Identification of the main phenolic compounds in wood of Ceratonia siliqua by GC‐MS

Abstract

The tannin composition of wood of Ceratonia siliqua (carob) was studied using GC-MS and classical chemical assays. Aqueous methanolic extracts of carob heartwood and sapwood were fractionated using organic solvents of increasing polarity, and GC-MS analyses were performed before and after hydrolysis. Prior to hydrolysis, gallic acid, catechin and its derivatives, methyl inositol and chalcone were determined as the major compounds found in the free form. Aqueous fractions of both wood types were hydrolysed with hydrochloric acid in methanol and extracted with organic solvents and water. These fractions were rich in methyl inositol, gallic acid, glucose and other monosaccharides. The results show that carob wood contains predominantly gallotannins and proanthocyanidins. The technique employed is shown to be a valuable tool and an alternative method to HPLC determination of hydrolysable tannin composition.

Characterization of methanol extracts from Quercus hartwissiana wood and bark

“…Two trees were analyzed separately. Each fraction was ground and sieved (40-100 mesh), then the same extraction-isolation and colorimetric estimation steps were followed as previously described in detail [8]. Briefly, samples were extracted with methanol-water-mixture (4:1) and soluble matter was fractionated into two parts as diethyl ethersoluble and water-soluble extractives.…”

“…Free and bound compounds were isolated using the following method [8]. The wood or bark meal (1 g) was soaked in methanol-water mixture (4:1 v/v) 3 times for 6 hours at room temperature.…”

Analysis of proanthocyanidins

“…To improve volatility, the use of derivatization is inevitable, and trimethylsilyl derivatives have been described previously [80]. Recently, a mixture of trimethylchlorsilane and bis-(trimethylsilyl)-trifluoroacetamide at a ratio 1:3 as derivative agent has also been reported [81]. Pyrolysis GC-MS methods have been reported as an alternative method, in which the procyanidin mixture is pyrolyzed at 5008C.…”

Identification and quantitative analysis of phenolic compounds naturally occuring in wood of selected European and exotic tree species

“…(Yokoi et al 2001) (wykryto w nim liczne kwasy fenolowe oraz substancje organiczne zawieraj¹ce grupy metoksylowe), wierzby iwy (Salix caprea L.) (Pohjamo et al 2003) (stwierdzono obecnooeae kwasu wanilinowego, alkoholu kumarynowego, alkoholu koniferylowego i in. ), szarañ-czynu str¹kowego (Ceratonia siliqua L.) (Balaban 2004), kakaowca (Theobroma cacao L.) (Alemanno et al 2003) i czeremchy amerykañskiej (Prunus serotina Borkh) (Mayer et al 2006). Wyniki powy¿szych badañ by³y zbli¿one do rezultatów przedstawionych w niniejszej pracy.…”