Photinia serrulata Lindl. belongs to the Rosaceae family and is distributed in Shanxi, Gansu, Anhui, Jiangsu, Henan, and Hunan Provinces in China [1]. Phytochemical research showed that triterpenoids and cyanophoric glycosides, for example, ursane triterpenoids and analogs, ursolic acid, oleanolic acid, prunasin, and saponin, were the main compounds in the leaves of P. serrulata [2–7]. Pharmacological investigations showed that the leaves of P. serrulata are toxic, possess antioxidant and antibacterial activity, can kill Tetranychus cinnabarinus and can suppress plant growth [6–11]. No research has so far been conducted concerning the chemical constituents of the essential oil of the flowers. In order to identify the chemical constituents of the essential oil of P. serrulata flowers, we used the HS-SPME technique with subsequent analysis by GC-MS. The flowers of P. serrulata were collected in Kaifeng, Henan, in July 2010. They were identified by Assoc. Prof. Changqian Li. A voucher specimen was deposited in the Institute of Chinese Materia Medica, Henan University. Volatile organic compounds were extracted in a manual SPME holder together with 5 mL vials and PDMS-DVB fibers (65 m) purchased from Supelco Inc. (Bellefonte, USA). The powder of P. serrulata flowers (about 0.7 g) was placed in vials (5 mL). PDMS-DVB fiber of the SPME was aged 10 min in the inlet of the GC, with carrier gas flow 1.0 mL per minute; then the SPME fiber was exposed in the upper space of the sealed vial for 30 min at 80C to adsorb the analytes. After that, the fiber was withdrawn and directly inserted into the GC-MS inlet for desorption of the volatiles for 1 min. HS-SPME-GC-MS analysis was carried out using an Agilent 6890 N gas chromatograph equipped with an HP-5 MS capillary column (5% phenylmethylsiloxane, 30 m 0.25 mm, film thickness 0.25 m, Agilent Technologies, USA) and coupled with a 5975B mass selective detector spectrometer from the same company. The front inlet was kept at 250C in the splitless mode. The temperature program was as follows: initial column temperature 50C, held for 2 min, then programmed to 120C at a rate of 8C per minute and held for 2 min and finally programmed to 220C at a rate of 4C per minute and held at 220C for 5 min. Flow rate of split injection was 1.0 mL per minute. As a carrier gas, helium at 1.0 mL per minute was used. The MS detector was used in the EI mode with an ionization voltage of 70 eV. The ion source temperature was at 230C. The transfer line was at 280C. The spectra were collected over the mass range (m/z) 30–440. Retention indices were calculated by using the retention times of n-alkanes that were injected at the same chromatographic conditions [12]. Compounds were identified by comparison of their relative retention indices and computer matching with the Wiley 275.L library. The volatiles in the flowers of P. serrulata are presented in Table 1. Thirty-three compounds were identified, which comprised 93.8% of the total volatiles. Volatiles in flowers of P. serrulata contained aldehydes (65.5%), esters (6.4%), ketones (7.0%), alcohols (5.5%), alkanes (3.6%), nitrogenous (2.1%), acids (2.5%), and phenols (1.3%). The main volatile components in the flowers were benzaldehyde (63.9%), dehydromevalonic lactone (5.0%), phenylethyl alcohol (3.9%), and hexahydrofarnesyl acetone (2.2%). Phenylethyl alcohol has the aroma of roses, while benzaldehyde has a bitter almond flavor and is an important raw material in medicaments, dyes, spices, and the resin industry. Results showed that phenylethyl alcohol and benzaldehyde were the main aroma components in flowers of P. serrulata.
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Jun 1, 2016
L.F Wang + 1
Open Access
