Alaa M. Nafady

Chemical composition of the stem bark and leaves of Ficus pandurata Hance

A new compound, 3-O-α-L-arabinopyranosyl-4-hydroxybenzoic acid (13), in addition to 16 newly reported compounds: α-amyrin acetate (1), β-amyrone (2), 3β-acetoxy-20-taraxasten-22-one (3), α-amyrin (4), ceryl alcohol (5), stigmasterol (6), β-sitosterol (7), 2α,3α-dihydroxy-lup-20(29)-en-28-oate (8), ursolic acid (9), β-sitosterol-3-O-glucosoide (10), protocatechuic acid (11), betulinic acid (12), quercetin (14), quercetin-3-O-β-D-glucoside (15), kampferol-3-O-β-neohesperidoside (16) and rutin (17) were isolated from the stem bark and leaves of Ficus pandurata (Hance) cultivated in Egypt. Identification of these compounds has been established by physical, chemical and spectral data (UV, IR, MS, 1H- and 13C-NMR), as well as comparison with authentic samples.

Two new acetylated flavonoid glycosides from Centaurium spicatum L

Two new acetylated flavonol glycosides, quercetin 3-O-[(2,4-diacetyl-α-l-rhamnopyranosyl)-(1→6)]-2,4-diacetyl-β-d-galactopyranoside (1) and quercetin 3-O-[(2,4-diacetyl-α-l-rhamnopyranosyl)-(1→6)]-3,4-diacetyl-β-d-galactopyranoside (2), in addition to two known acetylated quercetin glycosides quercetin 3-O-[(2,3,4-triacetyl-α-l-rhamnopyranosyl)-(1→6)-β-d-galactopyranoside (3) and quercetin 3-O-[(2,3,4-triacetyl-α-l-rhamnopyranosyl)-(1→6)-3-acetyl-β-d-galactopyranoside (4), were isolated from the aerial part of Centaurium spicatum (L.) Fritsch (Gentianaceae). Structure elucidation, especially the localization of the acetyl groups, and complete 1H and 13C NMR assignments of these biologically active compounds were carried out using one- and two-dimensional NMR measurements, including 1H- and 13C-NMR, DEPT-135, H–H COSY, HMQC and HMBC, in addition to HR-FAB/MS experiments.

Effect of polyphenols from Vicia faba L on lipase activity and melanogenesis

Abstract Two new flavonoid glycosides, kaempferol 3-O-α-L-rhamnopyranosyl (1→6) (3′′-acetyl)-β-D-galactopyranoside 1 and kaempferol 3-O-α-L-arabinopyranosyl-5-O-α-L-rhamnopyranoside 2, along with six known ones 3–8 were isolated from the flowers of Vicia faba L. (Fabaceae). Methanol extract and the isolated compounds were tested against lipase and melanogenesis inhibition activities and resulted in that compound 2 showed 53 and 77% lipase inhibition activity in concentrations of 400 and 800 μg/mL, respectively. For melanogenesis, compounds 2, 3 and 4 exhibited potent melanogenesis inhibition activity where the melanin content in melanoma cells was decreased to be about 57.5, 56 and 61%, respectively, with no obvious melanocytotoxicity. The rest of compounds showed weak to moderate activity. The results of melanogenesis inhibition activity of this study suggested the potential use of Vicia faba flowers as a skin-whitening agent and reveal the flowers to be a rich source of important phytochemicals with antilipase and melanogenesis inhibitory activity.

Polyphenols from aerial parts of Polygonum bellardii and their biological activities.

Abstract Context: Polygonum species have been used in the treatment of several types of inflammatory disorders and cancer. Nevertheless, there are no reports related to the anti-inflammatory and anti-proliferative activities of Polygonum bellardii All. (Polygonaceae). Objective: This study investigated the chemical composition of the methanol extract of P. bellardii. The anti-inflammatory and cytotoxic activities of methanol, n-butanol, ethyl acetate extracts and isolated polyphenols were determined. Materials and methods: The chemical structure of the isolated compounds was elucidated using different spectral techniques. MTT assay was used to evaluate the anti-proliferative activity in HeLa, MCF-7 and HepG-2 cells. Inhibition of 5-lipoxygenase (5-LOX) activity and prostaglandin E2 (PGE2) production in stimulated HepG-2 cells were used to assess the anti-inflammatory activity. Results: The present study resulted in isolation of five compounds (new for the species). They were identified as gallic acid (1), quercetin (2), myricetin (3), quercetin-3-O-β-d-glucopyranoside (5) and myricetin-3-O-α-arabinofuranoside (7). Additionally, a couple of previously isolated compounds such as quercetin-3-O-(5″-acetyl-α-arabinofuranoside) (4) and myricetin-3-O-(5″-acetyl-α-arabinofuranoside) (6) were detected. The n-butanol extract has the highest cytotoxicity in HeLa, MCF-7 and HepG-2 cells, with IC50 values of 15.26, 50.66 and 30.09 µg/ml, respectively. Compound 6 exhibited a marked cytotoxicity in HeLa (IC50 75.04 µg/ml) and HepG-2 (IC50 41.03 µg/ml) cells. Crude extracts and pure compounds inhibited the 5-LOX activity and PGE2 production in a dose-dependent manner (0.1–250 µg/ml). Discussion and conclusion: These results explain the traditional uses of P. bellardii and indicate that polyphenols, despite structural similarity, have different cytotoxic and anti-inflammatory effects.

