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

• properties (Figure 4c) [45]. Notably, one tetrahydrofuranoterpenoid 59 is also formed as a major product in the BcBoT2 reaction, despite the low sequence similarity between these sesqui-TSs, which could be explained by similar active-site conformations to stabilize prenyl substrates. Similarly, limonene

Synthesis and properties of 6-alkynyl-5-aryluracils

• Ruben Manuel Figueira de Abreu,
• Till Brockmann,
• Alexander Villinger,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 898–911, doi:10.3762/bjoc.20.80

• -highest overall absorption intensity after 5d and a similar absorption peak can be observed. The similarity could be due to the double bond and its ability to interact with the system as a π-donor group. Consequently, the double bond could similarly influence the system as the dimethylamino group. As

(Bio)isosteres of ortho- and meta-substituted benzenes

• H. Erik Diepers and
• Johannes C. L. Walker

Beilstein J. Org. Chem. 2024, 20, 859–890, doi:10.3762/bjoc.20.78

• close similarity to the corresponding ortho-benzenes (Figure 15) [14][51]. Even though no value for the dihedral angle θ of disubstituted cubane has been reported, it is likely that the values of θ are approximately equivalent, given the forced coplanarity of the substituents in both cubane and benzene

Activity assays of NnlA homologs suggest the natural product N-nitroglycine is degraded by diverse bacteria

• Kara A. Strickland,
• Brenda Martinez Rodriguez,
• Ashley A. Holland,
• Shelby Wagner,
• Michelle Luna-Alva,
• David E. Graham and
• Jonathan D. Caranto

Beilstein J. Org. Chem. 2024, 20, 830–840, doi:10.3762/bjoc.20.75

• ), limiting the use of this model to predict the heme environment. Nevertheless, this protein–ligand model heme binding between the β-sheet and an α-helix based on similarity to the oxygen-sensing dimeric DosH protein [34]. DosH is also a heme-binding PAS-domain containing protein, further validating the

• sequence similarity searches and used to infer phylogenetic relationships. An alignment of 11 amino acid sequences with 28 to 87% identity was prepared resulting in a maximum likelihood tree (Figure 6) [37]. This tree identifies clusters of sequences within taxonomic lineages, suggesting that the gene has

• nnlA gene, including those described here, were identified by sequence similarity searches and their predicted amino acid sequences were used to infer phylogenetic relationships. An alignment of 11 amino acid sequences with 28 to 87% identity was prepared using MUSCLE software (ver. 5.1) [48] and

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

• utilizing the EFI-genome neighborhood tool (EFI-GNT), sequence alignment, and manual BLAST analysis [33]. Leveraging our previous discovery of SsDMS from Streptomyces showdoensis, we identified a homologous terpene cyclase (sclav_p0068) in S. clavuligerus. This enzyme shares a 50% sequence similarity with

Isolation and structure determination of a new analog of polycavernosides from marine Okeania sp. cyanobacterium

• Kairi Umeda,
• Naoaki Kurisawa,
• Ghulam Jeelani,
• Tomoyoshi Nozaki,
• Kiyotake Suenaga and
• Arihiro Iwasaki

Beilstein J. Org. Chem. 2024, 20, 645–652, doi:10.3762/bjoc.20.57

• similarity to other cyanobacterial metabolites. In this study, polycavernoside E (1), a new polycavernoside analog, was isolated from a marine Okeania sp. cyanobacterium obtained from Okinawa Prefecture, Japan (Figure 1). This finding provides additional evidence that polycavernosides are secondary

A myo-inositol dehydrogenase involved in aminocyclitol biosynthesis of hygromycin A

• Michael O. Akintubosun and
• Melanie A. Higgins

Beilstein J. Org. Chem. 2024, 20, 589–596, doi:10.3762/bjoc.20.51

• annotations and in vivo studies [8]. However, validation by in vitro approaches or biochemical analysis of the individual enzymes is lacking. Here, we verify that Hyg17 is a myo-inositol dehydrogenase and show that it has a distinct substrate scope. In addition, we use sequence similarity networks to compare

