scholarly journals Phytotoxic Activity and Structure–Activity Relationships of Radicinin Derivatives against the Invasive Weed Buffelgrass (Cenchrus ciliaris)

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2793 ◽  
Author(s):  
Masi ◽  
Freda ◽  
Clement ◽  
Cimmino ◽  
Cristofaro ◽  
...  
Keyword(s):  
Specific Activity ◽  
Essential Feature ◽  
Spectroscopic Characterization ◽  
Hydroxyl Group ◽  
Cenchrus Ciliaris ◽  
Invasive Weed ◽  
Phytotoxic Activity ◽  
Structure Activity ◽  
Derivatives Of ◽  
Potential Use

Radicinin (1), is a fungal dihydropyranopyran-4,5-dione isolated together with some analogues, namely 3-epi-radicinin, radicinol, 3-epi-radicinol, and cochliotoxin (2–5), from the culture filtrates of the fungus Cochliobolus australiensis, a foliar pathogen of buffelgrass (Cenchrus ciliaris), an invasive weed in North America. Among the different metabolites 1 showed target-specific activity against the host plant and no toxicity on zebrafish embryos, promoting its potential use to develop a natural bioherbicide formulation to manage buffelgrass. These data and the peculiar structural feature of 1 suggested to carry out a structure-activity relationship study, preparing some key hemisynthetic derivatives and to test their phytotoxicity. In particular, p-bromobenzoyl, 5-azidopentanoyl, stearoyl, mesyl and acetyl esters of radicinin were semisynthesized as well as the monoacetyl ester of 3-epi-radicinin, the diacetyl esters of radicinol and its 3 epimer, and two hexa-hydro derivatives of radicinin. The spectroscopic characterization and the activity by leaf puncture bioassay against buffelgrass of all the derivatives is reported. Most of the compounds showed phytotoxicity but none of them had comparable or higher activity than radicinin. Thus, the presence of an α,β unsaturated carbonyl group at C-4, as well as, the presence of a free secondary hydroxyl group at C-3 and the stereochemistry of the same carbon proved to be the essential feature for activity.

scholarly journals Radicinin, a Fungal Phytotoxin as a Target-Specific Bioherbicide for Invasive Buffelgrass (Cenchrus ciliaris) Control

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1086 ◽  
Author(s):  
Marco Masi ◽  
Fabrizio Freda ◽  
Felicia Sangermano ◽  
Viola Calabrò ◽  
Alessio Cimmino ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Native Plants ◽  
Brachydanio Rerio ◽  
Cenchrus Ciliaris ◽  
Indigenous Plants ◽  
Invasive Weed ◽  
Natural Systems ◽  
Natural Herbicides ◽  
Phytotoxic Activity

The fungal pathogens Cochliobolus australiensis and Pyricularia grisea have recently been isolated from diseased leaves of buffelgrass (Cenchrus ciliaris) in its North American range, and their ability to produce phytotoxic metabolites that could potentially be used as natural herbicides against this invasive weed was investigated. Fourteen secondary metabolites obtained from in vitro cultures of these two pathogens were tested by leaf puncture assay on the host plant at different concentrations. Radicinin and (10S, 11S)-epi-pyriculol proved to be the most promising compounds. Thus, their phytotoxic activity was also evaluated on non-host indigenous plants. Radicinin demonstrated high target-specific toxicity on buffelgrass, low toxicity to native plants, and no teratogenic, sub-lethal, or lethal effects on zebrafish (Brachydanio rerio) embryos. It is now under consideration for the development of a target-specific bioherbicide to be used against buffelgrass in natural systems where synthetic herbicides cause excessive damage to native plants.

scholarly journals Structure–Activity Relationship of Phytotoxic Natural 10-Membered Lactones and Their Semisynthetic Derivatives

