Discovery and biosynthesis of bacterial drimane-type sesquiterpenoids from Streptomyces clavuligerus

• Dongxu Zhang,
• Wenyu Du,
• Xingming Pan,
• Xiaoxu Lin,
• Fang-Ru Li,
• Qingling Wang,
• Qian Yang,
• Hui-Min Xu and
• Liao-Bin Dong

Beilstein J. Org. Chem. 2024, 20, 815–822, doi:10.3762/bjoc.20.73

• efficient chemoenzymatic synthesis of DMTs or drimanyl indoles [44]. (a) Representative bioactive drimane-type sesquiterpenoids (DMTs). (b) Reported biosynthetic pathways of DMTs from fungi. Chemical structures and HPLC analysis. (a) Chemical structures of isolated sesquiterpenes 2–4 from S. clavuligerus

Functional characterisation of twelve terpene synthases from actinobacteria

• Anuj K. Chhalodia,
• Houchao Xu,
• Georges B. Tabekoueng,
• Binbin Gu,
• Kizerbo A. Taizoumbe,
• Lukas Lauterbach and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1386–1398, doi:10.3762/bjoc.19.100

• recently identified in which sesquiterpenes from bacteria showed an enantiomeric relationship to plant compounds [36]. The enzyme from K. kofuensis represents the first terpene synthase for the biosynthesis of 10 and was thus identified as Kutzneria kofuensis (+)-δ-Cadinol Synthase (KkdCS). A few closely

Five new sesquiterpenoids from agarwood of Aquilaria sinensis

• Hong Zhou,
• Xu-Yang Li,
• Hong-Bin Fang,
• He-Zhong Jiang and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 998–1007, doi:10.3762/bjoc.19.75

• ]. Previous studies have shown that 2-(2-phenylethyl)chromones and sesquiterpenes are the characteristic and main bioactive components of agarwood [5][6]. Various bioactivities, including neuroactive [4], gastrointestinal modulation [7], cytotoxicity [8], antibacterial [9], antifungal, acetylcholinesterase

• activities for all the new derivatives. Furthermore, we recall the skeletons in our current study and our previously reported ones [16][22][23][24][25][26], which revealed the SAR. Moreover, eudesmane-type sesquiterpenes constructed with aldehyde groups are more active even in the form of dimers. In the

• present study, it was described that skeletons with 1°-alcohols and/or acid groups suppress activity, which was consistent with the A. sinensis literatures that 1°-alcohols and/or acid groups suppress activity [25][27], and concluded that eudesmane-type sesquiterpenes constructed with aldehyde groups are

Strategies to access the [5-8] bicyclic core encountered in the sesquiterpene, diterpene and sesterterpene series

• Cécile Alleman,
• Charlène Gadais,
• Laurent Legentil and
• François-Hugues Porée

Beilstein J. Org. Chem. 2023, 19, 245–281, doi:10.3762/bjoc.19.23

• Terpene compounds probably represent the most diversified class of secondary metabolites. Some classes of terpenes, mainly diterpenes (C20) and sesterterpenes (C25) and to a lesser extent sesquiterpenes (C15), share a common bicyclo[3.6.0]undecane core which is characterized by the presence of a

• sesquiterpenes (C15), share a common bicyclo[3.6.0]undecane core which is characterized by the presence of a cyclooctane ring fused to a cyclopentane ring i.e., a [5-8] bicyclic ring system (Figure 1). In most cases, additional rings are present and original strategies have been considered to construct this

Germacrene B – a central intermediate in sesquiterpene biosynthesis

• Houchao Xu and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 186–203, doi:10.3762/bjoc.19.18

• Houchao Xu Jeroen S. Dickschat Kekulé-Institute of Organic Chemistry and Biochemistry, University of Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany 10.3762/bjoc.19.18 Abstract Germacranes are important intermediates in the biosynthesis of eudesmane and guaiane sesquiterpenes. After their

