Extraction of Quinolizidine Alkaloids in Non Aqueous Basic Conditions: The Case of Spartium junceum Flowers

In this work the use of basic nonaqueous conditions is suggested as a general method for the extraction of quinolizidine alkaloids. The extraction of quinolizidine alkaloids from fresh flowers of Spartium junceum is performed in ethanolic basic conditions. The procedure is efficient and selective. The extract is essentially formed by N-formylcytisine, N-methylcytisine, cytisine and anagyrine. The method allows a high recovery of N-formylcytisine which becomes the predominant alkaloid in S. Junceum flowers.     

The influence of pre-treatment of Spartium junceum L. fibres on the structure and mechanical properties of PLA biocomposites

Different chemical pre-treatments of Spartium junceum L. fibres using alkali (NaOH), nanoclay (MMT) and Citric acid (CA) with the aim of producing biodegradable composite material are discussed. As environmental requirements in processing technologies have been higher in recent years, the Polylactic acid (PLA) is used in this research as a matrix, due to its renewability, biodegradability and biocompatibility. Biocomposites are prepared by reinforcing PLA with randomly oriented, short Spartium junceum L. fibres in order to increase material strength. The effects of different pre-treatments of Spartium junceum L. fibres on the mechanical properties of final biocomposite material are examined. Fibre tenacity is studied using Vibroscop and Vibrodyn devices. Tensile strength of biocomposite material was measured on the universal electromechanical testing machine Instron 5584. The results indicate that biocomposites reinforced with fibres modified with MMT and CA show upgraded mechanical properties of the final composite material in comparison with the composite materials reinforced with referenced (nontreated) fibres. Infrared spectra of tested fibres and biocomposites were determined with Fourier transform infrared spectroscopy using Attenuated total reflection (FT-IR ATR) sampling technique and the influence of fibre modifications on the fibre/polymer interfacial bonding was investigated. The interface of Spartium/PLA composites was observed with scanning electron microscope (SEM) and it was clearly visible that biocomposites reinforced with fibres modified by MMT and CA showed better interaction of fibres and matrix.     

Indonesian propolis: chemical composition, biological activity and botanical origin

From a biologically active extract of Indonesian propolis from East Java, 11 compounds were isolated and identified: four alk(en)ylresorcinols (obtained as an inseparable mixture) (1-4) were isolated for the first time from propolis, along with four prenylflavanones (6-9) and three cycloartane-type triterpenes (5, 10 and 11). The structures of the components were elucidated based on their spectral properties. All prenylflavanones demonstrated significant radical scavenging activity against diphenylpicrylhydrazyl radicals, and compound 6 showed significant antibacterial activity against Staphylococcus aureus. For the first time Macaranga tanarius L. and Mangifera indica L. are shown as plant sources of Indonesian propolis.     

Eupatorium capillifolium essential oil: chemical composition, antifungal activity, and insecticidal activity

Natural plant extracts often contain compounds that are useful in pest management applications. The essential oil of Eupatorium capillifolium (dog-fennel) was investigated for antifungal and insecticidal activities. Essential oil obtained by hydrodistillation of aerial parts was analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS). The major components were determined to be thymol methyl ether (=methyl thymol) (36.3%), 2,5-dimethoxy-p-cymene (20.8%) and myrcene (15.7%). Antifungal activity of the essential oil was weak against the plant pathogens Colletotrichum acutatum, C. fragariae, and C. gloeosporioides in direct bioautography assay. The E. capillifolium oil showed promising repellent activity against the yellow fever mosquito Aedes aegypti, whereas the oil exhibited moderate activity against the mosquito's first instar larvae in a high throughput bioassay. Topical applications of the oil showed no activity against the blood-feeding female adults of A. aegypti. Eupatorium capillifolium essential oil showed a linear dose response between adult lace bug (Stephanitis pyrioides) mortality and increasing oil concentration in an adulticidal activity bioassay. The dog-fennel oil was more potent than the conventional insecticide malathion. In conclusion, these combined results showed Eupatorium capillifolium oil is a promising novel source of a biological insecticide with multiple modes of action.     

Essential oils of Retama raetam from Libya: chemical composition and antimicrobial activity

Retama raetam (Forssk) Webb & Berthel is well known in the folk medicine of North and East Mediterranean regions for the treatment of microbial infections. The powdered leaves are used to heal circumcision wounds and used as an antiseptic for wounds, skin rash and pruritus. In this study, to validate this antiseptic property, the chemical composition and antimicrobial activity of the essential oil from the flowers of R. raetam was evaluated. The oil was obtained using hydrodistillation and was analysed by gas chromatography-mass spectrometry. The antibacterial activity was achieved using disc diffusion and broth dilution assay against six bacteria species. Analysis of the essential oil revealed the presence of β-linalool (51%), 2-decen-1-ol (6.6%) and limonene (7.4%) as the major components. The results showed significant activity against microorganisms, especially Staphylococcus aureus, with inhibition zones and minimal inhibitory concentration values in the range of 5.0 mm and 3.0 mg mL?1, respectively. The results on the antibacterial activity provide scientific support for the use of these plants in traditional herbal preparations.     

