Methyltransferases from RiPP pathways: shaping the landscape of natural product chemistry

• Maria-Paula Schröder,
• Isabel P.-M. Pfeiffer and
• Silja Mordhorst

Beilstein J. Org. Chem. 2024, 20, 1652–1670, doi:10.3762/bjoc.20.147

• proteusin family of RiPPs. They are produced by the tunicate symbiont Candidatus Entotheonella factor and exhibit membrane activity against Gram-positive bacteria and are highly cytotoxic. Cytotoxicity was tested with murine leukaemia cells; polytheonamide A, B, and C showed IC50 values between 68 and 78 pg

• member of the channel-forming, cytotoxic proteusins. It is biosynthesised by Microvirgula aerodenitrificans. Like polytheonamide B, aeronamide A shows cytotoxic activity against HeLa cells, with an IC50 of 1.48 nM. AerE, the PoyE homologue, installs five methylations on the amides of Asn25, Asn31, Asn37

Polymer degrading marine Microbulbifer bacteria: an un(der)utilized source of chemical and biocatalytic novelty

• Weimao Zhong and
• Vinayak Agarwal

Beilstein J. Org. Chem. 2024, 20, 1635–1651, doi:10.3762/bjoc.20.146

• agarase was also reported from the same bacterium [27]. The recombinant enzyme (rAgaO) was expressed in B. subtilis cells to demonstrate that this enzyme was an endo-type β-agarase and degraded agarose to neoagarohexaose as the main product [27]. The enzyme rAgaO represents the first and only report on

• Gram-positive bacteria Kocuria rhizophila and S. aureus, Gram-negative bacterium Tenacibaculum maritimum, and a panel of fungi. These molecules also demonstrated moderate cytotoxicity against P388 murine leukemia cells. The bisindole alkaloid violacein (24, Figure 8) was isolated and characterized from

New triazinephosphonate dopants for Nafion proton exchange membranes (PEM)

• Fátima C. Teixeira,
• António P. S. Teixeira and
• C. M. Rangel

Beilstein J. Org. Chem. 2024, 20, 1623–1634, doi:10.3762/bjoc.20.145

• . Romão Ramalho, 59, 7000-671 Évora, Portugal 10.3762/bjoc.20.145 Abstract A new paradigm for energy is underway demanding decarbonized energy systems. Some of them rely on emerging electrochemical devices, crucial in hydrogen technologies, including fuel cells, CO2 and water electrolysers, whose

• N115, in the same experimental conditions. The Nafion-doped membrane with compound TP2 with a 1.0 wt % loading showed the highest proton conductivity with 84 mS·cm−1. Keywords: electrolyser; fuel cells; Nafion-modified membranes; phosphonates; proton exchange membranes; triazine; Introduction

• exchange membrane devices [5][6], such as proton exchange membrane fuel cells (PEMFCs) [3][7][8][9], due to their high-power density and high power-to-weight ratio, and CO2 electrolysers, which can reduce the polluting gas CO2 and produce syngas from the co-electrolysis of CO2 and water [10][11], or water

Supramolecular assemblies of amphiphilic donor–acceptor Stenhouse adducts as macroscopic soft scaffolds

• Ka-Lung Hung,
• Leong-Hung Cheung,
• Yikun Ren,
• Ming-Hin Chau,
• Yan-Yi Lam,
• Takashi Kajitani and
• Franco King-Chi Leung

Beilstein J. Org. Chem. 2024, 20, 1590–1603, doi:10.3762/bjoc.20.142

• functionalized with photoresponsive and photoabsorbing functional motifs, serving as the counterpart of natural photosystems. This allowed to construct smart materials that harvest light energy, e.g., solar cells, photosensitizers, and photochromic materials [1][2][3][4]. Supramolecular assemblies are commonly

• prepared by ejecting 5.0 wt % DAn solutions onto a bioinert glass-bottomed Petri dish by the shear-flow method, rinsing with PBS, and incubating with human-bone-marrow-derived mesenchymal stem cells (hBM-MSCs) at 37 °C and 5% CO2 for 3 days. hBM-MSCs have demonstrated importance in controlled

• differentiations and clinical translations. The DA11 scaffold remained intact after incubation at 37 °C, while the hBM-MSCs cells grew and attached onto the scaffold surface (Figure 6a and Figure 6b). However, the structural properties of the macroscopic soft DA11 scaffold could not be transferred to the attached