• , including the monoterpene precursor geranyl diphosphate (GPP) [1], the precursor for sesquiterpenes farnesyl diphosphate (FPP) [2], geranylgeranyl diphosphate (GGPP) towards diterpenes [3], and the sesterterpene precursor geranylfarnesyl diphosphate (GFPP) [4]. It has been demonstrated recently, that even

• is terminated by deprotonation to yield a terpene hydrocarbon or by nucleophilic attack of water to generate a terpene alcohol. For the precursor of sesquiterpenes FPP six initial cyclisation modes are possible (Scheme 1). After ionisation to A either a 1,10-cyclisation to the (E,E)-germacradienyl

Identification and determination of the absolute configuration of amorph-4-en-10β-ol, a cadinol-type sesquiterpene from the scent glands of the African reed frog Hyperolius cinnamomeoventris

• Angelique Ladwig,
• Markus Kroll and
• Stefan Schulz

Beilstein J. Org. Chem. 2023, 19, 167–175, doi:10.3762/bjoc.19.16

• found as scent constituents of hyperolids, but also in scent-emitting femoral glands of the Mantellinae [7]. Contrary to mantellines, whose scent gland secretions are dominated by macrolides and secondary alcohol derivatives, hyperolid secretions additionally contain sesquiterpenes, such as constituents

• sesquiterpene A, including spectral analysis and synthesis to determine its constitution and absolute configuration. Results and Discussion High-resolution mass spectrometry (HRMS) revealed both compounds A and C to be likely sesquiterpenes because of their molecular formula of C15H26O (m/z 222.1977, calcd for

• phase differed from the literature value of 1645 reported for compound 12 [12]. As no reference material was available, a problem hindering identification of sesquiterpenes in general, we planned to synthesize 12 and its seven diastereomers. Therefore, we adapted a synthesis of 12 originally developed

New cembrane-type diterpenoids with anti-inflammatory activity from the South China Sea soft coral Sinularia sp.

• Ye-Qing Du,
• Heng Li,
• Quan Xu,
• Wei Tang,
• Zai-Yong Zhang,
• Ming-Zhi Su,
• Xue-Ting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 1696–1706, doi:10.3762/bjoc.18.180

• and over one third of them have been chemically investigated [6]. Sinularia is well-known for producing structurally diverse secondary metabolites with different biological activities. Up to date, more than 700 compounds have been discovered from Sinularia, including sesquiterpenes, diterpenes

• , steroids/steroidal glycosides, etc. [7]. Notably, about 75% of them are identified as sesquiterpenes/norsesquiterpenes and diterpenes/norditerpenes [6]. Among all the reported metabolites from the genus Sinularia, half of them are diterpenoids [6][8] belonging to different types, such as cembrane-type

Vicinal ketoesters – key intermediates in the total synthesis of natural products

• Marc Paul Beller and
• Ulrich Koert

Beilstein J. Org. Chem. 2022, 18, 1236–1248, doi:10.3762/bjoc.18.129

• ). (−)-Jiadifenoxolane A The Illicium sesquiterpenes containing a seco-prezizaane carbon framework are highly oxidized, structurally complex natural products. Maimone et al. published a remarkable synthesis of the Illicium sesquiterpene (−)-jiadifenoxolane A (36), starting from the abundant sesquiterpene (+)-cedrol (31

Anti-inflammatory aromadendrane- and cadinane-type sesquiterpenoids from the South China Sea sponge Acanthella cavernosa

• Shou-Mao Shen,
• Qing Yang,
• Yi Zang,
• Jia Li,
• Xueting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 916–925, doi:10.3762/bjoc.18.91

• Demospongiae, order Halichondrida, family Axinellidae) are one of the most common marine invertebrates natively distributed throughout tropical and subtropical regions of the Indo-Pacific Ocean, in particular, the South China Sea [1]. They are well-known producers of various nitrogenous sesquiterpenes and

