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Chemo-type of essential oil of Ocimum basilicum *** DR Congo and relative in vitro antioxidant potential to the polarity of crude extracts

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Asian Pacific Journal of Tropical Biomedicine 2016年第12期6卷 1022-1028页

作者： Dorothee Dinangayi Tshilanda philippe Bila Babady Damase Nguwo Vele Onyamboko Christian Muamba Tshilolo Tshiongo Damien Sha-Tshibey Tshibangu Koto-te-Nyiwa Ngbolua philippe vuka tsalu Pius Tshimankinda Mpiana Department of Chemistry Faculty of ScienceUniversity of Kinshasa Bila Nutraceuticals Company Department of Biology Faculty of ScienceUniversity of Kinshasa

Objective:To carry out a phyto-chemical characterization of essential oil from Ocimum basilicum L.(***) harvested in DR Congo and to assess the antioxidant potential of crude extracts with respect to the polarity for comparison ***:The phyto-chemical characterization of essential oil produced by hydrodistillation was performed by coupled gas chromatography-mass spectrometer analysis and the antioxidant potential evaluation by in vitro 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity ***:A previously weighed amount of fresh leaves of *** produced 0.65%of essential oil that led to the identification of a set of 84.44%out of 99.98%as major compounds(> 1.5%).The chemo-type of this essential oil was linalool-methyl *** components of oil were characterized by oxygenated aromatic hydrocarbons(46.00%) and oxygenated monoterpenes(26.75%).With respect to the amount of components,methyl chavicol also known as estragole(35.72%) constituted the very large quantity afterward linalool(21.25%) and then epi-α-cadinol(8.02%),α-bergamotene(6.56%),eugenol(4.60%),1,8-cineole(4.04%),germacrene D(2.06%),thymol(1.64%),and(E)-citral(1.55%),*** oil exhibited antioxidant potential and IC_(50) =(1.180 ± 0.015) mg/***-polar crude extracts yields were low compared to the one of polar *** methanol and ethyl acetate had considerably manifested antioxidant potential with IC_(50) values equal to(0.025 ± 0.013) mg/mL and(0.085 ± 0.012) mg/mL,*** concerns to IC50 values,essential oil was less active than methanol and ethyl acetate *** methanol crude extract exhibited the highest ***-polar extracts showed insignificant radical scavenging ability that did not allow assessing IC50 *** results highlighted the occurrence of antioxidant potential compounds in polar ***:Essential oil and crude extracts of *** growing in DR Congo can be advocated as nat

关键词： Ocimum basilicum L. Essential oil Polar and non-polar crude extracts In vitro antioxidant potential GC-MS analysis

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Hydrogen Bonds of C=S, C=Se and C=Te with C-H in Small-Organic Molecule Compounds Derived from the Cambridge Structural Database (CSD)

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Crystal Structure Theory and Applications 2022年第1期11卷 1-22页

作者： Dikima D. Bibelayi Albert S. Lundemba philippe V. tsalu Pitchouna I. Kilunga Jules M. Tshishimbi Zéphirin G. Yav Department of Chemistry University of Kinshasa Kinshasa The Democratic Republic of Congo Austrian Institute of Technology Vienna Austria

Considerable interest in hydrogen bonding involving chalcogen has been growing since the IUPAC committee has redefined hydrogen bonding. Not only the focus is on unconventional acceptors, but also on donors not discussed before. It has been mentioned in previous studies that the proton of the H-C group could be involved in hydrogen bonding, but with conventional acceptors. In this study, we explored the ability of hydrogen bond formation of Se, S and Te acceptors with the H-C donor using Cambridge Structural Database in conjunction with Ab Initio calculations. In the CSD, there are respectively 256, 6249 and 11 R1,R2,-C=Se, R1,R2,-C=S and R1,R2,-C=Te structures that form hydrogen bonds, in which the N,N groups are majority. Except for C=S acceptor which can form a hydrogen bond with its C, C group, both C=Se and C=Te acceptors could form a hydrogen bond only with N,C and N,N groups. CSD analysis shows very similar d (norm) around -0.04 Å, while DFT-calculated interaction for N,C and N,N groups are also similar. Both interaction distances derived from CSD analysis and DFT-calculated interaction energies demonstrate that the acceptors form stable complexes with H-CF3. Besides hydrogen bonds, dispersion interactions are forces stabilizing the complexes since their contribution can reach 50%. Analysis of intra-molecular geometries and Ab Initio partial charges show that this bonding stems from resonance induced Cδ+=Xδ- dipoles. In many respects, both C=Se, C=S and C=Te are similar to C=S, with similar d (norm) and calculated interaction strengths.

