Novel polycyclic pyrroloquinazoline alkaloids from Anisotes trisulcus and their biological activity

Abstract

Two new polycyclic pyrroloquinazoline alkaloids with unprecedented skeleton, anisulcusines A (1) and B (2), along with four known compounds (3–6), were identified from the aerial parts of Anisotes trisulcus (Forssk.) Nees. To our knowledge, anisulcusines A and B are the first polycyclic pyrroloquinazoline alkaloids that possess a unique N-methyl-1,2-dihydro-1'H-spiro[benzo[d][1,3]oxazine moiety. The chemical structures of the new compounds were elucidated through extensive spectroscopic analyses and high-resolution mass spectroscopy. Anisulcusine B (2) exerted moderate cytotoxic effect on cultured human hepatoma (HuH7) cells, whereas compounds 1 and 3–5 exhibited mild cell proliferative or growth stimulatory activity.

HIGHLIGHTS

• Two new polycyclic pyrroloquinazoline alkaloids from Anisotes trisulcus.

• Structures were elucidated on the basis of 1D- and 2D-NMR and HR-ESI-MS spectra.

• Compound (2) exerted moderate cytotoxic effect against human hepatoma (HuH7) cells.

• Compounds (1, 3–5) exhibited mild cell proliferative or growth stimulatory activity.

Keywords:

• Anisotes trisulcus
• Acanthaceae
• pyrroloquinazoline alkaloids
• cytotoxic activity

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was funded by the deanship of scientific research at the Princess Nourah Bint Abdulrahman University through the Research Groups Program Grant (no. RGP-1440-0014).