Computational Study of Shuangancistrotectorine A …
201
and C–H···O (which can form between a CH and an OH of the same isoquinoline
moiety or between the two naphthalene moieties), and by the mutual orientations of
the moieties.
Since the two units are identical, the presence or the absence of a given IHB in only
one of the units has the same effects whether it occurs in unit S (O43–H52···O42) or
in unit S’ (O44–H54···O45). Therefore, the two conformers of a symmetric pair have
the same relative energy and similar molecular properties, such as dipole moments
and HOMO-LUMO energy gaps, and also rather close values of G solv .
The comparison of shuangancistrotectorine A, jozimine A 2 and michellamine A
shows that the conformational preferences of the three molecules are dominantly
influenced by the IHB patterns, with the O–H···O IHBs having principal stabilising role. The mutual orientations of the moieties also have significant influence on
conformational preferences.
The solvent effect (G solv ) is positive in chloroform and acetonitrile for all the
conformers of these three molecules. It is also positive in water for shuangancistrotectorine A, whereas it is negative for the other two molecules. A planned separate
study will consider adducts of these molecules with explicit water molecules, to
better understand their behaviours in water solution.
Acknowledgements The authors would like to thank the Centre for High Performance Computing
(South Africa) for providing computational resources used to conduct this work. M. K. Bilonda is
grateful to the National Research Foundation (NRF) of South Africa for a bursary to support her
PhD studies.
References
1. WHO 018 https://apps.who.int/iris/bitstream/handle/10665/275867/9789241565653-eng.pdf?
ua=1
2. Xu M, Bruhn T, Hertlein B, Brun R, Stich A, Wu J, Bringmann G (2010) Chem Eur J 16:4206–
4216
3. Mammino L, Bilonda MK (2016) Theor Chem Acc 135:101. https://doi.org/10.1007/s00214016-1843-7
4. Bilonda MK, Mammino L (2018) In: Wang Y, Thachuk M, Krems R, Maruani J (eds) Concepts,
methods and applications of quantum systems in chemistry and physics. Springer, Berlin, pp
305–328
5. Mammino L, Bilonda MK (2017) In: Tadjer A, Pavlov R, Maruani J, Brändas EJ, DelgadoBarrio G (eds) Quantum systems in physics, chemistry, and biology—advances in concepts
and applications, Springer, pp 303–316
6. Bilonda MK, Mammino L (2018) Theor Chem Acc 137:139. https://doi.org/10.1007/s00214018-2323-z
7. Bringmann G, Zhang G, Büttner T, Bauckmann G, Kupfer T, Braunschweig H, Brun R, Mudogo
V (2013) Chem Eur J 19:916–923
8. Boyd MR (1994) J Med Chem 37:1740–1745
9. Becke AD (1993) J Chem Phys 98:5648–5662
10. Lee C, Yang W, Parr RG (1988) Phys Rev B 37:785–789
11. Mammino L, Kabanda MM (2009) J Mol Struct (Theochem) 901:210–219
201
and C–H···O (which can form between a CH and an OH of the same isoquinoline
moiety or between the two naphthalene moieties), and by the mutual orientations of
the moieties.
Since the two units are identical, the presence or the absence of a given IHB in only
one of the units has the same effects whether it occurs in unit S (O43–H52···O42) or
in unit S’ (O44–H54···O45). Therefore, the two conformers of a symmetric pair have
the same relative energy and similar molecular properties, such as dipole moments
and HOMO-LUMO energy gaps, and also rather close values of G solv .
The comparison of shuangancistrotectorine A, jozimine A 2 and michellamine A
shows that the conformational preferences of the three molecules are dominantly
influenced by the IHB patterns, with the O–H···O IHBs having principal stabilising role. The mutual orientations of the moieties also have significant influence on
conformational preferences.
The solvent effect (G solv ) is positive in chloroform and acetonitrile for all the
conformers of these three molecules. It is also positive in water for shuangancistrotectorine A, whereas it is negative for the other two molecules. A planned separate
study will consider adducts of these molecules with explicit water molecules, to
better understand their behaviours in water solution.
Acknowledgements The authors would like to thank the Centre for High Performance Computing
(South Africa) for providing computational resources used to conduct this work. M. K. Bilonda is
grateful to the National Research Foundation (NRF) of South Africa for a bursary to support her
PhD studies.
References
1. WHO 018 https://apps.who.int/iris/bitstream/handle/10665/275867/9789241565653-eng.pdf?
ua=1
2. Xu M, Bruhn T, Hertlein B, Brun R, Stich A, Wu J, Bringmann G (2010) Chem Eur J 16:4206–
4216
3. Mammino L, Bilonda MK (2016) Theor Chem Acc 135:101. https://doi.org/10.1007/s00214016-1843-7
4. Bilonda MK, Mammino L (2018) In: Wang Y, Thachuk M, Krems R, Maruani J (eds) Concepts,
methods and applications of quantum systems in chemistry and physics. Springer, Berlin, pp
305–328
5. Mammino L, Bilonda MK (2017) In: Tadjer A, Pavlov R, Maruani J, Brändas EJ, DelgadoBarrio G (eds) Quantum systems in physics, chemistry, and biology—advances in concepts
and applications, Springer, pp 303–316
6. Bilonda MK, Mammino L (2018) Theor Chem Acc 137:139. https://doi.org/10.1007/s00214018-2323-z
7. Bringmann G, Zhang G, Büttner T, Bauckmann G, Kupfer T, Braunschweig H, Brun R, Mudogo
V (2013) Chem Eur J 19:916–923
8. Boyd MR (1994) J Med Chem 37:1740–1745
9. Becke AD (1993) J Chem Phys 98:5648–5662
10. Lee C, Yang W, Parr RG (1988) Phys Rev B 37:785–789
11. Mammino L, Kabanda MM (2009) J Mol Struct (Theochem) 901:210–219