scholarly journals Scalable Preparation of Enantioenriched (S)-5-methylhept-2-en-4-one. Synthesis and Aroma Properties of Achiral Analogues Thereof

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4497
Author(s):  
Eva Puchľová ◽  
Michal Dendys ◽  
Ivan Špánik ◽  
Peter Szolcsányi
Keyword(s):  
Natural Product ◽  
Title Compound ◽  
Structural Changes ◽  
Chemoenzymatic Synthesis ◽  
Synthetic Analogues ◽  
Purification Method ◽  
Flavour Compound ◽  
Sensory Analyses ◽  
And Shifts

(S)-5-Methylhept-2-en-4-one is a key flavour compound in hazelnuts. We have performed its chiral-pool-based chemoenzymatic synthesis with 39% overall yield (73% ee). The four-step aldol-based sequence avoids the use of highly reactive and/or toxic reagents, does not require anhydrous conditions and uses only distillation as the purification method. Thus, such methodology represents a green and scalable alternative to only two stereoselective approaches towards this natural product known so far. In addition, we have designed and prepared a set of new (di)enones as achiral synthetic analogues of the title compound. The results of their sensory analyses clearly show that relatively minor structural changes of the natural molecule significantly alter its olfactory properties. Thus, simple (poly)methylation completely changes the original hazelnut aroma of (S)-5-methylhept-2-en-4-one and shifts the odour of its analogues to eucalyptus, menthol, camphor, and sweet aroma.

A One-Pot Chemoenzymatic Synthesis of (2S,4R)-4-Methylproline Enables the First Total Synthesis of Antiviral Lipopeptide Cavinafungin B

2018 ◽  
Author(s):  
Christian R. Zwick ◽  
Hans Renata
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Complex Molecule ◽  
Molecular Target ◽  
Chemoenzymatic Synthesis ◽  
General Strategy ◽  
One Pot

We report an efficient ten-step synthesis of antiviral natural product cavinafungin B in 37% overall yield. By leveraging a one-pot chemoenzymatic synthesis of (2S,4R)-4-methylproline and oxazolidine-tethered (Rink-Boc-ATG-resin) SPPS methodology, the assembly of our molecular target could be conducted in an efficient manner.This general strategy could prove amenable to the construction of other natural and unnatural linear lipopeptides. The value of incorporating biocatalytic steps in complex molecule synthesis is highlighted by this work.

Synthesis and antibacterial activities of marine natural product Ianthelliformisamines and subereamine synthetic analogues

2021 ◽  
pp. 127883
Author(s):  
Shivaji Narayan Khadake ◽  
Shaik Karamathulla ◽  
Tapan Kumar Jena ◽  
Mohan Monisha ◽  
Nikhil Kumar Tuti ◽  
...  
Keyword(s):  
Natural Product ◽  
Antibacterial Activities ◽  
Marine Natural Product ◽  
Synthetic Analogues

Structure of [(CH3)2NH2]2CoCl4 at elevated temperatures

1999 ◽  
Vol 55 (5) ◽  
pp. 752-757 ◽  
Author(s):  
Amir H. Mahmoudkhani ◽  
Vratislav Langer
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Phase Transitions ◽  
Physical Properties ◽  
Electric Conductivity ◽  
Title Compound ◽  
Structural Changes ◽  
Elevated Temperatures ◽  
The Other ◽  
Cell Parameters

The crystal structure of the title compound, dimethylammonium tetrachlorocobaltate(II), has been determined at four temperatures between 297 and 366 K, in order to investigate possible phase transitions at 313 and 353 K [Kapustianik, Polovinko & Kaluza et al. (1996). Phys. Status Solidi A, 153, 117–122]. We found that there is no significant change either in the hydrogen-bonding network or in the cell parameters, apart from a linear dilatation with temperature. This study reveals that the anomalous variation in electric conductivity and some of the other physical properties of the compound cannot be explained by structural changes.

scholarly journals Solvent Derived Artifacts in Natural Products Chemistry

2009 ◽  
Vol 4 (3) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Federica Maltese ◽  
Frank van der Kooy ◽  
Robert Verpoorte
Keyword(s):  
Natural Products ◽  
Natural Product ◽  
Chemical Reactions ◽  
Critical Role ◽  
Total Yield ◽  
Purification Method ◽  
Active Compounds ◽  
Natural Product Chemistry ◽  
Extraction And Purification ◽  
Product Chemistry

