Constituents of <i>Cydonia vulgaris</i>: Isolation and Structure Elucidation of Four New Flavonol Glycosides and Nine New α-Ionol-Derived Glycosides

In a previous paper, we described the isolation of four new sesterterpenes from Cydonia vulgaris Pers. Here we report the isolation of four new flavonol glycosides (1−4) and nine new α-ionol-derived glycosides (5−13) together with the known 3-oxo-α-ionol 9-O-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside (14), vomifoliol 9-O-β-d-glucopyranoside (roseoside) (15), and vomifoliol 9-O-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside (16) from the MeOH extract of the aerial parts of C. vulgaris Pers. (Rosaceae). All structures were elucidated by spectroscopic methods, including the concerted application of one-dimensional NMR and two-dimensional NMR techniques (COSY-90 and HETCOR). Keywords: Cydonia vulgaris; Rosaceae; flavonol glycosides; α-ionol glycosides; 1H and 13C NMR (one- and two-dimensional

New Triterpene Glycosides from the Stems of <i>Anomospermum </i><i>g</i><i>randifolium</i>

Two new dammarane saponins identified as jujubogenin 3-O-α-l-arabinofuranosyl(1→2)-[β-d-glucopyranosyl(1→6) β-d-glucopyranosyl(1→3)]-α-l-arabinopyranoside (2) and jujubogenin 3-O-α-l-arabinofuranosyl(1→2)-{6-O-[3-hydroxy-3-methylglutaryl]-β-d-glucopyranosyl(1→3)}-α-l-arabinopyranoside (3) and a new lupane saponin, 3β-hydroxylup-20(29)-en-27,28-dioic acid 28-O-β-d-glucopyranosyl(1→2)-[β-d-xylopyranosyl(1→3)]-β-d-xylopyranosyl(1→2)-β-d-glucopyranoside ester (5), along with the known jujubogenin 3-O-α-l-arabinofuranosyl(1→2)-[β-d-glucopyranosyl(1→3)]-α-l-arabinopyranoside (1) and 3β-hydroxylup-20(29)-ene-27,28-dioic acid (4), were isolated from the methanol extract of the stems of Anomospermum grandifolium. The structures of the new compounds were established by spectral analysis. Antimicrobial activity screening of compounds 1−3 revealed antifungal properties against C. albicans ATCC 3153 for compounds 2 and 3. The antibacterial and antifungal activities of the petroleum ether, chloroform, and methanol extracts of A. grandifolium stems were also evaluated

Giffonins A–I, Antioxidant Cyclized Diarylheptanoids from the Leaves of the Hazelnut Tree (<i>Corylus avellana</i>), Source of the Italian PGI Product “Nocciola di Giffoni”

Eight new diaryl ether heptanoids, giffonins A–H (<b>1</b>–<b>8</b>), and one diaryl heptanoid, giffonin I (<b>9</b>), were isolated from the methanol extract of the leaves of <i>Corylus avellana</i>. Its hazelnut is the PGI product of the Campania region (Italy) known as “Nocciola di Giffoni”. The MeOH extract of <i>C. avellana</i> leaves and giffonins A–I (<b>1</b>–<b>9</b>) were evaluated for their inhibitory effects on human plasma lipid peroxidation induced by H₂O₂ and H₂O₂/Fe²⁺, by measuring the concentration of TBARS (thiobarbituric acid reactive substances). Compounds <b>4</b> and <b>8</b> at 10 μM reduced both H₂O₂- and H₂O₂/Fe²⁺-induced lipid peroxidation by more than 60% and 50%, respectively, indicating higher activity than curcumin used as reference compound

Xanthohumol Induces Apoptosis in Human Malignant Glioblastoma Cells by Increasing Reactive Oxygen Species and Activating MAPK Pathways

The effect of the biologically active prenylated chalcone and potential anticancer agent xanthohumol (1) has been investigated on apoptosis of the T98G human malignant glioblastoma cell line. Compound 1 decreased the viability of T98G cells by induction of apoptosis in a time- and concentration-dependent manner. Apoptosis induced by 1 was associated with activation of caspase-3, caspase-9, and PARP cleavage and was mediated by the mitochondrial pathway, as exemplified by mitochondrial depolarization, cytochrome c release, and downregulation of the antiapoptotic Bcl-2 protein. Xanthohumol induced intracellular reactive oxygen species (ROS), an effect that was reduced by pretreatment with the antioxidant N-acetyl-l-cysteine (NAC). Intracellular ROS production appeared essential for the activation of the mitochondrial pathway and induction of apoptosis after exposure to 1. Oxidative stress due to treatment with 1 was associated with MAPK activation, as determined by ERK1/2 and p38 phosphorylation. Phosphorylation of ERK1/2 and p38 was attenuated using NAC to inhibit ROS production. After treatment with 1, ROS provided a specific environment that resulted in MAPK-induced cell death, with this effect reduced by the ERK1/2 specific inhibitor PD98059 and partially inhibited by the p38 inhibitor SB203580. These findings suggest that xanthohumol (1) is a potential chemotherapeutic agent for the treatment of glioblastoma multiforme

