Cistus creticus subsp. eriocephalus as a Model for Studying Plant Physiological and Metabolic Responses to Environmental Stress Factors

Variations in physiology and metabolic products of Cistus creticus subsp. eriocephalus along an altitudinal gradient (350–750 m.a.s.l.) within the Monti Lucretili Regional Natural Park (central Italy) were studied. The results showed that the phenol production was in relationship with the net photosynthetic rates and the chlorophyll content. In particular, the increasing caffeic acid (CA) content with altitude suggested its role in providing an additional photo‐protection mechanism, by its ability to consume photochemical reducing power and acting as an alternative C‐atom sink under high light conditions. The metabolic production was tested by high performance thin layer chromatography (HPTLC) fingerprint analysis, highlighting the potential of this technique in biologic studies.     

Composition,Chemical Variability and Biological Activity of Cymbopogon schoenanthus Essential Oil from Central Algeria

Cymbopogon schoenanthus (L.) Spreng . (Poaceae) is an aromatic plant whose aerial parts and rhizome produced an essential oil with pleasant odor. A chemical variability has been observed depending of the countries where the plant grows wild, including Algeria. The chemical compositions of 24 oil samples isolated from plants harvested in Central Algeria have been investigated, to evidence homogeneity or chemical variability within a given area of harvest. Twenty of these were dominated by cis‐ and trans‐p‐menth‐2‐en‐1‐ols (22.6 %±3.6 and 14.3 %±1.7, resp.) beside four atypical compositions. Otherwise, aerial parts and rhizomes produced similar essential oils. Lastly, a fair antimicrobial activity was measured against Staphylococcus aureus strain, while the antioxidant potential was low.     

Composition and Chemical Variability of Enantia polycarpa Engl. & Diels Leaf Essential Oil from Côte d'Ivoire

The composition of Enantia polycarpa Engl . & Diels leaf essential oil has been investigated for the first time using a combination of chromatographic and spectroscopic techniques. The compositions of 52 leaf essential oil samples have been subjected to statistical analysis, hierarchical cluster analysis (HCA) and principal component analysis (PCA). Four groups were differentiated, of which the compositions were dominated by β‐elemene and germacrene B (Group III, 22/52 samples); germacrene D (Group I, 16/52 samples); β‐cubebene (Group IV, 8/52 samples) and by germacrene B and germacrene D (Group II, 6/52 samples). A special attention was brought to the quantification of the thermolabile components, germacrene A, germacrene B and germacrene C, as well as that of their rearranged compounds, β‐elemene, γ‐elemene and δ‐elemene. ¹³C‐NMR data of β‐cubebene have been provided.     

裂叶荆芥不同部位香精油组成研究

采用水蒸气蒸馏法,分别从裂叶荆芥的叶、茎和花三个不同部位提取香精油并进行气相色谱/质谱分析.结果发现,叶、茎、花的香精油分别含有23、29、26种组分.叶和花香精油的组成和含量基本相似,主要成分是含量分别为15.09%、14.51%的薄荷酮和29.26%、31.36%的(+)-胡薄荷酮等单萜化合物以及含量分别为17.09%、5.00%的α-律草烯等倍半萜.而茎香精油的萜类化合物含量较低,含薄荷酮为4.15%,(+)-胡薄荷酮为7.68%,但其乙酯含量相对较高,如(E)-9-十六碳烯酸乙酯含量为11.92%,异戊酸乙酯为9.38%.     

Ecophysiology of fire-stimulated seed germination in Cistus incanus ssp. creticus (L.) Hey wood and C. salvifolius L.