芳基脲类衍生物的合成、活性和量子化学计算

芳基脲类化合物是抑制细胞分裂生长的一种抑制剂。本研究报导合成的六个芳基脲类化合物,并利用油菜试法测定了它们抑制油菜胚根生长的生物活性;采用MOPAC程序中的PM3方法进行了量化计算,计算结果较好地解释了新合成化合物结构与生物活性的相关性。     

Exploring aromatic chemical space with NEAT: novel and electronically equivalent aromatic template

In this paper, we describe a lead transformation tool, NEAT (Novel and Electronically equivalent Aromatic Template), which can help identify novel aromatic rings that are estimated to have similar electrostatic potentials, dipoles, and hydrogen bonding capabilities to a query template; hence, they may offer similar bioactivity profiles. In this work, we built a comprehensive heteroaryl database, and precalculated high-level quantum mechanical (QM) properties, including electrostatic potential charges, hydrogen bonding ability, dipole moments, chemical reactivity, and othe properties. NEAT bioisosteric similarities are based on the electrostatic potential surface calculated by Brood, using the precalculated QM ESP charges and other QM properties. Compared with existing commercial lead transformation software, (1) NEAT is the only one that covers the comprehensive heteroaryl chemical space, and (2) NEAT offers a better characterization of novel aryl cores by using high-evel QM properties that are relevant to molecular interactions. NEAT provides unique value to medicinal chemists quickly exploring the largely uncharted aromatic chemical space, and one successful example of its application is discussed herein.     

Antioxidant activity and chemical composition of essential oil from Atriplex undulata

The essential oil from aerial parts (stems and leaves) of Atriplex undulata (Moq) D. Dietr. (Chenopodiaceae) has been studied for its in vitro antioxidant activity. The chemical composition of the oil obtained by hydrodistillation was determined by GC and GC-MS. The major constituents were p-acetanisole (28.1%), beta-damascenone (9.3%), beta-ionone (5.1%), viridiflorene (4.7%) and 3-oxo-alpha-ionol (2.2%). The antioxidant activity of the oil was determined by two methods: Crocin bleaching inhibition (Krel = 0.72 +/- 0.15) and scavenging of the DPPH radical (IC50 = 36.2 +/- 1.6 microg/mL). The presence of active compounds like p-acetanisole, carvone, vanillin, 4-vinylguaiacol, guaiacol, terpinen-4-ol and alpha-terpineol could explain the antioxidant activity observed for this oil.     

Natural product propolis: chemical composition

The chemical composition of propolis from East Mediterranean (Hatay, Adana and Mersin) was studied in order to determine the major compounds by using GC-MS. In this study, the ethanolic extract of propolis prepared by mixing 1900mL 70% ethanol and 100g propolis was used. Chemical analysis of propolis extracts indicated that the propolis samples had high concentrations of the aromatic acids, esters and other derivatives which are responsible for the anti-bacterial, anti-fungal, anti-viral, anti-inflammatory and anti-cancer properties of propolis such as benzyl cinnamate, methyl cinnamate, caffeic acid, cinnamyl cinnamate and cinnamoylglcine besides the most common compounds as fatty acid, terpenoids, esters, alcohols hydrocarbons and aromatic acids.     

Optical evodiamine derivatives:Asymmetric synthesis and antitumor activity

Evodiamine and its derivatives have an asymmetric center at the C13 b position.Herein,isomers of evodiamine derivatives 2 and 3 were obtained by straightforward asymmetric total synthesis.Their inhibitory activities toward topoisomerases I and II and their cytotoxicities in cancer cell lines were evaluated.All the four isomers exhibited good to excellent antitumor potency and the(S)-isomers were generally more active than the(R)-isomers.The binding modes of(S)-2 with topoisomerases I and II were also clarified by molecular docking.     

Study on chemical constituents of an edible mushroom Volvariella volvacea and their antitumor activity in vitro

Abstract

Phytochemical investigation of the fruiting body of Volvariella volvacea led to the isolation of a new furanone, 2(5H)-furanone-4-propionic acid named volvafuranone A (1), together with twelve known compounds (2–13). Compounds 2–7, 9–11 were isolated from this mushroom for the first time. The isolated compounds were assessed for their cytotoxicity against four human tumour lines (SGC-7901, PC-3M, MCF-7, HepG-2), and the results showed that compound 2, 3, 12, 13 have significant cytotoxicity with IC₅₀ values of 5.90?μM (HepG-2), 20.72?μM (HepG-2), 27.98?μM (PC-3M) and 23.15?μM (PC-3M), respectively.     

