间接顶空固相微萃取-气相色谱-质谱法对红花香雪兰天然花香成分的分析

建立了间接顶空固相微萃取-气相色谱-质谱对红花香雪兰天然花香成分的分析方法。首先利用气体采样装置对花香成分进行固相富集,富集后的花香成分在浸提液中解析,之后利用顶空固相微萃取方法对浸提液中的花香成分进行分析。红花香雪兰花香中主要成分(沉香醇、松油醇、紫罗兰酮和二氢紫罗兰酮)定量分析优化实验条件：Florisil(弗罗里硅土)作为吸附剂,水-甲醇混合液(9∶1, V/V)和0.6 mol/L HCl作为浸提液,萃取温度70℃,平衡时间为25 min。实验结果表明,沉香醇和松油醇在1~100μg/mL范围内有良好的线性关系(R2≥0.981),检出限分别为0.05和0.10μg;二氢紫罗兰酮和紫罗兰酮在0.5~50μg/mL范围内有良好的线性关系(R2≥0.988),检出限为0.02μg。     

Composition of the lipophilic extract from the sponge <Emphasis Type="Italic">Axinella carteri</Emphasis> collected from the Bay of Bengal of the Orissa coast

The composition of the lipophilic extract from the two specimen of the sponge Axinella carteri (Dendy) collected from two different depths of the Bay of Bengal of the Orissa coast were investigated. Fatty acids, as well as volatile compounds and sterols, were identified. A high concentration of polyunsaturated fatty acids was identified from depth species compared to the species collected from shallow water. The presence of a high concentration of a polymethyl-branched fatty acid, i.e., phytanic acid, and a demospongic acid (C26:2, Δ 5,9) were identified in both specimen, but the % composition of both acids were more in the species collected from depth than the species collected from shallow water. Important polyunsaturated fatty acids like 5,8,11,14-eicosatetraenoic acid and 5,8,11,14,17-eicosapentaenoic acid (EPA) were also found in depth species which were absent in the species collected from shallow water. Antimicrobial screening of the lipid extracts of A. carteri was also studied against different pathogens. Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 224–227, May–June, 2008.     

Current Advances in the Bacterial Toolbox for the Biotechnological Production of Monoterpene-Based Aroma Compounds

Monoterpenes are plant secondary metabolites, widely used in industrial processes as precursors of important aroma compounds, such as vanillin and (−)-menthol. However, the physicochemical properties of monoterpenes make difficult their conventional conversion into value-added aromas. Biocatalysis, either by using whole cells or enzymes, may overcome such drawbacks in terms of purity of the final product, ecological and economic constraints of the current catalysis processes or extraction from plant material. In particular, the ability of oxidative enzymes (e.g., oxygenases) to modify the monoterpene backbone, with high regio- and stereo-selectivity, is attractive for the production of “natural” aromas for the flavor and fragrances industries. We review the research efforts carried out in the molecular analysis of bacterial monoterpene catabolic pathways and biochemical characterization of the respective key oxidative enzymes, with particular focus on the most relevant precursors, β-pinene, limonene and β-myrcene. The presented overview of the current state of art demonstrates that the specialized enzymatic repertoires of monoterpene-catabolizing bacteria are expanding the toolbox towards the tailored and sustainable biotechnological production of values-added aroma compounds (e.g., isonovalal, α-terpineol, and carvone isomers) whose implementation must be supported by the current advances in systems biology and metabolic engineering approaches.     

Signaling in the Tomato Immunity against Fusarium oxysporum

New strategies of control need to be developed with the aim of economic and environmental sustainability in plant and crop protection. Metabolomics is an excellent platform for both understanding the complex plant–pathogen interactions and unraveling new chemical control strategies. GC-MS-based metabolomics, along with a phytohormone analysis of a compatible and incompatible interaction between tomato plants and Fusarium oxysporum f. sp. lycopersici, revealed the specific volatile chemical composition and the plant signals associated with them. The susceptible tomato plants were characterized by the over-emission of methyl- and ethyl-salicylate as well as some fatty acid derivatives, along with an activation of salicylic acid and abscisic acid signaling. In contrast, terpenoids, benzenoids, and 2-ethylhexanoic acid were differentially emitted by plants undergoing an incompatible interaction, together with the activation of the jasmonic acid (JA) pathway. In accordance with this response, a higher expression of several genes participating in the biosynthesis of these volatiles, such as MTS1, TomloxC, TomloxD, and AOS, as well as JAZ7, a JA marker gene, was found to be induced by the fungus in these resistant plants. The characterized metabolome of the immune tomato plants could lead to the development of new resistance inducers against Fusarium wilt treatment.     