Photoswitchable glycoligands targeting Pseudomonas aeruginosa LecA

• Yu Fan,
• Ahmed El Rhaz,
• Stéphane Maisonneuve,
• Emilie Gillon,
• Maha Fatthalla,
• Franck Le Bideau,
• Guillaume Laurent,
• Samir Messaoudi,
• Anne Imberty and
• Juan Xie

Beilstein J. Org. Chem. 2024, 20, 1486–1496, doi:10.3762/bjoc.20.132

• ] or to mannosyl azobenzene-modified human cells [21] through photoswitching the orientation of the attached mannoside [22]. Photoswitchable glycooligomers [23] or glycodendrimers [24] have been investigated for the inhibition of PA lectin PA-IL or LecA and LecB. A variation of the IC50 value by a

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

• seven analogs for cytotoxicity against human colon carcinoma HCT-116 cells. Unfortunately, none of the compounds up to 10 μM showed any activity when tested in MTT-based cell viability assays. Conclusion Eunicellane diterpenoids have been known for over 50 years, but it was not until recently that their

Sustainable tandem acylation/Diels–Alder reaction toward versatile tricyclic epoxyisoindole-7-carboxylic acids in renewable green solvents

• Ayhan Yıldırım

Beilstein J. Org. Chem. 2024, 20, 1308–1319, doi:10.3762/bjoc.20.114

• oligopeptidase inhibitory activity in human cells [117]. The solvent mixture used to precipitate the product was removed from the filtrate using a rotary evaporator and it was found that the used bio-based solvents could be recovered in a near quantitative amount for reuse. The recovered SSO solvent was reused

Synthesis of indano[60]fullerene thioketone and its application in organic solar cells

• Yong-Chang Zhai,
• Shimon Oiwa,
• Shinobu Aoyagi,
• Shohei Ohno,
• Tsubasa Mikie,
• Jun-Zhuo Wang,
• Hirofumi Amada,
• Koki Yamanaka,
• Kazuhira Miwa,
• Naoyuki Imai,
• Takeshi Igarashi,
• Itaru Osaka and
• Yutaka Matsuo

Beilstein J. Org. Chem. 2024, 20, 1270–1277, doi:10.3762/bjoc.20.109

• -withdrawing substituents. Computational studies with density functional theory revealed the unique vibrations of the thioketone group in FIDS. The molecular structure of FIDS was confirmed by single-crystal X-ray analysis. Bulk heterojunction organic solar cells using three evaporable fullerene derivatives

• (FIDO, FIDS, C60) as electron-acceptors were compared, and the open-circuit voltage with FIDS was 0.16 V higher than that with C60. Keywords: C60; evaporable fullerene derivatives; organic photovoltaics; organic solar cells; thioketone; Introduction Fullerene is a carbon allotrope that has attracted

• improving their thermal stability, and more specifically, of designing evaporable fullerene derivatives [16][17][18]. Recently, we reported on perovskite solar cells fabricated with indano[60]fullerene ketone (FIDO), which was synthesized through fullerene cation chemistry. These cells demonstrated long

Cofactor-independent C–C bond cleavage reactions catalyzed by the AlpJ family of oxygenases in atypical angucycline biosynthesis

• Jinmin Gao,
• Liyuan Li,
• Shijie Shen,
• Guomin Ai,
• Bin Wang,
• Fang Guo,
• Tongjian Yang,
• Hui Han,
• Zhengren Xu,
• Guohui Pan and
• Keqiang Fan

Beilstein J. Org. Chem. 2024, 20, 1198–1206, doi:10.3762/bjoc.20.102

• . Both plasmids were confirmed by sequencing and transformed into E. coli BL21(DE3). Protein overproduction was induced with 0.1 mM isopropyl β-ᴅ-thiogalactopyranoside at 16 °C for 15 h. Cells were collected by centrifugation (8,000g, 15 min) at 4 °C. The pellets were resuspended in ice-cold 50 mM 3-(N

• -morpholino)propanesulfonic acid (MOPS) buffer (pH 7.5), and the cells were disrupted by ultrasonication to obtain the cell extract. Cell debris was removed by centrifugation (14,000g, 15 min). The proteins were purified by Ni-NTA agarose chromatography, desalted, and concentrated by centrifugation (8,000g

