Abstract | Bioorgansko istraživanje 8 različitih uniflornih vrsta meda je temeljeno na primjeni plinske (GC) i tekućinske kromatografije (HPLC) s ciljem određivanja kemijskih profila i ciljanih organskih spojeva, među kojima su istaknuti potencijalni markeri botaničkog podrijetla. Primjena komplementarnih metoda ekstrakcije (HS-SPME, mikroekstrakcija vršnih para na krutoj fazi; USE, ultrazvučna ekstrakcija organskim otapalima; SPE, ekstrakcija na krutoj fazi) je omogućila dobivanje potpunijih kemijskih profila isparljivih i poluisparljivih spojeva. Glavni spojevi identificirani u vršnim parama Taraxacum officinale Weber meda su nitrili, posebice 3- metilpentanonitril (do 29,9%) i fenilacetonitril (do 20,9%). Pored nitrila, drugi značajni spojevi vršnih para identificirani u manjem postotku su razgranate alifatske kiseline i norizoprenoidi. Glavni spojevi identificirani u ekstraktima, feniloctena kiselina (do 24,0%) i dehidrovomifoliol (do 19,3%), nisu prethodno pronađeni u ovoj vrsti meda. Za razliku od feniloctene kiseline, dehidrovomifoliol se može smatrati karakterističnim spojem za med od maslačka. U kemijskim profilima isparljivih/poluisparljivih spojeva meda Coriandrum sativum L., identificirano je nekoliko korisnih kemijskih markera, posebno cis/trans-anhidrolinalool oksidi (ukupno 5,9%) u vršnim parama i 3,4,5-trimetoksibenzil-alkohol (do 26,3%) u ekstraktima. 3,4,5- Trimetoksibenzil-alkohol se može istaknuti kao specifičan kemijski marker, budući da do sada nije pronađen u drugim vrstama meda. Glavni spojevi vršnih para meda Trifolium pratense L. su izomeri aldehida jorgovana (7,6%-21,4%), nakon kojih slijede fenilacetaldehid (10,1-31,2%) i benzaldehid (7,0-15,7%). Profil vršnih para je važan za karakterizaciju navedene vrste meda, budući da se glavni spojevi ekstrakata, viši alifatski alkoholi i ugljikovodici, mogu povezati sa okolišem i sastavom saća. Glavni spojevi vršnih para meda Satureja subspicata Vis. su fenilacetaldehid (30,2%) i benzaldehid (23,8%). Spojevi identificirani u ekstraktima (pentan:dietil-eter, 1:2 (v/v); diklormetan) meda Satureja subspicata Vis. su metil-siringat (46,7%; 53,0%,), manji postotak drugih isparljivih derivata prefenata, te viši alifatski spojevi. Primjećena je značajna sličnost sa kemijskim profilom ekstrakata (pentan:dietil-eter, 1:2 (v/v)) meda Satureja montana L., u kojima je glavni spoj metil-siringat (53,8%), a potom siringaldehid (18,9%) i benzojeva kiselina (5,6%). Hotrienol je glavni spoj identificiran u vršnim parama (75,9-81,7%). U vršnim parama meda Satureja hortensis L. identificirani su, hotrienol (22,8%) i drugi derivati linaloola, benzaldehid (6,1%), fenilacetaldehid (4,9%) i nekoliko norizoprenoida, među kojima je safranal (7,6%) glavni spoj. Glavni spoj identificiran u ekstraktu (pentan:dietil-eter, 1:2 (v/v)), uz ostale derivate benzena, je metil-siringat (54,7%). HPLC-DAD se pokazala kao korisna metoda koja nadopunjuje dobivene GC-MS/FID rezultate kemijskog profiliranja uzoraka meda Satureja vrsta. HPLC-DAD analizom, u uzorcima meda Satureja subspicata Vis. je pronađen 3-4 puta viši sadržaj metil-siringata u usporedbi sa drugim Satureja vrstama meda. U Coffea spp. medu identificirani su glavni derivati ksantina (teobromin i kofein HPLC-DAD analizom i kofein GC-MS/FID analizom). Fenilacetaldehid je glavni spoj vršnih para meda Coffea spp. Enantioselektivnom HPLC analizom ekstrakata Galactites tomentosa Moench. meda određen je visok enantiomerni višak (–)-3-fenilmliječne kiseline (e.v. > 95%). Visoka enatiomerna čistoća ovog kemijskog markera može poslužiti u karakterizaciji i utvrđivanju botaničkog podrijetla Galactites tomentosa Moench. meda. |