Planifolin, a New Naphthopyranone Dimer and Flavonoids from <i>Paepalanthus </i><i>p</i><i>lanifolius</i>

A new naphthopyranone dimer (1) named planifolin was isolated from a methylene chloride extract of the capitula of Paepalanthus planifolius. The structure of 1 has been determined by chemical and spectroscopic means. In addition, a known dihydronaphthopyranone glycoside and seven known flavonoids were isolated from an ethanolic extract of the leaves of P. planifolius

Naphthopyranone Glycosides from <i>Paepalanthus </i><i>m</i><i>icrophyllus</i>

Three new naphthopyranone glycosides, paepalantine-9-O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranoside (1), paepalantine-9-O-α-l-arabinopyranosyl-(1→6)-β-d-glucopyranoside (2), and paepalantine-9-O-α-l-rhamnopyranosyl-(1→6)-β-d-glucopyranoside (3), along with the known paepalantine-9-O-β-d-glucopyranoside (4) were isolated from aerial parts of Paepalanthus microphyllus. These compounds were characterized by spectrometric methods, including electrospray mass spectrometry and 1D and 2D NMR experiments. As a part of our program for screening natural compounds for anti-HIV activity, compounds 1−4 were tested in C8166 cells infected with HIV-1MN

Sulfated Triterpene Derivatives from <i>Fagonia </i><i>arabica</i>

Two new sulfated triterpenes (1, 6) and four new sulfated triterpene glycosides (2−5) have been isolated from the aerial parts of Fagonia arabica. Their structures were established by spectroscopic data analysis. Compounds 1/2 and 3/4 are sulfated derivatives of the rare sapogenins 3β,27-dihydroxyolean-12-en-28-oic acid and 3β,27-dihydroxyurs-12-en-28-oic acid, respectively. Compound 5 is an unusual disulfated oleanene derivative characterized by the occurrence of a 13,18-double bond, while compound 6 is the first reported naturally occurring saturated and sulfated pentacyclic triterpene of the taraxastane series with a C-20,28 lactone unit

Antiproliferative Cardenolides from the Aerial Parts of <i>Pergularia tomentosa</i>

The LC-MS analysis of the MeOH extract of the aerial parts of Pergularia tomentosa led to the isolation of 23 compounds, of which the structures were elucidated unambiguously by NMR spectroscopic data analysis. Three new doubly linked cardenolides (4, 13, 14) along with several known cardenolides (1–3, 5, 7, 8, 15–23) and flavonol glycosides (6, 9–12) were identified. LC-HRESIMS analysis, in the negative-ionization mode, showed the absence of flavonoids in a methanol extract of the roots of P. tomentosa. On the basis of the antiproliferative activity reported for cardenolides, the isolated compounds were tested for their ability to decrease the cell viability of five different human cancer cell lines, PC3, HeLa, Calu-1, MCF-7, and U251MG, exhibiting IC50 values ranging from 0.2 to 8.0 μM. Moreover, an S-phase entry assay was performed to investigate if the compounds could affect the cell cycle progression of PC3 prostate carcinoma cells. The results obtained demonstrated that the compounds 4, 7, and 14 at 1 μM considerably reduced the number of cells in the S-phase

<i>Yucca gloriosa</i>: A Source of Phenolic Derivatives with Strong Antioxidant Activity

On the basis of the biological activities exhibited by the phenolic constituents of Yucca schidigera, the antioxidant activity of the methanol extract of Yucca gloriosa roots was evaluated in the TEAC assay. The strong activity exerted by this extract prompted investigation of its phenolic constituents, yielding three new phenolic derivatives, gloriosaols C, D, and E, along with gloriosaols A and B previously isolated from Y. gloriosa roots and yuccaols C−E isolated from Y. schidigera. ESIMS and NMR data of gloriosaols C−E closely resembled those reported for gloriosaols A and B, two diasteroisomers characterized by unusual spirostructures. Careful inspection of ROESY spectra revealed that gloriosaols C−E are diastereoisomers of gloriosaols A and B. A possible assignment of the relative configuration of gloriosaols C−E, derived according to an integrated NMR−quantum mechanical (QM) approach, which was already applied to the determination of the stereostructures of gloriosaols A and B, is also proposed. Gloriosaols A−E exhibited potent antioxidant activity measured by the TEAC assay, showing the potential use of Y. gloriosa as a source of antioxidant principles. Keywords: Yucca gloriosa; gloriosaols A−E; GIAO NMR; DFT calculations; radical scavenging activity; TEA

Oxylipins from <i>Dracontium loretense</i>

Four novel oxylipins (1−4) were isolated from the n-butanol extract of the corms of Dracontium loretense. Their structures were assigned by 1D and 2D NMR analyses and electrospray ionization multistage ion trap mass spectrometry (ESI-ITMSn) data. Relative configurations were assigned on the basis of combined analysis of homonuclear and heteronuclear 2,3J couplings, along with ROE data. Oxylipin 2 exhibited an immunostimulatory effect on human PBMC proliferation