HPW-Catalyzed environmentally benign approach to imidazo[1,2-a]pyridines

• Luan A. Martinho and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2024, 20, 628–637, doi:10.3762/bjoc.20.55

• -Aminopyridine (1a), 4-nitrobenzaldehyde (2a), and tert-butyl isocyanide (3a) were chosen as model substrates and different conditions were screened (Table 1). Glycerol, a green and sustainable solvent, was tried first, but unfortunately, the expected intense orange solid product 4a was obtained in low yields

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

• mL−1 tetracycline and grown at 200 rpm and 37 °C overnight. One liter of autoinduction media (20 g L−1 tryptone, 10 g L−1 yeast extract, 50 mM NH4Cl, 2 mM MgSO4, 0.5% glycerol, 17 mM KH2PO4, 72 mM K2HPO4, 0.05% glucose, and 0.2% lactose) supplemented with 10 μg mL−1 ampicillin and 1.5 μg mL−1

• coefficient 33,460 M−1 cm−1 and 38,350 M−1 cm−1 for Hyg17 and BsIDH, respectively [29]. Protein was flash frozen in liquid nitrogen at 100 μM in 20 mM Tris pH 8, 50 mM NaCl, and 10% glycerol and stored at −80 °C for biochemical assays. Enzyme assays Generally, 100 μL reactions contained 10 mM inositol

Synthesis and biological profile of 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines, a novel class of acyl-ACP thioesterase inhibitors

• Jens Frackenpohl,
• David M. Barber,
• Guido Bojack,
• Birgit Bollenbach-Wahl,
• Ralf Braun,
• Rahel Getachew,
• Sabine Hohmann,
• Kwang-Yoon Ko,
• Karoline Kurowski,
• Bernd Laber,
• Rebecca L. Mattison,
• Thomas Müller,
• Anna M. Reingruber,
• Dirk Schmutzler and
• Andrea Svejda

Beilstein J. Org. Chem. 2024, 20, 540–551, doi:10.3762/bjoc.20.46

• . Active fractions were pooled together, and the buffer was exchanged into 25 mM potassium phosphate buffer pH 7.3 containing 10% glycerol with PD10 columns (GE Healthcare). Aliquots of the protein solution were frozen in liquid nitrogen and stored at −80 °C. LpFAT A fluorescence polarization assay

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

• ; pH 7.0) as the starter and incubated at 180 rpm in a rotary shaker at 27 °C for 4 days. The 1% portion of the starter was transferred into 20 L of production medium (2% glycerol, 2% soybean meal, and 0.3% NaCl) in a jar fermenter and further incubated at 150 rpm, 27 °C, 0.5 VVM (volume per volume per

Green and sustainable approaches for the Friedel–Crafts reaction between aldehydes and indoles

• Periklis X. Kolagkis,
• Eirini M. Galathri and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2024, 20, 379–426, doi:10.3762/bjoc.20.36

• well as Lewis acids, such as FeCl3 [23][24], RuCl3·3H2O [25], AgNO3 [26], glycerol and [Fe(III)-(salen)]Cl [27], Fe(DS)3·nH2O [28], Sc(OTf)3 [29], B(C6F5)3 or PhSiCl3 [30] and Cp2TiCl2 [31]. However, most of these reactions face some serious drawbacks, such as the requirement of large quantities of the

Preparing a liquid crystalline dispersion of carbon nanotubes with high aspect ratio

• Keiko Kojima,
• Nodoka Kosugi,
• Hirokuni Jintoku,
• Kazufumi Kobashi and
• Toshiya Okazaki

Beilstein J. Org. Chem. 2024, 20, 52–58, doi:10.3762/bjoc.20.7

• with previous studies [22][23]. Initially, 100 mg of DWCNT powder was pre-dispersed in 100 mL of Wako glycerol with a stirrer (ASONE, HPS-100PD) rotating at 500 rpm for 18 hours. During the stirring, the DWCNTs were defibrated by the shear stress of the high-viscosity glycerol [36]. After suspension in