Abstract. Seed germination characteristics were investigated in the most common Cistus species in Greece, namely C. incanus ssp. creticus and C. salvifolius. In addition to the soft seed subpopulation, both species produce a large fraction of hardcoated, water-impermeable seeds which can be softened and, thus, promoted to germinate by mechanical scarification and thermal pretreatment. Temperature and light control of seed germination are unimportant. In the ecological context of the Mediterranean ecosystems, the eventually advantageous, opportunistic strategy of germination is based on: (a) seed heterospermy (which allows the smaller, softcoated fraction to germinate promptly each year while the majority of the seeds, the hard ones, accumulate in the soil); (b) the seed population heterogeneity in relation to coat hardness (so that any heat conditions produced by fire induce the softening and germination of a certain seed fraction); (c) the notably low germination rate (which suppresses premature germination); (d) the wide, Mediterranean-type (relatively cool), temperature range of germination (while higher temperatures simply inhibit but do not induce any dormancy); and (c) the apparent lack of photo-sensitivity (enabling germination under every light regime). In non-fire years, the temporal distribution of field germination and seedling appearance might be partly determined by the seed dispersal strategy of the individual Cistus species. Nevertheless, the post-fire regeneration response is manifested in the form of a huge wave of germination (of practically all seeds softened by the fire heat), shortly after the onset of the rainy season.     

Analytical Profiling of Phenolic Compounds in Extracts of Three Cistus Species from Sardinia and Their Potential Antimicrobial and Antioxidant Activity

The Cistaceae family is well represented in Sardinia, and the Cistus genus is widely used in traditional medicine. Nowadays only few studies have been performed on this genus vegetating in Sardinia in spite of its ethnobotanical importance. Moreover, in the past there have been conflicting opinions among botanists for the exact assignment of the species growing in Sardinia. We started several years ago to carried out studies on this genus and in the present study was to evaluate the in vitro activity of several samples of Cistus salvifolius L., Cistus monspeliensis L., and Cistus albidus L. collected in Sardinia as antimicrobial agents against Escherichia coli, Staphylococcus aureus, and four Candida species and their antioxidant activity using DPPH, ABTS, and FRAP assays. Furthermore, the phenolic content and composition of the extracts were first evaluated. Using statistical multivariate analysis on the complete metabolomics profile of all Cistus species growing wild in Sardinia, we confirmed the botanical classification, and we observed an interesting correlation between metabolomics profile and antioxidant activity.     

Composition and Chemical Variability of the Essential Oil from Aerial Parts of Cladanthus scariosus,an Endemic Species to the Moroccan High Atlas

Cladanthus scariosus (Ball) Oberpr. & Vogt is endemic to Moroccan High Atlas. It is known under the vernacular names Irezghi or Irezgui. Three essential oil samples have been isolated from aerial parts and analyzed by combination of chromatographic and spectroscopic techniques [gas chromatography (GC) in combination with retention indices (RI), gas chromatography-mass spectrometry (GC/MS) and ¹³C-NMR spectroscopy]. The compositions of oil samples were dominated by monoterpenes: α-pinene sabinene, and terpinen-4-ol. Chamazulene and dihydrochamazulene isomers as well as various hemiterpene esters and analogs have been identified. To evidence a chemical variability, statistical analysis performed on 13 oil sample compositions allowed partitioning into three groups, mainly differentiated by their contents of sabinene, camphor, borneol, terpinen-4-ol, and germacrene D.     

Phytochemical analysis of the labdanum-poor Cistus creticus subsp. eriocephalus (Viv.) Greuter et Burdet growing in central Italy

Phenolic constituents and essential oil from the aerial parts of Cistus creticus subsp. eriocephalus (Viv.) Greuter et Burdet growing in central Italy were analysed by HPLC-MSⁿ and GC–MS, respectively. Furthermore, six constituents were isolated by semipreparative HPLC from the methanol extract and their structures were determined on the basis of 1D and 2D NMR measurements as well as MS spectra. Isolated compounds were one new natural product, i.e. the shikimic acid ester 3,5-diihydroxy-4-(O-β-d-glucopyranosyl)-cyclohex-1-en-1-(O-β-d-glucopyranosyl)-ester (27), and six flavonoid glycosides, namely quercetin-3-O-β-D glucopyranoside (16), quercetin-3-O-rhamnoside (17), tricetin-4′-O-β-D glucopyranoside (24), tricetin-4′-O-β-D rutinoside (21), 3′-methoxy-quercetin-3-O-(3-β-Dglucopyranosyl-2-rhamnopyranosil-4-glucopyranosyl-2-rhamnopyranosil)-glucoside (25) and 3′,4′dimethoxyquercetin-3-O-rhamnopyranoside (26). GC–MS analysis of the essential oil highlighted the occurrence of aliphatic compounds, mainly fatty acids, whereas labdane-type compounds were very scant. Our results showed that C. creticus subsp. eriocephalus has a different chemical profile with respect to the other subspecies due to the lack of labdane derivatives. On the other hand, this subspecies contains several phenolic constituents like ellagitannins, gallotannins and flavonoids, some of which can be of chemotaxonomic value.     