Xanthone and lignan glycosides from the aerial parts of Polygonum bellardii all growing in Egypt

A new long chain fatty alcohol acetate identified as 17-hydroxypentacosanyl acetate, (1) together with a new xanthone identified as 1,8-Dihydroxy-3,6-dimethoxy-xanthone-5-O-[α-L-rhamnopyranosyl-(1′′→2′)]-β-D-glucopyranoside (3), as well as two new lignans identified as (+)-Lyoniresinol-3a-O-[α-L-rhamnopyranosyl-(1′′′→6′′)]-β-D-glucopyranoside (4) and (+)-Isolariciresinol-3a-O-[α-L-rhamnopyranosyl-(1′′′→2′′)-α-L-rhamnopyranosyl-(1′′′′→6′′)]-β-D-glucopyranoside (5), in addition to β-sitosterol-3-O-acetate (2) were isolated from the methanolic extract of the aerial parts of Polygonum bellardii growing in Egypt. Their structures were elucidated on the basis of different chemical and spectroscopic evidences. The total extract and its fractions, in addition to compounds (3, 4 and 5) showed significant antioxidant potential by DPPH· scavenging activity technique.

A new oleanene triterpene from Gladiolus segetum Ker-Gawl

A new pentacyclic oleanene triterpene, 2β, 3β, 16α, 28-tetrahydroxy-olean-12-ene-23-oic acid (1), as well as the known pentacyclic triterpene medicagenic acid (2), have been isolated by different chromatographic techniques from the acid hydrolysate of the saponin fraction of Gladiolus segetum. The identification of these compounds was established by different methods of physical, chemical and spectral evidence.

Mangostanaxanthone VIII, a new xanthone from Garcinia mangostana and its cytotoxic activity.

Abstract A new prenylated xanthone, mangostanaxanthone VIII (7) and six known metabolites: gartanin (1), 1,3,8-trihydroxy-2-(3-methyl-2-butenyl)-4-(3-hydroxy-3-methylbutanoyl)-xanthone (2), rubraxanthone (3), 1,3,6,7-tetrahydroxy-8-prenylxanthone (4), garcinone C (5), and xanthone I (9-hydroxycalabaxanthone) (6) were separated from the EtOAc-soluble fraction of the air-dried pericarps of Garcinia mangostana (Clusiaceae). Their structures have been verified on the basis of spectroscopic data analysis as well as comparison with the literature. The cytotoxic activity of 7 was assessed against MCF7, A549, and HCT116 cell lines using sulforhodamine B (SRB) assay. Compound 7 showed significant cytotoxic potential against MCF7 and A549 cell lines with IC50s 3.01 and 1.96 μM, respectively compared to doxorubicin (0.06 and 0.44 μM, respectively). However, it exhibited moderate activity towards HCT116 cell line.

Forsskamide, a new ceramide from aerial parts of Forsskaolea tenacissima Linn.

Abstract Although the various folk medicine uses and the biological activity of Forsskaolea tenacissima L., few chemical constituents of this plant have been reported, this provoked us to make our study. Forsskamide, a new ceramide was isolated from aerial parts of F. tenacissima L. (Urticaceae). The chemical structure was established by different spectroscopic methods (1H, 13C-NMR, HMBC, HSQC, ROESY, FAB-MS and HR-FAB-MS). Forsskamide showed a moderate cytotoxic activity by (MTT) method against human colorectal carcinoma cell line (HCT-116) with IC50 33.25 μM in comparison with 5-fluorouracil IC50 26.42 μM. While, it did not show any activity against human hepatocarcinaoma cell line (HepG-2).