Computation-guided scaffold exploration of 2E,6E-1,10-trans/cis-eunicellanes

• Zining Li,
• Sana Jindani,
• Volga Kojasoy,
• Teresa Ortega,
• Erin M. Marshall,
• Khalil A. Abboud,
• Sandra Loesgen,
• Dean J. Tantillo and
• Jeffrey D. Rudolf

Beilstein J. Org. Chem. 2024, 20, 1320–1326, doi:10.3762/bjoc.20.115

• ) of alkenes in the 10-membered ring (Figure 1A). During biosynthesis, the eunicellane skeleton is first constructed by terpene synthases that cyclize the diterpene precursor geranylgeranyl diphosphate (Figure 1B) [5][6][7][8][9]. The latter two structural elements, the configurations of the 6/10

• system and the C2–C3 alkene, are instilled by these terpene synthases. Four types of eunicellane synthases are known (Figure 1B). The first eunicellane synthase identified, Bnd4 from the biosynthesis of benditerpenoic acid in Streptomyces sp. (CL12-4) [5], forms a cis-eunicellane named benditerpetriene

Stability trends in carbocation intermediates stemming from germacrene A and hedycaryol

• Naziha Tarannam,
• Prashant Kumar Gupta,
• Shani Zev and
• Dan Thomas Major

Beilstein J. Org. Chem. 2024, 20, 1189–1197, doi:10.3762/bjoc.20.101

• (GPP, FPP, GGPP) undergo highly complex cyclisation cascades forming terpenes and terpenoids that often have great structural complexity. For class I terpene synthases this multistep process is initiated by a heterolytic C–O bond cleavage, separating the diphosphate and isoprenoid ion pairs [3][4]. The

• stereochemistry. Theory is an important tool in understanding the complex chemistry in terpene synthesis. Gas-phase and in-enzyme tools have been employed extensively to understand terpene chemistry in general and terpene synthases in particular [21][22][23][24][25][26][27][28][29]. In the current work, we

Enhancing structural diversity of terpenoids by multisubstrate terpene synthases

• Min Li and
• Hui Tao

Beilstein J. Org. Chem. 2024, 20, 959–972, doi:10.3762/bjoc.20.86

• TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, Hubei 430071, China 10.3762/bjoc.20.86 Abstract Terpenoids are one of the largest class of natural products with diverse structures and activities. This enormous diversity is embedded in enzymes called terpene synthases (TSs), which

• multisubstrate terpene synthases (MSTSs) and highlight their potential applications. Keywords: noncanonical terpene; substrate promiscuity; synthetic biology; terpene synthase; terpenoid; Introduction Terpenoids constitute the largest class of natural products with more than 80000 known structures [1] and a

• converted into (poly)cyclic skeletons, including hemiterpenes, monoterpenes, sesquiterpenes, diterpenes, sesterterpenes, and triterpenes, by a large class of enzymes called terpene synthases (TSs) (Figure 1). The reactions of TSs are one of the most important factors contributing to terpene diversity, as

Confirmation of the stereochemistry of spiroviolene

• Yao Kong,
• Yuanning Liu,
• Kaibiao Wang,
• Tao Wang,
• Chen Wang,
• Ben Ai,
• Hongli Jia,
• Guohui Pan,
• Min Yin and
• Zhengren Xu

Beilstein J. Org. Chem. 2024, 20, 852–858, doi:10.3762/bjoc.20.77

• are assembled by prenyltransferases to afford oligoprenyl pyrophosphates, such as farnesyl pyrophosphate (FPP, 3 × C5) and geranylgeranyl pyrophosphate (GGPP, 4 × C5), with varied C5 units. The linear oligoprenyl pyrophosphates are typically converted by terpene synthases in a chemo- and

Genome mining of labdane-related diterpenoids: Discovery of the two-enzyme pathway leading to (−)-sandaracopimaradiene in the fungus Arthrinium sacchari

