Cyclopeptide Alkaloids from Ziziphus apetala

Abstract

Six novel Ia₃-type cyclopeptide alkaloids (1-6) were isolated from stems of Ziziphus apetala. Compound 5 and the known compounds mauritine A (7) and mauritine F (8) were isolated from the roots. Their structures were determined by spectroscopic analyses and chemical methods. The total alkaloids from the roots and the isolated cyclopeptide alkaloids were tested for antidepressant behavior on mice, cytotoxicity, and 11β-hydroxysteroid dehydrogenase (11β-HSD) inhibition in vitro. Only mauritine A (7) showed inhibitory activity on 11β-HSD1, with IC₅₀ values of 52.0 (human) and 31.2 μg/mL (mouse).

New bioactive cyclopeptide alkaloids with rare terminal unit from the root bark ofZiziphus cambodiana

“…For instances, the D-erythro (8R,9R) of scutianine E, 36 and D-threo (8R,9S) of scutianene L, 37 were isolated from Scutia buxifolia; whereas epimauritine A and its N-oxide obtained from Z. apetala showed the R-conguration at the terminal unit. 38 Formation of the imidazolidinone ring in cyclopeptide has been implicated from the reaction between the amino acid residue and aldehyde. 34,39 The imidazolidinone ring in compounds 1 and 3 could therefore arise through the condensation of 2 with the respective corresponding carbonyl compounds without an alteration in the amino acid stereocenter.…”

“…None of the compounds were toxic to the non-cancerous Vero cells, except for 6, which showed weak action with an IC 50 of 48.2 mM. To date, only two studies on the in vitro cytotoxicity of natural rhamnaceous cyclopeptide alkaloids have been reported, 38,49 although the weak activity of some representative synthetic 13-and 15-membered ring cyclopeptides was described recently. 50…”

Plant Alkaloids as an Emerging Therapeutic Alternative for the Treatment of Depression

“…Mitagynine i.p injection significantly reduced the immobility time of mice in both forced swim test and tail suspension test without any significant effect on locomotor activity (Idayu et al, 2011 ). A team from the Republic of China outlined Mauritine A as an active compound found in Ziziphus apetala which showed strong activity against 11-β-hydroxysteroid dehydrogenase inhibition in vitro (Han et al, 2011 ). The diterpene alkaloids (Napelline, songorine, hypaconitine, and mesaconitine) has been isolated from Aconitum baicalens exhibited an antidepressant-like effect in an animal model of depression (Nesterova et al, 2011 ).…”

“…Mitagynine exhibited antidepressant-like action by reducing the release of corticosterone (Idayu et al, 2011 ). Mauritine A show strong activity against 11-β-hydroxysteroid dehydrogenase inhibition in vitro and, therefore, could be the possible mechanism for its antidepressant effect (Han et al, 2011 ). The diterpene alkaloids of Aconitum baicalense , improved serotonergic system activity in an animal model of depression (Nesterova et al, 2011 ).…”

Cyclopeptide Alkaloids from Hymenocardia acida

“…MHz) and13 C NMR (methanol-d 4 , 100 MHz), see Tables 1 and 2, respectively; HRESIMS m/z 691.3855 [M + H] + and 713.3605 [M + Na] + (calcd for C 37 H 51 N 6 O 7 , 691.3814). Hymenocardine-H (4): white powder (12 mg); [α] D −55.5 (c 0.9 CH 3 OH); UV λ max 206, 266 nm; 1 H NMR (DMSO-d 6 , 400 MHz) and 13 C NMR (DMSO-d 6 , 100 MHz), see Tables 1 and 2, respectively; HRESIMS m/z 654.4018 [M + H] + ; 676.3837 [M + Na] + ; and 692.3620 [M + K] + (calcd for C 34 H 52 N 7 O 6 , 654.3974).…”