New pregnane and phenolic glycosides from Solenostemma argel.

From the aerial parts, pericarps and roots of Solenostemma argel, three new pregnane glycosides (1-3) with two known ones and a new phenolic glycoside (4) have been isolated. Their structures were established by extensive 1D - and 2D NMR and mass spectroscopic analysis. The cytotoxicity of all compounds was evaluated against two human tumor cell lines (SW 480, MCF-7), but none of them was active in the concentration range 0.9-59.0µM. Compounds 2 and the known argeloside F at non toxic concentrations for the PBMCs (27.3µM and 27.6µM, respectively) significantly decreased the Il-1ß production by LPS-stimulated PBMCs. All isolated compounds showed a significant antioxidant potential with ORAC values in the concentration range 3481-9617µmoleq. Trolox/100g.

A New Aromatic Compound from the Stem Bark of Terminalia catappa.

A new aromatic compound 3,4,5-trimethoxyphenyl-1-O-(4-sulfo)-ß-D-glucopyranoside (1), in addition to two triterpenoid saponins (chebuloside II, arjunoglucoside II), two triterpenes (arjunolic acid and 3-betulinic acid) and sitosterol-3-O-ß-D-glucopyranoside have been isolated from the barks of Terminalia catappa. Their structures have been established on the basis of spectroscopic techniques (1D/2D NMR) and MS. Their cytotoxicity and antiinflammatory activity, together with the antioxidant capacity of compound 1 were also evaluated.

Paradoxically, iron overload does not potentiate doxorubicin-induced cardiotoxicity in vitro in cardiomyocytes and in vivo in mice.

Doxorubicin (DOX) is known to induce serious cardiotoxicity, which is believed to be mediated by oxidative stress and complex interactions with iron. However, the relationship between iron and DOX-induced cardiotoxicity remains controversial and the role of iron chelation therapy to prevent cardiotoxicity is called into question. Firstly, we evaluated in vitro the effects of DOX in combination with dextran-iron on cell viability in cultured H9c2 cardiomyocytes and EMT-6 cancer cells. Secondly, we used an in vivo murine model of iron overloading (IO) in which male C57BL/6 mice received a daily intra-peritoneal injection of dextran-iron (15mg/kg) for 3weeks (D0-D20) and then (D21) a single sub-lethal intra-peritoneal injection of 6mg/kg of DOX. While DOX significantly decreased cell viability in EMT-6 and H9c2, pretreatment with dextran-iron (125-1000µg/mL) in combination with DOX, paradoxically limited cytotoxicity in H9c2 and increased it in EMT-6. In mice, IO alone resulted in cardiac hypertrophy (+22%) and up-regulation of brain natriuretic peptide and ß-myosin heavy-chain (ß-MHC) expression, as well as an increase in cardiac nitro-oxidative stress revealed by electron spin resonance spectroscopy. In DOX-treated mice, there was a significant decrease in left-ventricular ejection fraction (LVEF) and an up-regulation of cardiac ß-MHC and atrial natriuretic peptide (ANP) expression. However, prior IO did not exacerbate the DOX-induced fall in LVEF and there was no increase in ANP expression. IO did not impair the capacity of DOX to decrease cancer cell viability and could even prevent some aspects of DOX cardiotoxicity in cardiomyocytes and in mice.

Cytotoxic steroidal glycosides from Allium flavum.

Three new spirostane-type glycosides (1-3) were isolated from the whole plant of Allium flavum. Their structures were elucidated mainly by 2D NMR spectroscopic analysis and mass spectrometry as (20S,25R)-2α-hydroxyspirost-5-en-3ß-yl O-ß-D-xylopyranosyl-(1→3)-[ß-D-galactopyranosyl-(1→2)]-ß-D-galactopyranosyl-(1→4)-ß-D-galactopyranoside (1), (20S,25R)-2α-hydroxyspirost-5-en-3ß-yl O-ß-D-xylopyranosyl-(1→3)-[ß-D-glucopyranosyl-(1→2)]-ß-D-galactopyranosyl-(1→4)-ß-D-galactopyranoside (2), and (20S,25R)-spirost-5-en-3ß-yl O-α-L-rhamnopyranosyl-(1→4)-[ß-D-glucopyranosyl-(1→2)]-ß-D-glucopyranoside (3). The three saponins were evaluated for cytotoxicity against a human cancer cell line (colorectal SW480).