关键词： Hydrogen Bond Cambridge Structural Database Survey Frequency of Occurrence (FoO) Ab Initio Calculation Interaction Geometry and Energy

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Chalcogen Bonds in Small-Organic Molecule Compounds Derived from the Cambridge Structural Database (CSD)

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Crystal Structure Theory and Applications 2021年第4期10卷 57-69页

作者： Albert S. Lundemba Dikima D. Bibelayi philippe V. tsalu Peter A. Wood Jason Cole Jean S. Kayembe Zephirin G. Yav Department of Chemistry University of Kinshasa Kinshasa XI The Democratic Republic of Congo AIT-Austrian Institute of Technology Vienna Austria The Cambridge Crystallographic Data Centre Cambridge UK

Growing interest in non-covalent interactions involving chalcogen atoms has been ascribed to their importance in crystal engineering, molecular recognition and macromolecular edifices. The present study is dealing with chalcogen bonds involving divalent Sulphur, Selenium and Tellurium atoms, acting as sigma-hole donors, in small-molecule compounds using the Cambridge Structural Database (CSD) in conjunction with ab initio calculations. Results derived from CSD surveys and computational study revealed that nucleophiles formed complexes with the chalcogen-bond donors R1-X-R2 (X = S, Se or Te). The main forces stabilizing the complexes were chalcogen bonds, enhanced by dispersion interactions. Complexation pattern and energetics show that nucleophile bonding at divalent S, Se and Te atoms is a relatively strong and directed interaction. The bond consists of a charge transfer from a nucleophile atom lone pair to an X-R1 or X-R2 antibonding orbital.

关键词： Chalcogen Bond CSD Ab Initio Calculation Interaction Geometry Interaction Energy

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Chemical Fingerprint and Anti-Sickling Activity of Rosmarinic Acid and Methanolic Extracts from Three Species of Ocimum from DR Congo

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Journal of Biosciences and Medicines 2016年第1期4卷 59-68页

作者： Dorothée D. Tshilanda Paulin K. Mutwale Damase V. N. Onyamboko philippe B. Babady philippe V. tsalu Damien S. T. Tshibangu Nadege K. Ngombe M. Frederich Koto-te-Nyiwa Ngbolua Pius T. Mpiana Department of Chemistry Faculty of Science University of Kinshasa Kinshasa Democratic Republic of the Congo Centre d’Etudes des Substances Naturelles d’Origine Végétale (CESNOV) Faculty of Pharmaceutical Sciences University of Kinshasa Kinshasa Democratic Republic of the Congo Bila Nutraceuticals Company Dartmouth Canada Laboratory of Pharmacognosy Department of Pharmacy CIRM University of Liège CHU Liège Belgium Department of Biology Faculty of Science University of Kinshasa Kinshasa Democratic Republic of the Congo

The aim of this study was to characterize the polyphenolic composition by determination of chemical fingerprints of Methanolic extracts of Ocimum canum Sims, Ocimum basilicum L. and Ocimum gratissimum L. from Democratic Republic of Congo and to compare their antisickling activity of that of rosmarinic acid, the major compound to those of methanolic extracts. Phytochemical analysis performed by TLC and HPLC analysis, showed that rosmarinic acid is the most abundant phenolic acid in these Ocimum species according to the following order O. basilicum L., O. gratissimum L. and O. canum Sims. Methanolic extracts of these three species and pure rosmarinic acid showed significant antisickling activities with minimal concentration of normalization values of 0.18 ± 0.03, 0.23 ± 0.04, 0.26 ± 0.04 and 0.31 ± 0.05 mg/mL for rosmarinic acid, O. basilicum L., O. gratissimum L. and O. canum Sims methanolic extracts respectively. The antisickling activity order is the same as that of the rosmarinic acid content, indicating that this polyphenolic acid would be among the main active molecules in these extracts.

