Ab Initio and DFT Computational Study
of Myristinin A and a Structurally
Related Molecule
Neani Tshilande and Liliana Mammino
Abstract Anti-inflammatory drugs are drugs used for the relief of pain, fever and
inflammations. Acylphloroglucinols are phloroglucinol derivatives characterised by
the presence of a CRO group. The current work presents the results of a computational study of two acylphloroglucinols of plant origin having potent antiinflammatory activity: myristinin A and a structurally-related molecule here concisely denoted as DBPO. The molecules have the same 2-(4-hydroxyphenyl)-3,4dihydro-2H-chromen-7-ol substituent in meta to CRO and differ only by the R chain.
DBPO can exist as cis or trans isomers because of the presence of a C=C double
bond in R; the two isomers are studied individually. The sp
2 O atom in CRO can
form an intramolecular hydrogen bond (IHB) with either phenol OH ortho to CRO.
The phenol OHs neighbouring the substituent can form O–H···π IHBs with one of its
aromatic rings, if suitably oriented. The conformational preferences and other computable molecular properties have been investigated in vacuo and in three suitably
selected solvents. The results show that the O–H···O IHB is the dominant stabilising
factor, followed by the O–H···π IHB. Other factors having significant influence on
conformational preferences are the orientation of the rings in the substituent, the
mutual orientation of the OHs in the phloroglucinol moiety, the orientation of the
OHs in the substituent, and also the geometry of the R chain. Comparisons of the
results of the three molecules highlight similarity of trends and frequent closeness
of individual values of the properties considered. The results in solution highlight
narrowing of the energy gaps between conformers and increase of the dipole moment
as the medium polarity increases.
Keywords Acylphloroglucinols · Anti-inflammatories · Cis-trans isomers ·
Intramolecular hydrogen bonding · Myristinin A · Solvent effect · Solute-solvent
interactions
Electronic supplementary material The online version of this chapter
(https://doi.org/10.1007/978-3-030-34941-7_11) contains supplementary material, which is
available to authorized users.
N. Tshilande · L. Mammino (B)
School of Mathematical and Natural Sciences, University of Venda, Thohoyandou, South Africa
© Springer Nature Switzerland AG 2020
L. Mammino et al. (eds.), Advances in Quantum Systems in Chemistry,
Physics, and Biology, Progress in Theoretical Chemistry and Physics 32,
https://doi.org/10.1007/978-3-030-34941-7_11
205
of Myristinin A and a Structurally
Related Molecule
Neani Tshilande and Liliana Mammino
Abstract Anti-inflammatory drugs are drugs used for the relief of pain, fever and
inflammations. Acylphloroglucinols are phloroglucinol derivatives characterised by
the presence of a CRO group. The current work presents the results of a computational study of two acylphloroglucinols of plant origin having potent antiinflammatory activity: myristinin A and a structurally-related molecule here concisely denoted as DBPO. The molecules have the same 2-(4-hydroxyphenyl)-3,4dihydro-2H-chromen-7-ol substituent in meta to CRO and differ only by the R chain.
DBPO can exist as cis or trans isomers because of the presence of a C=C double
bond in R; the two isomers are studied individually. The sp
2 O atom in CRO can
form an intramolecular hydrogen bond (IHB) with either phenol OH ortho to CRO.
The phenol OHs neighbouring the substituent can form O–H···π IHBs with one of its
aromatic rings, if suitably oriented. The conformational preferences and other computable molecular properties have been investigated in vacuo and in three suitably
selected solvents. The results show that the O–H···O IHB is the dominant stabilising
factor, followed by the O–H···π IHB. Other factors having significant influence on
conformational preferences are the orientation of the rings in the substituent, the
mutual orientation of the OHs in the phloroglucinol moiety, the orientation of the
OHs in the substituent, and also the geometry of the R chain. Comparisons of the
results of the three molecules highlight similarity of trends and frequent closeness
of individual values of the properties considered. The results in solution highlight
narrowing of the energy gaps between conformers and increase of the dipole moment
as the medium polarity increases.
Keywords Acylphloroglucinols · Anti-inflammatories · Cis-trans isomers ·
Intramolecular hydrogen bonding · Myristinin A · Solvent effect · Solute-solvent
interactions
Electronic supplementary material The online version of this chapter
(https://doi.org/10.1007/978-3-030-34941-7_11) contains supplementary material, which is
available to authorized users.
N. Tshilande · L. Mammino (B)
School of Mathematical and Natural Sciences, University of Venda, Thohoyandou, South Africa
© Springer Nature Switzerland AG 2020
L. Mammino et al. (eds.), Advances in Quantum Systems in Chemistry,
Physics, and Biology, Progress in Theoretical Chemistry and Physics 32,
https://doi.org/10.1007/978-3-030-34941-7_11
205