Composition of Free and Glycosidically Bound Volatiles of Mentha aquatica L.

Free and glycosidically bound volatiles of mentha aquatica L. were investigated. Free volatile compounds were isolated from the dried plant material by hydrodistillation and glycosides by extraction with water during hydrodistillation. Free volatile compounds (essential oil) as well as the aglycones obtained after the hydrolysis of glycosides were analyzed by gas chromatography-mass spectrometry (GC-MS). The essential oil was composed of monoterpene hydrocarbons (10.47%), sesquiterpene hydrocarbons (20.09%) and oxygen containing compounds (68.42%). The major components of the essential oil were: menthofuran (3978.08 mg kg-1), 1,8-cineole (1716.44 mg kg-1) and trans-caryophyllene (1109.20 mg kg-1). After enzymatic hydrolysis, the major volatile aglycones were: 1-octen-3-ol (30.22 mg kg-1), eugenol (10.21 mg kg-1), 2-phenylethanol (6.81 mg kg-1), 3-hexen-1-ol (5.35 mg kg-1), perilla alcohol (4.13 mg kg-1), 1-hexanol (3.58 mg kg-1), and 3-octanol (2.44 mg kg-1). Moderate similarity was found between volatile aglycones and the corresponding free volatiles in the essential oil. Acidic hydrolysis, after enzymatic hydrolysis, liberated additional amounts of aglycones. Approx. 38% of the glycosides were not hydrolyzed by the used enzyme

GC-MS Characterization of Acetylated β-D-glucopyranosides: Transglucosylation of Volatile Alcohols Using Almond β-glucosidase

β-D-Glucopyranosides of pentan-1-ol, (±)-pentan-2-ol, hexan-1-ol, octan-1-ol, benzyl alcohol, 2-phenylethanol, (±)-2-phenyl-propan-1-ol, 3-phenyl-propan-1-ol, geraniol and nerol were synthesized by transglucosylation of the respective alcohols with cellobiose using almond β-glucosidase. The reaction was carried out in acetonitrile with acetate buffer (vol. ratio 9:1), with the yields 14.4–45.0 %. Transglucosylation was not enantioselective. The products were characterized by GC-MS analysis of prepared tetraacetyl glucosides. Fragment ion characteristics of the aglucone moiety are present in all mass spectra, along with the fragments obtained from acetylated glucose. Acetylated glucosides are separable on HP-101 column (even diastereomeric tetraacetyl β-glucosides of enantiomeric alcohols)

Volatile Organic Compounds of Marine Sponge Petrosia ficiformis from the Adriatic Sea

Volatile organic compounds (VOCs) of Petrosia ficiformis were investigated for the first time. The VOCs from fresh and air-dried sponge were obtained by hydrodistillation and headspace-solid phase microextraction and they were analysed by coupled gas chromatography-mass spectrometry. Aliphatic compounds with octan-3-one (up to 24.02 %), oct-1-en-3-ol (up to 8.65 %) and heptadecane (up to 39.37 %) were the most abundant in the fresh sponge along with benzaldehyde (up to 18.59 %) and diisobutyl phthalate (up to 8.44 %). Higher percentage of N,N-dimethylmethanamine (up to 19.08 %) was found in dried sample headspace and the loss of octan-3-one and benzaldehyde and increase of benzyl alcohol (up to 18.90 %) were noted. The great difference among the fresh and dried sponge VOCs obtained by hydrodistillation was noticed for fatty acids and derivatives abundance and 1H-indole increased (up to 6.00 %) in the dried sponge. Both methods enabled obtaining more complete VOCs profile and drying significantly changed their composition

Chemical profile of the organic residue from ancient amphora found in the Adriatic Sea determined by direct GC and GC-MS analysis

An ancient organic residue was collected from the bottom of a Greco-Italian amphora found in the Adriatic Sea and investigated by direct GC and GC- MS analysis. The headspace composition was determined by HS-SPME using: (1) DVB/CAR/PDMS and (2) PDMS/DVB fibres. Higher percentages of benzene derivatives, monoterpenes and other low- molecular aliphatic compounds were obtained by method (1) in contrast to higher percentage of naphthalene and phenanthrene derivatives found by method (2). In comparison with the composition of pine resin, it is more likely that the found low- molecular aliphatic alcohols, acids, esters and carbonyls with 2-phenylethanol were trapped and preserved within the organic residue from stored wine – the amphora’s originally content. Semi- volatile diterpenes methyl dehydroabietate (33.6%) and retene (24.1%) were dominant in the residue CH2Cl2 solution. Other abundant compounds were 1, 4-dimethoxyphenanthrene (6.8%) as well as other naphthalene and/or phenanthrene derivatives [7-(1- methylethyl)-1, 4a-dimethyl-1, 2, 3, 4, 4a, 9, 10, 10a- octahydronaphthalene, 7-(1-methylethyl)-1, 4a- dimethyl-2, 3, 4, 4a, 9, 10-hexahydrophenanthrene, 7- (1-methylethyl)-1, 4a-dimethyl-1, 2, 3, 4, 4a, 9, 10, 10a- octahydro-phenanthrene, 3, 6-dimethylphenanthrene and 2, 3, 5-trimethylphenanthrene]. Possible sources and formation pathways of the major compounds in the residue were discussed

Primjena mikroekstrakcije vršnih para na čvrstoj fazi kao preparativni pristup za plinsku kromatografiju sa spektrometrijom masa

Reviewed in brief are the selected results of the application of headspace solid-phase microextraction as a preparative approach for gas chromatography – mass spectrometry (HS-SPME/GC-MS) for natural organic compounds research at the University of Split, Faculty of Chemistry and Technology. A wide variety of headspace compounds from different natural sources has been identified: lower aliphatic compounds (e.g., C5- and C6-compounds), aromatic compounds, monoterpenes (e.g., linalool derivatives (oxides, anhydro-oxides, epoxides), hotrienol), sesquiterpenes (e.g., eudesmol isomers, hydrocarbons), and C9- and C13-norisoprenoids (e.g., 3,4-dihydro-3-oxoedulan, 4-oxoisophorone, trans-β-damascenone). These compounds are important phytochemicals as flavour/fragrance compounds, chemical markers of the botanical origin or others (e.g., allelochemicals, pheromones, or acaricide residue). This work is licensed under a Creative Commons Attribution 4.0 International License.Ukratko su prikazani odabrani rezultati primjene mikroekstrakcije vršnih para na čvrstoj fazi kao preparativnog pristupa plinskoj kromatografiji – spektrometriji masa (HS-SPME/GC-MS) za istraživanje prirodnih spojeva, koje je provedeno na Kemijsko-tehnološkom fakultetu Sveučilištu u Splitu. Velika raznolikost spojeva vršnih para istražena je iz različitih prirodnih izvora: niži alifatski spojevi (npr. C5- i C6-spojevi), aromatski spojevi, monoterpeni (npr. derivati linaloola (oksidi, anhidro-oksidi, epoksidi), hotrienol), seskviterpeni (npr. eudezmol izomeri, ugljikovodici) te C9- i C13-norizoprenoidi (npr. 3,4-dihidro-3-oksoedulan, 4-oksoisoforon, trans-β-damascenon). Ti su spojevi važne fitokemikalije kao spojevi aroma/mirisa, kemijski marker botaničkog podrijetla ili drugo (npr. aleokemikalije, feromoni ili ostatci akaricida). Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna