A DFT analysis on the radical scavenging activity of oxygenated terpenoids present in the extract of the buds of Cleistocalyx operculatus

Ngo, Thị Chinh; Dao, Duy Quang; Nguyễn, Minh Thông; Nam, Pham Cam

doi:10.1039/c7ra04798c

Cited by 29 publications

(27 citation statements)

References 37 publications

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“…This observation can be explained by a better deprotonation process in aqueous media. [11,12] Similar trends are obtained in the case of PT reactions with HO • radical. In fact, the ∆H 0 for PT reactions between compound 1 and HO • are found being 188.3, 51.7 and 100.9 kcal/mol in the gas phase, water and PEA, in sequence.…”

Section: Proton Transfer (Pt) Reactionssupporting

confidence: 75%

Photoprotective properties of natural antioxidant flavonoids: A DFT and TD‐DFT study on acridone derivatives

Chinh

Anh

Thảo

et al. 2020

Vietnam Journal of Chemistry

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Antioxidant and photoprotective properties of two natural acridone derivatives namely Paratrimerin C (1) and Citrusinine-I (2) have been studied by DFT and TD-DFT at the M05-2X/6-311++G(3df, 3p)//M05-2X/6-31+G(d) level of theory. Three common mechanisms characterized for the antioxidant properties including H-atom transfer (HAT) and proton transfer (PT) towards HOO • /HO • radicals and single electron transfer (SET) were investigated in the gas phase, water and pentyle thanoate. The DFT results revealed that both compounds can efficiently scavenge HOO • and HO • radicals via HAT mechanism in all media. Particularly, the HAT reactions of 2 with HO • radical in water are the most favored reaction (∆H -37.7 kcal/mol). In addition, the efficient UV-absorption ability of the studied compound was elucidated by TD-DFT. All compounds can absorb UV radiations in the range of 200-335 nm, for which the easiest excitations are at 334-332 nm and the strongest absorptions were found at 234-227 nm, for 1 and 2, respectively. The HOMO to LUMO and HOMO-3 to LUMO (π-π*) transitions are assigned for the corresponding UV-absorption.

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Section: Proton Transfer (Pt) Reactionssupporting

confidence: 75%

Photoprotective properties of natural antioxidant flavonoids: A DFT and TD‐DFT study on acridone derivatives

Chinh

Anh

Thảo

et al. 2020

Vietnam Journal of Chemistry

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“…Wherein the compounds (4) and (5) represent as the most potential antioxidant with the lowest BDE in the gas phase being 73.2 and 74.8 kcal/ mol. In comparison with the BDEs values of other well-known antioxidants such as phenol (87.2 kcal/mol) [10], α-terpinene (74.4 kcal/mol) [11], wasabidienone E, mactanamide, cycloechinulin may be considered as potential antioxidant.…”

Section: Hydrogen Atom Transfer (Hat) Mechanismmentioning

confidence: 99%

“…By comparing with the IP of phenol, i.e. 8.49 ± 0.02 eV [12] and other well-known antioxidant such as falcarinol, α-vetivone with IP being 8.35, 8.06 eV [11], respectively, these values are considerably low.…”

Section: Single Electron Transfer (Set) Mechanismmentioning

confidence: 99%

Antioxidant Potential of Five Compounds Extract From the Marine Fungus Aspergillus Flocculosus by DFT Method: Hat and Set Mechanism.

Trang

Vân

Chinh

et al. 2019

JST

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Antioxidant potential of five compounds include ochraceopone F (1), aspertetranone D (2), cycloechinulin (3), wasabidienone E (4) and mactanamide (5) in the extracts from marine fungus Aspergillus flocculosus in Nha Trang was investigated by computational chemistry methods. All calculations were performed at the theoretical level M05-2X/6-311++G(d, p)//M05-2X/6-31+G(d) in the gas phase. The physicochemical properties such as bond dissociation energies (BDE), ionization energies (IE), electron affinity (EA) characterizing HAT (Hydrogen atom transfer) and SET (Single electronic transfer) antioxidant mechanisms were calculated.As a result, the H-atom donating ability of the studies compounds increases in the descending order of BDE value (1) > (2) > (3) > (4) » (5). Wherein the compounds (4) and (5) represent as the most potential antioxidant with the lowest BDE in the gas phase being 74.9 and 75.1 kcal/ mol. Moreover, the electronic donating ability of the compounds increases as function of the descending order of IE value (2) > (1) > (5) > (3) > (4). And the electron accepting abitlity decreases in decreasing EA value (4) > (3) > (2) > (5) > (1). Compound (4) (wasabidienone E) has the smallest IE value of 6.56 eV and has the largest EA value of 2.33 eV.

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“…So, the PT step plays an important role in influencing to the preponderance of the SPL-ET mechanism. [10] The reaction enthalpies (H°) and Gibbs free energies (G°) of the PT reactions (R5) between the thiamine and HO  /HOO  radicals are resumed in tables 1 and 2. Optimized structures and Cartesians coordinates of all the neutral compounds resulted from the deprotonating process of thiamine are listed in Table S4 of Supporting Information.…”

Section: Proton Transfer (Pt)mentioning

confidence: 99%

Unraveling the antioxidant potential of thiamine: Thermochemical and kinetics studies in aqueous phase using DFT

Nga

Dao

2019

Vietnam Journal of Chemistry

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The scavenging mechanism of thiamine (or vitamin B1) towards HO  and HOO  radicals has been revisited using density functional theory (DFT) at the M05-2X/6-311++G (d,p) level of theory. Enthalpies and Gibbs free energies of four common antioxidant reactions, i.e. formal hydrogen transfer (FHT), proton transfer (PT), single electron transfer (SET) and radical adduct formation (RAF), have been systematically calculated in the aqueous phase. Potential energy profiles accompanied with the optimized structures of all transition states (TS) and intermediate ones were also established. As a result, thiamine represents as a potent antioxidant notably via RAF mechanism with the lowest H 0 values at C12 position equal to -37.5 and -9.2 kcal/mol towards HO  and HOO  radicals, respectively. The reactions are also favorable with G 0 values of -28.8 and 2.8 kcal/mol, respectively. The order of the decrease in preponderance of the studied mechanism is as follows: RAF > FHT > SET > PT. The scavenging reactivity towards HO  radical is considerably higher than the one toward HOO  radical as expected. In comparing with trolox and ascorbic acid, their antioxidant potential could be classified in the decreasing order: ascorbic acid > thiamine > trolox.

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A DFT analysis on the radical scavenging activity of oxygenated terpenoids present in the extract of the buds of Cleistocalyx operculatus

Abstract: The antioxidant capacity of twenty-one oxygenated monoterpene and oxygenated desquiterpene compounds in the extract from Cleistocalyx operculatus has been computationally evaluated.

Cited by 29 publications

References 37 publications

Photoprotective properties of natural antioxidant flavonoids: A DFT and TD‐DFT study on acridone derivatives

Photoprotective properties of natural antioxidant flavonoids: A DFT and TD‐DFT study on acridone derivatives

Antioxidant Potential of Five Compounds Extract From the Marine Fungus Aspergillus Flocculosus by DFT Method: Hat and Set Mechanism.

Unraveling the antioxidant potential of thiamine: Thermochemical and kinetics studies in aqueous phase using DFT

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