2021 ◽  
Vol 7 (10) ◽  
pp. 829
Author(s):  
Anna Dalinova ◽  
Anatoly Fedorov ◽  
Vsevolod Dubovik ◽  
Olga Voitsekhovskaja ◽  
Elena Tyutereva ◽  
...  
Keyword(s):  
Rational Design ◽  
Fungicidal Activity ◽  
Structural Features ◽  
Hydroxyl Group ◽  
High Yield ◽  
Sf9 Cells ◽  
Structure Activity ◽  
Relationship Of ◽  
Derivatives Of ◽  
Target Activity

Ten-membered lactones (nonenolides) demonstrate phytotoxic, antimicrobial, and fungicidal activity promising for the development of natural product-derived pesticides. The fungus Stagonospora cirsii is able to produce phytotoxic stagonolides A (1), J (2), K (3) and herbarumin I (4) with high yield. The aim of this study was to create a set of structurally related nonenolides and to reveal the structural features that affect their biological activity. Stagonolide A (1) and C-7 oxidized stagonolide K (11) showed the highest phytotoxicity in leaf puncture assay and agar seedlings assay. The oxidation of C-7 hydroxyl group (as in 1, acetylstagonolide A (10) and (11) led to the manifestation of toxicity to microalgae, Bacillus subtilis and Sf9 cells regardless of the configuration of C-9 propyl chains (R in 1 and 10, S in 11). C-7 non-oxidized nonenolides displayed none or little non-target activity. Notably, 7S compounds were more phytotoxic than their 7R analogues. Due to the high inhibitory activity against seedling growth and the lack of side toxicity, mono- and bis(acetyl)- derivatives of herbarumin I were shown to be potent for the development of pre-emergent herbicides. The identified structural features can be used for the rational design of new herbicides.

scholarly journals N4-amino-acid derivatives of 6-azacytidine: structure-activity relationship.

2000 ◽  
Vol 47 (1) ◽  
pp. 95-101 ◽  
Author(s):  
I Alexeeva ◽  
L Palchikovskaya ◽  
A Shalamay ◽  
L Nosach ◽  
V Zhovnovataya ◽  
...  
Keyword(s):  
Amino Acid ◽  
Antiviral Activity ◽  
Chemical Structure ◽  
Specific Activity ◽  
Biological Properties ◽  
Activity Relationship ◽  
Amino Acid Derivatives ◽  
Condensation Method ◽  
Structure Activity ◽  
Derivatives Of

Several N4-derivatives of 6-azacytidine were synthesized using of Vorbrüggen's condensation method. Their antiviral activity with respect to the adenovirus serotypes 2 and 5 in Hep-2 cells culture was studied and primary specific activity was determined. Correlation between chemical structure of new 6-azacytidine derivatives and their biological properties is discussed.

scholarly journals Mechanistic Insights into the Chaperoning of Human Lysosomal-Galactosidase Activity: Highly Functionalized Aminocyclopentanes and C-5a-Substituted Derivatives of 4-epi-Isofagomine

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 4025
Author(s):  
Patrick Weber ◽  
Martin Thonhofer ◽  
Summer Averill ◽  
Gideon J. Davies ◽  
Andres Gonzalez Santana ◽  
...  
Keyword(s):  
Lysosomal Storage Diseases ◽  
Hydroxyl Group ◽  
Glycosidase Inhibitors ◽  
Lysosomal Storage ◽  
X Ray ◽  
Pharmacological Chaperones ◽  
X Ray Crystallography ◽  
Structure Activity ◽  
New Compounds ◽  
Derivatives Of

Glycosidase inhibitors have shown great potential as pharmacological chaperones for lysosomal storage diseases. In light of this, a series of new cyclopentanoid β-galactosidase inhibitors were prepared and their inhibitory and pharmacological chaperoning activities determined and compared with those of lipophilic analogs of the potent β-d-galactosidase inhibitor 4-epi-isofagomine. Structure-activity relationships were investigated by X-ray crystallography as well as by alterations in the cyclopentane moiety such as deoxygenation and replacement by fluorine of a “strategic” hydroxyl group. New compounds have revealed highly promising activities with a range of β-galactosidase-compromised human cell lines and may serve as leads towards new pharmacological chaperones for GM1-gangliosidosis and Morquio B disease.

