Potent antitrypanosomal triterpenoid saponins from Mussaenda luteola

Abstract

Five new triterpenoid saponins, heinsiagenin A 3-O-[α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranosyl-(1→2)]-β-d-glucopyranoside (1), heinsiagenin A 3-O-[α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranosyl-(1→2)]-[β-d-glucopyranosyl-(1→4)]-β-d-glucopyranoside (2), 2α-hydroxyheinsiagenin A 3-O-[α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranosyl-(1→2)]-β-d-glucopyranoside (3), 2α-hydroxyheinsiagenin A 3-O-[β-d-glucopyranosyl-(1→2)]-[β-d-glucopyranosyl-(1→4)]-β-d-glucopyranoside (4) and N-(2S, 3R, 4R-3-methyl-4-pentanolid-2-yl)-18-hydroxylanosta-8 (9), 22E, 24E-trien-27-amide-3-O-[α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranosyl-(1→2)]-[β-d-glucopyranosyl-(1→4)]-β-d-glucopyranoside (5) were isolated from the aerial parts of Mussaenda luteola Delile (Rubiaceae). Structural elucidation was based on the analysis of spectroscopic data (1D and 2D NMR) and HR-ESI-MS. Compound 1 showed potent antitrypanosomal activity with an IC50 value of 8.80 μM. Compounds 2–4 showed highly potent antitrypanosomal activity with IC50 values ranging between (2.57–2.84 μM) and IC90 values ranging between (3.36–4.35 μM), which are 5 fold greater than the positive control DFMO (IC50 and IC90 values of 13.06 and 28.99 μM, respectively). Compounds 1 and 2 showed moderate affinity to μ-opioid receptors with Ki values of 9.936 μM and 0.872 μM, respectively compared to a Ki value of 1.958 nM for the positive control, naloxone HCl.

New cycloartane saponin and monoterpenoid glucoindole alkaloids from Mussaenda luteola

“…The structure of the sugar moiety was established on the basis of HMBC correlations between H G-1 /C-3, and H G'-1 /C G-2 . It should be noted that Δ 22 unsaturated triterpenes are very common in Mussaenda saponins [10]. Therefore, the cyclopropane function in the side chain through bioalkylation of this nucleophilic site (Δ 22 double bond precursor) is possible [16].…”

“…In a previous paper, we have reported the isolation and structure elucidation of five new antitrypanosomal saponins from Mussaenda luteola [10]. In continuation of our studies, the aerial plant materials were further investigated.…”

Triterpenoids

“…81,82 Cycloartane saponins with known genins include amphipaniculosides C and D from Amphilophium paniculatum 83 and saponins from Cimicifuga foetida 84 and Mussaenda luteola. 55 The cucurbitacins have interesting pharmaceutical potential. 85,86 Cucurbitacin E has been investigated for a wide range of activities.…”

Evaluation of Bioactive Metabolites Isolated from Endophytic Fungus Chaetomium cupreum of the Plant Mussaenda luteola

“…13 The plant has been reported to produce several bioactive metabolites like iridoids, rutin, quercetin, flavonol, flavonoids, anthocyanins, triterpenes, triterpenoid saponins and many more. 14,15 In the present study, we isolated secondary metabolites from the endophytic fungus C. cupreum and evaluated the antimycobacterial, antioxidant and anti-proliferative potential.…”