Mechanism of Action of Endophytic Fungi Hypocrea lixii and Beauveria bassiana in Phaseolus vulgaris as Biopesticides against Pea Leafminer and Fall Armyworm

Endophytic fungal isolates Hypocrea lixii F3ST1 and Beauveria bassiana G1LU3 were evaluated for their potential to endophytically colonize and induce active compounds in Phaseolus vulgaris, as a defense mechanism against pea leafminer (Liriomyza huidobrensis) and fall armyworm (Spodoptera frugiperda). Endophytic colonization was achieved through seed inoculation with the volatile emissions from P. vulgaris plants being analyzed using GC-MS. The crude extracts of P. vulgaris obtained using methanol and dichloromethane were assayed against leafminer and fall armyworm larvae using leaf dipping and topical application, respectively. The two isolates successfully colonized the entire host plant (roots, stems, and leaves) with significant variation (p < 0.001) between fungal isolates and the controls. The results showed qualitative differences in the volatile profiles between the control plants, endophytically colonized and insect-damaged plants attributed to fungal inoculation and leafminer damage. The crude methanol extracts significantly reduced the percentage pupation of 2nd instar leafminer larvae (p < 0.001) and adult-flies emergence (p < 0.05). The survival of the 1st instar fall armyworm larvae was also significantly reduced (p < 0.001) compared to the controls. This study demonstrated the high potential of endophytic fungi H. lixii and B. bassiana in inducing mainly specific defense compounds in the common bean P. vulgaris that can be used against pea leafminer and fall armyworm.     

Headspace Volatiles and Endogenous Extracts of Prunus mume Cultivars with Different Aroma Types

Prunus mume is a traditional ornamental plant, which owed a unique floral scent. However, the diversity of the floral scent in P. mume cultivars with different aroma types was not identified. In this study, the floral scent of eight P. mume cultivars was studied using headspace solid-phase microextraction (HS-SPME) and organic solvent extraction (OSE), combined with gas chromatography-mass spectrometry (GC-MS). In total, 66 headspace volatiles and 74 endogenous extracts were putatively identified, of which phenylpropanoids/benzenoids were the main volatile organic compounds categories. As a result of GC-MS analysis, benzyl acetate (1.55–61.26%), eugenol (0.87–6.03%), benzaldehyde (5.34–46.46%), benzyl alcohol (5.13–57.13%), chavicol (0–5.46%), and cinnamyl alcohol (0–6.49%) were considered to be the main components in most varieties. However, the volatilization rate of these main components was different. Based on the variable importance in projection (VIP) values in the orthogonal partial least-squares discriminate analysis (OPLS-DA), differential components of four aroma types were identified as biomarkers, and 10 volatile and 12 endogenous biomarkers were screened out, respectively. The odor activity value (OAV) revealed that several biomarkers, including (Z)-2-hexen-1-ol, pentyl acetate, (E)-cinnamaldehyde, methyl salicylate, cinnamyl alcohol, and benzoyl cyanide, contributed greatly to the strong-scented, fresh-scented, sweet-scented, and light-scented types of P. mume cultivars. This study provided a theoretical basis for the floral scent evaluation and breeding of P. mume cultivars.     

Developmental variation in floral volatiles composition of a fragrant orchid Zygopetalum maculatum (Kunth) Garay

Emitted scent volatile profile of an orchid species Zygopetalum maculatum was studied using dynamic headspace sampling technique with four different adsorbent matrices, namely Porapak Type Q polymer (mesh size: 80/100), Tenax (mesh size: 60/80), activated charcoal and graphite. In addition, developmental variations in scent emissions and endogenous volatile levels were also investigated. Gas chromatography-mass spectrometry analysis revealed the presence of 21 volatile compounds in the headspace, which was predominantly enriched with benzenoid compounds. Among these benzenoids, o-diethylbenzene and p-diethylbenzene were the major compounds followed by benzyl acetate and methyl salicylate. Among the phenylpropanoid compounds, 2-phenylethyl acetate was the major volatile. However, as compared to benzenoids, the quantity was much lesser, indicating the inclination of phenylalanine flux towards benzenoid pathway. The outcome of this study has the implications in enhancing fragrance and vase life of orchids of the Sikkim Himalaya region and thus may further help to meet the growing market demand.     