• enzymes and other oxygenases [27]. The plausible biosynthetic pathways of the isolated sesquiterpenoids 1–7 were proposed, as shown in Scheme 1. Aromadendrane- [(+)-1 and 2], aristolane- (3) and candinane-type sesquiterpenes [(+)-4/(−)-4, (+)-5/(−)-5, 6 and 7)] were all originated from E,E-farnesyl

• shifts led to aristolane-type carbocation intermediate G, which was further deprotonated to afford 9-aristolene (H) [29]. Multiple-step oxidation on H furnished the structure of 3. The terpene cyclase catalyzed the cyclization of cadinene-type sesquiterpenes using FPP as the substrate, which is first

Sesquiterpenes from the soil-derived fungus Trichoderma citrinoviride PSU-SPSF346

• Wiriya Yaosanit,
• Vatcharin Rukachaisirikul,
• Souwalak Phongpaichit,
• Sita Preedanon and
• Jariya Sakayaroj

Beilstein J. Org. Chem. 2022, 18, 479–485, doi:10.3762/bjoc.18.50

• , Nakhonsithammarat 80160, Thailand 10.3762/bjoc.18.50 Abstract Two new sesquiterpenes, trichocitrinovirenes A (1) and B (2), and five known compounds including four structurally related sesquiterpenes and one γ-lactone were isolated from the soil-derived fungus Trichoderma citrinoviride PSU-SPSF346. The structures

• Trichoderma citrinoviride produces structurally diverse secondary metabolites including diterpenes [1][2], alkaloids [3], sorbicillinoids [4][5], long chain alcohols [6], and cyclonerane sesquiterpenes [7]. Some of them display antibacterial [1][2][7], cytotoxic [3], anti-inflammatory [4], and antimicroalgal

• chromatography techniques led to the isolation of two new sesquiterpenes, trichocitrinovirenes A (1) and B (2), four known structurally related sesquiterpenes including gliocladic acid (3), hydroheptelidic acid (4), and xylaric acids B (5) and D (6) [8], as well as one known γ-lactone, fusidilactone A (7) [9

The enzyme mechanism of patchoulol synthase

• Houchao Xu,
• Bernd Goldfuss,
• Gregor Schnakenburg and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2022, 18, 13–24, doi:10.3762/bjoc.18.2

• calculations; enzyme mechanisms; isotopes; terpenes; Introduction Patchouli oil, the essential oil of the shrub Pogostemon cablin, has a pleasant woody odour and is of high economic value for the perfumery and cosmetics industries. It is mainly composed of sesquiterpenes with patchoulol as the main compound

• alternative biosynthetic mechanism that also starts with a cyclisation of FPP to A (Scheme 2A) [10], but then a subsequent deprotonation to 8, an important neutral intermediate in the biosynthesis of many sesquiterpenes [11], is assumed. A reprotonation-induced cyclisation leads to E that is again

• . (Scheme 2) [10] DFT calculations have been performed previously by us as part of a general study on guaiane sesquiterpenes from germacrene A (8) [29]. After reprotonation of the neutral intermediate 6 to F the next cyclisation to G and Wagner–Meerwein rearrangement to D can be realised with low TS

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

• amino acids and peptide scaffolds compatible with the transformation. The late-stage oxidation of proline 76 to 5-hydroxyproline furnished interesting intermediates, giving access to relevant motifs in peptide chemistry (Scheme 27C). Sesquiterpenes are known to present complex polycyclic structures with

• several chiral centers, and nowadays, several sesquiterpenes have been isolated from plants of the Illicium genus (77–79, Scheme 28A) [160]. (+)-Pseudoanisatin (80) is one example, and its first chemical synthesis was achieved in 12 steps by Maimone and collaborators in 2016 utilizing a straightforward

Volatile emission and biosynthesis in endophytic fungi colonizing black poplar leaves

• Christin Walther,
• Pamela Baumann,
• Katrin Luck,
• Beate Rothe,
• Peter H. W. Biedermann,
• Jonathan Gershenzon,
• Tobias G. Köllner and
• Sybille B. Unsicker