Two-fold addition reaction of silylene to C₆₀: structural and electronic properties of a bis-adduct

• Masahiro Kako,
• Masato Kai,
• Masanori Yasui,
• Michio Yamada,
• Yutaka Maeda and
• Takeshi Akasaka

Beilstein J. Org. Chem. 2024, 20, 1179–1188, doi:10.3762/bjoc.20.100

• with excellent properties as organic photovoltaic materials [9][10][11][12][13][14]. Furthermore, regioisomerically pure bis-functionalized fullerenes function better as electron acceptors in organic thin-film solar cells than mixtures of the corresponding regioisomers do [12][13][14]. Therefore

Bismuth(III) triflate: an economical and environmentally friendly catalyst for the Nazarov reaction

• Manoel T. Rodrigues Jr.,
• Aline S. B. de Oliveira,
• Ralph C. Gomes,
• Amanda Soares Hirata,
• Lucas A. Zeoly,
• Hugo Santos,
• João Arantes,
• Catarina Sofia Mateus Reis-Silva,
• João Agostinho Machado-Neto,
• Leticia Veras Costa-Lotufo and
• Fernando Coelho

Beilstein J. Org. Chem. 2024, 20, 1167–1178, doi:10.3762/bjoc.20.99

• 3-aryl-1-indanones) in good to excellent yield. The reaction did not require additives and was insensitive to both air and moisture. Preliminary biological evaluation of some indanones showed a promising profile against some human cancer line cells. Keywords: bismuth; catalysis; heterocycles

• ] and the broad spectrum of biological activities. Among the five-membered ring compounds, we find indanone (1, Figure 1). Within the class of indanones, we can highlight some interesting compounds. For example, nakiterpiosinone (2), which inhibits the growth of P388 mouse leukemia cells with an average

• tumor lines, HCT116 (colon adenocarcinoma), MCF7 (breast adenocarcinoma), SK-MEL-28 (melanoma), and NB4 (acute leukemia) by methylthiazol tetrazolium (MTT) assay, as previously described [85]. Among the tested cells, NB4 cells were the most sensitive ones, with 7 compounds (10aa,bk and 11aa,ad,ae,dc,bj

Synthesis of 1,4-azaphosphinine nucleosides and evaluation as inhibitors of human cytidine deaminase and APOBEC3A

• Maksim V. Kvach,
• Stefan Harjes,
• Harikrishnan M. Kurup,
• Geoffrey B. Jameson,
• Elena Harjes and
• Vyacheslav V. Filichev

Beilstein J. Org. Chem. 2024, 20, 1088–1098, doi:10.3762/bjoc.20.96

• bacteria and fungi but not in mammalian cells, acts only on cytosine. Cytidine deaminase (CDA) as a key enzyme in the pyrimidine salvage pathway in mammals deaminates both cytidine and 2'-deoxycytidine. Members of the apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like (APOBEC) family, such as

• (MDS) and chronic myelomonocytic leukaemia (CMML) [8]. In normal human cells, the enzyme family A3 [9][10][11][12] disables pathogens by scrambling ssDNA by cytosine to uracil mutation (Figure 1A) [9][10][13][14]. However, several enzymes, particularly A3A, A3B, A3H and A3G, deaminate cytosine in human

• nuclear and mitochondrial genomes [15]. This A3-induced mutational activity is used by viruses and cancer cells to increase the rates of mutagenesis, which allows them to escape adaptive immune responses and become drug resistant [16][17][18][19][20], leading to poor clinical outcomes. A range of genetic

Structure–property relationships in dicyanopyrazinoquinoxalines and their hydrogen-bonding-capable dihydropyrazinoquinoxalinedione derivatives

• Tural N. Akhmedov,
• Ajeet Kumar,
• Daken J. Starkenburg,
• Kyle J. Chesney,
• Khalil A. Abboud,
• Novruz G. Akhmedov,
• Jiangeng Xue and
• Ronald K. Castellano

Beilstein J. Org. Chem. 2024, 20, 1037–1052, doi:10.3762/bjoc.20.92

• 40 μM solutions of the DCPQs and DPQDs on a Cary 100 Bio spectrophotometer using 1 cm quartz cells. All solvents were HPLC grade (purchased from Fisher) and stored over 4 Å molecular sieves. The absorption intensity at λmax was then plotted against the concentration in all cases to confirm, by