• efficiency can be attributed to the reduced kcat and increased KM for scyllo-inositol over myo-inositol. We also found that the catalytic efficiency for NAD+ was 452.4 ± 54.49 M−1 s−1 (Table 1 and Figure 2f). Sequence similarity network We generated a sequence similarity network (SSN) for the protein family

• determining the slope of the reaction from 0 to 5 min. Results were analyzed using Microsoft Excel and GraphPad Prism version 9.5.1 for Windows, GraphPad Software, Boston, Massachusetts USA, https://www.graphpad.com. SSN network generation and genome mining The sequence similarity network was generated using

A new analog of dihydroxybenzoic acid from Saccharopolyspora sp. KR21-0001

• Rattiya Janthanom,
• Yuta Kikuchi,
• Hiroki Kanto,
• Tomoyasu Hirose,
• Arisu Tahara,
• Takahiro Ishii,
• Arinthip Thamchaipenet and
• Yuki Inahashi

Beilstein J. Org. Chem. 2024, 20, 497–503, doi:10.3762/bjoc.20.44

• , Okinawa, Japan. The 16S rRNA gene sequence (GenBank accession number: PP237390) showed the highest similarity values with Saccharopolyspora shandongensis 88T (similarity: 99.6%) and Saccharopolyspora elongate 7K502T (similarity: 99.0%). Phylogenetic analysis of the 16S rRNA gene sequences showed that the

• strain KR21-0001 was clustered with them (Figure 1). The similarity of 16S rRNA gene sequence and phylogenetic analysis indicated that strain KR21-0001 belongs to the genus Saccharopolyspora. Saccharopolyspora sp. KR21-0001 was incubated in a jar fermenter containing 20 L of production medium for 7 days

• Island, Ou, Kumejima, Shimajiri District, Okinawa, Japan. Genomic DNA was prepared, and the 16S rRNA gene was amplified by PCR using the method of Inahashi and co-workers [23]. The sequencing analysis was performed by Eurofins Genomics. Similarity of 16S rRNA gene sequence was computed by using

Synthesis of 2,2-difluoro-1,3-diketone and 2,2-difluoro-1,3-ketoester derivatives using fluorine gas

• Alexander S. Hampton,
• David R. W. Hodgson,
• Graham McDougald,
• Linhua Wang and
• Graham Sandford

Beilstein J. Org. Chem. 2024, 20, 460–469, doi:10.3762/bjoc.20.41

• , electrophilic reagent to be important. Given the structural similarity of 1,4-diazabicyclo[2.2.2]octane (DABCO) to the Selectfluor system, a 10% v/v mixture of fluorine in nitrogen was passed through a solution of 1a in acetonitrile containing one equivalent of DABCO, using a fluorination apparatus and gas flow

Elucidating the glycan-binding specificity and structure of Cucumis melo agglutinin, a new R-type lectin

• Jon Lundstrøm,
• Emilie Gillon,
• Valérie Chazalet,
• Nicole Kerekes,
• Antonio Di Maio,
• Ten Feizi,
• Yan Liu,
• Annabelle Varrot and
• Daniel Bojar

Beilstein J. Org. Chem. 2024, 20, 306–320, doi:10.3762/bjoc.20.31

• profiling, thereby advancing both diagnostic methods and biomarker discovery. Examples include arrays that can rapidly profile alterations in glycosylation patterns, pivotal in many diseases and inflammatory changes [10][11]. Traditionally, lectins are divided into classes based on structural similarity and

• , by extension, common folds [12]. Still, shared binding specificity does not always follow from structural similarity, exemplified by divergent evolution within lectin families as well as independent emergence of similar binding patterns [13]. Many of the most commonly used lectins for the

• the resulting alignment distances, which is shown as a cladogram. For each protein, we only used the lectin domain, as annotated by UniProt or InterPro. For each protein, a representative binding specificity, based on literature reports, is provided. (b) Similarity of the two CBM13 domains in CMA1

Photochromic derivatives of indigo: historical overview of development, challenges and applications