Volatile Organic Compound Profiles of Cystoseira corniculata (Turner) Zanardini 1841 and Ericaria amentacea (C.Agardh) Molinari and Guiry 2020 (ex. Cystoseira amentacea (C.Agardh) Bory de Saint-Vincent, 1832)

The volatile organic compounds (VOCs) of fresh (FrCC) and air-dried (DrCC) Cystoseria corniculata and fresh (FrEA) and air-dried (DrEA) Ericaria amentacea from the Adriatic Sea were investigated by headspace solid-phase microextraction (HS-SPME) and hydrodistillation (HD) and analysed by gas chromatography and mass spectrometry (GC-MS). In HS-FrCC and HS-DrCC, aliphatic compounds were dominant, with decan-5-ol as the most abundant in HS-FrCC, but in HS-DrCC pentadecane dominated. Monoterpenes (β-cyclocitral, β-citral, and β-cyclohomocitral) and sesquiterpenes (cubenol) were abundant in HS-FrCC. Notable differences between fresh and air-dried samples were found for benzene derivatives. Fatty acids and their derivatives were the most abundant in HD-FrCC and HD-DrCC. In HS-FrEA and HS-DrEA, saturated aliphatic compounds as well as unsaturated aliphatic compounds (particularly hexan-1-ol and (Z)-hex-3-en-1-ol) predominantly showed decrements after drying. Pentadecane, heptadecane, pentadecanal, and hexan-1-ol were predominant in HD-FrEA, and their percentage decreased in HD-DrEA. The percentage of monoterpenes decreased after drying, but the percentages of diterpenes and especially sesquiterpenes increased. δ-Selinene was the major terpene and the most abundant in HD-DrEA. A significant increment after drying could be noticed for fatty acids and their derivatives. The great diversity of identified VOCs among these two macroalgae supports their different botanical classifications.     

赖百当挥发性香气成分的研究

本文采用循环吹气吸附法捕集赖百当头香。用GC/MS/DS及毛细管气相色谱双柱保留指数的办法进行了分析鉴定。共鉴定了39种成分,占总峰面积的96.7%,其中5种在有关精油文献中未曾报道过,萜类化合物含量显著,是赖百当头香的一个特点。尝试了在头香分析中应用GC/FTIR联用技术。     

Phytochemical Characterization of Rhus coriaria L. Extracts by Headspace Solid-Phase Micro Extraction Gas Chromatography,Comprehensive Two-Dimensional Liquid Chromatography,and Antioxidant Activity Evaluation

Rhus coriaria L. (Anacardiaceae), commonly known as sumac, has been used since ancient times for many different applications, and nowadays is used mostly as a spice obtained from its in the Mediterranean and the Middle ground fruits and employed for flavoring and garnishing food, predominantly Eastern regions. Traditionally, sumac has been also used in popular medicine for the treatment of many ailments including hemorrhoids, wound healing, diarrhea, ulcers, and eye inflammation. Sumac drupes are indeed rich in various classes of phytochemicals including organic acids, flavonoids, tannins, and others, which are responsible of their powerful antioxidant capacity, from which treatment of many common diseases such as cardiovascular disease, diabetes, and cancer could benefit. In this work we evaluated the influence of fruit ripeness, conservation, and processing. To this aim, a phytochemical characterization of six different samples of Rhus coriaria L. was carried out. Specifically, headspace solid-phase micro extraction gas chromatography coupled to mass spectrometry and comprehensive two-dimensional liquid chromatography coupled to photodiode array and mass spectrometry detection, were employed. A total of 263 volatile compounds, including terpene hydrocarbons, acids, and aldehydes, as well as 83 polyphenolic compounds, mainly gallic acid derivatives, were positively identified. All samples showed a significant antioxidant activity by means of oxygen radical absorbance capacity, in line with their polyphenolic content and composition. Such findings set a solid ground to support the utilization of this plant as an attractive target for novel nutraceutical approaches and for drug discovery.