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

• ; nevertheless, some promiscuous TSs accept multiple prenyl substrates and produce various products. In nature, the biosynthesis of prenyl substrates may have subcellular locations, and the available types of prenyl substrates are limited, especially for noncanonical substrates in living cells. Therefore, the

Monitoring carbohydrate 3D structure quality with the Privateer database

• Jordan S. Dialpuri,
• Haroldas Bagdonas,
• Lucy C. Schofield,
• Phuong Thao Pham,
• Lou Holland and
• Jon Agirre

Beilstein J. Org. Chem. 2024, 20, 931–939, doi:10.3762/bjoc.20.83

• modelling of glycoproteins and protein–carbohydrate complexes is pivotal in understanding the complex biochemical interactions that affect the physiological function of cells [1]. Any mechanistic analysis done with finely grained approaches such as QM/MM [2] relies heavily on the correctness of the starting

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

• that the distance between the molecules within the unit cell is higher than the distance between the unit cells. In addition, the molecules are arranged parallel-displaced to each other, which is considered to be more stable than the sandwich arrangement [64][65][66][67][68]. Consequently, the distance

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

• experiments comparing the toxicity of NNG towards wild-type cells expressing NnlA and NnlA knockout mutant strains would test this hypothesis. Conclusion In this study the NNG degradation activity of five Vs NnlA homologs was screened in E. coli transformants, providing evidence that all five degrade NNG. Of

• pET-28a(+)-TEV by GenScript. For protein expression, plasmids were electroporated into E. coli BL21(DE3) cells and protein was expressed and purified by immobilized metal affinity chromatography (IMAC) as previously described for Vs NnlA [21]. The only modification was that plasmids using pET-28a

• cells were then plated on LB agar plates containing ampicillin (100 µg/mL) or kanamycin (50 µg/mL) as appropriate and incubated overnight at 37 °C. Three colonies from each plate were picked with a toothpick and then resuspended in 0.2 mL of sterile water. Thirty microliter aliquots of suspended cells

Synthesis of new representatives of A₃B-type carboranylporphyrins based on meso-tetra(pentafluorophenyl)porphyrin transformations

• Victoria M. Alpatova,
• Evgeny G. Rys,
• Elena G. Kononova and
• Valentina A. Ol'shevskaya

Beilstein J. Org. Chem. 2024, 20, 767–776, doi:10.3762/bjoc.20.70

• molecules which have been also used for selective delivery of the drug to cancer cells [45]. Here, biotin was conjugated to porphyrin 12 which was obtained by alkylation of the amino group in compound 5 with chloroacetyl chloride (10) to give porphyrin biotin conjugate 14 in 76% yield (Scheme 4). We also

Methodology for awakening the potential secondary metabolic capacity in actinomycetes

• Shun Saito and
• Midori A. Arai

Beilstein J. Org. Chem. 2024, 20, 753–766, doi:10.3762/bjoc.20.69

• . At a concentration of 182 μM, murecholamide exhibits biological activity in inhibiting the migration of HT29 cancer cells. The second HSM is noaoxazole (39), which was discovered in Streptomyces sp. HR41 [79]. This substance has a chemical structure with a methylated oxazole ring at the end of a

• Streptomyces and mycolic acid-containing bacteria (MACB) activates secondary metabolism [111]. In their method, direct attachment by live MACB cells is thought to alter secondary metabolism in the Streptomyces cells [112]. Using this method, Onaka et al. identified a variety of new compounds, such as

• , a unique case of activation of secondary metabolite biosynthetic genes by co-culture of actinomycetes and animal cells has been reported, which we outline in detail below. If microorganisms and animal cells are used, one might first imagine the interaction between humans and intestinal bacteria

Research progress on the pharmacological activity, biosynthetic pathways, and biosynthesis of crocins

• Zhongwei Hua,
• Nan Liu and
• Xiaohui Yan

Beilstein J. Org. Chem. 2024, 20, 741–752, doi:10.3762/bjoc.20.68

• -synuclein (αS), thereby alleviating the apoptosis of neuronal cells and cognitive impairment [30][31][32][33]. Lastly, the extract of C. sativus can also improve the chronic stress-induced loss of learning and memory by reducing the ROS level or regulating the synthesis of superoxide dismutase (SOD) and