• Gökhan Kaplan,
• Zeynel Seferoğlu and
• Daria V. Berdnikova

Beilstein J. Org. Chem. 2024, 20, 228–242, doi:10.3762/bjoc.20.23

• 9a in benzene was unambiguously proven by comparison with the oxalyl derivative 10 comprising the Z-double bond. Thus, the absorption band of Z-9a at about 430 nm closely matched the absorption maximum of the oxalyl indigo 10 (436 nm) pointing out the similarity of the chromophoric structures of both

Optimizing reaction conditions for the light-driven hydrogen evolution in a loop photoreactor

• Pengcheng Li,
• Daniel Kowalczyk,
• Johannes Liessem,
• Mohamed M. Elnagar,
• Dariusz Mitoraj,
• Radim Beranek and
• Dirk Ziegenbalg

Beilstein J. Org. Chem. 2024, 20, 74–91, doi:10.3762/bjoc.20.9

• the contrary, expanding photocatalytic systems, particularly those employing powdered photocatalysts, to a larger scale is notably more straightforward [17][18]. However, complications arise when attempting to scale up reactors solely based on geometric similarity, as alterations in mixing and

Identification of the p-coumaric acid biosynthetic gene cluster in Kutzneria albida: insights into the diazotization-dependent deamination pathway

• Seiji Kawai,
• Akito Yamada,
• Yohei Katsuyama and
• Yasuo Ohnishi

Beilstein J. Org. Chem. 2024, 20, 1–11, doi:10.3762/bjoc.20.1

• ) [13]. CmaA2 and CmaA3 showed relatively high amino acid sequence similarity to AvaA2 and AvaA3, respectively (≈50% identity; see Table S2 in Supporting Information File 1). In contrast, low similarities were observed between CmaA2 and AvaA3, and between CmaA3 and AvaA2 (Table S2, Supporting

• insights into how highly reducing type II PKSs control starter substrate incorporation. The only difference between avenalumic acid and p-coumaric acid is the chain length. The CLF CmaA5 shows 35.4% identity to AvaA5, which is the lowest similarity score among Ava and Cma protein pairs (Table 1). This is

• belong to different clades, and the proteins belonging to the third clade have a low sequence similarity to both AvaA5 and CmaA6. Thus, the ava cluster-related BGCs that encode a CLF belonging to the third clade likely produce analog compounds with different chain lengths. p-Coumaric acid is an

Studying specificity in protein–glycosaminoglycan recognition with umbrella sampling

• Mateusz Marcisz,
• Sebastian Anila,
• Margrethe Gaardløs,
• Martin Zacharias and
• Sergey A. Samsonov

Beilstein J. Org. Chem. 2023, 19, 1933–1946, doi:10.3762/bjoc.19.144

• (Figure 3), and this is also reflected in very low RMSD values (3 to 4 Å for such long and flexible molecules is considered to reflect high structural similarity). Ligand 3. Similar to the other ligands, when pulled away from the binding site the RMSD of ligand 3 gradually increased and during pulling in

Controlling the reactivity of La@C₈₂ by reduction: reaction of the La@C₈₂ anion with alkyl halide with high regioselectivity

• Yutaka Maeda,
• Saeka Akita,
• Mitsuaki Suzuki,
• Michio Yamada,
• Takeshi Akasaka,
• Kaoru Kobayashi and
• Shigeru Nagase

Beilstein J. Org. Chem. 2023, 19, 1858–1866, doi:10.3762/bjoc.19.138

• @C2v-C82(CHClC6H3Cl2) [19] and La@C2v-C82(CBr(CO2Et)2) [23], by single-crystal X-ray diffraction (SC-XRD) analysis. Based on the similarity in the absorption spectra of La@C2v-C82(CHClC6H3Cl2), the addition site of 3a–c was expected to be at the C10 (for the numbering of carbon atoms in La@C2v-C82; see

• Figure 6d). Takano et al. estimated the addition sites of the 3,5-dimethylphenylmethyl group on Ce@C2v-C82 (Ce@C2v-C82(CH2C6H3Me2)) through temperature-dependent paramagnetic shifts of its nuclear magnetic resonance signals [25]. The similarity in the HPLC separation behavior and absorption spectra