• Fumito Sato,
• Terutaka Sonohara,
• Shunta Fujiki,
• Akihiro Sugawara,
• Yohei Morishita,
• Taro Ozaki and
• Teigo Asai

Beilstein J. Org. Chem. 2024, 20, 714–720, doi:10.3762/bjoc.20.65

• existing in their substrates. From a structural point of view, TCs consist of α, β, and γ domains in various combinations. As these TCs are assumed to be evolved by fusion and loss of domains [2][3][4], the functional analysis of terpene synthases of unique domain organization is of great significance to

Functions of enzyme domains in 2-methylisoborneol biosynthesis and enzymatic synthesis of non-natural analogs

• Binbin Gu,
• Lin-Fu Liang and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1452–1459, doi:10.3762/bjoc.19.104

• residue switches also allow for the acceptance of 2-Me-GPP and conversion into C11 compounds by plant terpene synthases during heterologous expression in yeast [32]. These findings prompted us to investigate in a second aspect of this study whether 2MIBS is able to convert non-natural GPP analogs with

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

• synthase homologs from diverse actinobacteria that were selected based on a phylogenetic analysis of more than 4000 amino acid sequences were investigated for their products. For four enzymes with functions not previously reported from bacterial terpene synthases the products were isolated and their

• structures were elucidated by NMR spectroscopy, resulting in the discovery of the first terpene synthases for (+)-δ-cadinol and (+)-α-cadinene, besides the first two bacterial (−)-amorpha-4,11-diene synthases. For other terpene synthases with functions reported from bacteria before the products were

• ; biosynthesis; enzymes; NMR spectroscopy; terpenes; Introduction Terpene synthases are remarkable enzymes that can convert acyclic and achiral oligoprenyl pyrophosphates into terpene hydrocarbons or alcohols of high structural complexity. These enzymatic reactions are initiated by ionisation of the substrate

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

• farnesylfarnesyl diphosphate (FFPP) can serve as a precursor to triterpenes [5], a compound class that was believed to be solely derived from squalene. Terpene synthases convert these linear precursors through cationic cascade reactions into terpene hydrocarbons or alcohols [6][7][8]. For type I terpene synthases

• of the δ-selinene synthase (ag4) from Abies grandis [66] and a product of several terpene synthases from C. sativa (CsTPS7, CsTPS8 and CsTPS22) [67], while 10 is the main product of the bacterial selinadiene synthase from Streptomyces pristinaespiralis [36][68]. It has recently been shown by a

Characterization of a new fusicoccane-type diterpene synthase and an associated P450 enzyme

• Jia-Hua Huang,
• Jian-Ming Lv,
• Liang-Yan Xiao,
• Qian Xu,
• Fu-Long Lin,
• Gao-Qian Wang,
• Guo-Dong Chen,
• Sheng-Ying Qin,
• Dan Hu and
• Hao Gao

Beilstein J. Org. Chem. 2022, 18, 1396–1402, doi:10.3762/bjoc.18.144

• become a promising strategy for targeted discovery of natural products [10][11][12], which can also provide enzymatic tools toward combinatorial biosynthesis [13][14]. As terpene synthases play a fundamental role in constructing molecular skeletons, great efforts have been devoted to mining novel

Enzymes in biosynthesis

• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2022, 18, 1131–1132, doi:10.3762/bjoc.18.116

• remarkable transformations in nature. Some of the most interesting transformations catalyzed by enzymes are known from the biosynthetic pathways towards natural products. For instance, class I terpene synthases can convert highly complex transformations of an acyclic precursor, such as farnesyl or

• geranylgeranyl diphosphate, into sesqui- or diterpenes, respectively. As has been described recently, even farnesylfarnesyl diphosphate can be converted into triterpenes, a substance class that was previously believed to originate exclusively from squalene by class II terpene synthases [1]. These conversions