Synthesis, characterization and antitumor activity study of some cyclometalated organoplatinum(II) complexes containing aromatic N-donor ligands

A general approach has been designed to synthesize some mononuclear and binuclear cyclometalated platinum(II) complexes, containing aromatic N-donor ligands with the presence of one Cl⁻trans to carbon. In this way, cyclometalated platinum(II) complex [Pt(C^N)Cl(dmso)], 1, C^N = N(1),C(2′)-chelated, deprotonated 2-phenylpyridine and dmso = dimethylsulfoxide, was used as a precursor to react with imidazole derivatives (1-methylimidazole, 2a, imidazole, 2b,), monodentate pyridine derivatives (4-methylpyridine, 2c, pyridine, 2d,) and bidentate pyridine derivative (4,4′-bipyridine, 3 and 4,). Synthesized complexes were fully characterized by using multinuclear NMR spectroscopy (¹H, ¹³C{¹H} and ¹⁹⁵Pt), correlation NMR spectroscopy (¹H-¹H COSY, ¹³C{¹H}-¹H Heteronuclear Multiple Quantum Correlation, HMQC, Heteronuclear Multiple Bond Correlation, HMBC, ¹⁵N-¹H HETCOR), elemental analysis, X-ray crystallography and ESI-Mass spectrometry. Antitumor effects of mononuclear cyclometalated platinum(II) complexes 2a, 2c, 2d and 3 were determined on Jurkat, K562, and Raji cell lines and results showed reasonable cytotoxicities.     

Analysis of essential oils from Voacanga africana seeds at different hydrodistillation extraction stages: chemical composition,antioxidant activity and antimicrobial activity

In this study, essential oils from Voacanga africana seeds at different extraction stages were investigated. In the chemical composition analysis, 27 compounds representing 86.69–95.03% of the total essential oils were identified and quantified. The main constituents in essential oils were terpenoids, alcohols and fatty acids accounting for 15.03–24.36%, 21.57–34.43% and 33.06–57.37%, respectively. Moreover, the analysis also revealed that essential oils from different extraction stages possessed different chemical compositions. In the antioxidant evaluation, all analysed oils showed similar antioxidant behaviours, and the concentrations of essential oils providing 50% inhibition of DPPH-scavenging activity (IC₅₀) were about 25 mg/mL. In the antimicrobial experiments, essential oils from different extraction stages exhibited different antimicrobial activities. The antimicrobial activity of oils was affected by extraction stages. By controlling extraction stages, it is promising to obtain essential oils with desired antimicrobial activities.     

The Thai medicinal plant Gynura pseudochina var. hispida: chemical composition and in vitro NF-kappaB inhibitory activity

Gynura pseudochina (L.) var. hispida Thv. (Asteraceae) has been used in traditional medicine in Thailand for the treatment of conditions associated with chronic and acute inflammation. In continuation of our search for bioactive natural products from Thai medicinal plants, G. pseudochina var. hispida showed potential in vitro NF-kappaB (Nuclear Factor kappa B) inhibitory activity and, therefore, was chosen for bio-assay-guided isolation of active compounds. Bioassay-guided fractionation of the methanol extract of the leaves of G. pseudochina var. hispida led to the isolation and identification, by spectroscopic and mass spectrometric methods, of four compounds previously not reported from this poorly studied species: Quercetin 3- rutinoside (1), 3,5-di-caffeoylquinic acid (2), 4,5-di-caffeoylquinic acid (3), and 5-monocaffeoylquinic acid (4). This paper discusses the current knowledge of these active components as NF-kappaB inhibitors, which lends some support to the use of this plant in traditional medicine. Potential risks associated with pyrrolizidine alkaloids will, however, have to be investigated further.     

Chemical modification of an antitumor alkaloid camptothecin: synthesis and antitumor activity of 7-C-substituted camptothecins.

A radical substitution reaction of 20(S)-camptothecin (1) with methanol furnished 7-hydroxymethylcamptothecin (2). Reaction of 1 with primary alcohols higher than methanol gave 7-alkylcamptothecins (4), of which alkyl groups were one carbon less than the alcohols used and also 7-hydroxyalkylcamptothecins (5). For the preparation of 7-alkylcamptothecin (4), aldehydes were used as a radical source and several alkylated derivatives were synthesized. 7-Acyloxymethyl derivatives (6), 7-carbaldehyde (7), iminomethyl derivatives (10), acid (11), esters (12) and amides (13) were synthesized starting from 2. 7-Ethyl- (4b) and 7-propylcamptothecin (4c), acyloxymethyl compounds 6a, 6c and ethyl ester (12b) exhibited higher antitumor activity than 1 against L1210 in mice.     

Synthesis and antitumor activity of 7-azaindirubin

Twenty 7-azaindirubin derivatives were designed and synthesized.Their antitumor activities were evaluated in vitro against DU145 cell line.The pharmacological results showed that most of the prepared compounds displayed the excellent activity.Compound 18 exhibited the most potent antitumor activity among the tested compounds.