Charge carrier transport in perylene-based and pyrene-based columnar liquid crystals

• Alessandro L. Alves,
• Simone V. Bernardino,
• Carlos H. Stadtlober,
• Edivandro Girotto,
• Giliandro Farias,
• Rodney M. do Nascimento,
• Sergio F. Curcio,
• Thiago Cazati,
• Marta E. R. Dotto,
• Juliana Eccher,
• Leonardo N. Furini,
• Hugo Gallardo,
• Harald Bock and
• Ivan H. Bechtold

Beilstein J. Org. Chem. 2023, 19, 1755–1765, doi:10.3762/bjoc.19.128

• monomeric species [34]. It agrees with the intensity inversion of the vibronic absorption bands and PL redshift in the spin-coated film compared to the solution. The intensity inversion suggests formation of H-aggregates, leading to excimer fluorescence [35]. Due to the similarity to the lifetime in

Decarboxylative 1,3-dipolar cycloaddition of amino acids for the synthesis of heterocyclic compounds

• Xiaofeng Zhang,
• Xiaoming Ma and
• Wei Zhang

Beilstein J. Org. Chem. 2023, 19, 1677–1693, doi:10.3762/bjoc.19.123

• sequence using stabilized AMYs was also reported from our lab [72]. The triazolobenzodiazepines obtained through this highly efficient one-pot synthesis have structure similarity with some drug molecules shown in Figure 4 [71]. One-pot synthesis of pyrroloquinazolines and pyrrolobenzodiazepines We

• could also be applied for the synthesis of pyrrolobenzodiazepines when using 2-bromoketones instead of the acid chlorides affording products 24a–g in 59–77% yields with 3:1 to 6:1 dr (Scheme 15). The pyrroloquinazolines and pyrrolobenzodiazepines made by this route have structure similarity with

Synthesis and biological evaluation of Argemone mexicana-inspired antimicrobials

• Jessica Villegas,
• Bryce C. Ball,
• Katelyn M. Shouse,
• Caleb W. VanArragon,
• Ashley N. Wasserman,
• Hannah E. Bhakta,
• Allen G. Oliver,
• Danielle A. Orozco-Nunnelly and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2023, 19, 1511–1524, doi:10.3762/bjoc.19.108

• kinase C [25]. Due to the wide range of biological activities for both berberine and chelerythrine, several reports have been made on structural derivatives of these compounds [16][23][26][27][28][29][30][31][32][33]. Given the extreme structural similarity between chelerythrine and sanguinarine

• variants was largely inspired by a recent report that prepared flexible secondary ammonium cations with structural similarity to chelerythrine, wherein the authors did see notable biological potential in these flexible variants [32]. The influence of a fixed charge was also assessed, as protonated compound

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• ligands in organometallic chemistry. After the first synthesis of stable monomeric NHCs, spectroscopic studies promptly revealed their similarity with phosphines. Indeed, both these classes of ligands are σ-donor ligands with low π-backdonating character [16][17]. In the beginning, the NHCs were perceived

Radical ligand transfer: a general strategy for radical functionalization

• David T. Nemoto Jr,
• Kang-Jie Bian,
• Shih-Chieh Kao and
• Julian G. West

Beilstein J. Org. Chem. 2023, 19, 1225–1233, doi:10.3762/bjoc.19.90

• . Further, we demonstrated that diazidation could be rendered catalytic using Fe(III) nitrate hydrate III as the iron source and performing the reaction under continuous flow conditions. Interestingly, this mechanism bears some similarity to Lin’s electrocatalytic diazidation, where azido radical generation

Two new lanostanoid glycosides isolated from a Kenyan polypore Fomitopsis carnea

• Winnie Chemutai Sum,
• Sherif S. Ebada,
• Didsanutda Gonkhom,
• Cony Decock,
• Rémy Bertrand Teponno,
• Josphat Clement Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2023, 19, 1161–1169, doi:10.3762/bjoc.19.84