• 200 mL of water, the DWCNT-glycerol mixture was filtered through a 1.0 μm pore size polytetrafluoroethylene (PTFE) membrane (Merck, Omnipore 47mm). To ensure complete removal of glycerol from the DWCNTs, we repeated the washing process until 2 L of water had passed through the membrane, resulting in

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

• -cmaA3 into E. coli BL21(DE3). The obtained strain was cultured in 1 L of Terrific broth (24 g/L yeast extract, 12 g/L tryptone, 0.8% glycerol, 0.94% K2HPO4, and 0.22% KH2PO4) with ampicillin and chloramphenicol (if necessary for sfp expression) and incubated with shaking (150 rpm) at 37 °C until the

• were harvested by centrifugation and suspended in lysis buffer (20 mM HEPES-NaOH, 10% glycerol, and 200 mM NaCl2; pH 8.0). The cells were disrupted by sonication on ice, and cell debris was removed by centrifugation. The recombinant protein was purified using His60 Ni Superflow Resin (TaKaRa Bio Inc

• [13] were used in the current experiment. In vitro analysis of CmaA1, CmaA3, AvaA1, and AvaA3 A reaction mixture (50 µL) containing 4 µM CmaA1 or AvaA1, 40 µM CmaA3 or AvaA3, 2.5 mM 3,4-AHBA, 1 mM ATP, 5 mM MgCl2, 20 mM HEPES-NaOH (pH 8.0), 10% glycerol, and 200 mM NaCl was prepared and incubated at

Synthesis of 5-arylidenerhodanines in L-proline-based deep eutectic solvent

• Stéphanie Hesse

Beilstein J. Org. Chem. 2023, 19, 1537–1544, doi:10.3762/bjoc.19.110

• characterized; a pH value of 10.07 was measured at 30 °C by Shah et al. [16] and a viscosity of 750 cP at 25 °C was reported by Mjalli et al. [17] (Table 1). It remains today one of the most used DES and studies on it are still conducted [14]. ChCl/glycerol (ChCl/Gly; 1:2) is another classical DES with a

• synthesis of NaDES plays a major role in the resulting viscosity [20]. For example, ʟ-proline/glycerol (Pro/Gly; 1:2) was found to have a pH value of 7.25 and a viscosity of 5064 cP [20]. In 2018, Molnar et al. reported the antioxidant activity of a series of rhodanine derivatives synthesized by a

• Knoevenagel condensation is well documented [21]. Moreover, the low cost and high availability of ʟ-proline has attracted attention to ʟ-proline-based DES. Especially, in 2022, Detsi [20] has synthesized and characterized three ʟ-proline-based NaDES: proline/oxalic acid (1:1), proline/glycerol (1:2), and

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

• living organisms including humans that feature an ether bond linkage at the sn-1 position of the glycerol. This class of lipids features singular structural roles and biological functions. Alkyl ether lipids and alkenyl ether lipids (also identified as plasmalogens) correspond to the two sub-classes of

• compounds. Keywords: amphiphiles; edelfosine; GAEL; glycerol lipids; glycolipids; ohmline; plasmalogen; Introduction Ether lipids (ELs) are natural compounds that feature a glycerol unit linked with an ether function to an alkyl (alkyl acyl ether lipid) or alkenyl (plasmalogen) lipid chain. For the

• alkenyl compounds, the vinyl ether function is characterized by a (Z)-configuration as shown in Figure 1. In addition, an acyl group is present on the secondary alcohol of the glycerol. This acyl group is constituted by a saturated or unsaturated lipid chain or, in the case of platelet-activating factor

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

• was weighed out into 10 × 500 mL Erlenmeyer flasks, each containing 90 mL of deionized H2O and autoclaved. In addition, 20 × 200 mL Erlenmeyer flasks containing cotton seed flour (Q6/2) liquid-state fermentation media were prepared as follows: media components (ᴅ-glucose 2.5 g/L, glycerol 10 g/L

Nostochopcerol, a new antibacterial monoacylglycerol from the edible cyanobacterium Nostochopsis lobatus

• Naoya Oku,
• Saki Hayashi,
• Yuji Yamaguchi,
• Hiroyuki Takenaka and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2023, 19, 133–138, doi:10.3762/bjoc.19.13

