Supercritical fluid extraction of daphne (Laurus nobilis L.) seed oil

Laurus nobilis L., commonly known as daphne tree, is an evergreen that belongs to the Lauraceae family. Daphne trees produce grape-sized shiny purplish berries having three parts: flesh, skin, and an inner kernel (single seed). This study examines supercritical CO₂ (SC-CO₂) extraction of oil from daphne seeds. The oil yield of ground seeds varied from 14 to 28% depending on the method and particle size used for oil recovery. Yields were similar for both petroleum ether and SC-CO₂ extraction. The extraction yield decreased significantly with increasing particle size. The amount of extract collected increased exponentially with increasing SC-CO₂ pressure. The highest extraction yield was obtained at the highest temperature studied, 75°C. More than 45% of the oil was lauric acid. SC-CO₂ is a viable technique to obtain high-purity L. nobilis L. seed oil, which is a potential ingredient for the cosmetic industry.     

瑞香属植物化学成分及生物活性研究进展

瑞香属植物自古是药用性植物。近年来研究发现,瑞香属植物主要含二萜类、香豆素类、木脂素类、黄酮及双黄酮类等多种活性成分。研究证明其具有抗炎、免疫调节、镇痛、抑菌、抗肿瘤、降血压、抗HIV、抗白血病、抗血栓形成和抑制蛋白激酶等生物活性。全文简要综述了国内外对瑞香属植物化学成分及生物活性的新近研究进展。     

Micromorphological evaluation of Daphne mucronata Royle and Myrtus communis L. using scanning electron microscopic techniques

The present study was undertaken to establish micromorphological standards of Daphne mucronata Royle and Myrtus communis (L.). Daphne mucronata Royle is a xerophytic perennial shrub while, Myrtus communis is an evergreen shrub or small tree. Micromorphological investigation is one of the cheapest methods. It will be helpful in the accurate identification of these plants from other species. Results of macroscopic evaluation showed various organoleptic features. Anatomy of the selected plant parts was carried out. It showed a typical dicot structure as it revealed the presence of epidermal cells, crystals, trichomes, cuticle, mesophyll tissues, xylem, phloem, paracytic, and dicytic stomata. Anatomical study facilitates the detection of adulteration with inferior commercial varieties, exhausted drugs, cheaper natural substances, and chemicals. Stomatal number, types, and size of stomata, and palisade ratio of Myrtus communis were observed. These observations will be helpful in the preparation of taxonomic key for the identification of selected species. Powder drug study [scanning electron microscopy (SEM)] showed characteristics histological differentiation. The methods cited here can be measured as characteristics to identify and validate these drugs.     

GENDER DIMORPHISM AND ALTITUDINAL VARIATION OF SECONDARY COMPOUNDS IN LEAVES OF THE GYNODIOECIOUS SHRUB <Emphasis Type="Italic">Daphne laureola</Emphasis>

In this article, we analyzed the concentration of coumarins in leaves of female and hermaphrodite individuals of the gynodioecious shrub Daphne laureola, along an elevational gradient in southern Spain. Combining HPLC and NMR techniques, we identified three different glycosides of 7-methoxy-coumarin in leaves of this species. Total coumarin concentration averaged between 60 and 120 mg/g dry weight for mature summer leaves of D. laureola growing at six different populations. As predicted by optimal theory, females tended to have a higher concentration of coumarins than hermaphrodites, thus upholding the idea that male reproductive function is costly for hermaphrodites. Furthermore, concentrations in females but not hermaphrodites were positively correlated with increasing population altitude, and the magnitude of gender divergence in coumarin concentration varied among populations, suggesting that the cost of the male function may be context dependent. To our knowledge, this is the first evidence of gender differences in chemical defenses of a gynodioecious species in the field.     

Daphne oleoides: An alternative source of important sesquiterpenes

This study was targeted to characterize the chemical composition and antibacterial properties of Daphne oleoides subsp. oleoides essential oil. The essential oil was analyzed and quantified by gas chromatography and gas chromatography/mass spectrometry. Additionally, the broth dilution method was used to evaluate its antibacterial activity against Bacillus cereus (ATCC 11778), Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 25923), Staphylococcus epidermidis (ATCC 12228), Streptococcus faecalis (ATTC 29212), Escherichia coli (ATCC 25922), Proteus mirabilis (ATCC 25933), Proteus vulgaris (ATCC 13315), Pseudomonas aeruginosa (ATCC 27853), and Salmonella typhi Ty2 (ATCC 19430). Seventy-nine compounds were identified, representing 95.2% of the total oil. Nootkatone (18.5%), nootkatin (12.1%), and daphnauranol C (11.7%) were determined as the main constituents in the oil. Oxygenated sesquiterpenes were dominating in the oil (43.0%), followed by fatty acid derivatives (13.7%) and carbonylic compounds (9.6%). The minimal inhibitory/bactericidal concentrations of essential oils of D. oleoides were in the range from 25–100 μg/mL, which can be considered as high activity in comparison with the reference antibiotic which was active in the rangefrom 3.12–100 μg/mL. The greatest minimal inhibitory concentration value was determined as 25 µg/mL against both two Bacillus strains and S. epidermidis, B. cereus, B. subtilis, and S. aureus were the most sensitive strains against essential oils when compared with the minimal inhibitory concentrations of control antibiotic. Consequently, Daphne oleoides subsp. oleoides can be exploited as a source of natural antibacterial agents and nootkatone for the pharmaceutical, food, and agricultural industries.     