关键词： Antisickling Chemical Fingerprint O. canum O. basilicum O. gratissimum Rosmarinic Acid

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Distortions and Deformations of Metaled Meso-Substituted and Unsubstituted Porphyrins and Derivatives in Crystal Structures

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Crystal Structure Theory and Applications 2016年第1期5卷 1-15页

作者： philippe V. tsalu Tharcisse O. Monama Hilaire V. Mambo Dorothée D. Tshilanda Pius T. Mpiana Bodrique M. Nsimba Virima Mudogo Pitchou N. Bokolombe Damien S. T. Tshibangu Zephyrin G. Yav Department of Chemistry Faculty of Science University of Kinshasa Kinshasa Democratic Republic of the Congo Departement de Géochimie Appliquée Centre de Recherches Géologiques et Minières Kinshasa Democratic Republic of the Congo

Experimental crystallographic structural parameters of a range of metaled meso-substituted and unsubstituted porphyrins were reviewed to show how far the meso-substitution by any functional group and the insertion of metal in the porphyrins core macrocycle may affect the geometry. The analysis of twists and angles has shown two kinds of distortions: external [T(Cβ-Cα-Cmeso-Xn) and T(Cβ-Cα-Cmeso-Cα)] and internal [T(Nm-Cα-Cmeso-Xn) and T(Nn-Cα-Cmeso-Cα)] with averages of [+6°and –6°] and [–5°and +5°], respectively. In the meso-substituted case, the external and internal twists Cβ-Cα-Cmeso-X and N-Cα-Cmeso-X, respectively are oppositely orientated. Similar effect is observed in meso-unsubstituted of Cβ-Cα- Cmeso-H and N-Cα-Cmeso-H. However, the external distortions are more significant than internal. Considering the same order, the limit of distortions is [97°and 132°(–48°)] for external and [91°(–89°) and 52°] for internal. In the two cases, the substituents have opposite directions of distortions. The meso-substituted porphyrins have a high limit of twisting than usubstituted one, depending of the weight of substituents. The average of the bond angular deformations is 168°, almost planar. However, the limit of angular deformation is 94°.

关键词： Metaled Meso-Substituted and Unsubstituted Porphyrins and Derivates Crystals Structures Distortions and Bonds Angular Deformations

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Interaction of Iron(III)-5,10,15,20-Tetrakis (4-Sulfonatophenyl) Porphyrin with Chloroquine, Quinine and Quinidine

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Crystal Structure Theory and Applications 2017年第3期6卷 25-38页

作者： Dikima D. Bibelayi Pitchouna I. Kilunga Albert S. Lundemba Matthieu K. Bokolo Pius T. Mpiana philippe V. tsalu Juliette Pradon Colin C. Groom Celine W. Kadima Luc Van Meervelt Zephyrin G. Yav Department of Chemistry University of Kinshasa Kinshasa Democratic Republic of Congo Department of Chemistry University of Ulsan Ulsan Republic of Korea The Cambridge Crystallographic Data Centre Cambridge UK Department of Chemistry State University of New York at Oswego Oswego USA Department of Chemistry Katholieke Universiteit Leuven Leuven Belgium

Iron(III)-5,10,15,20-tetrakis(4-sulfonatophenyl) porphyrin (FeTPPS) is used as non-physiological metalloporphyrin model for the natural iron (III)-protoporphyrin IX (FePPIX) resulting from hemoglobin degradation to investigate ligand binding reactions in aqueous solution. Studies were conducted on the interaction of FeTPPS with Chloroquine, Quinine, and Quinidine, which are historically the most common quinoline-based drugs used to treat malaria, an infectious disease afflicting several hundred millions every year worldwide, mainly in tropical regions. Using UV-Visible spectrophotometry, the binding reaction was studied at pH 7.40 in purely aqueous solution, and in aqueous solution containing NaNO3 at concentration of 0.1 M. Fitted titration curves obtained were in agreement with experimental data according to a formation scheme of 1:1 complex (1 FeTPPS μ-oxo-dimer: 1 Antimalarial). Values of apparent binding constant (K) obtained were between 4.3 × 103 M-1 to 7.59 × 104 M-1, demonstrating that FeTPPS and the antimalarials formed stable complexes. The stability of the complex decreased when NaNO3 was added to the solution. This ionic strength dependence was ascribed to electrostatic effects. Quinine and Chloroquine interacted with FeTPPS stronger than Quinidine did. Chloroquine showed the strongest affinity to FeTPPS. These findings revealed the influence of steric and stereochemical factors. Molecular electrostatic potentials (MEP) calculated with Hartree-Fock theory argue in favor of π-π and electrostatic interactions between reaction partners as driving forces for the complex formation. In the case of FeTPPS: Chloroquine interaction, it is suggested that an intramolecular hydrogen bond is formed between phenyl??and quinuclidine N-H+ as additional force stabilizing the complex. Analysis of crystallographic data using the Cambridge Structural Database (CSD) gave evidence of the hydrogen bond formation between phenyl??and N-H+ groups in 370 structures.

关键词： FeTPPS Apparent Binding Constant (K) Molecular Electrostatic Potential (MEP) Cambridge Structural Database (CSD)

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