potential antihypertensive pharmaceuticals [40][41][42]. The synthesis of two ACE inhibitory peptides proceeded smoothly in

Volatiles from three genome sequenced fungi from the genus Aspergillus

• Jeroen S. Dickschat,
• Ersin Celik and
• Nelson L. Brock

Beilstein J. Org. Chem. 2018, 14, 900–910, doi:10.3762/bjoc.14.77

• the penny bun (Boletus edulis) [7], but can also inhibit the growth of other fungi [8] which likely contributes to the induction of systemic resistance in plants by Trichoderma [9]. Fungal volatiles can also act as self-inhibitors of fungal germination [10] or as attractants for insects involved in

Volatiles from the xylarialean fungus Hypoxylon invadens

• Jeroen S. Dickschat,
• Tao Wang and
• Marc Stadler

Beilstein J. Org. Chem. 2018, 14, 734–746, doi:10.3762/bjoc.14.62

• (2), another widespread fungal volatile, a plant growth promoting effect and an induction of systemic resistance in plants against fungi was observed [5]. The significant biological effects of these and other fungal volatiles recently resulted in a considerable interest of natural product chemists

One-pot preparation of 4-aryl-3-bromocoumarins from 4-aryl-2-propynoic acids with diaryliodonium salts, TBAB, and Na₂S₂O₈

• Teppei Sasaki,
• Katsuhiko Moriyama and
• Hideo Togo

Beilstein J. Org. Chem. 2018, 14, 345–353, doi:10.3762/bjoc.14.22

• coumarins arises from the fact that the coumarin skeleton is present in many natural products extracted from plants [1][2][3] and some of them show potent pharmacological activities, such as antidepressant [4], antimicrobial [5][6], antioxidants [7][8], anti-inflammatory [9][10], antinociceptive [11

Volatiles from the tropical ascomycete Daldinia clavata (Hypoxylaceae, Xylariales)

• Tao Wang,
• Kathrin I. Mohr,
• Marc Stadler and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2018, 14, 135–147, doi:10.3762/bjoc.14.9

• widespread fungal volatile is 6-pentyl-2H-pyran-2-one (2) that was first isolated from Trichoderma and exhibits a strong coconut aroma [5]. For fungi producing 2 a plant-growth promoting effect and an induction of systemic resistance in plants has been observed which makes these fungi interesting as

Aminomethylation/hydrogenolysis as an alternative to direct methylation of metalated isoquinolines – a novel total synthesis of the alkaloid 7-hydroxy-6-methoxy-1-methylisoquinoline

• Benedikt C. Melzer,
• Jan G. Felber and
• Franz Bracher

Beilstein J. Org. Chem. 2018, 14, 130–134, doi:10.3762/bjoc.14.8

• considerable relevance in drug development, since it is found in both complex [1] and “simple” alkaloids (variously substituted derivatives of the native isoquinoline) isolated from different plants [2], and antiviral and antimicrobial activities have been found for numerous isoquinoline alkaloids [3]. Further

Aminosugar-based immunomodulator lipid A: synthetic approaches

• Alla Zamyatina

Beilstein J. Org. Chem. 2018, 14, 25–53, doi:10.3762/bjoc.14.3

• response in plants during symbiosis in root cells. Additionally, certain Rhizobium sin-1 lipid A isolates were shown to inhibit the LPS induced toxic effects in human immune cells [115]. To determine the structural features which are responsible for the LPS antagonizing properties of the heterogeneous

A concise flow synthesis of indole-3-carboxylic ester and its derivatisation to an auxin mimic

• Marcus Baumann,
• Ian R. Baxendale and
• Fabien Deplante

Beilstein J. Org. Chem. 2017, 13, 2549–2560, doi:10.3762/bjoc.13.251

• pharmaceuticals [1][2][3][4]. Indoles also play a significant role as phytohormones that promote and regulate the growth and development of plants. Indeed, four of the five endogenously synthesised auxins produced by plants contain the indole motif (Figure 1, structures 3–7). As a consequence of their regulatory

Herpetopanone, a diterpene from Herpetosiphon aurantiacus discovered by isotope labeling

• Xinli Pan,
• Nicole Domin,
• Sebastian Schieferdecker,
• Hirokazu Kage,
• Martin Roth and
• Markus Nett

Beilstein J. Org. Chem. 2017, 13, 2458–2465, doi:10.3762/bjoc.13.242

• resemblance to cadinane-type sesquiterpenes from plants, but is structurally entirely unprecedented in bacteria. Based on its molecular architecture, a possible biosynthetic pathway is postulated. Keywords: genome mining; herpetopanone; Herpetosiphon; isotope labeling; terpene; Introduction Terpenoids

• were mainly reported from plants and, to a lesser degree, also from fungi and marine invertebrates. In recent years, however, the discovery of terpenoids from prokaryotes has gained momentum. The ease of DNA sequencing has strongly favored this development, contributing to the identification of

• , whereas a plant-derived sesquiterpene with this feature was already reported in 1965. Oplopanone (2, Figure 3) was originally isolated from Oplopanax japonicus [18][19], but can also be found in a number of other plants as well as red algae [20][21]. Comparison of the chemical shifts in 1 with published

Synthesis of ergostane-type brassinosteroids with modifications in ring A

• Vladimir N. Zhabinskii,
• Darya A. Osiyuk,
• Yuri V. Ermolovich,
• Natalia M. Chaschina,
• Tatsiana S. Dalidovich,
• Miroslav Strnad and
• Vladimir A. Khripach

Beilstein J. Org. Chem. 2017, 13, 2326–2331, doi:10.3762/bjoc.13.229

• moieties, exhibit hormonal activity in plants, whereas other BS are considered to be either biosynthetic precursors or metabolites of the “real” phytohormones [2]. All these compounds are part of a multidimensional biosynthetic metabolic network, the functioning of which is still far from being completely

Diosgenyl 2-amino-2-deoxy-β-D-galactopyranoside: synthesis, derivatives and antimicrobial activity

• Henryk Myszka,
• Patrycja Sokołowska,
• Agnieszka Cieślińska,
• Andrzej Nowacki,
• Maciej Jaśkiewicz,
• Wojciech Kamysz and
• Beata Liberek

Beilstein J. Org. Chem. 2017, 13, 2310–2315, doi:10.3762/bjoc.13.227

• the obtained compounds are active against Gram-positive bacteria and Candida type fungi. Keywords: antimicrobial activities; D-galactosamine; diosgenin; glycosylation; saponin; tetrachlorophthalimido derivatives; Introduction Saponins are steroid or triterpenoid glycosides found in various plants [1

• glycosides constitute a very important group among spirostanol saponins. Diosgenin has a double bond between the C-5 and C-6 atoms of the spirostanol skeleton and can be found in combination with different sugars in Costus, Discorea, Paris, Solanum, Yucca, and Trillium plants [11]. The plants containing

• directly bound with sapogenin are rarely found in plants, there are some examples of such galactosides. For example, timosaponin, isolated from an Anemarrhena asphodeloides plant, is a natural spirostanol saponin, which has D-galactose bound with sarsapogenin [15]. Tribulus plants are known to contain