New 21-nordammarane saponins with anti-inflammatory and cytotoxic activities from Lavigeria macrocarpa Oliv.

Chemical investigation of the ethanol extract from the stems and roots of the medicinal plant Lavigeria macrocarpa led to the isolation and structure elucidation of three previously unreported 21-nordammarane-type saponins namely 6α,27-dihydroxy-3,20-dioxo-21-nordammar-24-(Z)-ene 27-O-[α-L-rhamnopyranosyl-(1→2)-ß-D-glucopyranoside] (1), 6α,27-dihydroxy-3-oxo-21-nordammar-24-(Z)-ene 27-O-ß-D-glucopyranoside (2), and 2α,3ß,6α,27-tetrahydroxy-21-nordammar-24-(Z)-ene 27-O-ß-D-glucopyranoside (3) trivially named lavigemacrocarposide A-C, along with eight known secondary metabolites. Acid hydrolysis of lavigemacrocarposide A yielded a new prosapogenin namely 6α,27-dihydroxy-3,20-dioxo-21-nordammar-24-(Z)-ene 27-O-ß-D-glucopyranoside (1a) and the previously unreported artefactual aglycones 1b and 1c. Their structures were elucidated by spectroscopic analyses including mass spectrometry, 1D and 2D NMR as well as chemical evidence. The EtOH extract, some isolated compounds as well as the prosapogenin (1a) and compounds 1b and 1c were evaluated for anti-inflammatory and cytotoxic activity. Icacine (5) exhibited a significant cytotoxicity against both HeLa and MCF-7 cell lines with an IC50 value of 0.78 µg/mL. All the tested compounds showed more that 50% inhibition of NO production, except for 1 and 2.

A New Chalcone and Antimicrobial Chemical Constituents of Dracaena stedneuri.

Microbial infections are leading causes of death and morbidity all over the world due to the development of the resistance to antibiotics by certain microorganisms. In this study, the chemical exploration of the ethanol (EtOH) extract of the aerial part of Dracaena stedneuri (Dracaenaceae) led to the isolation of one previously unreported chalcone derivative, i.e., 2',4'-dihydroxy-2,3'-dimethoxychalcone (1), together with 12 known compounds: 8-(C)-methylquercetagetin-3,6,3'-trimethyl ether (2), methylgalangine (3), quercetin (4), kaempferol (5), 6,8-dimethylchrysin (6), ombuine-3-O-rutinoside (4',7-dimethylquercetin-3-O-α-L-rhamnopyranosyl-(1 → 6) -ß-D-glucopyranoside) (7), alliospiroside A (8), ß-sitosterol 3-O-glucopyranoside (9), ishigoside (10), betulinic acid (11), oleanolic acid (12), and lupeol (13). The structures were determined by spectroscopic and spectrometric analysis including 1- and 2-Dimensional Nuclear Magnetic Resonance (1D- and 2D-NMR), High-Resolution Electrospray Ionization Mass Spectrometry (HRESIMS), and comparison with literature data. The isolated secondary metabolites and crude extract displayed antibacterial activity against some multidrug-resistant strains with minimal inhibitory concentration (MIC) values ranging from 32 to 256 µg/mL. The antibacterial activity of compound 13 against Enterobacter aerogenes ATCC13048 (MIC value: 32 µg/mL) was higher than that of chloramphenicol used as the reference drug (MIC = 64 µg/mL).

Manniosides B-F, five new triterpenoid saponins from the leaves of Schefflera mannii (Hook.f.) Harms.

Fifteen triterpenoid saponins including five new compounds (Mannioside B: 3ß-[(ß-d-glucopyranosyl)oxy]urs-12-en-28-oic acid α-l-rhamnopyranosyl-(1 â†’ 4)-ß-d-glucopyranosyl-(1 â†’ 6)-ß-d-glucopyranosyl ester (1), mannioside C: 3ß-[(ß-d-glucopyranosyl)23-dioxy]urs-12-en-28-oic acid α-l-rhamnopyranosyl-(1 â†’ 4)-ß-d-glucopyranosyl-(1 â†’ 6)-ß-d-glucopyranosyl ester (2), mannioside D: 3ß,23-dihydroxyurs-12-en-28-oic acid ß-d-glucopyranosyl-(1 â†’ 6)- ß-d-glucopyranosyl ester (3), mannioside E: 3ß-hydroxy-23-oxolup-20(29)-en-28-oic acid α-l-rhamnopyranosyl-(1 â†’ 4)-ß-d-glucopyranosyl-(1 â†’ 6)-ß-d-glucopyranosyl ester (4) and mannioside F: (22S)-27ß-[(ß-d-glucopyranosyl)oxy]-22-hydroxyprotosta-12,24-dien-3ß-yl ß-d-glucopyranoside (5)) were isolated from the leaves of Schefflera mannii (Hook.f.) Harms. Their structures were established on the basis of 1D and 2D NMR data, mass spectrometry and chemical methods. The major isolated compounds were tested for their antiproliferative activity on human malignant epithelial (HeLa) cells but were not efficient at the concentration of 33 mM.

A new ursane-type triterpene oxoglucopyranoside from Crossopteryx febrifuga.

