Liu AiYing

FATTY ACID COMPOSITION OF CICADA SLOUGH

Cicada slough is the shell of insect Cryptotympana pustulata Fabricius, the family of Cicadidae. It is often used in folk medicine to disperse pathogenic wind-heat from the lung channel, dispel wind to promote eruption, treat sore throat and hoarseness, clear heat from the liver, dispel pathogenic wind to relieve spasm, and to treat infantile convulsion and several other diseases 1–4 . This drug is produced throughout China but mainly in Shandong, Hebei, Henan, and Jiangsu Province. However, there has been a relative scarcity of papers on the chemical composition of Cicada slough. Recent investigations have shown that there are 24 kinds of trace elements 5 , a lot of amino acids, protein, chitin, and three acetyl-dopaamine dimers in the Cicada slough 6 . Fatty acids exhibit anti-inflammatory activity and affect the biosynthesis of prostaglandins, which play an important role in diseases that damage the skeletal-muscular system. Typically, fatty acids are analyzed after being converted into the methyl esters prior to analysis by GC or GC/MS 7 . The advantage of the derivatization is that the esters afford sharp peaks and better resolution. However, there are some drawbacks such as incomplete esterification, the possible generation of artifacts due to side reactions, and contamination of the sample with impurities in the reagent. The most crucial limitation of derivatization is that it prevents the study of naturally occurring fatty acid methyl esters (FAMEs) 8 . Occasionally, free fatty acids have also been analyzed successfully 9 . In order to expand the raw material base of folk medicine, in this study we analyzed the composition and relative content of fatty-acids in Cicada slough without previous derivatization. Cicada slough was bought from Beijing Tong Ren Tang Chinese Medicine Corporation. Samples were dried at 50 C to constant weight and ground to a fine powder. Total lipids from finely ground Cicada slough were extracted three times using four different solvents (absolute n-hexane, absolute methylene chloride, absolute petroleum ether, and absolute ethyl acetate) with the assistance of ultrasound at room temperature. The combined extracts were then dried over anhydrous Na2SO4, filtered, and concentrated to dryness under reduced pressure to 1 mL by rotary evaporation at 40 C. The lipophilic extracts were directly analyzed by GC-MS. Gas chromatography-mass spectrometry (GC-MS) analysis was performed on an Agilent 7890 GC instrument equipped with a 5975 C mass elective detector and an Agilent DB-FFAP capillary column (30 m 0.25 mm, film thickness 0.25 m). The column temperature was programmed from 80 to 250 C at a rate of 20 C/min and held at 100 C for 2 min, from 100 to180 C at a rate of 15 C min–1 and held at 180 C for 2 min, then from 180 to 250 C at 6 C min–1 with the final temperature held for 20 min. The inlet and interface temperatures were 230 C and 220 C, respectively. The sample (0.1 L) was injected with a split of 10:1. Electron impact mass spectrometry was carried out at 70 eV. Ion source and quadrupole temperatures were maintained at 230 C and 150 C, respectively, mass range m/z 50–550 Da. The components of fatty acid were identified by direct comparison of their mass spectral pattern and retention time with those published in the literature and by matching their recorded mass spectra with the corresponding data (NIST08Library). The percentage composition of fatty acids was computed by the normalization method from the GC peak areas, assuming identical mass response factor for all compounds. All samples were analyzed in duplicate.

Screening and breeding of Beauveria bassiana for controlling tobacco beetles

Screening and breeding of drought-resistant and high temperature-resistant Beauveria bassiana was conducted so as to make it adaptable in leaf tobacco warehouse. GZUIFR-GL5-08 i strains were screened out through a combined ultraviolet and microwave mutagenic experiment. Results showed that GZUIFR-GL5-08 i sustained stable growth on the condition of water potential 0.8Mpa and temperature 35 ℃. Content of protein, proiline, SOD, CAT, POD were higher than that before mutation, which showed similarity in draught-resistance mechanism between entomogenous fungi and plants.