Abstract (english) | Bioorganic research of 8 different unifloral honeys was based on gas chromatography (GC) and liquid chromatography (HPLC) in order to determine chemical profiles and targeted organic compounds, among which potential markers of botanical origin were highlighted. The application of complementary extraction methodologies (HS-SPME, headspace solid-phase mixroextraction; USE, ultrasonic solvent extraction; SPE, solid-phase extraction) enabled comprehensive chemical profiles of volatile and semivolatile compounds. The dominant compounds of Taraxacum officinale Weber headspace were nitriles, particularly 3- methylpentanenitrile (up to 29.9%) and phenylacetonitrile (up to 20.9%). Besides nitriles, lower methyl branched aliphatic acids and norisoprenoids were relevant minor constituents of the headspace. Major compounds identified in the extracts, phenylacetic acid (up to 24.0%) and dehydrovomifoliol (up to 19.3%), were not previously found in this honey type. Dehydrovomifoliol can be considered as characteristic compound of dandelion honey in distinction from phenylacetic acid. In volatile/semivolatile chemical profiles of Coriandrum sativum L. honey, several useful chemical markers were identified, particularly cis/trans- anhydro-linalool oxides (total 5.9%) found in the headspace and 3,4,5-trimethoxybenzyl alcohol (up to 26.3%) found in the extracts. 3,4,5-Trimethoxybenzyl alcohol can be emphasized as a specific chemical marker, as it has not so far been found in other honey types. Lilac aldehyde isomers dominated in the headspace (7.6%-21.4%) of Trifolium pratense L. honey, followed by phenylacetaldehyde (10.1-31.2 %) and benzaldehyde (7.0-15.7 %). The HS-SPME profile is valuable for characterization of this honey type, as predominant constituents of the honey extracts, higher aliphatic alcohols and hydrocarbons, could be associated with the comb environment. Major compounds of Satureja subspicata Vis. honey headspace were phenylacetaldehyde (30.2%) and benzaldehyde (23.8%). The extracts (pentane:diethyl ether, 1:2 (v/v); dichloromethane) from Satureja subspicata Vis. honey contained methyl syringate (46.7%, 53.0%,) and minor abundance of other volatile prephenate derivatives, as well as higher aliphatic compounds. Significant composition similarity is noticed with the chemical profile of the extracts from S. montana L. honey samples, with methyl syringate (53.8% ) as predominant compound, followed by syringaldehyde (18.9%) and benzoic acid (5.6%). Hotrienol was identified in headspace as the dominant compound (75.9-81.7%). Hotrienol (22.8 %) along with other linalool derivatives, benzaldehyde (6.1 %), phenylacetaldehyde (4.9 %) and few norisoprenoids (safranal (7.6 %) as the major) were identified in Satureja hortensis L. honey headspace. Dominant compound identified in the extract, along with other benzene derivatives, was methyl syringate (54.7%). HPLC-DAD was useful method which supplements the results obtained by GC-MS/FID chemical profiling of Satureja honey types. HPLC-DAD analysis of the samples of S. subspicata Vis. honey revealed 3–4 times higher amount of methyl syringate compared with other Satureja honey types. In Coffea spp. honey dominant xanthine derivatives were identified (theobromine and caffeine with HPLC-DAD and caffeine by USE/GC- MS/FID). Phenylacetaldehyde was the major headspace compound of Coffea spp. honey. Using enantioselective HPLC analysis of Galactites tomentosa Moench. honey extracts high enantiomeric excess of (–)-3-phenyllactic acid (ee > 95%) was determined. High enantiomeric purity of this chemical marker can be useful for Galactites tomentosa Moench. honey characterization and determination of its botanical origin. |