Composition and Intraspecific Chemical Variability of Leaf Essential Oil of Laggera pterodonta from Côte d'Ivoire

The chemical composition of 44 leaf oil samples of Laggera pterodonta (DC.) Sch.Bip. ex Oliv. (Asteraceae) from Côte d'Ivoire was investigated, using combination of chromatographic (GC‐FID) and spectroscopic (GC/MS, ¹³C‐NMR) techniques. Two oil samples chosen according to their chromatographic profiles were submitted to column chromatography and all fractions of CC were analyzed by GC‐FID, GC/MS and ¹³C‐NMR. In total, 83 components accounting for 96.5 to 99.4 % of the whole chemical composition were identified. Significant variations were observed within terpene classes: monoterpene hydrocarbons (0.4–22.7 %), oxygenated monoterpenes (32.9–54.9 %), sesquiterpene hydrocarbons (18.6–38.3 %) and oxygenated sesquiterpenes (3.5–38.4 %). Thus, the 44 compositions were subjected to hierarchical cluster analysis (HCA) and principal component analysis (PCA). Two groups were differentiated according to their composition. All the samples contained 2,5‐dimethoxy‐p‐cymene, α‐humulene and (E)‐β‐caryophyllene among the main components. Other components were present at appreciable contents and allowed differentiation of two groups: sabinene and germacrene D for Group I; 10‐epi‐γ‐eudesmol and eudesm‐7(11)‐en‐4α‐ol for Group II. All the samples collected in Eastern Côte d'Ivoire constituted Group I, while samples collected in the Central area of the country constituted Group II.     

Essential Oil of Thymus munbyanus subsp. coloratus from Algeria: Chemotypification and in vitro Biological Activities

Thymus munbyanus subsp. coloratus (Lamiaceae) is a small shrub endemic to Algeria and Morocco where is found in lawns, rockeries and mountainous regions. From a phytochemical point of view this taxon has never been characterized. In this work we have analysed the chemical compositions of the essential oils obtained from inflorescences and vegetative parts by GC/MS. A new chemotype, i.e. borneol‐chemotype, was characterized for the first time in the species. Furthermore, we assessed the biological activities of essential oils, namely the antioxidant, antimicrobial and cytotoxicity on tumor cells that were evaluated by the DPPH, ABTS, and FRAP, disc diffusion, and MTT methods, respectively. Biological assays highlighted a moderate inhibitory effect on Staphylococcus aureus, Escherichia coli and Candida albicans (inhibition zone diameter in the range 9 – 10 mm), and noteworthy cytotoxicity on A375 human melanoma cells (IC₅₀ of 46.95 μg/ml).     

Chemical Composition and Biological Studies of the Essential Oil from Aerial Parts of Beta vulgaris subsp. maritima (L.) Arcang. Growing in Tunisia

The chemical composition, antioxidant, cytotoxic, anticholinesterase and anti‐tyrosinase activities of the hydrodistilled essential oil of the aerial parts of Beta vulgaris subsp. maritime (L.) Arcang . from Tunisia have been evaluated. The chemical composition of the oil (yield 0.037% [w/w]), determined by GC‐FID and GC/MS is reported for the first time. Twenty five components, accounting for 98.1% of the total oil have been identified. The oil was characterized by a high proportion of oxygenated sesquiterpenes (39.2%), followed by sesquiterpene hydrocarbons (30.3%) and one apocarotenoids (26.3%). The main compounds were γ‐irone (26.3%), α‐cadinol (12.1%), T‐cadinol (10.6%), bicyclogermacrene (10.4%) and δ‐cadinene (6.0%). The isolated oil was tested for its antioxidant activity using the DPPH^·, ABTS^+·, catalase, and paraoxonase assays and also for its cytotoxic, anticholinesterase, and anti‐tyrosinase activities. The essential oil exhibited high antioxidant activity (IC₅₀ = 0.055 ± 0.006 mg/ml) and important result oncatalase (524.447 ± 2.58 Units/mg protein). Furthermore, it exerted a significant cytotoxic effect against A549 cell line, with IC₅₀ = 42.44 ± 1.40 μg/ml. The results indicate that the essential oil of B. vulgaris subsp. maritima (L.) Arcang . aerial parts may be used in future as an alternative to synthetic antioxidant agents, with potential application in the food and pharmaceutical industries.     

