EFFECTS OF SUBSTITUENTS ON CH BOND DISSOCIATION ENTHALPIES OF ENT-KAURANE DITERPENOIDS: A DFT STUDY

Authors

  • Hai Ngo Truong Dang Faculty of Pharmacy, Duy Tan University
  • Chinh Thi NGO Institute of Research and Development, Duy Tan University
  • Quan Minh PHAM Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology https://orcid.org/0000-0001-6922-1627
  • Long Quoc PHAM Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology
  • Quang Duy Dao Institute of Research and Development, Duy Tan University

DOI:

https://doi.org/10.15625/2525-2518/56/4A/12923

Keywords:

DFT, BDE, ent-kaurane diterpenoids, substituent, antioxidant

Abstract

C-H bond dissociation enthalpies (BDEs) of seven ent-kaurane diterpenoids extracted from Croton tonkinensis Gagnep. have been investigated by using density functional theory (DFT) method. The calculations were performed at the M05-2X/6-31+G(d) level of theory. Additionally, insight into the effects of different substituents including –NH2, –OH, –NO2, –SH, –CN, –Cl, –CONH2, –CH-(CH3)2, –NHCOCH3, –OCOCH3 and –C2H5 on BDE have also been provided. The results showed that the BDE value of ent-16(S)-18-acetoxy-7b-hydroxykaur-15-one compound is lowest, being 83.5 kcal/mol. Among substituents binding at C16 position of this molecule, –NH2 has the most remarkable influence on the BDE (C-H) value. Indeed, the BDE of C16-H significantly decreases from 83.5 to 68.4 kcal/mol when replacing –CH3 group by –NH2 one at the C16 position. The obtained results may provide more information for organic synthesis of ent-kaurane based – novel antioxidant compounds.

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Author Biographies

Hai Ngo Truong Dang, Faculty of Pharmacy, Duy Tan University

Faculty of Pharmacy

Chinh Thi NGO, Institute of Research and Development, Duy Tan University

Institute of Research and Development

Quan Minh PHAM, Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology

Biochemistry Department

Long Quoc PHAM, Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology

Biochemistry

Quang Duy Dao, Institute of Research and Development, Duy Tan University

Institute of Research and Development

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Published

2018-10-19

Issue

Section

The 6th National Workshop on Research and Development of Natural Products