• alleviate gestational hypertension. Therefore, crocins have the potential to prevent pregnancy-induced hypertension [45]. Anticancer Crocins exhibit potent anticancer activity against various cancer cell lines. Jiang et al. found that crocins reduce the survival and activity of cervical cancer cells [46

• ]. Mollaei et al. observed an increased Bax/Bcl-2 ratio in crocin-treated cancer cells. Therefore, crocins are proposed to exert anticancer activity by promoting apoptosis of cancer cells [47]. This mechanism is consistent with the results of Hoshyar et al., who observed the apoptosis-promoting activity of

Substrate specificity of a ketosynthase domain involved in bacillaene biosynthesis

• Zhiyong Yin and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2024, 20, 734–740, doi:10.3762/bjoc.20.67

• organism shares the same habitat with the predator Myxococcus xanthus that feeds on other bacteria including B. subtilis, and bacillaene is the primary factor conferring B. subtilis cells resistance to predation by M. xanthus [8]. The identification of its biosynthetic gene cluster (bae) revealed that the

Chemoenzymatic synthesis of macrocyclic peptides and polyketides via thioesterase-catalyzed macrocyclization

• Senze Qiao,
• Zhongyu Cheng and
• Fuzhuo Li

Beilstein J. Org. Chem. 2024, 20, 721–733, doi:10.3762/bjoc.20.66

• brevis [27], can penetrate the lipid phase of a Gram-positive inner cell membrane [28][29]. Despite exhibiting high antimicrobial activity, this compound also disrupts the membranes of higher mammalian cells, as evidenced by their pronounced hemolytic activity [30]. Establishing a concise and diverse

New variochelins from soil-isolated Variovorax sp. H002

• Jabal Rahmat Haedar,
• Aya Yoshimura and
• Toshiyuki Wakimoto

Beilstein J. Org. Chem. 2024, 20, 692–700, doi:10.3762/bjoc.20.63

• 2xR2A three times, and the pellets were resuspended with 500 mL of 2xR2A. The OD600 values of the donor (E. coli S17-1 λpir) and recipient (Variovorax sp. H002) cells were set to 2.0 and mixed in a 1:1 ratio. The mixtures were spotted onto 2xR2A plates and incubated at 30 °C for two days. The colonies

Organic electron transport materials

• Joseph Cameron and
• Peter J. Skabara

Beilstein J. Org. Chem. 2024, 20, 672–674, doi:10.3762/bjoc.20.60

• transport materials for organic semiconductor devices due to their potential to be applied in various technologies. For example, such materials can be used to improve charge balance in the emissive layer of an organic light-emitting diode, charge extraction in perovskite solar cells or used as the

• , meaning organic materials can be used effectively in a range of applications. For example, while a non-fullerene acceptor material might not be suitable as an electron transport layer in OPVs due to dissolution of layers, it can used in perovskite solar cells where it can be successfully deposited through

• soluble in ethyl acetate, a green solvent, and solution-processed for PM6:Y6 bulk-heterojunction solar cells with power conversion efficiency > 13% [6]. In addition to orthogonal processing, it has been shown that treatment with base [7] or photo-crosslinking [8] can insolubilise solution-processed layers

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

• , containing 50 μL of culture medium. Subsequently, 50 μL of a parasite suspension with a concentration of 4.0 × 104 cells/mL was introduced into each well. Cultures were incubated for 69 h at 37 °C under a humidified 5% CO2 atmosphere. After this time, 10 μL of resazurin (12.5 mg resazurin (Sigma) dissolved

• in 100 mL phosphate-buffered saline) was added to each well. The plates were incubated for an additional 3 h. The plates were read in a SpectraMax Gemini XS microplate fluorescence scanner (Molecular Devices) using an excitation wavelength of 536 nm and an emission wavelength of 588 nm. WI-38 cells

• assay In a manner analogous to [7], WI-38 cells were cultured at 37 °C with 5% CO2 in DMEM (Nissui) supplemented with 10% heat-inactivated FBS, 100 units/mL penicillin, 100 μg/mL streptomycin, 0.25 μg/mL amphotericin, 300 μg/mL ʟ-glutamine, and 2.25 mg/mL NaHCO3. Cells were seeded at 4 × 103 cells/well