Solvents play an important and critical role in natural product chemistry. They are mainly used during the extraction and purification of metabolites from a biological matrix. To a lesser extent, solvents are also used as reagents or catalysts to perform chemical reactions. This review focuses on the most important classes of solvents, including alcohols, halogen-containing solvents, esters, ethers, acids and bases. The chemical reactions associated with the use of these solvents to form the so-called “artifacts” are discussed and the most common contaminants found in these solvents are also reviewed. The formation of artifacts and the use of contaminated solvents mainly leads to the formation of new compounds, loss of activity of active compounds, formation of active compounds from inactive ones (false positives), loss in total yield of important compounds during isolation, formation of toxic compounds and difficulty in reproducing an extraction or purification method. Finally, the need for stability studies of purified natural products is emphasized, as this is a common overlooked aspect in natural product chemistry.

4-Methyl-3H-pyrrolo[2,3-c]quinoline

2006 ◽  
Vol 62 (7) ◽  
pp. o2728-o2730 ◽  
Author(s):  
Akkharawit Kanjana-opas ◽  
Somrak Panphon ◽  
Hoong-Kun Fun ◽  
Suchada Chantrapromma
Keyword(s):  
Crystal Structure ◽  
Natural Product ◽  
Dihedral Angle ◽  
Title Compound ◽  
Marine Natural Product ◽  
Asymmetric Unit ◽  
Compound C ◽  
Gliding Bacterium ◽  
First Time ◽  
Hydrogen Bonded

The title compound, C12H10N2, is a new marine natural product which was isolated for the first time from a novel marine gliding bacterium. The asymmetric unit contains a pair of achiral molecules. Both the molecules are essentially planar and they form a dihedral angle of 83.81 (3)°. In the crystal structure, the molecules exist as N—H...N hydrogen-bonded tetramers.

The antimicrobial natural product chuangxinmycin and Some synthetic analogues are potent and selective inhibitors of bacterial tryptophanyl tRNA synthetase

2002 ◽  
Vol 12 (21) ◽  
pp. 3171-3174 ◽  
Author(s):  
Murray J. Brown ◽  
Paul S. Carter ◽  
Ashley E. Fenwick ◽  
Andrew P. Fosberry ◽  
Dieter W. Hamprecht ◽  
...  
Keyword(s):  
Natural Product ◽  
Trna Synthetase ◽  
Selective Inhibitors ◽  
Synthetic Analogues

The Synthesis of (R)-2',3'-Dihydroxypropyl 5-Deoxy-5-Dimethylarsinyl-β-D-Riboside, a Naturally Occurring Arsenic-Containing Carbohydrate

1987 ◽  
Vol 40 (11) ◽  
pp. 1901 ◽  
Author(s):  
DP Mcadam ◽  
AMA Perera ◽  
RV Stick
Keyword(s):  
Natural Product ◽  
Hydroxy Group ◽  
Title Compound ◽  
Protecting Groups ◽  
Giant Clam ◽  
Free Hydroxy Group ◽  
Naturally Occurring ◽  
Step Procedure ◽  
Tridacna Maxima ◽  
Subsequent Chemical

The synthesis of the title compound, isolated from the brown kelp ( Ecklonia radiata ) or the giant clam (Tridacna maxima), is reported. Glycosidation of 1-O-acetyl-2,3,5-tri- O- benzoyl -β-D-ribose, either directly with (S)-1,2-di-O-benzylglycerol or via the derived orthoester with (S)-1,2-O-isopropylideneglycerol, led to two fully protected glycerol β-D- ribofuranosides. Subsequent chemical manipulations led to a common intermediate having a free hydroxy group at C5 of the D-ribose residue. Replacement of this hydroxy group by a chlorine atom allowed the introduction of the dimethylarsinyl group at C5 in a two-step procedure, and removal of protecting groups provided the natural product.

scholarly journals Alterations to the structure of Leishmania major induced by N-arylisoquinolines correlate with compound accumulation and disposition