• factories is easier to read than for terpene synthases, the functions of which are difficult to predict, but their size makes the megasynthases much more difficult to handle in the laboratory. Besides these core enzymes of the biosynthetic machineries to some of the most important classes of natural

Understanding the competing pathways leading to hydropyrene and isoelisabethatriene

• Shani Zev,
• Marion Ringel,
• Ronja Driller,
• Bernhard Loll,
• Thomas Brück and
• Dan T. Major

Beilstein J. Org. Chem. 2022, 18, 972–978, doi:10.3762/bjoc.18.97

• Translational Neuroscience – DANDRITE, Universitetsbyen 81, 8000 Aarhus C, Denmark 10.3762/bjoc.18.97 Abstract Terpene synthases are responsible for the biosynthesis of terpenes, the largest family of natural products. Hydropyrene synthase generates hydropyrene and hydropyrenol as its main products along with

• . We show that there is a great thermodynamic preference for hydropyrene and hydropyrenol formation, and hence most likely in the synthesis of the isoelisabethatriene products kinetic control is at play. Keywords: diterpenes; enzyme mechanism; quantum mechanics; terpene synthases; thermodynamic and

• kinetic control; Introduction Terpenes constitute a ubiquitous class of natural molecules that are synthesized by terpene synthases (TPS). TPS generate a plethora of terpenes employing rich carbocation chemistry from a very limited number of substrates, known as geranyl pyrophosphate (GPP), farnesyl

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

• . Several examples of enantiomers formation catalyzed by different terpene synthases were also reported. Jiang et al. characterized two new fungal bifunctional terpene synthases, FoFS and AtAS (identity 27.8%), that catalyzed the formation of a pair of enantiomeric sesterterpenes [23]. Two groups

• ). Different enantiomeric ratios could explain the properties of the active sites in the corresponding terpene synthases, which remain unclear for further investigations [22]. The diversified structures of terpenes were constructed by terpene synthase [26] along with the post-modification enzymes, such as P450

• aristolane cyclization. The ubiquitous co-existence of enantiomeric cadinane-type sesquiterpenoids in the sponge revealed the unique catalytic properties of sponge-derived terpene synthases, which attracts our attention for further investigation of their structure–function relationship. Further elucidation

Targeting active site residues and structural anchoring positions in terpene synthases

• Anwei Hou and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 2441–2449, doi:10.3762/bjoc.17.161

• , turning SmTS1 from a sesterterpene into a diterpene synthase. This article gives rational explanations for these findings that may generally allow for protein engineering of other terpene synthases to improve their catalytic efficiency or to change their functions. Keywords: biosynthesis; enzyme

• (GFPP, C25) for sesterterpene biosynthesis. Type I terpene synthases (TPSs) activate these acyclic molecules by the abstraction of diphosphate to produce a reactive allyl cation that can initiate a cascade reaction through typical carbocation chemistry, including cyclisation reactions by intramolecular

• from A222V (37% ee), A222L (7% ee) and A222I (32% ee). Conclusion Terpene synthases contain several well-known highly conserved motifs and single residues that are believed to be generally important for structure and function. As we show here, in special cases such as the sestermobaraene synthase SmTS1

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

• -insect interactions. Keywords: Ascomycota; Cladosporium; Salicaceae; terpene synthases; volatile organic compound (VOC); Introduction Plant volatile organic compounds (VOCs) can mediate plant–insect, plant–microbe, and plant–plant interactions [1][2][3][4]. The constitutive and herbivore-induced

• by the mevalonate pathway in fungi [42]. The condensation of DMAPP with varying numbers of IPP residues results in products of various chain lengths: geranyl diphosphate (GPP, C10), farnesyl diphosphate (FPP, C15), and geranylgeranyl diphosphate (GGPP, C20). Terpene synthases (TPS) then convert the

• precursors GPP, FPP, and GGPP into the different terpene skeletons [42][43][44]. However, our knowledge on terpene synthases of endophytic fungi is scarce, specifically in comparison to the vast knowledge on these enzymes in plants and bacteria [44][45]. Typical monoterpenes like limonene and linalool (5