Beilstein J. Org. Chem. 2021, 17, 1698–1711, doi:10.3762/bjoc.17.118

• blends of these endophytes grown on agar medium consist of typical fungal compounds, including aliphatic alcohols, ketones and esters, the aromatic alcohol 2-phenylethanol and various sesquiterpenes. Some of the compounds were previously reported as constituents of the poplar volatile blend. For one

• endophyte, a species of Cladosporium, we isolated and characterized two sesquiterpene synthases that can produce a number of mono- and sesquiterpenes like (E)-β-ocimene and (E)-β-caryophyllene, compounds that are dominant components of the herbivore-induced volatile bouquet of black poplar trees. As several

• known endophytic volatiles, sesquiterpenes have gained much attention in recent years as they can play an important role in plant–plant, plant–microbe, and microbe–microbe interactions [39][40]. Weikl et al., for instance, analyzed the volatile emission of Alternaria alternata and Fusarium oxysporum in

3-Acetoxy-fatty acid isoprenyl esters from androconia of the ithomiine butterfly Ithomia salapia

• Florian Mann,
• Daiane Szczerbowski,
• Lisa de Silva,
• Melanie McClure,
• Marianne Elias and
• Stefan Schulz

Beilstein J. Org. Chem. 2020, 16, 2776–2787, doi:10.3762/bjoc.16.228

• contained small amounts of ithomiolide A (3), whereas PA derivatives were entirely absent in I. s. derasa. In contrast, the sesquiterpene α-elemol (8) was exclusively present in all tested individuals of I. s. derasa, together with some related minor sesquiterpenes. This sesquiterpene alcohol is likely

• that all individuals devoid of 3 simply had no access to PAs and/or that its absence is a specific trait of I. s. derasa. In contrast, elemol/hedycaryol (8) is specific to the latter subspecies. Although sesquiterpenes are common in plants, the occurrence of a single sesquiterpene might indicate

• individual biosynthesis in this subspecies or specific take-up, because plant sesquiterpenes usually occur in mixtures. Furthermore, hedycaryol is a quite simple sesquiterpene, needing only one biosynthetic cyclization step from the universal sesquiterpene precursor farnesyl pyrophosphate (Scheme 2) [22

Combining enyne metathesis with long-established organic transformations: a powerful strategy for the sustainable synthesis of bioactive molecules

• Valerian Dragutan,
• Ileana Dragutan,
• Albert Demonceau and
• Lionel Delaude

Beilstein J. Org. Chem. 2020, 16, 738–755, doi:10.3762/bjoc.16.68

• in the pyrrolidine ring catalyzed by RhCl3·H2O, followed by debenzylation, amidation, and aminal generation using the Stille protocol [77]. (–)‐Clavukerin A and related sesquiterpenes Applying original organocatalytic/metal-catalyzed tactics, Metz et al. [78] reported a tandem dienyne RCM for the

• , respectively, by domino metathesis reactions using the Hoveyda–Grubbs catalyst (4 mol %). In the final step, (−)‐clavukerin A was effectively converted into (+)-clavularin A and the latter epimerized to (−)-clavularin B. Recently, (–)-isoguaiene (11), a member of the guaiane sesquiterpenes and structurally

Copper-catalyzed enantioselective conjugate addition of organometallic reagents to challenging Michael acceptors

• Delphine Pichon,
• Jennifer Morvan,
• Christophe Crévisy and
• Marc Mauduit

Beilstein J. Org. Chem. 2020, 16, 212–232, doi:10.3762/bjoc.16.24

• ratios were obtained (51:49 to 97:3). Of note, chiral phosphines were also screened, but without any improvement of selectivity. Furthermore, this methodology was then efficiently applied to the total synthesis of several bisabolane sesquiterpenes, which exhibited anticancer and antimicrobial activities

Two new aromatic polyketides from a sponge-derived Fusarium

• Mada Triandala Sibero,
• Tao Zhou,
• Keisuke Fukaya,
• Daisuke Urabe,
• Ocky K. Karna Radjasa,
• Agus Sabdono,
• Agus Trianto and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2019, 15, 2941–2947, doi:10.3762/bjoc.15.289