• , Japan 10.3762/bjoc.19.13 Abstract A new antibacterial 3-monoacyl-sn-glycerol, nostochopcerol (1), was isolated from a cultured algal mass of the edible cyanobacterium Nostochopsis lobatus MAC0804NAN. The structure of compound 1 was established by the analysis of NMR and MS data while its chirality was

• commercially available, methyl linoleate, having the same degree of unsaturation with a longer chain length by two carbons, was used as a source of the acyl chain. Linoleic acid, obtained by saponification of methyl linoleate, was condensed either with (R)- or (S)-solketal (isopropylidene glycerol) by Steglich

• esterification. The resulting ester 2a or 2b was purified by reversed-phase HPLC and deprotected by a short treatment with 80% aqueous acetic acid at 58–59 °C to give 1-linoleoyl-sn-glycerol (3a) or 3-linoleoyl-sn-glycerol (3b), respectively (Scheme 1). Similarly, to our experience during the isolation of

A Streptomyces P450 enzyme dimerizes isoflavones from plants

• Run-Zhou Liu,
• Shanchong Chen and
• Lihan Zhang

Beilstein J. Org. Chem. 2022, 18, 1107–1115, doi:10.3762/bjoc.18.113

• NaCl, 1 mM TCEP, 10% glycerol, pH 7.5) and stored at −80 °C for further use. The P450 partner proteins, FdR and Fdx, were constructed according to the reported method [40]. For in vitro biochemical assays, the reaction mixture (50 µL) contained 0.4 mM substrate, 3 µM P450 enzyme, 5 µM FdR, 5 µM Fdx, 1

Automated grindstone chemistry: a simple and facile way for PEG-assisted stoichiometry-controlled halogenation of phenols and anilines using N-halosuccinimides

• Dharmendra Das,
• Akhil A. Bhosle,
• Amrita Chatterjee and
• Mainak Banerjee

Beilstein J. Org. Chem. 2022, 18, 999–1008, doi:10.3762/bjoc.18.100

• relatively inferior results than EtOH (Table 1, entry 3). The use of ethylene glycol and glycerol as the grinding matrix showed improved yields with the monobromo product 2a formed in 81% and 85% yield, respectively within 10 min (Table 1, entries 4 and 5). Next, liquid polyethylene glycol, PEG-400 was

Efficient production of clerodane and ent-kaurane diterpenes through truncated artificial pathways in Escherichia coli

• Fang-Ru Li,
• Xiaoxu Lin,
• Qian Yang,
• Ning-Hua Tan and
• Liao-Bin Dong

Beilstein J. Org. Chem. 2022, 18, 881–888, doi:10.3762/bjoc.18.89

• -kaurene production were created. Next, DL10003–10006 were fermented in Lysogeny broth (LB) medium supplied with 1% glycerol, 6 mM ISO/DMAA 3:1, and 0.1 mM isopropyl β-ᴅ-1-thiogalactopyranoside (IPTG) inducer. In comparison with the negative control of wild-type E. coli BL21 (DE3), all strains successfully

• and DMAPP. Given that the commercial DMAA is cheaper than ISO, our result in merely using DMAA should be helpful in decreasing the overall cost for the production of other terpenes using this two-step artificial pathway [22]. Optimizing the concentrations of glycerol and IPTG, and fermentation time

• course Three orthogonal experiments were run to examine the effects of varying glycerol and IPTG concentrations and fermentation time, all in an effort to optimize terpentetriene and ent-kaurene production. Given that the carbon source is vital for overproducing natural products in E. coli, and glycerol

Identification of the new prenyltransferase Ubi-297 from marine bacteria and elucidation of its substrate specificity

• Jamshid Amiri Moghaddam,
• Huijuan Guo,
• Karsten Willing,
• Thomas Wichard and
• Christine Beemelmanns

Beilstein J. Org. Chem. 2022, 18, 722–731, doi:10.3762/bjoc.18.72

• performed in a 75 L X-Cube Bioreactor (Braun Biotech International) using 30 L of Terrific Broth medium (Carl Roth GmbH) enriched with 4 mL/L glycerol and 60 mg/L kanamycin. Similar to the in vivo culture assays, the culture was cooled to 16 °C at an OD600 of 1 and heterologous production induced with IPTG

