Sector-specific development and policy vulnerability in the Philippines

Ministry of Education, Singapore under its Academic Research Funding Tier

Chemical composition, antioxidant activity and cytotoxicity on tumour cells of the essential oil from flowers of <i>Magnolia grandiflora</i> cultivated in Iran

<p><i>Magnolia grandiflora</i> (Magnoliaceae) is an evergreen tree with fragrant and showy flowers native to southeastern USA but widely cultivated all over the world and used in cosmetics industry in treatment of skin diseases. Here, we report on the chemical analysis of the essential oil obtained from flowers of plants cultivated in Iran, together with the evaluation of its antioxidant and cytotoxic activities. The essential oil composition was dominated by bioactive sesquiterpenes, namely <i>β</i>-elemene, bicyclogermacrene, germacrene D and (<i>E</i>)-caryophyllene. The oil exhibited moderate radical scavenging activity towards the radical, and mild non-selective inhibitory effects against A375, MDA-MB 231 and T98 G tumour cell lines. The latter were influenced by the presence of the anticancer <i>β</i>-elemene. These results provided new insights for potential application of <i>M. grandiflora</i> volatile oil in the pharmaceutical and cosmetics industry where only the non-volatile magnolol and honokiol have hitherto been fully exploited.</p

Essential oil composition and biological activity from <i>Artemisia caerulescens</i> subsp. <i>densiflora</i> (Viv.) Gamisans ex Kerguélen & Lambinon (Asteraceae), an endemic species in the habitat of La Maddalena Archipelago

<p>The purpose of this study was to investigate the composition of the essential oil obtained from a population of <i>Artemisia caerulescens</i> subsp. <i>densiflora</i> growing in Razzoli, an island in the La Maddalena Archipelago (Sardinia, Italy). <i>A. caerulescens</i> sups. <i>densiflora</i> Viv. (Asteraceae), a wild herb, seldom studied in the Mediterranean, represents one of the many rare endemic species growing in North Sardinia. The essential oil composition was analysed by means of GC/MS analysis, which showed davana ethers as the major volatile components, accounting together for 17.5%, followed by (E)-nerolidol (4.5%), <i>β</i>-oplopenone (3.3%), cis-sabinene hydrate (5.2%) and terpinen-4-ol (4.7%). The oil was tested for antioxidant activity by means of DPPH test, inhibition of lipid oxidation test and hypochlorous acid test, which showed a quite interesting scavenger capacity. For the first time, we reported the cytotoxic activity of the essential oil of <i>A. caerulescens</i> subsp. densiflora, against three human tumour cell lines (A375, MDA-MB231 and HCT116), with IC₅₀ values in the range 5.20–7.61 μg/mL, which deserved further studies to support its use as chemopreventive agent. Finally, the antimicrobial activity of the essential oil, displayed on a panel of human pathogens, was very low.</p> <p><i>Artemisia caerulescens</i> subsp. <i>densiflora</i> (Viv.) Gamisans ex Kerguélen & Lambinon (Asteraceae)</p

Synthesis, Antimicrobial and Antiproliferative Activity of Novel Silver(I) Tris(pyrazolyl)methanesulfonate and 1,3,5-Triaza-7-phosphadamantane Complexes

Five new silver(I) complexes of formulas [Ag(Tpms)] (<b>1</b>), [Ag(Tpms)(PPh₃)] (<b>2</b>), [Ag(Tpms)(PCy₃)] (<b>3</b>), [Ag(PTA)][BF₄] (<b>4</b>), and [Ag(Tpms)(PTA)] (<b>5</b>) {Tpms = tris(pyrazol-1-yl)methanesulfonate, PPh₃ = triphenylphosphane, PCy₃ = tricyclohexylphosphane, PTA = 1,3,5-triaza-7-phosphaadamantane} have been synthesized and fully characterized by elemental analyses, ¹H, ¹³C, and ³¹P NMR, electrospray ionization mass spectrometry (ESI-MS), and IR spectroscopic techniques. The single crystal X-ray diffraction study of <b>3</b> shows the Tpms ligand acting in the N₃-facially coordinating mode, while in <b>2</b> and <b>5</b> a N₂O-coordination is found, with the SO₃ group bonded to silver and a pendant free pyrazolyl ring. Features of the tilting in the coordinated pyrazolyl rings in these cases suggest that this inequivalence is related with the cone angles of the phosphanes. A detailed study of antimycobacterial and antiproliferative properties of all compounds has been carried out. They were screened for their in vitro antimicrobial activities against the standard strains <i>Enterococcus faecalis</i> (ATCC 29922), <i>Staphylococcus aureus</i> (ATCC 25923), <i>Streptococcus pneumoniae</i> (ATCC 49619), <i>Streptococcus pyogenes</i> (SF37), <i>Streptococcus sanguinis</i> (SK36), <i>Streptococcus mutans</i> (UA159), <i>Escherichia coli</i> (ATCC 25922), and the fungus <i>Candida albicans</i> (ATCC 24443). Complexes <b>1</b>–<b>5</b> have been found to display effective antimicrobial activity against the series of bacteria and fungi, and some of them are potential candidates for antiseptic or disinfectant drugs. Interaction of Ag complexes with deoxyribonucleic acid (DNA) has been studied by fluorescence spectroscopic techniques, using ethidium bromide (EB) as a fluorescence probe of DNA. The decrease in the fluorescence of DNA–EB system on addition of Ag complexes shows that the fluorescence quenching of DNA–EB complex occurs and compound <b>3</b> is particularly active. Complexes <b>1</b>–<b>5</b> exhibit pronounced antiproliferative activity against human malignant melanoma (A375) with an activity often higher than that of AgNO₃, which has been used as a control, following the same order of activity inhibition on DNA, i.e., <b>3</b> > <b>2</b> > <b>1</b> > <b>5</b> > <b>AgNO</b>_<b>3</b>≫ <b>4</b>