Recent progress in high-pressure studies on organic conductors

Abstract

Recent high-pressure studies of organic conductors and superconductors are reviewed. The discovery of the highest T_c superconductivity among organics under high pressure has triggered the further progress of the high-pressure research. Owing to this finding, various organic conductors with the strong electron correlation were investigated under high pressures. This review includes the pressure techniques using the cubic anvil apparatus, as well as high-pressure studies of the organic conductors up to 10 GPa showing extraordinary temperature and pressure dependent transport phenomena.     

Uttarakhand: A State Rich in Plant Fibers

ABSTRACT

A diverse range of natural fibers is produced in many countries providing an important source of income for farmers and local communities. With the UN declaring 2009 as the Year of Natural Fibres, for the state of Uttarakhand the development comes as a fillip to its efforts toward promoting the use of natural fibers. Some of the commercially important natural fibers found in Uttarakhand are obtained from Sisal, Agave, Bhimal, Hemp, Jute, and Nettle. This review article describes some of the fiber-yielding plants of North West Himalayas with special reference to Uttarakhand. Many of the natural fibers described have been traditionally used by the rural communities; some of the traditional processing techniques employed have been described along with other natural fiber plant species that have the potential to provide alternative employment opportunities. This review article aims to compile the record of fiber-yielding plants of Uttarakhand, which will lead to increase the contribution of fiber-yielding plants in the rural economy and ecosystem of the state for achieving sustainable socioeconomic development.     

瑞香科植物芫花杀虫有效成分研究

通过水煮沸、热苯萃取、95%乙醇重结晶方法从野生植物芜花中提取到一种黄色结晶，生测实验证明该物质具有良好的杀虫效果，使用柱层析法对这种物质进行再提纯，进而通过UV、NMR及化学方法，证明这种黄色结晶为5，4′-二羟基-7-甲氧基黄酮（芜花素）。     

Attraction of Dibrachys cavus (Hymenoptera: Pteromalidae) to its Host Frass Volatiles

The European grapevine moth, Lobesia botrana (Lepidoptera: Tortricidae), is a polyphagous insect able to develop on grapes and wild plants. We tested the hypothesis that the parasitoid Dibrachys cavus (Hymenoptera: Pteromalidae) uses the larval frass in its host search. A two-armed olfactometer was used to measure the attractiveness of L. botrana larvae, their silk, or their frass after larvae were fed on different host plants. Frass of three Lepidoptera (L. botrana, Eupoecillia ambiguella, Sphinx ligustri) and one Orthoptera (Chorthippus brunneus) was assayed, but only L. botrana was used to test an effect of the larval host plant (two grape cultivars and three other plant species) to D. cavus females. Larvae without frass did not attract D. cavus whatever their origin, but their frass was attractive at a dose of 2–3 days equivalent of larval frass production. The silk produced by a single larva (L. botrana) was not attractive to D. cavus. The parasitoid was most attracted to the odor of S. ligustri; the frass of L. botrana was more attractive than that of E. ambiguella, irrespective of the species on which D. cavus had been reared. There was no difference in attractiveness of frass collected from L. botrana raised on food containing different plants. Chemical extracts using five different polarity solvents (acetone, dichloromethane, hexane, methanol, and water) differed in attractiveness to D. cavus. Water and dichloromethane were the most attractive. This suggests that a complex volatile signal made from intermediate to polar volatiles may be involved in attraction. D. cavus used frass to discriminate between different potential host species. Our results revealed that the larval food of L. botrana did not modify frass attractiveness, but that the moth species did.     

长白瑞香提取物的急性毒性及其体外抗弓形虫的研究

为研究长白瑞香提取物的急性毒性及其体外抗弓形虫的作用,采用最大耐受量法测定小鼠口服长白瑞香乙醇提取物的急性毒性,采用四唑盐(MTT)比色法测定长白瑞香乙醇提取物及其4个萃取物体外抗弓形虫的作用.结果显示:在观察期14 d内,高(10 g/kg)、低(5 g/kg)剂量组均未见小鼠死亡,且小鼠体重和主要脏器无变化; 长白瑞香乙醇提取物对小鼠的半数致死量(LD₅₀)大于10 g/(kg·BW),属实际无毒.乙酸乙酯和二氯甲烷萃取物抗弓形虫的作用较为明显,二者对感染弓形虫前后的HeLa细胞