Bioactivity of Essential Oil of Zingiber purpureum Rhizomes and Its Main Compounds against Two Stored Product Insects.

The insecticidal and repellent activities of the essential oil extracted from Zingiber purpureum Roscoe rhizomes were evaluated against Tribolium castaneum (Herbst) and Lasioderma serricorne (L.) adults. During our screening program for agrochemicals from Chinese medicinal herbs and wild plants, the essential oil of Z. purpureum rhizomes was found to possess strong contact toxicity against T. castaneum and L. serricorne adults, with LD50 values of 39.0 and 16.3 µg per adult, respectively, and also showed strong fumigant toxicity against the two grain storage insects with LC50 values of 13.6 and 9.3 mg/liter of air, respectively. The essential oil obtained by hydrodistillation was investigated by gas chromatography-mass spectrometry. The main components of the essential oil were identified to be sabinene (48.1%), terpinen-4-ol (25.1%), and γ-terpinene (6.7%), followed by α-terpinene (4.3%), ß-thujene (3.4%), and α-phellandrene (2.7%). Sabinene, terpinen-4-ol, and γ-terpinene were separated and purified by silica gel column chromatography and preparative thin-layer chromatography. Terpinen-4-ol showed the strongest contact toxicity against T. castaneum and L. serricorne (LD50=19.7 and 5.4 µg per adult, respectively) and also the strongest fumigant toxicity against T. castaneum and L. serricorne (LC50=3.7 and 1.3 mg/liter of air, respectively). Otherwise, sabinene and terpinen-4-ol were strongly repellent against T. castaneum as well as the essential oil, while γ-terpinene exhibited weaker repellency against T. castaneum compared with the positive control, DEET (N, N-diethyl-3-methylbenzamide). Moreover, only the essential oil exhibited strong repellency against L. serricorne, the three compounds exhibited weaker repellency against L. serricorne relative to DEET.

[Studies on the fingerprint of radix notoginseng and its preparation].

OBJECTIVE: A fingerprint of raw material, extracted and injections of radix notoginseng has been studied and provides the quality information. METHOD: Polaris C18-A column was used, with mixtures of acetonitrile and water as mobile phase in a gradient mode. The wavelength of measurement was 203 nm. RESULT: According to the selected chromatographic conditions, a good fingerprint of radix notoginseng and its extract, preparation has been described. CONCLUSION: The method is simple, accurate with good reproducibility. It may be practical value for the quality control of sample for radix notoginseng and its preparation.

[Contents of total flavonoids in Rhizoma Arisaematis].

OBJECTIVE: Comparing the contents of total flavonoides of Rhizoma Arisaematis, which collected in different time, regions, different varieties and processed. METHOD: Determining the contents by ultraviolet spectro-photometry. RESULT AND CONCLUSION: The contents were found in the following sequence: 1. the end of July, the begin of July, August, September; 2. Beijing, Shanxi, Sichuan, Anhui; 3. Arisaema erubenscens, A. heterophyllum, A. amurense; 4. unprocessed product, processed product.