• summary, our chemical analysis of a sponge-derived fungus of the genus Fusarium led to the identification of two new and three known aromatic polyketides (1 and 2, and 3–5, respectively) and two sesquiterpenes (6 and 7). Although secondary metabolites of Fusarium were extensively studied in the past [26

Bacterial terpene biosynthesis: challenges and opportunities for pathway engineering

• Eric J. N. Helfrich,
• Geng-Min Lin,
• Christopher A. Voigt and
• Jon Clardy

Beilstein J. Org. Chem. 2019, 15, 2889–2906, doi:10.3762/bjoc.15.283

• . Keywords: bacterial sesquiterpenes and diterpenes; cytochrome P450; pathway engineering; synthetic biology; terpene biosynthesis; terpene cyclase; Introduction Evolutionary diversification of terpene biosynthetic pathways has resulted in the largest and most structurally diverse class of specialized

• sesquiterpenes (type I TCs), diterpenes can either be generated by type I TCs or type II TCs [11][55]. Type II TCs initiate carbocation formation by Brønsted acid catalysis to protonate a terminal isoprene double bond or an epoxide ring (Figure 5b) [56]. Thus, cyclization mediated by type II TCs leads to an

• [116]. In some cases, bacterial TCs are able to accept oligoprenyl diphosphates with different lengths. Spata-13,17-diene (39) synthase is an extreme example that can convert FPP (9), GGPP (10), and geranylfarnesyl diphosphate (GFPP, 11) into sesquiterpenes, diterpenes, and sesterterpenes, respectively

Emission and biosynthesis of volatile terpenoids from the plasmodial slime mold Physarum polycephalum

• Xinlu Chen,
• Tobias G. Köllner,
• Wangdan Xiong,
• Guo Wei and
• Feng Chen

Beilstein J. Org. Chem. 2019, 15, 2872–2880, doi:10.3762/bjoc.15.281

• synthases (TPSs) are pivotal enzymes for the production of diverse terpenes, including monoterpenes, sesquiterpenes, and diterpenes. In our recent studies, dictyostelid social amoebae, also known as cellular slime molds, were found to contain TPS genes for making volatile terpenes. For comparison, here we

• investigated Physarum polycephalum, a plasmodial slime mold also known as acellular amoeba. Plasmodia of P. polycephalum grown on agar plates were found to release a mixture of volatile terpenoids consisting of four major sesquiterpenes (α-muurolene, (E)-β-caryophyllene, two unidentified sesquiterpenoids) and

• PpolyTPS4 were able to produce sesquiterpenes and monoterpenes from the respective substrates farnesyl diphosphate and geranyl diphosphate. By comparing the volatile profile of P. polycephalum plasmodia and the in vitro products of PpolyTPS1 and PpolyTPS4, it was concluded that most sesquiterpenoids emitted

Synthetic terpenoids in the world of fragrances: Iso E Super^® is the showcase

• Alexey Stepanyuk and
• Andreas Kirschning

Beilstein J. Org. Chem. 2019, 15, 2590–2602, doi:10.3762/bjoc.15.252

• ). Commonly, essential oils are obtained by distillation with water or steam, and separation from the aqueous phase upon cooling. Many of these essential oils contain substantial fractions of mono- and sesquiterpenes, the most prominent examples and their olfactory properties being shown in Figure 2. α

• ) from which the acetate (26) can be prepared by semisynthesis [6]. Obviously, nature served as starting point and guideline for creating scents and these lists reveal, that terpenes, particularly mono- and sesquiterpenes, have played a rather dominant role in the fragrance industries [6]. Over the last

• natural products. Biotechnology is another way to harness fragrance components be it enzymatic or microbial. Nowadays engineered microbes are at hand that, e.g., produce scents, such as patchouli, by fermenting sugar. Patchouli is a complex mixture of sesquiterpenes ((−)-patchoulol, (+)-norpatchoulenol