苔藓Bazzania japonica挥发油的化学成分研究

采用水蒸气蒸馏法提取苔藓Bazzania japonica的挥发油,用毛细管色谱法对挥发油进行了分析,采用归一化法确定各组分的相对含量,并用GC-MS联用技术对分离的化学成分进行鉴定。经计算机检索并结合文献调研,共鉴定出38个化合物,占挥发油总量的83％,其中含2个单萜、31个倍半萜（其中11个为含氧倍半萜）和4个二萜（其中1个为含氧二萜）,主要成分为4-epi-11-nor—aristola-1（10）,11-diene（10．5％）,4-epi-11-nor-aristo-la-1,9,11-triene（6．5％）,β-caryophyllene（8．0％）,β—barbatene（7．2％）,globulol（8．8％）,aristol-1（10）-en-12-ol（9．1％）,和tridensenone（8．7％）.     

Chemical Composition of Juniperus communis L. Cone Essential Oil and Its Variability among Wild Populations in Kosovo

Ripe cones of Juniperus communis L. (Cupressaceae) were collected from five wild populations in Kosovo, with the aim of investigating the chemical composition and natural variation of essential oils between and within wild populations. Ripe cones were collected, air dried, crushed, and the essential oils obtained by hydrodistillation. The essential‐oil constituents were identified by GC‐FID and GC/MS analyses. The yield of essential oil differed depending on the population origins and ranged from 0.4 to 3.8% (v/w, based on the dry weight). In total, 42 compounds were identified in the essential oils of all populations. The principal components of the cone‐essential oils were α‐pinene, followed by β‐myrcene, sabinene, and D ‐limonene. Taking into consideration the yield and chemical composition, the essential oil originating from various collection sites in Kosovo fulfilled the minimum requirements for J. communis essential oils of the European Pharmacopoeia. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) were used to determine the influence of the geographical variations on the essential‐oil composition. These statistical analyses suggested that the clustering of populations was not related to their geographic location, but rather appeared to be linked to local selective forces acting on the chemotype diversity.     

Chemical Composition of Essential Oil from Mosses from the Brazilian Atlantic Forest

This study aimed to report the unprecedented volatile composition of the mosses Phyllogonium viride BRID, Orthotichella rigida (MÜLL.HAL.) B. H. ALLEN & MAGILL and Schlotheimia rugifolia (HOOK.) SCHWÄGR occurring in the Brazilian Atlantic Forest, in order to elucidate the chemical composition of these species and enrich the chemotaxonomic knowledge of mosses. 28 compounds were identified, the major constituent being hexadecanoic acid, also known as palmitic acid, specifically P. viride com (38.55 %), O. rigida com (17.17 %) and S. rugifolia com (24.94 %), followed by phytol, P. viride com (3.92 %), O. rigida com (28.57 %) and S. rugifolia com (36.13 %). In addition, there was a prevalence of aliphatic hydrocarbons (25 %) and fatty acids (17.8 %) in the evaluated samples. These data contribute to the generation of new scientific information about the chemical constitution of mosses, still little studied, enriching the chemotaxonomic collection of the taxon.     

