Secondary metabolites from selected species of genus Allium sect. Codonoprasum Rchb. – biological activities, phytochemical and chemotaxonomic aspects

Abstract

<p>U ovoj doktorskoj disertaciji ispitan je hemijski sastav i biolo&scaron;ke aktivnosti<br />ekstrakata deset&nbsp; samoniklih&nbsp; taksona roda&nbsp; <em>Allium</em>&nbsp; sect.&nbsp;<em> Codonoprasum:&nbsp; A. carinatum</em>&nbsp;subsp. <em>pulchellum,&nbsp; A. carinatum&nbsp;</em> subsp. <em>carinatum,&nbsp; A. fuscum&nbsp;</em> var. <em>gracile,&nbsp; A. fuscum&nbsp;</em> var.&nbsp;<em>fuscum,&nbsp; A. flavum</em> subsp. <em>flavum,&nbsp; A. melanantherum,&nbsp; A. paniculatum&nbsp;</em> subsp.&nbsp;<em> marginatum,&nbsp;A. pallens</em>&nbsp; subsp. <em>tenuiflorum,&nbsp; A. oleraceum&nbsp; </em>i&nbsp;<em> A. rhodopeum</em>, sakupljenih na&nbsp; 27 lokaliteta&nbsp;u Srbiji. Cilj rada bio je da se dobiju podaci o sadržaju biolo&scaron;ki aktivnih jedinjenja u&nbsp;ovim, do sada veoma malo ispitanim vrstama roda&nbsp; <em>Allium</em>, i utvrdi njihova potencijalna&nbsp;lekovita vrednost.</p><p>Analiza hemijskog sastava obuhvatila je: analizu volatilnih komponenti svežih&nbsp;<br />lukovica primenom headspace GC-MS tehnike, kvalitativnu analizu metanolnih &nbsp;<br />ekstrakata primenom tečnohromatografskih metoda (LC-DAD-MS i LC-MS-MS), &nbsp;<br />kvantitativnu analizu odabranih fenolnih jedinjenja LC-MS-MS tehnikom,&nbsp; određivanje&nbsp;sadržaja ukupnih&nbsp; monomernih&nbsp; antocijana&nbsp; i određivanje aktivnosti aliinaze. Ispitivanja&nbsp;biolo&scaron;kih aktivnosti ekstrakata obuhvatila su: određivanje antioksidantne,&nbsp;antiinflamatorne, antimikrobne, antimutagene i genotoksične aktivnosti, kao i ispitivanje&nbsp;uticaja na rast zdravih i tumorskih ćelija i sposobnosti indukcije ćelijske smrti.&nbsp;</p><p>Sumiranjem dobijenih rezultata može se zaključiti da ispitivani predstavnici roda&nbsp;<br /><em>Allium&nbsp;</em> sect.&nbsp; <em>Codonoprasum&nbsp;</em> predstavljaju bogate izvore biolo&scaron;ki aktivnih jedinjenja sa&nbsp;&scaron;irokim spektrom biolo&scaron;kih aktivnosti. Sa hemotaksonomskog aspekta značajno je da se&nbsp;dimetil-disulfid&nbsp; izdvaja kao&nbsp; najdominantnija&nbsp; i često jedina&nbsp; isparljiva komponenta, da&nbsp;ekstrakti većine vrsta&nbsp; sadrže veliku količinu flavonoida (prvenstveno derivata&nbsp;kvercetina), da se vrste&nbsp;<em> A. pallens&nbsp;</em> i&nbsp; <em>A. oleraceum</em>&nbsp; izdvajaju od ostalih po tome &scaron;to ne&nbsp;sadrže rutin&nbsp; a sadrže&nbsp; hiperozid,&nbsp; da je vrsta&nbsp;<em> A. rhodopeum</em>&nbsp; siroma&scaron;na fenolnim&nbsp;jedinjenjima i da su sve vrste, osim vrste&nbsp; <em>A.&nbsp; flavum</em>, bogate antocijanima. Aktivnost&nbsp;aliinaze je visoka u svim ispitivanim vrstama. Većina ispitivanih ekstrakata, izuzev&nbsp;ekstrakata vrsta&nbsp; <em>A. carinatum&nbsp;</em>i <em>A. melanantherum</em>, pokazala je izraženu antioksidantnu&nbsp;aktivnost, dok su ekstrakti vrsta <em>A. flavum</em>, <em>A. rhodopeum</em>, <em>A. oleraceum </em>i <em>A. paniculatum&nbsp;</em>snažni antiinflamatorni agensi. Ekstrakti ispitivanih predstavnika sect.&nbsp;<em> Codonoprasum&nbsp;</em>nisu pokazali antimikrobnu i antimutagenu aktivnost. Takođe, ovi ekstrakti nisu ispoljili&nbsp;genotoksični efekat na ćelije zdravog tkiva (izuzev slabog genotoksičnog efekta ekstrakta&nbsp;nadzemnih delova&nbsp;<em> A. flavum</em>), &scaron;to ukazuje na bezbednost upotrebe vrsta sect.&nbsp;<em>Codonoprasum&nbsp;</em> kao hrane ili u obliku lekova. Ekstrakti celih biljaka&nbsp;<em>A. paniculatum</em> i <em>A.&nbsp;rhodopeum</em>, kao i ekstrakt nadzemnih delova &nbsp;<em>A. melanantherum</em>&nbsp; pokazali su snažnu&nbsp;antiproliferativnu aktivnost sa povoljnim ne-tumor/tumor koeficijentima i indukovali&nbsp;apoptozu u tumorskim ćelijama, iz čega se može zaključiti da imaju visok potencijal&nbsp;primene u antitumorskoj terapiji.&nbsp;</p>