scholarly journals (+)-epi-Epoformin, a Phytotoxic Fungal Cyclohexenepoxide: Structure Activity Relationships

2018 ◽  
Author(s):  
Antonio Cala ◽  
Marco Masi ◽  
Alessio Cimmino ◽  
José M.G. Molinillo ◽  
Francisco A. Macías ◽  
...  
Keyword(s):  
Fungal Pathogen ◽  
Biological Activities ◽  
Spectroscopic Characterization ◽  
Structure Activity Relationship ◽  
Significant Loss ◽  
Cork Oak ◽  
Activity Relationship ◽  
Wheat Coleoptile ◽  
Phytotoxic Activity ◽  
Structure Activity

(+)-epi-Epoformin (1), is a fungal cyclohexene epoxide isolated together with diplopimarane and sphaeropsidins A and C, a nor-ent-pimarane and two pimaranes, from the culture filtrates of Diplodia quercivora, a fungal pathogen for cork oak in Sardinia, Italy. Compound 1 possesses a plethora of biological activities including: antifungal, zootoxic and phytotoxic activity. The last activity and the peculiar structural feature of 1 suggested to carry out a structure activity relationship study, preparing eight key hemisynthetic derivatives and their phytotoxicity was assayed. The complete spectroscopic characterization and the activity in the etiolated wheat coleoptile bioassay of all the compounds is reported. Most of the compounds inhibited growth and some of them had comparable or higher activity than the natural product and the reference herbicide Logran. As regards the structure-activity relationship, the carbonyl proved to be essential for their activity of 1, as well as the conjugated double bond, while the epoxide could be altered with no significant loss.

Therapeutic Journey of 5-Pyrazolones as a Versatile Scaffold: A Review

2021 ◽  
Vol 21 ◽  
Author(s):  
Ravinder Sharma ◽  
Pooja A. Chawla ◽  
Viney Chawla ◽  
Rajeev Verma ◽  
Nandita Nawal ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Protease Inhibitor ◽  
Medicinal Chemistry ◽  
Membered Ring ◽  
Present Review ◽  
Biological Profile ◽  
3C Protease ◽  
Structure Activity ◽  
Derivatives Of ◽  
Heterocyclic Moiety

Abstract: A sizeable proportion of currently marketed drugs come from heterocycles. The heterocyclic moiety 5-pyrazolone is well known five membered ring containing nitrogen. Derivatives of this wonder nucleus have exhibited activities as diverse as antimicrobial, anti-inflammatory, analgesic, antidepressant, anticonvulsant, antidiabetic, antihyperlipidemic, antiviral, antitubercular, antioxidant, anticancer and antiviral including action against severe acute respiratory syndrome (SARS) or 3C protease inhibitor. A number of drugs based on this motif have already made it to the market. Standard texts and literature on medicinal chemistry cite different approaches for the synthesis of 5-pyrazolones. The present review provides an insight view to 5-pyrazolone synthesis, their biological profile and structure activity relationship studies.

Synthesis and Antimicrobial Activity of Adamantyl Substituted Pyridoxine Derivatives

2019 ◽  
Vol 16 (12) ◽  
pp. 1360-1369 ◽  
Author(s):  
Rail Khaziev ◽  
Nikita Shtyrlin ◽  
Roman Pavelyev ◽  
Raushan Nigmatullin ◽  
Raylya Gabbasova ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Lipid Membranes ◽  
Specific Activity ◽  
Tuberculosis H37rv ◽  
Microbial Pathogens ◽  
Adamantane Derivatives ◽  
Carbon Cage ◽  
H37rv Strain ◽  
Derivatives Of

Background: Adamantane derivatives possess multiple pharmacological activities such as antiviral, anticancer, antimycobacterial, antidiabetic, antiparkinsonian and others. The interest of medicinal chemists in adamantane compounds is due to their unique spatial structure, high lipophilicity, and carbon cage rigidity. As a result, these molecules can easily penetrate biological lipid membranes and often have unique target-specific activity profile. Another pharmacophore studied in this work is pyridoxine (vitamin B6). Pyridoxine plays highly important roles in living cells as a key cofactor of many enzymes. On the other hand, its molecular scaffold is a valuable structural platform which has led to the development of several launched drugs (Pyritinol, Pirisudanol, Cycletanine, Mangafodipir) and a wide number of preclinical and clinical drug candidates. Objective: The objective of this study is a synthesis of pyridoxine-adamantane and pyridoxinecyclooctane dipharmacophore molecules. The underlying idea was to assess the antibacterial and antiviral potential of such dipharmacophores, based on multiple examples of promising antiinfective agents which have in their structures adamantane and pyridoxine moieties. Another specific reason was to explore the ability of pyridoxine pharmacophore to suppress the potential of microbial pathogens to develop resistance to drug molecules. Methods: In this study, a series of pyridoxine-adamantane and pyridoxine-cyclooctane dipharmacophore molecules were synthesized based on reactions of three different cycloalkyl amines with the corresponding electrophilic derivatives of pyridoxine aldehydes, chlorides and acetates. All synthesized compounds have been tested for their in vitro activity against M. tuberculosis H37Rv strain and H3N2 (A/Aichi/2/68) influenza virus. Results: Series of pyridoxine-adamantane and pyridoxine-cyclooctane dipharmacophore molecules were synthesized based on reactions of three different cycloalkylamines with the corresponding electrophilic derivatives of pyridoxine aldehydes, chlorides and acetates. Reaction of cycloalkylamines with pyridoxine derivatives, in which meta-hydroxyl and ortho-hydroxymethyl groups are protected by acetyl groups, represents a useful alternative to reductive amination of aldehydes and nucleophilic substitution of alkyl halides. According to a tentative mechanism, it proceeds via paraand ortho-pyridinone methides which readily react with nucleophiles. None of the synthesized dipharmacophore compounds showed activity against M. tuberculosis H37Rv strain. At the same time, three compounds demonstrated some antiviral activity against H3N2 (A/Aichi/2/68) influenza virus (EC50 52-88 µg/mL) that was comparable to the activity of Amantadine, though lower than the activity of Rimantadine. The results of this work can be useful in the design of physiologically active derivatives of pyridoxine and adamantane. Conclusion: The results of this work can be useful in the design of physiologically active derivatives of pyridoxine and adamantane.

Structure-Activity Relationship and Antimicrobial Evaluation of N-Phenylpyrazole Curcumin Derivatives

2020 ◽  
Vol 16 (4) ◽  
pp. 481-488
Author(s):  
Heli Sanghvi ◽  
Satyendra Mishra
Keyword(s):  
Antibacterial Activity ◽  
Gram Negative Bacteria ◽  
Pyrazole Derivatives ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Curcumin Derivatives ◽  
Structure Activity ◽  
Electron Donating Groups ◽  
Derivatives Of

Background: Curcumin, one of the most important pharmacologically significant natural products, has gained significant consideration among scientists for decades since its multipharmacological activities. 1, 3-Dicarbonyl moiety of curcumin was found to be accountable for the rapid degradation of curcumin molecule. The aim of present work is to replace 1, 3-dicarbonyl moiety of curcumin by pyrazole and phenylpyrazole derivatives with a view to improving its stability and to investigate the role of substitution in N-phenylpyrazole curcumin on its antibacterial activity against both Gram-positive as well as Gram-negative bacteria. Methods: Pyrazole derivatives of curcumin were prepared by heating curcumin with phenyhydrazine/ substituted phenyhydrazine derivatives in AcOH. The residue was purified by silica gel column chromatography. Structures of purified compounds were confirmed by 1H NMR and Mass spectroscopy. The synthesized compounds were evaluated for their antibacterial activity by the microdilution broth susceptibility test method against gram positive (S. aureus) and gram negative (E. coli). Results: Effects of substitution in N-phenylpyrazole curcumin derivatives against S. aureus and E. coli were studied. The most active N-(3-Nitrophenylpyrazole) curcumin (12) exhibits twenty-fold more potency against S. aureus (MIC: 10μg/mL)) and N-(2-Fluoroophenylpyrazole) curcumin (5) fivefold more potency against E. coli (MIC; 50 μg/mL) than N-phenylpyrazole curcumin (4). Whereas, a remarkable decline in anti-bacterial activity against S. aureus and E. coli was observed when electron donating groups were incorporated in N-phenylpyrazole curcumin (4). Comparative studies of synthesized compounds suggest the effects of electron withdrawing and electron donating groups on unsubstituted phenylpyrazole curcumin (4). Conclusion: The structure-activity relationship (SAR) results indicated that the electron withdrawing and electron donating at N-phenylpyrazole curcumin played key roles for their bacterial inhibitory effects. The results of the antibacterial evaluation showed that the synthesized pyrazole derivatives of curcumin displayed moderate to very high activity in S. aureus. In conclusion, the series of novel curcumin derivatives were designed, synthesized and tested for their antibacterial activities against S. aureus and E. coli. Among them, N-(3-Nitrophenylpyrazole curcumin; 12) was most active against S. aureus (Gram-positive) and N-(2-Fluoroophenylpyrazole) curcumin (5) against E. coli (Gram-negative) bacteria.