2010 ◽  
Vol 59 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Alicia Ponte-Sucre ◽  
Tanja Gulder ◽  
Tobias A. M. Gulder ◽  
Gerina Vollmers ◽  
Gerhard Bringmann ◽  
...  
Keyword(s):  
Cell Death ◽  
Host Cell ◽  
Mechanism Of Action ◽  
Structural Changes ◽  
Leishmania Major ◽  
Ultrastructural Changes ◽  
Synthetic Analogues ◽  
Intracellular Compartments ◽  
Intracellular Organelles ◽  
Fluorescent Derivative

Naphthylisoquinoline alkaloids equipped with a N,C-hetero-‘biaryl’ axis, and, in particular, simplified synthetic analogues thereof, kill intracellular Leishmania major at concentrations in the low submicromolar range, while being significantly less toxic to their major host cell, the macrophage, at the same concentrations. To further investigate their mechanism of action we evaluated the morphological and ultrastructural changes induced by specific N-arylisoquinolines in L. major, and the correlation of these changes with compound accumulation and disposition by the parasite. After 24 h of treatment with the synthetic arylisoquinolinium salts 3 or 4, dramatic structural changes and cell death were observed. Furthermore, the auto-fluorescent derivative salt 3 accumulates continually in intracellular compartments. Our results thus suggest that the leishmanicidal effect of arylisoquinolinium salts may involve their ability to accumulate and precipitate in intracellular organelles, form a huge vacuole and eventually promote cell lysis.

scholarly journals The application of ATR-FTIR Spectroscopy and the Reversible DNA Conformation as a Sensor to Test the Effectiveness of Platinum(II) Anticancer Drugs

2018 ◽  
Author(s):  
Khansa Al-Jorani ◽  
Anja Rüther ◽  
Miguela Martin ◽  
Rukshani Haputhanthri ◽  
Glen B. Deacon ◽  
...  
Keyword(s):  
Ftir Spectroscopy ◽  
Cancer Cells ◽  
Structural Changes ◽  
Isotonic Saline ◽  
Platinum Complexes ◽  
Attenuated Total Reflection ◽  
Dna Conformation ◽  
Acetone Water ◽  
Intensity Changes ◽  
And Shifts

Platinum(II) complexes have been found to be effective against cancer cells. Cisplatin curbs cell replication by interacting with the deoxyribonucleic acid (DNA), eventually leading to cell death and reducing cell proliferation. In order to investigate the ability of platinum complexes to affect cancer cells, two examples from the class of polyflurophenylorganoamidoplatinum(II) complexes were synthesised and tested on isolated DNA. The two compounds trans-[N,N’-bis(1,2,3,5,6-pentafluorophenyl)ethane-1,2-diaminato(1-)](2,3,4,5,6-pentafluorobenzoato)(pyridine)platinum(II) (PFB), and trans-[N,N’-bis(1,2,3,5,6-pentafluorophenyl)ethane-1,2-diaminato(1-)](2,4,6-trimethylbenzoato)(pyridine)platinum(II) (TMB) were compared with cisplatin through their reaction with DNA. Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy was applied to analyse the interaction of the Pt(II) complexes with DNA in the hydrated, dehydrated and rehydrated state. These were compared with control DNA in acetone/water (PFB, TMB) and isotonic saline (cisplatin) under the same conditions. Principle Component Analysis (PCA) was applied to compare the ATR-FTIR spectra of the untreated control DNA with spectra of PFB and TMB treated DNA samples. Disruptions in the conformation of DNA treated with the Pt(II) complexes upon rehydration were mainly observed by monitoring the position of the IR-band around 1711 cm-1 assigned to the DNA base-stacking vibration. Furthermore, other intensity changes in the phosphodiester bands of DNA at ~1234 cm-1 and 1225 cm-1 and shifts in the dianionic phosphodiester vibration at 966 cm-1 were observed. The isolated double stranded DNA (dsDNA) or single stranded DNA (ssDNA) showed different structural changes when incubated with the studied compounds. PCA confirmed PFB had the most dramatic effect by denaturing both dsDNA and ssDNA. Both compounds, along with cisplatin, induced changes in DNA bands at 1711, 1088, 1051 and 966 cm-1 indicative of DNA conformation changes. The ability to monitor conformational change with infrared spectroscopy paves the way for a sensor to screen for new anticancer therapeutic agents.

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