Anomeric 1,2,3-triazole-linked sialic acid derivatives show selective inhibition towards a bacterial neuraminidase over a trypanosome trans-sialidase

• Peterson de Andrade,
• Sanaz Ahmadipour and
• Robert A. Field

Beilstein J. Org. Chem. 2022, 18, 208–216, doi:10.3762/bjoc.18.24

• [4]. For instance, hydrophobic pockets in the glycerol- and acetamide-binding subsites have been reported for neuraminidases [10][37] as well as for TcTS, which has a more spacious and hydrophobic active site around C9 of sialic acid [16]. Nonetheless, a simple comparison from the crystal structures

Isolation and characterization of new phenolic siderophores with antimicrobial properties from Pseudomonas sp. UIAU-6B

• Emmanuel T. Oluwabusola,
• Olusoji O. Adebisi,
• Fernando Reyes,
• Kojo S. Acquah,
• Mercedes De La Cruz,
• Larry L. Mweetwa,
• Joy E. Rajakulendran,
• Digby F. Warner,
• Deng Hai,
• Rainer Ebel and
• Marcel Jaspars

Beilstein J. Org. Chem. 2021, 17, 2390–2398, doi:10.3762/bjoc.17.156

• Erlenmeyer flask containing 150 mL modified SGG medium (glycerol 10 g, corn steep powder 2.5 g, peptone 5 g, soluble starch 10 g, yeast extract 2 g, CaCO3 3 g, NaCl 1 g, in 1 L H2O, pH adjusted to 7.3) [45]. The flask was left shaking at 160 rpm in a closed system shaker for ten days at 28 °C. Subsequently

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

• : initiation and activation of polymerase (95 °C/5 min); followed by 35 cycles of denaturation (95 °C/30 s), annealing (65 °C/30 s) and elongation (72 °C/90 s) and a single, final elongation step (72 °C/10 min). For gel electrophoresis, 4 µL PCR product was mixed with one drop loading dye (0.3 mL 30% glycerol

• by a 4 × 20 s treatment with a sonicator (Bandelin UW2070, Berlin, Germany) in chilled extraction buffer (10 mM Tris-HCl, pH 7.5, 1 mM dithiothreitol, 10% (v/v) glycerol). Cell fragments were removed by centrifugation at 14,000g and the supernatant was further processed via an Illustra NAP-5 gravity

Fritsch–Buttenberg–Wiechell rearrangement of magnesium alkylidene carbenoids leading to the formation of alkynes

• Tsutomu Kimura,
• Koto Sekiguchi,
• Akane Ando and
• Aki Imafuji

Beilstein J. Org. Chem. 2021, 17, 1352–1359, doi:10.3762/bjoc.17.94

• JNM-LA 500, Bruker AVANCE DPX 300, and Bruker AVANCE DPX 400 spectrometers. Mass spectrometry (MS) experiments were conducted at 70 eV by direct injection with a HITACHI M-80B mass spectrometer. Fast atom bombardment (FAB) mass spectra were obtained with a mixture of m-nitrobenzyl alcohol and glycerol

A new glance at the chemosphere of macroalgal–bacterial interactions: In situ profiling of metabolites in symbiosis by mass spectrometry

• Marine Vallet,
• Filip Kaftan,
• Veit Grabe,
• Fatemeh Ghaderiardakani,
• Simona Fenizia,
• Aleš Svatoš,
• Georg Pohnert and
• Thomas Wichard

Beilstein J. Org. Chem. 2021, 17, 1313–1322, doi:10.3762/bjoc.17.91

• . MS6 and Roseovarius sp. MS2 forming a tripartite community [3][7][8] (see also Figure 1a and the Graphical Abstract). In turn, Roseovarius sp. benefits from the released photosynthate glycerol as a carbon source [9]. Axenic Ulva germ cells (i.e. gametes) develop into a callus-like phenotype composed