A new saponin, 3-O-ß-d-3-oxo-glucopyranosyl-ursa-12,20(30)-diene-27,28-dioic acid (1), was isolated from the methanol extract of stem bark of Crossopteryx febrifuga together with the known 3ß-d-glucopyranosyl-ursa-12,20(30)-diene-27,28-dioic acid (2), shanzhiside methyl ester (3), shanzhiside (4), ß-sitosterol (5), ß-sitosterol-3-O-ß-d-glucopyranoside (6), ursa-12,20(30)-diene-27,28-dioic acid (7), hederagenin (8), and oleanolic acid (9). The structures were established by comprehensive interpretation of their spectral data 1D- (1H and 13C), 2D-NMR (1H-1H COSY, HMQC, HMBC), spectroscopic, and electrospray ionisation time-of-flight mass spectrometry analysis. The isolated compounds and extracts were screened for their antibacterial properties. Although the EtOAc and n-BuOH extracts exhibited considerable antibacterial activity against Pseudomonas aeruginosa with minimum inhibitory concentration (MIC) value of 32 µg/mL, compounds 2 and 8 showed moderate activity against Enterococcus faecalis with MIC values of 256 and 128 µg/mL, respectively. The new compound (1) exhibited a moderate antibacterial activity against Staphylococcus aureus with an MIC value of 512 µg/mL.

Steroidal saponins from the aerial parts of Cordyline fruticosa L. var. strawberries.

A new sulfated steroidal derivative (fruticogenin A: 1-sulfo-australigenin-3-sodium sulphate, 1) and three new steroidal saponins named fruticoside K (3-sulfo-spirostan-25(27)-ene-1ß,3ß-diol-1-O-[α-L-rhamnopyranosyl-(1 → 4)-ß-D-fucopyranoside], 2), fruticoside L (3-sulfo-spirostan-25(27)-ene-1ß,3ß,6α-triol-1-O-[α-L-rhamnopyranosyl-(1 → 4)-ß-D-fucopyranoside], 3) and fruticoside M (spirostan-25(27)-ene-1ß,3α-diol-1-O-[α-L-rhamnopyranosyl-(1 → 2)-α-L-rhamnopyranoside], 4) were isolated from the aerial parts of Cordyline fruticosa L. var. strawberries. Their structures were established on the basis of 1D and 2D NMR data, mass spectrometry and chemical methods. Compounds 2 and 4 exhibited weak cytotoxicity against melanoma (A375), breast adenocarcinoma (MDA-MB-231), and colon carcinoma (HCT116) human tumor cell lines.

Antioxidant C-glycosylflavones of Drymaria cordata (Linn.) Willd.

A new C-glycosylflavone, drymaritin E (6-C-(3-keto-ß-digitoxopyranosyl)-4'-O-(ß-D-glucopyranosyl)-7-methoxyl-5,4'-dihydroxylflavone) 1 was isolated from the oily upper phase (SU) of the MeOH extract from aerial parts of Drymaria cordata together with two known compounds (cassiaoccidentalin A 2 and anemonin 3) and an inseparable mixture of two known C-glycosylflavones 5,4'-dihydroxy-7-methoxyflavone-6-C-(2''-O-α-L-rhamnopyranosyl)-ß-D-glucopyranoside 4a and 5,7,3',4'-tetrahydroxyflavone-6-C-(2''-O-α-L-rhamnopyranosyl)-ß-D-glucopyranoside 4b. The alkaline hydrolysis of 3 led to a new hemisynthetic derivative, sodium anemonate (sodium 2-((1'E) 2'-sodium-carboxylate-vinyl)-5-oxo-cyclohex-1-ene carboxylate) 3a. The chemical structures were determined by spectroscopic methods ((1)H NMR, (13)C NMR, (1)H-(1)H COSY, HMBC, HSQC, and NOESY) and mass spectrometry (ESI-MS). C-glycosylflavones had significant free radical-scavenging activities on the radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). However, SU and compounds 3 and 3a exhibited no activity. In particular, compound 1 exhibited a concentration-dependent radical scavenging activity on DPPH with EC50 of 31.43 µg/mL.

Cytotoxic and antioxidant triterpene saponins from Butyrospermum parkii (Sapotaceae).

Three new triterpenoid saponins, elucidated as 3-O-ß-D-glucopyranosyloleanolic acid 28-O-ß-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-ß-D-xylopyranoside (parkioside A, 1), 3-O-[ß-D-apifuranosyl-(1→3)-ß-D-glucopyranosyl]oleanolic acid 28-O-[ß-D-apifuranosyl-(1→3)-ß-D-xylopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(1→3)]-α-L-rhamnopyranosyl-(1→2)ß-D-xylopyranoside (parkioside B, 2) and 3-O-ß-D-glucuronopyranosyl-16α-hydroxyprotobassic acid 28-O-α-L-rhamnopyranosyl-(1→3)-ß-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-ß-D-xylopyranoside (parkioside C, 3), were isolated from the n-BuOH extract of the root bark of Butyrospermum parkii, along with the known 3-O-ß-D-glucopyranosyloleanolic acid (androseptoside A). The structures of the isolated compounds were established on the basis of chemical and spectroscopic methods, mainly 1D and 2D NMR data and mass spectrometry. The new compounds were tested for both radical scavenging and cytotoxic activities. Compound 2 showed cytotoxic activity against A375 and T98G cell lines, with IC(50) values of 2.74 and 2.93 µM, respectively. Furthermore, it showed an antioxidant activity comparable to that of Trolox or butylated hydroxytoluene (BHT), used as controls, against 2,2-diphenyl-1-picryl hydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), oxygen and nitric oxide radicals.