Computational Study of
Shuangancistrotectorine A:
A Naphthylisoquinoline Alkaloid
with Antimalarial Activity
Mireille K. Bilonda and Liliana Mammino
Abstract Shuangancistrotectorines A, B, C, D and E are naphthylisoquinoline
alkaloids isolated from the twigs of Ancistrocladus tectorius, an indigenous plant in
China and South East Asia. Their molecules are all C 2 -symmetric, i.e., they consist
of two identical units. Each unit contains a naphthalene moiety and an isoquinoline moiety. Shuangancistrotectorine B and E are atropo-diastereomers of shuangancistrotectorine A and D respectively. Shuangancistrotectorine A, B and D exhibit
very good and specific antimalarial activity, with shuangancistrotectorine A being the
most active. The current work presents the results of a detailed conformational study
of shuangancistrotectorine A, performed in vacuo and in three solvents with different polarities and different H-bonding abilities (chloroform, acetonitrile and water),
using two levels of theory, HF/6-31G(d,p) and DFT/B3LYP/6-31+G(d,p). Particular
attention is given to intramolecular hydrogen bonds’ patterns. The results show that
intramolecular hydrogen bonds are the dominant factor influencing conformational
preferences and energies, and also the other computable molecular properties. The
mutual orientation of the moieties is also an energy-influencing factor, and the results
show that all the moieties prefer to be perpendicular to each other. Comparisons with
the results of other previously-investigated dimeric naphthylisoquinoline alkaloids
are also included.
Keywords Alkaloids · Antimalarials · Intramolecular hydrogen bonding · Mutual
orientation of aromatic rings · Shuangancistrotectorine A · Naphthylisoquinoline
alkaloids · Solute-solvent interactions
Electronic supplementary material The online version of this chapter
(https://doi.org/10.1007/978-3-030-34941-7_10) contains supplementary material, which is
available to authorized users.
M. K. Bilonda · L. Mammino (B)
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_10
183
Shuangancistrotectorine A:
A Naphthylisoquinoline Alkaloid
with Antimalarial Activity
Mireille K. Bilonda and Liliana Mammino
Abstract Shuangancistrotectorines A, B, C, D and E are naphthylisoquinoline
alkaloids isolated from the twigs of Ancistrocladus tectorius, an indigenous plant in
China and South East Asia. Their molecules are all C 2 -symmetric, i.e., they consist
of two identical units. Each unit contains a naphthalene moiety and an isoquinoline moiety. Shuangancistrotectorine B and E are atropo-diastereomers of shuangancistrotectorine A and D respectively. Shuangancistrotectorine A, B and D exhibit
very good and specific antimalarial activity, with shuangancistrotectorine A being the
most active. The current work presents the results of a detailed conformational study
of shuangancistrotectorine A, performed in vacuo and in three solvents with different polarities and different H-bonding abilities (chloroform, acetonitrile and water),
using two levels of theory, HF/6-31G(d,p) and DFT/B3LYP/6-31+G(d,p). Particular
attention is given to intramolecular hydrogen bonds’ patterns. The results show that
intramolecular hydrogen bonds are the dominant factor influencing conformational
preferences and energies, and also the other computable molecular properties. The
mutual orientation of the moieties is also an energy-influencing factor, and the results
show that all the moieties prefer to be perpendicular to each other. Comparisons with
the results of other previously-investigated dimeric naphthylisoquinoline alkaloids
are also included.
Keywords Alkaloids · Antimalarials · Intramolecular hydrogen bonding · Mutual
orientation of aromatic rings · Shuangancistrotectorine A · Naphthylisoquinoline
alkaloids · Solute-solvent interactions
Electronic supplementary material The online version of this chapter
(https://doi.org/10.1007/978-3-030-34941-7_10) contains supplementary material, which is
available to authorized users.
M. K. Bilonda · L. Mammino (B)
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_10
183