Geschmack ist vorhersagbar: Mit FlavorMiner. FlavorMiner heißt das Tool, das IPB-Chemiker und Partner aus Kolumbien jüngst entwickelt haben. Das Programm kann, basierend auf maschinellem Lernen (KI), anhand der…
Seit Februar 2021 bietet Wolfgang Brandt, ehemaliger Leiter der Arbeitsgruppe Computerchemie am IPB, sein Citizen Science-Projekt zur Pilzbestimmung an. Dafür hat er in regelmäßigen Abständen öffentliche Vorträge zur Vielfalt…
Mpetga, J. D. S.; Nago, R. D. T.; Tamokou, J.-D.-D.; Fobofou, S. A. T.; Bitchagno, G. T. M.; Wessjohann, L. A.; Tene, M.; Ngouela, A. S.;A new ceramide from Cissus aralioides Baker (Vitaceae) and its antimicrobial activityChem. Biodivers.19e202200678(2022)DOI: 10.1002/cbdv.202200678
Purification through repeated column chromatography over silica gel and Sephadex LH-20 of the ethanol extract of the stems of Cissus aralioides (Baker) Planch. resulted in the isolation of a new ceramide, aralioidamide A (1) along with five known compounds (2-6). Their structures were determined by the extensive analysis of their spectroscopic (1D and 2D NMR) and spectrometric data, and comparison with those reported in the literature. Aralioidamide A (1) displayed weak antibacterial activity (MIC = 256 μg/mL) against Bacillus subtilis, Staphylococcus aureus and Shigella flexneri and was inactive (MIC > 256 μg/mL) against the tested fungi.
Publikation
Farag, M. A.; Al-Mahdy, D. A.; Salah El Dine, R.; Fahmy, S.; Yassin, A.; Porzel, A.; Brandt, W.;Structure-Activity Relationships of Antimicrobial Gallic Acid Derivatives from Pomegranate and Acacia Fruit Extracts against Potato Bacterial Wilt PathogenChem. Biodivers.12955-962(2015)DOI: 10.1002/cbdv.201400194
Bacterial wilts of potato, tomato, pepper, and or eggplant caused by Ralstonia solanacearum are among the most serious plant diseases worldwide. In this study, the issue of developing bactericidal agents from natural sources against R. solanacearum derived from plant extracts was addressed. Extracts prepared from 25 plant species with antiseptic relevance in Egyptian folk medicine were screened for their antimicrobial properties against the potato pathogen R. solancearum by using the disc‐zone inhibition assay and microtitre plate dilution method. Plants exhibiting notable antimicrobial activities against the tested pathogen include extracts from Acacia arabica and Punica granatum. Bioactivity‐guided fractionation of A. arabica and P. granatum resulted in the isolation of bioactive compounds 3,5‐dihydroxy‐4‐methoxybenzoic acid and gallic acid, in addition to epicatechin. All isolates displayed significant antimicrobial activities against R. solanacearum (MIC values 0.5–9 mg/ml), with 3,5‐dihydroxy‐4‐methoxybenzoic acid being the most effective one with a MIC value of 0.47 mg/ml. We further performed a structure–activity relationship (SAR) study for the inhibition of R. solanacearum growth by ten natural, structurally related benzoic acids.
Publikation
Wittmann, I.; Schierling, A.; Dettner, K.; Göhl, M.; Schmidt, J.; Seifert, K.;Detection of a New Piperideine Alkaloid in the Pygidial Glands of Some Stenus BeetlesChem. Biodivers.121422-1434(2015)DOI: 10.1002/cbdv.201400391
Rove beetles of the genus Stenus produce and store bioactive alkaloids like stenusine (3), 3‐(2‐methylbut‐1‐enyl)pyridine (4), and cicindeloine (5) in their pygidial glands to protect themselves from predation and microorganismic infestation.The biosynthesis of stenusine (3), 3‐(2‐methylbut‐1‐enyl)pyridine (4), and cicindeloine (5) was previously investigated in Stenus bimaculatus, Stenus similis, and Stenus solutus, respectively. The piperideine alkaloid cicindeloine (5) occurs also as a major compound in the pygidial gland secretion of Stenus cicindeloides. The three metabolites follow the same biosynthetic pathway, where the N‐heterocyclic ring is derived from L‐lysine and the side chain from L‐isoleucine. The different alkaloids are finally obtained by few modifications of shared precursor molecules, such as 2,3,4,5‐tetrahydro‐5‐(2‐methylbutylidene)pyridine (1). This piperideine alkaloid was synthesized and detected by GC/MS and GC at a chiral phase in the pygidial glands of Stenus similis, Stenus tarsalis, and Stenus cicindeloides.
Publikation
Wessjohann, L.; Schneider, A.;Synthesis of Selenocysteine and Its Derivatives with an Emphasis on Selenenylsulfide (-Se-S-) FormationChem. Biodivers.5375-388(2008)DOI: 10.1002/cbdv.200890038
A short survey of historic and current methods for the synthesis of selenocysteine, selenocystine, and derivatives and related compounds is presented, with an additional emphasis on the formation of selenocysteine‐derived SeS bridges. The majority of methods to the amino acid starts with protected and O ‐activated serine, but also other concepts are included such as radical or multicomponent strategies, the latter allowing also direct access to peptoids in one pot. Of special importance is the monomeric oxidative cyclization of selenocysteine–cysteine peptides to eight‐membered and larger rings with a selenenylsulfide bridge, a crucial element in several selenoproteins.