A detailed analysis of the volatile fraction of Dendrobium is reported in the literature only for some main species. In this paper the volatile fraction of five species of the Dendrobium genus has been characterized for the first time: Dendrobium brymerianum, Dendrobium crysotoxum, Dendrobium thyrsiflorum, Dendrobium sulcatum and Dendrobium farmeri. The study was conducted through headspace analysis with solid phase microextraction (SPME) coupled to gas chromatography combined with mass spectrometry (GC-MS). 63 compounds were identified, distributed in 10 chemical classes, with different distributions depending on the plant variety analyzed. For all varieties, the dominant class is represented by aldehydes (range 37.48%-67.36%) of which the main compounds are: hexanal, trans-2-hexenal, cis-2-hexenal, nonanal, 2,4-hexadienal and Z-2-nonenal. Terpenes are particularly abundant in D. farmeri, D. chrysotoxum, D. thyrsiflorum and D. sulcatum, ranged from 36.51% to 18.68%. Within this class the main compounds are: limonene, γ-terpinene, ο-cymene, m-cymene, and dihydromyrcenol. In the Dendrobium brymerianum species, sesquiterpenes represent 19.83% and in this class they are more abundant: trans-caryophyllene, aromadendrene and β-elemene. Esters are present in all varieties with a percentage ranged from 2.67% to 4.30%. The presence of methyl and ethyl esters was detected in D. farmeri (2.42% and 1.55%), and in D. chrysotoxum (1.96%). Coumarin was detected in D. sulcatum (8.74%) and D. farmeri (1.32%), and D. brymerianum (0.06%), but absent in the remaining varieties. The isolation technique using SPME and GC-MS analysis, developed for the study, proved to be rapid, effective and precise in identifying the compounds present in the different species. The study, in collaboration with the Felsinea Society of Orchidophilia, the Dendrobium & Fukirian association, and numerous Italian orchidophiles, sees the continuation of the characterization of other species of the Dendrobium genus in order to obtain an aromatic fingerprint of the entire genus.
Un’analisi dettagliata della frazione volatile dei Dendrobium è riportata, in letteratura, solo per alcune specie principali. Nel presente elaborato è stata caratterizzata per la prima volta la frazione volatile di cinque specie del genere Dendrobium: Dendrobium brymerianum, Dendrobium crysotoxum, Dendrobium thyrsiflorum, Dendrobium sulcatum e Dendrobium farmeri. Lo studio è stato condotto attraverso l’analisi dello spazio testa con microestrazione in fase solida (SPME) accoppiato a gas cromatografia abbinata a spettrometria di massa (GC-MS). Sono stati identificati 63 composti, distribuiti in 10 classi chimiche, con diversa distribuzione a seconda della varietà vegetale analizzata. La classe dominante è rappresentata, per tutte e cinque le varietà dalle aldeidi (range 37.48%-67.36%) di cui i composti principali sono: esanale, trans-2-esenale, cis-2-esenale, nonanale, 2,4-esadienale e Z-2-nonenale. I terpeni risultano particolarmente abbondanti in D. farmeri, D. chrysotoxum, D. thyrsiflorum e D. sulcatum con un range che va dal 36.51% al 18.68%. All’interno di questa classe i composti principali sono: limonene, γ-terpinene, ο-cimene , m-cimene e diidromircenolo. Nella specie Dendrobium brymerianum, i sesquiterpeni rappresentano il 19.83% e in questa classe risultani più abbondanti: trans-cariofillene, aromadendrene e il β-elemene. Gli esteri, presenti in tutte e cinque le varietà, rappresentano un range di percentuali che va dal 2.67% al 4.30%. E’ stata rilevata in tutte le specie la presenza di metil ed etil esteri in D. farmeri (2.42 % e 1.55 %) e in D. chrysotoxum (1.96 %). La cumarina è stata rilevata in D. sulcatum (8.74%) e D. farmeri (1.32%) e D. brymerianum (0.06%). Risulta assente nelle rimanenti varietà. La tecnica di isolamento mediante SPME e l’analisi GC-MS, sviluppate per lo studio, si sono rivelate rapide, efficaci e precise nell’individuazione dei composti presenti nelle diverse specie. Lo studio, in collaborazione con la Società Felsinea di Orchidofilia, l’associazione Dendrobium & Fukirian, e di numerosi orchidofili italiani, vede come proseguimento la caratterizzazione di altre specie del genus Dendrobium al fine di ottenere un fingerprint aromatico dell’intero genere.
Caratterizzazione della frazione volatile di cinque Dendrobium appartenenti alla sezione Callista.
UBOLDI, ELENA
2022/2023
Abstract
A detailed analysis of the volatile fraction of Dendrobium is reported in the literature only for some main species. In this paper the volatile fraction of five species of the Dendrobium genus has been characterized for the first time: Dendrobium brymerianum, Dendrobium crysotoxum, Dendrobium thyrsiflorum, Dendrobium sulcatum and Dendrobium farmeri. The study was conducted through headspace analysis with solid phase microextraction (SPME) coupled to gas chromatography combined with mass spectrometry (GC-MS). 63 compounds were identified, distributed in 10 chemical classes, with different distributions depending on the plant variety analyzed. For all varieties, the dominant class is represented by aldehydes (range 37.48%-67.36%) of which the main compounds are: hexanal, trans-2-hexenal, cis-2-hexenal, nonanal, 2,4-hexadienal and Z-2-nonenal. Terpenes are particularly abundant in D. farmeri, D. chrysotoxum, D. thyrsiflorum and D. sulcatum, ranged from 36.51% to 18.68%. Within this class the main compounds are: limonene, γ-terpinene, ο-cymene, m-cymene, and dihydromyrcenol. In the Dendrobium brymerianum species, sesquiterpenes represent 19.83% and in this class they are more abundant: trans-caryophyllene, aromadendrene and β-elemene. Esters are present in all varieties with a percentage ranged from 2.67% to 4.30%. The presence of methyl and ethyl esters was detected in D. farmeri (2.42% and 1.55%), and in D. chrysotoxum (1.96%). Coumarin was detected in D. sulcatum (8.74%) and D. farmeri (1.32%), and D. brymerianum (0.06%), but absent in the remaining varieties. The isolation technique using SPME and GC-MS analysis, developed for the study, proved to be rapid, effective and precise in identifying the compounds present in the different species. The study, in collaboration with the Felsinea Society of Orchidophilia, the Dendrobium & Fukirian association, and numerous Italian orchidophiles, sees the continuation of the characterization of other species of the Dendrobium genus in order to obtain an aromatic fingerprint of the entire genus.È consentito all'utente scaricare e condividere i documenti disponibili a testo pieno in UNITESI UNIPV nel rispetto della licenza Creative Commons del tipo CC BY NC ND.
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https://hdl.handle.net/20.500.14239/16767