Inductive effect in EI-mass spectra of some 5,6-dihalogenides and 5,6-halohydrins of 5α-cholestan-3β-ol and 3β-acetoxy-5α-cholestane

1982 ◽  
Vol 47 (11) ◽  
pp. 2946-2960 ◽  
Author(s):  
Antonín Trka ◽  
Alexander Kasal
Keyword(s):  
Mass Spectra ◽  
Inductive Effect ◽  
Molecular Ions ◽  
Hydroxyl Group ◽  
Halogen Atoms ◽  
Derivatives Of

Partial EI-mass spectra of 3β-hydroxy- and 3β-acetoxy-5α-cholestanes substituted in positions 5α-, 6β- or 5α,6β- with a hydroxyl group or halogen atoms (fluorine, chlorine, bromine) are presented. The molecular ions of 5α,6β-disubstituted derivatives of 3β-hydroxy-5α-cholestane (or of its 3-acetate) are considerably more stable than the corresponding monosubstituted derivatives if at least one of the pair of the vicinal substituents is chlorine or fluorine. This increase in stability, most striking in 5α- and 6β-fluoro compounds, is explained by the inductive effect.

scholarly journals The Inhibitory Effects of Plant Derivate Polyphenols on the Main Protease of SARS Coronavirus 2 and Their Structure–Activity Relationship

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1924
Author(s):  
Thi Thanh Hanh Nguyen ◽  
Jong-Hyun Jung ◽  
Min-Kyu Kim ◽  
Sangyong Lim ◽  
Jae-Myoung Choi ◽  
...  
Keyword(s):  
Structure Activity Relationship ◽  
Garlic Extract ◽  
Activity Relationship ◽  
Hydroxyl Group ◽  
Inhibitory Effects ◽  
Structure Activity ◽  
Main Protease ◽  
Ic50 Values ◽  
Km Value ◽  
Novel Coronavirus

The main protease (Mpro) is a major protease having an important role in viral replication of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the novel coronavirus that caused the pandemic of 2020. Here, active Mpro was obtained as a 34.5 kDa protein by overexpression in E. coli BL21 (DE3). The optimal pH and temperature of Mpro were 7.5 and 37 °C, respectively. Mpro displayed a Km value of 16 μM with Dabcyl-KTSAVLQ↓SGFRKME-Edans. Black garlic extract and 49 polyphenols were studied for their inhibitory effects on purified Mpro. The IC50 values were 137 μg/mL for black garlic extract and 9–197 μM for 15 polyphenols. The mixtures of tannic acid with puerarin, daidzein, and/or myricetin enhanced the inhibitory effects on Mpro. The structure–activity relationship of these polyphenols revealed that the hydroxyl group in C3′, C4′, C5′ in the B-ring, C3 in the C-ring, C7 in A-ring, the double bond between C2 and C3 in the C-ring, and glycosylation at C8 in the A-ring contributed to inhibitory effects of flavonoids on Mpro.

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