• zwitterion dimethylsulphoniopropionate (DMSP), resulting in biofilm formation on the algal surrounding [9]. The bacterium subsequently uses the provided glycerol for growth and transforms DMSP into methanethiol and dimethyl sulphide [9]. The metabolic activities of marine bacteria and algae can be surveyed

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Nitroalkene reduction in deep eutectic solvents promoted by BH₃NH₃

• Chiara Faverio,
• Monica Fiorenza Boselli,
• Patricia Camarero Gonzalez,
• Alessandra Puglisi and
• Maurizio Benaglia

Beilstein J. Org. Chem. 2021, 17, 1041–1047, doi:10.3762/bjoc.17.83

• product was isolated in 27% yield. For sake of comparison, the reaction was also performed in water, where a negligible amount of the product was detected, and in glycerol, which proved to be a good reaction medium (41% yield) [17]. In order to further speed up the reaction and suppress the byproducts

• formation [18], the reaction was performed at 60 °C for 18 h on a 0,1 M substrate concentration (entries 6–9, Table 1). Under those conditions, the product was isolated after chromatographic purification in a higher yield; in DES B, 41% yield was reached, while in glycerol, the reaction gave 61% yield

• (entries 6 and 8, Table 1). Therefore, DES mixture B (ChCl/gly 1:2) and glycerol were selected as reaction media of choice to further investigate the reduction of nitroalkenes mediated by ammonia borane. Both solvent systems represent promising alternatives, green solvents for organic reactions; glycerol

Synthesis of 10-O-aryl-substituted berberine derivatives by Chan–Evans–Lam coupling and investigation of their DNA-binding properties

• Peter Jonas Wickhorst,
• Mathilda Blachnik,
• Denisa Lagumdzija and
• Heiko Ihmels

Beilstein J. Org. Chem. 2021, 17, 991–1000, doi:10.3762/bjoc.17.81

• low fluorescence quantum yields are caused by conformational changes in the excited state, the fluorescence was recorded in media with different viscosity, namely in glycerol at different temperatures (Figure 2, Figure S2, Supporting Information File 1). It was observed that the derivatives 5a–e have

• significantly higher, but still relatively low emission quantum yields in glycerol at room temperature (Φfl = 0.009–0.031, 20 °C, η = 1412 cP) [41], whereas the emission intensity decreased with increasing temperature (Φfl = 0.001–0.002, 80 °C, η = 32 cP) [41]. Such a behavior usually indicates a radiationless

• deactivation of the excited state by conformational changes, e.g., torsional relaxation [42][43]. Since the fluorescence quantum yield of the parent berberine (1a) does not correlate well with the viscosity of the medium [40], it was concluded that the weak light-up effect in glycerol is mainly caused by the

Beyond ribose and phosphate: Selected nucleic acid modifications for structure–function investigations and therapeutic applications

• Christopher Liczner,
• Kieran Duke,
• Gabrielle Juneau,
• Martin Egli and
• Christopher J. Wilds

Beilstein J. Org. Chem. 2021, 17, 908–931, doi:10.3762/bjoc.17.76

• (R) or (S) starting material, respectively. These simple nucleic acid building blocks were first synthesized in 1971 by Ueda et al. [96]. The group was able to synthesize adenine, cytosine, and uracil GNA analogues by reacting these bases with glycerol α-chlorohydrin or glycidol. The following year

• glycerol α-chlorohydrin, the ratio of I/II was 1:4 with II being the preferred isomer but when using glycidol, this ratio shifted to 3:1 in the favor of the desired isomer [96][97]. From there on, the use of glycidol for the preparation of GNA analogues became the gold standard. The first GNA polymers were

Kinetics of enzyme-catalysed desymmetrisation of prochiral substrates: product enantiomeric excess is not always constant

• Peter J. Halling

Beilstein J. Org. Chem. 2021, 17, 873–884, doi:10.3762/bjoc.17.73

• diol ester hydrolysis, Keq will probably depend significantly on the positions of the hydroxy groups with respect to each other. A value around 40 M was found for glycerol dioctanoate [35]. Effect of eeDP and k−4 · Keq/k4 on the product ee at high conversion for “ping-pong, first” kinetics. S0 = 0.2 M