Dennis Abatis

Dr. Dennis Abatis

National & Kapodistrian University of Athens
orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 June 2021 in Molecules
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Journal Article
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Mostafa A. AsmaeyMostafa A. Asmaey
Mostafa A. Asmaey
DADennis Abatis
Dennis Abatis
AAAhmed Abdel-Razek
Ahmed Abdel-Razek
GLGeorge Lambrinidis
George Lambrinidis
Ioanna ChinouIoanna Chinou
Ioanna Chinou
NANektarios Aligiannis
Nektarios Aligiannis
The fungal strain was isolated from a soil sample collected in Giza province, Egypt, and was identified as Aspergillus ochraceopetaliformis based on phenotypic and genotypic data. The ethyl acetate extract of the fungal strain exhibited promising activity levels against several pathogenic test organisms and through a series of 1H NMR guided chromatographic separations, a new α-pyrone-C-lyxofuranoside (1) along with four known compounds (2–5) were isolated. The planar structure of the new metabolite was elucidated by detailed analysis of its 1D/2D NMR and HRMS/IR/UV spectroscopic data, while the relative configuration of the sugar moiety was determined by a combined study of NOESY and coupling constants data, with the aid of theoretical calculations. The structures of the known compounds—isolated for the first time from A. ochraceopetaliformis—were established by comparison of their spectroscopic data with those in the literature. All isolated fungal metabolites were evaluated for their antibacterial and antifungal activities against six Gram-positive and Gram-negative bacteria as well as against three human pathogenic fungi.

27 July 2010 in African Journal of Traditional, Complementary and Alternative Medicines
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Journal Article
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CMC Mutai
C Mutai
CBC Bii
C Bii
GRG Rukunga
G Rukunga
JOJ Ondicho
J Ondicho
PMP Mwitari
P Mwitari
JKJ Kirui
J Kirui
Acacia mellifera has been used widely in traditional African medicines against various diseases. Among the Kipsigis community of Kenya, water extracts from the plant is used for the treatment of skin diseases, coughs and gastrointestinal ailments. The aim of the study was to provide scientific rationale for the use of the plant in traditional medicine through bioassay-guided fractionation of A. mellifera stem bark. Bioactivity testing was done against selected microbes using disc diffusion technique as outlined in Clinical Laboratory Standard Institute (CLSI). Structure elucidation of the isolated compounds was based primarily on 1D and 2D NMR analyses, including HMQC, HMBC, and NOESY correlations. Fractionation yielded three triterpenoids; (20S)-oxolupane-30- al, (20R)-oxolupane-30-al, and betulinic acid. The three compounds were active against Staphylococcus aureus ATCC 25923 and only (20S)-oxolupane-30-al against clinical isolate of Microsporum gypseum. The three compounds had no activity against Escherichia coli ATCC 25922, Enterococcus feacalis, Candida albicans ATCC 90028, Cryptococcus neoformans, Trichophyton mentagrophyte, Candida krusei, Microsporum gypseum, and Sacharomyces cerevisiae. These results explain and support the use of A. mellifera stem barks for the treatment of infectious diseases in traditional Kenya medicine.It also shows that the antimicrobial activity is concentrated in the triterpenoid fractions. Keywords: Acacia mellifera; Antimicrobial pentacyclic triterpenes; Kenya medicinal plant.

1 July 2024 in Chemistry of Natural Compounds
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Journal Article
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VAVaios Amountzias
Vaios Amountzias
DADennis Abatis
Dennis Abatis
NANektarios Aligiannis
Nektarios Aligiannis

10 July 2024 in Acta Crystallographica Section C Structural Chemistry
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Journal Article
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Mostafa A. AsmaeyMostafa A. Asmaey
Mostafa A. Asmaey
DKDimitris A. Kalofolias
Dimitris A. Kalofolias
MCMaria-Despoina Charavgi
Maria-Despoina Charavgi
Ismail Abdel-RahimIsmail Abdel-Rahim
Ismail Abdel-Rahim
Evangelia ChrysinaEvangelia Chrysina
Evangelia Chrysina
DADennis Abatis
Dennis Abatis
The highly cytotoxic macrocyclic trichothecene Isororidin A (C 29 H 40 O 9 ) was isolated from the fungus Myrothesium verrucaria endophytic on the wild medicinal plant `Datura' ( Datura stramonium L.) and was characterized by one- (1D) and two-dimensional (2D) NMR spectroscopy. The three-dimensional structure of Isororidin A has been confirmed by X-ray crystallography at 0.81 Å resolution from crystals grown in the orthorhombic space group P 2 1 2 1 2 1 , with one molecule per asymmetric unit. Isororidin A is the epimer of previously described (by X-ray crystallography) Roridin A at position C-13′ of the macrocyclic ring.