Synthesis, Antimicrobial and Antiproliferative Activity of Novel Silver(I) Tris(pyrazolyl)methanesulfonate and 1,3,5-Triaza-7-phosphadamantane Complexes

Five new silver(I) complexes of formulas [Ag(Tpms)] (<b>1</b>), [Ag(Tpms)(PPh₃)] (<b>2</b>), [Ag(Tpms)(PCy₃)] (<b>3</b>), [Ag(PTA)][BF₄] (<b>4</b>), and [Ag(Tpms)(PTA)] (<b>5</b>) {Tpms = tris(pyrazol-1-yl)methanesulfonate, PPh₃ = triphenylphosphane, PCy₃ = tricyclohexylphosphane, PTA = 1,3,5-triaza-7-phosphaadamantane} have been synthesized and fully characterized by elemental analyses, ¹H, ¹³C, and ³¹P NMR, electrospray ionization mass spectrometry (ESI-MS), and IR spectroscopic techniques. The single crystal X-ray diffraction study of <b>3</b> shows the Tpms ligand acting in the N₃-facially coordinating mode, while in <b>2</b> and <b>5</b> a N₂O-coordination is found, with the SO₃ group bonded to silver and a pendant free pyrazolyl ring. Features of the tilting in the coordinated pyrazolyl rings in these cases suggest that this inequivalence is related with the cone angles of the phosphanes. A detailed study of antimycobacterial and antiproliferative properties of all compounds has been carried out. They were screened for their in vitro antimicrobial activities against the standard strains <i>Enterococcus faecalis</i> (ATCC 29922), <i>Staphylococcus aureus</i> (ATCC 25923), <i>Streptococcus pneumoniae</i> (ATCC 49619), <i>Streptococcus pyogenes</i> (SF37), <i>Streptococcus sanguinis</i> (SK36), <i>Streptococcus mutans</i> (UA159), <i>Escherichia coli</i> (ATCC 25922), and the fungus <i>Candida albicans</i> (ATCC 24443). Complexes <b>1</b>–<b>5</b> have been found to display effective antimicrobial activity against the series of bacteria and fungi, and some of them are potential candidates for antiseptic or disinfectant drugs. Interaction of Ag complexes with deoxyribonucleic acid (DNA) has been studied by fluorescence spectroscopic techniques, using ethidium bromide (EB) as a fluorescence probe of DNA. The decrease in the fluorescence of DNA–EB system on addition of Ag complexes shows that the fluorescence quenching of DNA–EB complex occurs and compound <b>3</b> is particularly active. Complexes <b>1</b>–<b>5</b> exhibit pronounced antiproliferative activity against human malignant melanoma (A375) with an activity often higher than that of AgNO₃, which has been used as a control, following the same order of activity inhibition on DNA, i.e., <b>3</b> > <b>2</b> > <b>1</b> > <b>5</b> > <b>AgNO</b>_<b>3</b>≫ <b>4</b>

Phenolic acids, antioxidant and antiproliferative activities of Naviglio® extracts from <i>Schizogyne sericea</i> (Asteraceae)

<p><i>Schizogyne sericea</i>, well-known as ‘salado’, is a halophytic shrub widespread on coastal rocks of Tenerife (Canary Islands). This plant is used traditionally as analgesic, astringent, anti-inflammatory and vulnerary agent. In the present work, we have analysed the aqueous and ethanolic extracts of <i>S. sericea</i> for the content of phenolic acids by HPLC-DAD. The dynamic solid–liquid Naviglio® extractor was used to extract the flowering aerial parts. Aqueous extracts showed higher levels of phenolics than ethanolic extracts. <i>S. sericea</i> extracts were rich in chlorogenic and isochlorogenic acids. The Naviglio® extracts obtained were assayed for <i>in vitro</i> biological activities, namely antioxidant, antimicrobial and cytotoxicity on tumour cells by DPPH, ABTS, FRAP, agar disc-diffusion and MTT methods, respectively. Results showed that aqueous extracts, being richer in phenolic acids, are endowed with relevant radical scavenging activity (TEAC values in the range 208–960 μmol TE/g) while ethanolic extracts exhibited noteworthy antiproliferative effects on tumour cells.</p