Chemical Composition of Ambrosia trifida Essential Oil and Phytotoxic Effect on Other Plants

This study aimed to identify the main components of an essential oil produced from leaves of Ambrosia trifida and to evaluate its potential allelopathic effect on seed germination and seedling growth of lettuce, watermelon, cucumber and tomato. The essential oil was obtained by hydrodistillation and characterized chemically by gas chromatography (GC) coupled with both mass spectrometry (MS) and flame ionization detector (FID). Total 69 compounds were identified, with limonene (20.7 %), bornyl acetate (15.0 %), borneol (14.7 %) and germacrene D (11.6 %) as the major components. The working solutions of the essential oil emulsified with Tween 20 and dissolved in distilled water were prepared at four concentration levels (0.01, 0.1, 0.5 % and 1 %, v/v). The results obtained showed that increase in essential oil concentration leads to decrease in seed germination, as well as shoot and radical length of lettuce, watermelon, cucumber and tomato. The obtained data revealed a highly significant effect (p<0.05) between control and 1 % and 0.5 % oil concentrations in all treatments. The essential oil of A. trifida exhibited more powerful phytotoxic effects on lettuce, watermelon and tomato than on cucumber regarding germination and early seedling growth.     

Chemical Composition and in Vitro Antioxidant,Anti-Alzheimer,Anti-Diabetic,Anti-Tyrosinase,and Antimicrobial Properties of Essential Oils and Extracts Derived from Various Parts of the Algerian Calendula Suffruticosa Vahlsubsp. boissieri Lanza

Calendula suffruticosa Vahl subsp. boissieri Lanza is well-known for its medicinal properties in northeastern Algeria. As far as literature has been able to prove, no study has attempted to make a phytochemical or biological activity evaluation (antioxidants, enzyme inhibitors and antimicrobial potential). This work intends to evaluate, for the first time, the chemical constituents and study the previously mentioned biological activities of C. suffruticosa boissieri essential oil and different sections (flowers, leaves, roots) as well as the effect of changing the solvent (ethanol 70 %) and (methanol 70 %) on these activities. The essential oil of aerial parts of this plant was investigated using GC/MS, and 45 compounds were discovered, accounting for 98.01 % of the essential oil, including 23 monoterpenes, 6 sesquiterpenes, 12 diterpenes, 1 coumarin, 3 alkanes, methyl-cyclohexane (23.73 %), limonene (25.02 %), and o-cymene (13.20 %). Five methods were used to study the antioxidant activity (ABTS, DPPH, CUPRAC, reducing power, and β-carotene bleaching assay), where the results were impressive, especially for the essential oil. In addition, the hydroethanolic solvent (70 %) was found to be the most effective solvent for extraction in general compared to the hydromethanolic solvent (70 %). The extracts and essential oils of C. suffruticosa boissieri also showed a strong inhibiting ability against cholinesterase, tyrosinase, anti-α-amylase, α-glucosidase, and antimicrobials, a very valuable antioxidant, which is a real discovery. Based on these results, it can be said that this plant has important biological activities, so it can be used in the phytotherapy, food, or pharmaceutical sectors.     

玫瑰精油的化学成分及其抗菌活性

通过水蒸汽同步蒸馏法提取玫瑰精油,采用GC-MS方法分析了玫瑰精油的化学组成,共鉴定出其中14个化学成分并测定其相对含量,占总含量的95.25%。香茅醇为玫瑰精油的主要成分,相对含量为90.37%。体外抑菌实验表明,玫瑰精油除对黑曲霉没有抗菌活性外,对其它7种供试菌均具有不同程度的抑制作用,其中对表皮葡萄球菌、金黄色葡萄球菌和大肠杆菌的最小抑菌浓度(MIC)为0.063%(v/v),对枯草芽孢杆菌、变形杆菌和白色念珠菌的最小抑菌浓度（MIC）为0.125%(v/v),而对绿脓杆菌(Pseudomonas aeruginosa)的抗菌活性相对较弱,MIC为0.5%(v/v)。抑菌直径结果也表明了玫瑰精油除对黑曲霉、绿脓杆菌的抗菌活性较弱外,对其它6种菌株的抑菌直径都大于8.5 mm。考察了玫瑰精油对3种敏感菌株包括金黄色葡萄球菌(革兰氏阳性菌)、大肠杆菌(革兰氏阴性菌)和白色念珠菌(真菌)的杀菌动态过程,为玫瑰精油的应用提供了理论依据。     

