Two Antiproliferative Triterpene Saponins from Nematostylis anthophylla from the Highlands of Central Madagascar

Abstract

Investigation of the endemic Madagascan plant Nematostylis anthophylla (Rubiaceae) for antiproliferative activity against the A2780 ovarian cancer cell line led to the isolation of the known triterpene saponin randianin (1) and the two new bioactive triterpene saponins 2″-O-acetylrandianin (2) and 6″-O-acetylrandianin (3). The structures of the two new compounds were elucidated based on analysis of their 1D and 2D NMR spectra, and mass spectrometric data. The three isolated triterpene saponins displayed moderate but selective antiproliferative activity, with IC50 values of 1.2, 1.7 and 2.2 μM, respectively, against the A2780 ovarian cancer, but only weak inhibition of the proliferation of A2058 melanoma and the H522 lung cancer cell lines.

Natural Compounds in Sex Hormone-Dependent Cancers: The Role of Triterpenes as Therapeutic Agents

“…Baill. were investigated in terms of antiproliferative activity on the A2780 ovarian cancer cell line; a moderate but selective cytotoxic activity was found ( 156 ). Interestingly, the highest activity was noticed for acetylated compounds thus suggesting that an increased lipophilicity through acetylation may facilitate cellular uptake and anticancer efficacy.…”

Antiproliferative and Anti-Inflammatory Activity From Aerial Parts of Psychotria Cupularis (Rubiaceae) / Atividade Antiproliferativa E Anti-Inflamatória Das Partes Aéreas De Psychotria Cupularis (Rubiaceae)

“…Flavonoids were widely related in literature and also presented antiproliferative activity against tumor human cells as gastric adenocarcinoma, promyelocromucemic cells and colon carcinoma (Moghaddan et al 2012), and lung non-small cells (Santos et al 2015). The selectivity of HF against ovary cell line may be explained by the presence of triterpenes and steroids (Topçu et al 2011;Dai et al 2013;Zhang et al 2014).…”

Novel Bioactive Natural Products Isolated from Madagascar Plants and Marine Organisms (2009–2017)

“…As stated in their report, those three novel compounds may have been artifacts formed through spontaneous oxidation and tertiary amine quaternization during plant extraction. 7) Three novel alkaloids, isohalitulin (22) and haliclorensins B (23) and C (24), together with the three known compounds halitulin, haliclorensin, and isohalicloresin, were isolated from the chloroform (CHCl 3 )-MeOH (2 : 1) extract of the Madagascan sponge Haliclona telearensis (class Demospongiae, order Haplosclerida, family Chalinidae), collected in Salary Bay, north of Tulear, Madagascar. All three new compounds were tested for their toxicity against brine shrimp, and the results indicated that all exhibited moderate activity, with LD 50 values of 0.9, 2.2, and 2.1 µM, respectively.…”

“…Both compounds displayed moderate antiproliferative activity against A2780 human ovarian cancer cells, with IC 50 values of 7.6 and 4.0 µM, respectively. 24) Investigation of the endemic Madagascan plant Nematostylis anthophylla (Rubiaceae) for antiproliferative activity against the A2780 ovarian cancer cell line led to the isolation of two new bioactive triterpene saponins 2″-O-acetylrandianin (64) and 6″-O-acetylrandianin (65), and the known triterpene saponin randianin. The two new saponins displayed moderate but selective antiproliferative activity, with IC 50 values of 1.2 and 1.7 µM, respectively, against the A2780 ovarian cancer cell line but only weak inhibition of the proliferation of A2058 melanoma and H522 lung cancer cell lines.…”