Bioinformatic prediction of the stereoselectivity of modular polyketide synthase: an update of the sequence motifs in ketoreductase domain

• Changjun Xiang,
• Shunyu Yao,
• Ruoyu Wang and
• Lihan Zhang

Beilstein J. Org. Chem. 2024, 20, 1476–1485, doi:10.3762/bjoc.20.131

• collected polyketide products were manually checked by literature searches. Absolute configurations determined entirely by chemical methods, such as crystal structures, NMR, chemical degradation and derivatization, were considered reliable. Alternatively, relative configurations determined by NMR methods

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

• proceeded with full retainment of the labelling in both cases (Scheme 1B). Subsequent chemical degradation through acid catalysed conversion into 5, oxidative cleavage to the diketone 13, BF3∙OEt2 mediated ring closure by aldol reaction and catalytic hydrogenation gave 14. For both experiments a full

Progress and challenges in the synthesis of sequence controlled polysaccharides

• Giulio Fittolani,
• Theodore Tyrikos-Ergas,
• Denisa Vargová,
• Manishkumar A. Chaube and
• Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

• activity, as demonstrated using partially acetylated COS obtained by enzymatic degradation of chitosan promoted by hydrolases [221]. Chemical degradation of chitin promoted by acid treatment [222][223][224][225][226][227][228] or using chitinases and chitosanases [229][230][231] generates mixtures of short

Synthesis of acylhydrazino-peptomers, a new class of peptidomimetics, by consecutive Ugi and hydrazino-Ugi reactions

• Angélica de Fátima S. Barreto,
• Veronica Alves dos Santos and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2016, 12, 2865–2872, doi:10.3762/bjoc.12.285

• effect on the physical properties of a peptide as well as on its structural characteristics. The semicarbazide constraints tend to facilitate interactions with protein receptors due to turn geometry within the azapeptide. As a result, their stability over enzymes and chemical degradation may be enhanced

Recent highlights in biosynthesis research using stable isotopes

• Jan Rinkel and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2015, 11, 2493–2508, doi:10.3762/bjoc.11.271

• consequence that chemical degradation methods in natural products chemistry are almost vanished today. The usage of isotopically labeled precursors depends on careful interpretations of the incorporation pattern, which sometimes may lead to errors if unknown metabolic pathways are involved, as in the

Organic chemistry on surfaces: Direct cyclopropanation by dihalocarbene addition to vinyl terminated self-assembled monolayers (SAMs)

• Malgorzata Adamkiewicz,
• David O’Hagan and
• Georg Hähner

Beilstein J. Org. Chem. 2014, 10, 2897–2902, doi:10.3762/bjoc.10.307

• were stirred at room temperature for fixed periods of time (see Supporting Information File 1). SAMs on silicon substrates form stable films [6][7], however, they can be vulnerable to chemical degradation particularly in aqueous base [28][35][36]. For this reason the NaOH concentration and reaction

Photo, thermal and chemical degradation of riboflavin

• Muhammad Ali Sheraz,
• Sadia Hafeez Kazi,
• Sofia Ahmed,
• Zubair Anwar and
• Iqbal Ahmad

Beilstein J. Org. Chem. 2014, 10, 1999–2012, doi:10.3762/bjoc.10.208

• this field has been made and all those factors that affect the photo, thermal and chemical degradation of RF have been discussed. RF undergoes degradation through several mechanisms and an understanding of the mode of photo- and thermal degradation of RF may help in the stabilization of the vitamin. A

• general scheme for the photodegradation of RF is presented. Keywords: chemical degradation; degradation products; photodegradation; riboflavin; stability; thermal degradation; Review The study of photo, thermal and chemical degradation in the stability of drugs is one of the most concerned areas in the

• of amber colored bottles or light resistant packaging. Thermal sensitivity can be dealt by manufacturing and storing the drug under controlled temperature conditions. Similarly, the chemical degradation of the drug may be controlled by changes in pH, buffer, solvent composition, exclusion of air and

[²H₂₆]-1-epi-Cubenol, a completely deuterated natural product from Streptomyces griseus

• Christian A. Citron and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 2841–2845, doi:10.3762/bjoc.9.319

• important, because incorporation can be detected with high sensitivity by scintillation counting or autoradiography. However, the site of incorporation was in most cases difficult to deduce, requiring a complex and laborious chemical degradation that was sometimes even performed without knowledge of the

The total synthesis of D-chalcose and its C-3 epimer

• Jun Sun,
• Song Fan,
• Zhan Wang,
• Guoning Zhang,
• Kai Bao and
• Weige Zhang

Beilstein J. Org. Chem. 2013, 9, 2620–2624, doi:10.3762/bjoc.9.296

• ] (Scheme 1). After its structure was determined using chemical degradation and spectroscopic analyses, several syntheses of chalcose were reported. The conversion of desosamine into D-chalcose was described by Westwood’s group [6]. A small number of stereospecific syntheses beginning from carbohydrate

Studies on the photodegradation of red, green and blue phosphorescent OLED emitters

• Susanna Schmidbauer,
• Andreas Hohenleutner and
• Burkhard König

Beilstein J. Org. Chem. 2013, 9, 2088–2096, doi:10.3762/bjoc.9.245

• emitters – which is called the triplet harvesting effect [1]. However, while OLEDs with efficiencies comparable to fluorescent tube lamps have been realized [2], the operational stability of the devices remains to be a challenge in this field. In particular, the chemical degradation of the materials during

• films. To gain information on the chemical degradation mechanisms, we tried to identify deterioration products by liquid chromatography mass spectrometry (LC–MS) and other analytical methods where applicable. Results and Discussion For our investigations, we chose the four iridium complexes depicted in

Stereoselective synthesis of the C79–C97 fragment of symbiodinolide

• Hiroyoshi Takamura,
• Takayuki Fujiwara,
• Isao Kadota and
• Daisuke Uemura

Beilstein J. Org. Chem. 2013, 9, 1931–1935, doi:10.3762/bjoc.9.228

• . Therefore, in order to complete the configurational elucidation of 1, we are now investigating its chemical degradation [1][2][3] and chemical synthesis of the fragments [4][5][6][7][8][9][10][11]. Previously, we reported the stereoselective synthesis of the spiroacetal C79–C96 fragment [4], which is

Inclusion of the insecticide fenitrothion in dimethylated-β-cyclodextrin: unusual guest disorder in the solid state and efficient retardation of the hydrolysis rate of the complexed guest in alkaline solution

• Dyanne L. Cruickshank,
• Natalia M. Rougier,
• Raquel V. Vico,
• Susan A. Bourne,
• Elba I. Buján,
• Mino R. Caira and
• Rita H. de Rossi

Beilstein J. Org. Chem. 2013, 9, 106–117, doi:10.3762/bjoc.9.14

• in this and previous studies that we have undertaken, give indications of which type of cyclodextrin may be best suited in an agrochemical formulation to ensure resistance of sensitive bioactive compounds to chemical degradation, thus maximising their intended biological effect. Thermodynamic data