<p>In the present doctoral thesis the chemical composition and biological activities&nbsp; of&nbsp;<br />10 wild growing taxa of genus&nbsp; <em>Allium</em>&nbsp; sect. <em>Codonoprasum</em>&nbsp; (<em>A. carinatum&nbsp;</em> subsp.&nbsp;<br /><em>pulchellum,&nbsp; A. carinatum&nbsp;</em> subsp.&nbsp; <em>carinatum,&nbsp; A. fuscum&nbsp;</em> var.&nbsp; <em>gracile,&nbsp; A. fuscum</em>&nbsp; var.&nbsp;<br /><em>fuscum,&nbsp; A. flavum&nbsp;</em> subsp.&nbsp; <em>flavum,&nbsp; A. melanantherum,&nbsp; A. oleraceum,&nbsp; A. paniculatum</em><br />subsp. <em>marginatum, A. pallens</em> subsp. <em>tenuiflorum</em> and <em>A. rhodopeum</em>) were investigated.&nbsp;The samples were&nbsp; collected from 27 locations in Serbia. The aim of the study was to&nbsp;obtain data on the content of biologically active compounds in extracts of &nbsp;these&nbsp;unexplored species of the genus Allium and to determine their potential medicinal value.</p><p>Phytochemical caracterisation included: headspace GC-MS analysis of fresh bulb&nbsp;<br />volatiles, LC-DAD-MS and LC-MS-MS qualitative analysis of methanol extracts, LC-MS-MS quantitative analysis of 44 selected phenolic compounds in methanol extracts,&nbsp;determination of total monomeric anthocyanins content and alliinase activity. In order to&nbsp;assess the biological potential of methanol extracts, the antioxidant, anti-inflammatory,&nbsp;antimicrobial, antimutagenic, genotoxic and antiproliferative activities of &nbsp;the extracts&nbsp;were studied.</p><p>Summing up all the results obtained, it can be concluded that species of genus&nbsp;<em>Allium&nbsp;</em> sect.&nbsp; <em>Codonoprasum&nbsp;</em> are rich sources of biologically active compounds with a&nbsp;broad spectrum of biological activities. Dimethyl disulfide is the most dominant and&nbsp;often the only volatile component of most species, which is significant from&nbsp;chemotaxonomic point of view. The methanol extracts of investigated species contain&nbsp;high levels of flavonoids (primarily quercetin derivatives). Specificity of&nbsp; <em>A. pallens</em>&nbsp; and&nbsp;<em>A. &nbsp;oleraceum</em>&nbsp; extracts is that they do not contain rutin, but contain hyperoside, while&nbsp;small quantity of phenolic compounds&nbsp; is characteristic for&nbsp; <em>A. rhodopeum</em>&nbsp; extract. All&nbsp;investigated species, except of <em>A. flavum</em>, are rich in anthocyanins. Alliinase activity was&nbsp;high in&nbsp; all examined species. Most of the extracts, except&nbsp; <em>A. carinatum</em>&nbsp; and&nbsp; <em>A.&nbsp;melanantherum</em>&nbsp; extracts, express considerable antioxidant activity, &nbsp;while extracts of&nbsp;<em> A.&nbsp;flavum</em>,&nbsp; <em>A. rhodopeum</em>,&nbsp; <em>A. paniculatum</em>&nbsp; and&nbsp; <em>A. oleraceum&nbsp;</em> are potent anti-inflammatory&nbsp;agents. The investigated&nbsp; <em>Allium</em>&nbsp; extracts did not show antimicrobial and antimutagenic&nbsp;activity. Also, the extracts did not express genotoxic effect on healthy tissue cells&nbsp;(except the weak genotoxic effects of aerial parts extract of&nbsp; <em>A. flavum</em>), indicating that&nbsp;the use&nbsp; of these species as a food or as a drug is safe. Whole plant extracts of&nbsp; <em>A.&nbsp;paniculatum</em>&nbsp; and&nbsp;<em> A. rhodopeum</em>, as well as aerial parts extract of&nbsp;<em> A. melanantherum</em>&nbsp;showed strong antiproliferative activity (with a favorable &nbsp;non-tumor/tumor ratios) and&nbsp;induced apoptosis in tumor cells, suggesting that these plants have a high potential for&nbsp;application in antitumor therapy.</p>