On the mass spectrometric fragmentations of the bacterial sesterterpenes sestermobaraenes A–C

• Anwei Hou and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2020, 16, 2807–2819, doi:10.3762/bjoc.16.231

• allows to identify interesting candidate genes coding for terpene synthases for further studies by genome mining. A major difficulty in the GC–MS-based identification of terpenes is associated with the high similarity of the mass spectra of structurally related terpenes. For this reason, the unambiguous

• -labelled oligoprenyl diphosphates are at hand, is superior to any other approach for the introduction of labellings, also because the labelled terpene precursors can be used for studies on many different terpenes for which terpene synthases are available. In the present case it is intriguing to learn that

Understanding the role of active site residues in CotB2 catalysis using a cluster model

• Keren Raz,
• Ronja Driller,
• Thomas Brück,
• Bernhard Loll and
• Dan T. Major

Beilstein J. Org. Chem. 2020, 16, 50–59, doi:10.3762/bjoc.16.7

• interactions with N103, I181, and W186, which likely made similar stabilizing contributions as in cation H. It is well established that the inherent reactivity of carbocations [27], as well as correct substrate folding in the active site [3], play crucial roles in terpene synthases. The current results

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

• different precursors and enzymes, and different organisms utilize either or both pathways. A typical textbook description then divides terpene biosynthesis into two phases (Figure 4): 1) hydrocarbon backbone assembly and cyclization catalyzed by oligoprenyl synthetases and terpene cyclases (terpene

• synthases, TCs), respectively, to generate terpene scaffolds and 2) the decoration phase, during which the terpene scaffold can get heavily modified by tailoring enzymes [45][46][47]. Phase 1) terpene scaffold generation Unlike core biosynthetic enzymes or domains of other natural product classes (PKSs and

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

• relatedness to bacterial TPSs. The biological role of the volatile terpenoids produced by the plasmodia of P. polycephalum is discussed. Keywords: amoebae; evolution; terpene synthases; volatiles; Introduction Volatile organic compounds (VOCs) are used by many living organisms as chemical languages for

• ]. The MVA pathway is found in eukaryotes, archaea, and a few bacteria, and the MEP pathway is present in several photosynthetic eukaryotes and bacteria [11]. Isoprenyl diphosphate synthases (IDSs) catalyze the formation of prenyl diphosphates of various chain length [12]. After that, terpene synthases

• similarities occurred between PpolyTPS1 and PpolyTPS4 (72%) and between PpolyTPS2 and PpolyTPS3 (64%). PpolyTPS1/4 and PpolyTPS2/3, however, showed only ≈30% sequence similarity to each other. Terpene synthases can be classified into class I and class II, based on the reaction mechanisms they catalyze. These

Nanangenines: drimane sesquiterpenoids as the dominant metabolite cohort of a novel Australian fungus, Aspergillus nanangensis

• Heather J. Lacey,
• Cameron L. M. Gilchrist,
• Andrew Crombie,
• John A. Kalaitzis,
• Daniel Vuong,
• Peter J. Rutledge,
• Peter Turner,
• John I. Pitt,
• Ernest Lacey,
• Yit-Heng Chooi and
• Andrew M. Piggott

Beilstein J. Org. Chem. 2019, 15, 2631–2643, doi:10.3762/bjoc.15.256

• -type sesquiterpenoids from farnesyl diphosphate is proposed to proceed via the protonation-initiated mechanism (class II terpene synthases) [24], which is distinct from the ionisation-initiated mechanism (class I) terpene synthases, where a carbocation is generated by the release of a diphosphate group

• [30]. Therefore, the drimane synthase is likely to be different from the commonly observed sesquiterpene synthase, which belongs to the class I terpene synthases. Recently, the drimane synthase AstC involved in biosynthesis of the astellolides was identified and shown to be a novel member of the