燕子掌挥发油化学成分的研究

应用气象色谱-质谱联用技术对燕子掌挥发油化学成分进行了分析研究,共鉴定出66种组分与燕子掌主要挥发性化学成分以苯乙醇、2,6,6-三甲基-2,4-环庚二烯-1-酮、6,10,14-三甲基十五烷-2-酮、十六烷酸甲酯、十六烷酸乙酯、十八烷酸甲酯为主要成分,化合物类型以酮、酯、类等化合物为主,其中十六烷酸甲酯的含量最高,占挥发油总量的26．13％。     

Chemical Composition and Insecticidal Activity against Tribolium Castaneum of Thapsia garganica L. Seed Essential Oil

Due to the several side effects of synthetic pesticides, including environmental pollution, threats to human health, and the development of pest resistance to insecticides, the use of alternative healthy, available and efficient agents in pest management strategies is necessary. Recently, the use of essential oil obtained from aromatic plants has shown significant potential for insect pest management. For this reason, the essential oil isolated from seeds of Thapsia garganica L. was investigated for the first time for its chemical profile, and its toxicity and repellency effects against Tribolium castaneum adults. Qualitative and quantitative analyses of the chemical composition by gas chromatography coupled to mass spectrometry (GC/MS) revealed the presence of 18 organic volatiles representing 96.8 % of the total constituents. The main compounds were 1,4-dimethylazulene (51.3 %) followed by methyl palmitate (8.2 %), methyl linoleate (6.2 %) and costol (5.1 %). Concerning the repellent effect, results revealed that SEO (Seed Essential Oil) was very repellent towards T. castaneum adults, with 100 % repellency after 2 h of exposure. Furthermore, the essential oil exhibited remarkable contact toxicity against T. castaneum (93.3 % of mortality) at the concentration of 10 % (v/v). The median lethal dose (LD₅₀) of the topical application of the seed essential oil was 4.4 %. These encouraging outcomes suggested that the essential oil from T. garganica seeds could be considered a potent natural alternative to residual persistent and toxic insecticides.     

Tolerance and bioaccumulation of heavy metals in five populations of Cistus ladanifer L. subsp. ladanifer

The effects of heavy metals on the growth, mineral composition (P, K, Fe and Mn) and metal accumulation of five populations of Cistus ladanifer subsp. ladanifer from NE Portugal were investigated in hydroponic experiments. Plants were exposed to increasing concentrations (0–2000 M) of one of eight heavy metals: Cd, Co, Cr, Cu, Mn, Ni, Pb or Zn. Populations of C. ladanifer, whose origin was ultramafic soils (S and UB) or soils developed on basic rocks (B), showed a higher tolerance to the metals Cd, Co, Cr, and Mn, and a considerable degree of tolerance to Ni. In contrast, populations originating on acid-rock soils (M and SC) showed higher tolerance to the metals Cu and Zn. Populations showed different patterns of metal accumulation and distribution in the plant parts, suggesting different mechanisms of metal tolerance are used. The more Cd-, Co- and Mn-tolerant populations (S, UB, B and SC (Cd)) showed accumulation of these three metals in the shoots (shoot:root metal concentration ratios (S:R) > 1). Shoot concentrations of up to 309 g Cd g^–1, 2667 g Co g^–1 and 6214 g Mn g^–1 were found in these populations. The populations, UB and M, showed considerable tolerance to Ni and Zn, respectively. These populations accumulated up to 4164 g Ni g^–1 and 7695 g Zn g^–1 in their shoot tissues, and these metals were efficiently transported from the roots to aerial parts (S:R > 3 (Ni), S:R > 1 (Zn)). In contrast, the S and SC populations maintained higher growth rates in the presence of Ni and Zn, respectively, but showed exclusion mechanisms of metal tolerance: reduced Ni and Zn transport to shoots (S:R < 1). Cistus ladanifer was not able to efficiently transport Cr, Cu or Pb from its roots to its aerial parts (S:R ranged from 0–0.4). The more Cu-tolerant populations, M and SC, showed a greater restriction of Cu transport to the shoots than the ultramafic- or basic-rock populations. Significant changes in the plant mineral composition were found, however, concentrations were generally above mineral deficiency levels. Based on these preliminary results the possible usefulness of this plant for phytoremediation technologies is discussed. However, further investigations are necessary to evaluate its growth and metal accumulation under soil and field conditions.