Protolimonoids and norlimonoids from the stem bark of Toona ciliata var. pubescens

Abstract

Six new tirucallane protolimonoids, toonapubesins A-F (1-6), one new rearranged tirucallane protolimonoid, toonapubesin G (7), and two new 21,22,23-trinorapotirucallane limonoids, toonapubesic acids A (8) and B (9), possessing an unprecedented carbon skeleton, along with five known tirucallane protolimonoids (10-14) and one known apotirucallane limonoid (15), were isolated from the stem bark of Toona ciliata var. pubescens. Their structures and relative configurations were determined by detailed spectroscopic analysis and by chemical methods. The proposed structures of 8 and 11 were confirmed by X-ray diffraction analysis of their respective derivatives (8a and 11a). The absolute configuration of 8 was determined by a novel solid-state TDDFT ECD approach on its derivative 8a while the absolute configuration of 10 was determined by the modified Mosher's method. In addition, the structures of dyvariabilin H (10c) proposed by Sticher et al. and cneorin-NP(36) (11b) by Mondon et al. were corrected as 10 and 11, respectively. Toonapubesin G (7) showed promising inhibitory activity against CDC25B with an IC(50) value of 2.1 μM, while compound 8a showed significant cell protecting activity against H(2)O(2)-induced SH-SY5Y cell damage with 11.5% increase in cell viability.

Lepidotrichilins A and B, New Protolimonoids with Cytotoxic Activity from Trichilia Lepidota (Meliaceae)

“…In contrast to our data, the limonoids isolated from Toona ciliata var. pubescens [16] were inactive or had weak activity on cancer and non-cancer cell line, but were able to inhibit CDC25B dual specificity phosphatase. Altogether, these data suggest a range of biological activity associated with a variety of limonoids molecules structures.…”

Tirucallane-Type Triterpenoids from the Fruit of <i>Ficus carica</i> and Their Cytotoxic Activity

“…[25][26][27][28][29] However, the bioactive compounds responsible for antitumor remained elusive. Since cytotoxic activities of tirucallane-type triterpenoids had been reported, 15,30) we further examined the cytotoxic activities of compounds 1-9 using three human cancer cell lines by MTT assay. As shown in Table 3 Additionally, it was found that, compounds 1 and 2 showed the higher activities against MCF-7 and HepG-2 cell lines than compounds 3-7, indicating that the presence of the α,β-unsaturated ketone moiety at C-6, C-7 and C-8 might play an important role in the cytotoxicities.…”

Antibacterial Activity of Copper Nanoparticles and Copper Nanocomposites against Escherichia Coli Bacteria

“…In fact, the lower agglomeration provides more available surface area for interaction with bacterial membranes and for solubilisation of copper ions, which leads to more toxicity. Metallic and ionic forms of copper produce hydroxyl radicals that damage essential proteins and DNA [17]. Copper dissolves on surface of the bacteria and penetrate to the bacteria cells thereby breaking cell membrane.…”