• -reducing PKS (FE257_006541) and a FAD-binding oxidoreductase (FE257_006543). AstC, though annotated as a HAD-like hydrolase and having low sequence homology to other characterised terpene synthases, contains sequence motifs conserved across both class I (DDxxD/E) and class II (DxDD, QW) terpene synthases

Current understanding and biotechnological application of the bacterial diterpene synthase CotB2

• Ronja Driller,
• Daniel Garbe,
• Norbert Mehlmer,
• Monika Fuchs,
• Keren Raz,
• Dan Thomas Major,
• Thomas Brück and
• Bernhard Loll

Beilstein J. Org. Chem. 2019, 15, 2355–2368, doi:10.3762/bjoc.15.228

• product-shaped architecture of the active site. Catalytic motifs of CotB2 Mg2+ coordination by the aspartate-rich and NSE motif Instead of the classical DDxxD motif for class I TPS, CotB2 contains a modified 110DDxD113 motif, which is neither characteristic for class I nor class II terpene synthases. In

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

• biosynthetic reaction order is expandable to other terpene synthases to generate libraries of unnatural sesquiterpenoids with a wide range of potential uses and applications across many areas of human activity. Total-ion chromatogram of the pentane extractable products formed in an incubation of ADS with 8

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

• invertebrates [1][2]. More than 80,000 terpenoids have been identified and characterised [3][4][5]. These diverse and complex natural products are mostly derived from carbocation cyclisation with linear C5 isoprene precursors, which are catalysed by terpene synthases (TPSs) [6]. TPSs can be classified into

• . Four (10%) and eight (7%) membered ring structures (e.g. asteriscanolide) are seldom found [14]. With the lower costs of gene sequencing, recent developments in genome mining by sequencing and annotation have led to the discovery of a large number of functionally unknown terpene synthases [15][16][17

• products, heterologous expression of various sources of terpene synthases in Escherichia coli and Saccharomyces cerevisiae is a feasible approach [25][26]. In this study, a combination of genome mining and metabolic engineering was used for sesquiterpenoid discovery, utilizing farnesyl diphosphate

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

• backbone of 1–11 remains unknown. Given that the genome of B. sorokiniana BRIP10943 has been sequenced [14], we surveyed the genome for potential terpene synthases that may be responsible for the biosynthesis of these compounds. Four putative sesquiterpene synthases were found, corresponding to the genes

Inherent atomic mobility changes in carbocation intermediates during the sesterterpene cyclization cascade

• Hajime Sato,
• Takaaki Mitsuhashi,
• Mami Yamazaki,
• Ikuro Abe and
• Masanobu Uchiyama

Beilstein J. Org. Chem. 2019, 15, 1890–1897, doi:10.3762/bjoc.15.184

• these two methyl groups are critical for the preorganization of GFPP in the biosynthetic pathways leading to sesterfisherol and quiannulatene. Keywords: biosynthesis; carbocation; DFT; substrate recognition; terpene cyclase; Introduction Terpene synthases are thought to have four main roles: (i

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

• /bjoc.15.115 Abstract Terpene synthases are widely distributed among microorganisms and have been mainly studied in members of the genus Streptomyces. However, little is known about the distribution and evolution of the genes for terpene synthases. Here, we performed whole-genome based phylogenetic

• analysis of Streptomyces species, and compared the distribution of terpene synthase genes among them. Overall, our study revealed that ten major types of terpene synthases are present within the genus Streptomyces, namely those for geosmin, 2-methylisoborneol, epi-isozizaene, 7-epi-α-eudesmol, epi-cubenol

• , caryolan-1-ol, cyclooctat-9-en-7-ol, isoafricanol, pentalenene and α-amorphene. The Streptomyces species divide in three phylogenetic groups based on their whole genomes for which the distribution of the ten terpene synthases was analysed. Geosmin synthases were the most widely distributed and were found