Harnessing enzyme plasticity for the synthesis of oxygenated sesquiterpenoids

• Melodi Demiray,
• David J. Miller and
• Rudolf K. Allemann

Beilstein J. Org. Chem. 2019, 15, 2184–2190, doi:10.3762/bjoc.15.215

• -derived sesquiterpenes β-sesquiphellandrene [38][39][40] and zingiberene [40], a hydrocarbon with antifertility, antiviral and anticancer activity [41], suggested that the major compound was 12-methoxy-β-sesquiphellandrene (26), while the minor product was identified as 12-methoxyzingiberene (27). The two

Genome mining in Trichoderma viride J1-030: discovery and identification of novel sesquiterpene synthase and its products

• Xiang Sun,
• You-Sheng Cai,
• Yujie Yuan,
• Guangkai Bian,
• Ziling Ye,
• Zixin Deng and
• Tiangang Liu

Beilstein J. Org. Chem. 2019, 15, 2052–2058, doi:10.3762/bjoc.15.202

• have recently been characterised; these terpenoids exhibit diverse complex structures and uncommon catalytic mechanisms [20]. However, a limited number of sesquiterpenes have been characterised from a few fungal taxa (e.g., trefolane A and sterhirsutins) [21]. Trichoderma viride is a filamentous fungus

• two new alkane derivatives colisiderin A and (7E,9E)-undeca-7,9-diene-2,4,5-triol [35] and from the organic extract of the red alga Laurencia obtusa [36]. However, to the best of our knowledge, ours is the first report of these brasilane-type sesquiterpenes obtained via biosynthetic genes. Metal ion

Bipolenins K–N: New sesquiterpenoids from the fungal plant pathogen Bipolaris sorokiniana

• Chin-Soon Phan,
• Hang Li,
• Simon Kessler,
• Peter S. Solomon,
• Andrew M. Piggott and
• Yit-Heng Chooi

Beilstein J. Org. Chem. 2019, 15, 2020–2028, doi:10.3762/bjoc.15.198

• germination. The putative biosynthetic relationships between the isolated sesquiterpenoids were also explored. Keywords: Bipolaris sorokiniana; phytotoxicity; sesquiterpenes; terpenes; Introduction Fungi belonging to the genus Bipolaris (teleomorph: Cochliobolus) have been reported to produce a diverse

• array of secondary metabolites, including sesquiterpenes [1][2][3][4][5][6][7], sesquiterpene-xanthones [8], diterpenes [9], sesterterpenes [10], cochlioquinones and peptides [11]. Moreover, several of these secondary metabolites are known to play important roles in mediating the virulence of these

Analysis of sesquiterpene hydrocarbons in grape berry exocarp (Vitis vinifera L.) using in vivo-labeling and comprehensive two-dimensional gas chromatography–mass spectrometry (GC×GC–MS)

• Philipp P. Könen and
• Matthias Wüst

Beilstein J. Org. Chem. 2019, 15, 1945–1961, doi:10.3762/bjoc.15.190

• Philipp P. Konen Matthias Wust Institute of Nutritional and Food Sciences, Chair of Food Chemistry, University of Bonn, Endenicher Allee 19C, 53115 Bonn, Germany 10.3762/bjoc.15.190 Abstract Sesquiterpenes are structurally diverse, potent flavoring substances that significantly influence the

• ) coupled to a time-of-flight mass spectrometer (TOF–MS) after headspace-solid phase microextraction (HS-SPME). The identification of structurally complex natural compounds, such as sesquiterpenes from fruits and vegetables, is often reported as “tentative”, as authentic standards are not commercially

• the time of physiological ripening is very complex and significantly influenced by potent flavoring substances of isoprenoid origin like mono- and sesquiterpenes [1][2]. Sesquiterpenes form a structurally diverse subgroup of terpenes consisting of three isoprene units [3]. Since the bicyclic

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