• additional oxygen atom compared to compound 1. The 1H, 13C NMR, and HSQC spectral data of compound 2 (Table 1) revealed a close similarity to forpinioside B (1) apart from the presence of an additional aliphatic methine proton at δH 4.02 (ddd, J = 12.3, 4.3, 2.9 Hz; δC 66.5) which exhibited an obvious spin

Synthesis, structure, and properties of switchable cross-conjugated 1,4-diaryl-1,3-butadiynes based on 1,8-bis(dimethylamino)naphthalene

• Semyon V. Tsybulin,
• Ekaterina A. Filatova,
• Alexander F. Pozharskii,
• Valery A. Ozeryanskii and
• Anna V. Gulevskaya

Beilstein J. Org. Chem. 2023, 19, 674–686, doi:10.3762/bjoc.19.49

• methoxyphenyl and the accepting protonated DMAN fragments becomes preferable (Figure 10). This is supported by a comparison of the absorption spectra of salt 11b and protonated forms of diyne 1 [15] and monomer 6b (salts 1·2HBF4 and 6b·HBF4), which demonstrates an obvious similarity of spectral curves of 11b

Cassane diterpenoids with α-glucosidase inhibitory activity from the fruits of Pterolobium macropterum

• Sarot Cheenpracha,
• Ratchanaporn Chokchaisiri,
• Lucksagoon Ganranoo,
• Sareeya Bureekaew,
• Thunwadee Limtharakul and
• Surat Laphookhieo

Beilstein J. Org. Chem. 2023, 19, 658–665, doi:10.3762/bjoc.19.47

• , and one oxygenated sp3 at δC 72.2). The 1H and 13C NMR spectroscopic data of 1 showed great similarity to those of 12α,14β-dihydroxycassa-13(15)-en-12,16-olide (2) isolated from Caesalpinia bonduc [18]. The difference evident was that compound 1 displayed an extended conjugate π-system with an α,β

A new oxidatively stable ligand for the chiral functionalization of amino acids in Ni(II)–Schiff base complexes

• Alena V. Dmitrieva,
• Oleg A. Levitskiy,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2023, 19, 566–574, doi:10.3762/bjoc.19.41

• has the same configuration (ʟ), which was additionally confirmed by the similarity of the H-8 proton chemical shifts for all these complexes (the value falls within the 8.27–8.30 ppm range). It should be emphasized that the H-8 chemical shift is very sensitive to the configuration of the α

• ]. Meanwhile, an important difference is the reversibility of the oxidation observed at low potential scan rates (100 mV/s) for the complexes (GlyNi)L7 and (ΔAlaNi)L7 (see Figure 4), in contrast to their t-Bu-free analogs. The similarity of the potential values for the complexes derived from L1 and L7 allows

Discrimination of β-cyclodextrin/hazelnut (Corylus avellana L.) oil/flavonoid glycoside and flavonolignan ternary complexes by Fourier-transform infrared spectroscopy coupled with principal component analysis

• Nicoleta G. Hădărugă,
• Gabriela Popescu,
• Dina Gligor (Pane),
• Cristina L. Mitroi,
• Sorin M. Stanciu and
• Daniel Ioan Hădărugă

Beilstein J. Org. Chem. 2023, 19, 380–398, doi:10.3762/bjoc.19.30

• total number of 26 variables). Other valuable classifications were obtained for the antioxidant flavonoids, with a high similarity for hesperidin and naringin, according to FTIR–PCA, as well as for ternary complexes depending on molar ratios. The FTIR–PCA coupled technique is a fast, nondestructive and

• cheap method for the evaluation of quality and similarity/characteristics of these new types of cyclodextrin-based ternary complexes having enhanced properties and stability. Keywords: antioxidant; cyclodextrin; flavonoid; hazelnut vegetable oil; ternary supramolecular inclusion complex; Introduction

• suitable for the evaluation of such ternary complexes. The coupling of FTIR or other spectroscopic or chromatographic techniques with a multivariate statistical analysis method (e.g., principal component analysis, PCA) allows the evaluation of the similarity/dissimilarity of complexes, as well as the