New triterpenoid estersaponins from the root barks of Pittosporum verticillatum subsp. verticillatum and evaluation of cytotoxicities.

The phytochemical investigation of the root barks of Pittosporum verticillatum Bojer subsp. verticillatum led to the isolation of three new triterpene saponins, 3-O-[ß-D-glucopyranosyl-(1→2)]-[α-L-arabinopyranosyl-(1→3)]-[α-L-arabinofuranosyl-(1→4)]-ß-D-glucuronopyranosyl-21-O-(2-acetoxy-2-methylbutanoyl)-R1-barrigenol (1), 3-O-[ß-D-glucopyranosyl-(1→2)]-[α-L-arabinopyranosyl-(1→3)]-[α-L-arabinofuranosyl-(1→4)]-ß-D-glucuronopyranosyl-21-O-(2-acetoxy-2-methylbutanoyl)-28-O-acetyl-R1-barrigenol (2), 3-O-[ß-D-glucopyranosyl-(1→2)]-[α-L-arabinopyranosyl-(1→3)]-[α-L-arabinofuranosyl-(1→4)]-ß-D-glucuronopyranosyl-21-O-ß,ß-dimethylacryloyl-22-O-angeloyl-R1-barrigenol (3), and one known saponin senaciapittoside B (4). Their structures were elucidated mainly by 1D- and 2D-NMR spectroscopy and HRESIMS. Compounds 1-4 were evaluated for their cytotoxicity against one human cancer cell line (SW480) and one rat cardiomyoblast cell line (H9c2).

Steroidal saponins from Dracaena marginata.

Three new steroidal saponins and ten known ones were isolated from the bark of Dracaena marginata, along with two known steroidal saponins from the roots. Their structures were elucidated on the basis of extensive 1D and 2D NMR experiments and mass spectrometry as (25R)-26-(beta-D-glucopyranosyloxy)3beta,22alpha-dihydroxyfurost-5-en-1beta-yl O-alpha-L-rhamnopyranosyl-(1 --> 2)-[alpha-L-rhamnopyranosyl-(1 --> 4)]-beta-D-glucopyranoside (1), (25R)-26-(beta-D-glucopyranosyloxy)-3beta,22alpha-dihydroxyfurost-5-en-1beta-yl O-alpha-L-rhamnopyranosyl-(1 --> 2)-4-O-sulfo-alpha-L-arabinopyranoside (2), and (25S)-3beta-hydroxyspirost-5-en-1beta-yl O-alpha-L-rhamnopyranosyl-(1 --> 2)-4-O-sulfo-alpha-L-arabinopyranoside (3).

Solanum incanum and S. heteracanthum as sources of biologically active steroid glycosides: confirmation of their synonymy.

A new spirostanol saponin (1), along with four known saponins, dioscin (2), protodioscin (3), methyl-protodioscin (4), and indioside D (5), and one known steroid glycoalkaloid solamargine (6) were isolated from the two synonymous species, Solanum incanum and S. heteracanthum. The structure of the new saponin was established as (23S,25R)-spirost-5-en-3ß,23-diol 3-O-{ß-D-xylopyranosyl-(1→2)-O-α-L-rhamnopyranosyl-(1→4)-[O-α-L-rhamnopyranosyl-(1→2)]-ß-D-glucopyranoside}, by using a combination of 1D and 2D NMR techniques including (1)H, (13)C, COSY, TOCSY, NOESY, HSQC and HMBC experiments and by mass spectrometry. The compounds 1, 3, 4 and 5 were evaluated for cytotoxicity against five cancer cell lines and for antioxidant and cytoprotective activity.