Antitumor Properties of the Essential Oil From the Leaves of Duguetia gardneriana

Duguetia gardneriana, popularly known in the Brazilian northeast as "jaquinha", is a species belonging to the family Annonaceae. The aim of this work was to assess the chemical composition and antitumor properties of the essential oil from the leaves of D. gardneriana in experimental models. The chemical composition of the essential oil was analyzed via gas chromatography-flame ionization detector and gas chromatography-mass spectrometry. In vitro cytotoxic activity was determined in cultured tumor cells, and in vivo antitumor activity was assessed in B16-F10-bearing mice. The identified compounds were β-bisabolene (80.99%), elemicin (8.04%), germacrene D (4.15%), and cyperene (2.82%). The essential oil exhibited a cytotoxic effect, with IC50 values of 16.89, 19.16, 13.08, and 19.33 µg/mL being obtained for B16-F10, HepG2, HL-60, and K562 cell lines, respectively. On the other hand, β-bisabolene was inactive in all of the tested tumor cell lines (showing IC50 values greater than 25 µg/mL). The in vivo analysis revealed tumor growth inhibition rates of 5.37-37.52% at doses of 40 and 80 mg/kg/day, respectively. Herein, the essential oil from the leaves of D. gardneriana presented β-bisabolene as the major constituent and showed cytotoxic and antitumor potential.

A Multi-Target Approach toward the Development of Novel Candidates for Antidermatophytic Activity: Ultrastructural Evidence on α-Bisabolol-Treated Microsporum gypseum

Multi-target strategies are directed toward targets that are unrelated (or distantly related) and can create opportunities to address different pathologies. The antidermatophytic activities of nine natural skin lighteners: α-bisabolol, kojic acid, β-arbutin, azelaic acid, hydroquinone, nicotinamide, glycine, glutathione and ascorbyl tetraisopalmitate, were evaluated, in comparison with the known antifungal drug fluconazole, on nine dermatophytes responsible for the most common dermatomycoses: Microsporum gypseum, Microsporum canis, Trichophyton violaceum, Nannizzia cajetani, Trichophyton mentagrophytes, Epidermophyton floccosum, Arthroderma gypseum, Trichophyton rubrum and Trichophyton tonsurans. α-Bisabolol showed the best antifungal activity against all fungi and in particular; against M. gypseum. Further investigations were conducted on this fungus to evaluate the inhibition of spore germination and morphological changes induced by α-bisabolol by TEM.

(-)-α-Bisabolol, a Promising Oral Compound for the Treatment of Visceral Leishmaniasis

The aim of the present study was to assess the in vitro and in vivo activity of (-)-α-bisabolol (1) against the etiological agents of visceral leishmaniasis. Bone-marrow-derived macrophages were infected with Leishmania infantum or L. donovani promastigotes and incubated with (-)-α-bisabolol at different concentrations. Pentamidine isethionate and meglumine antimoniate were used as reference drugs. Inhibitory concentration 50% (IC50) and cytotoxic concentration 50% (CC50) were calculated. Balb/c mice were infected intraperitoneally with stationary-phase promastigotes. They were treated with (-)-α-bisabolol at different doses orally, meglumine antimoniate at 104 mg Sb(V)/kg, or a combination of both. (-)-α-Bisabolol proved to be innocuous to mammal cells and active against L. infantum and L. donovani intracellular amastigotes (IC50 55 and 39 μM, respectively). Compound 1 also proved to be active in an in vivo model of visceral leishmaniasis due to L. infantum, as it reduced parasite load in the spleen and liver by 71.60% and 89.22%, respectively, at 200 mg/kg without showing toxicity. (-)-α-Bisabolol (1) is a nontoxic compound that was proven to be active against visceral leishmaniasis in an in vivo murine model orally. It was more effective than meglumine antimoniate at reducing spleen parasite load and as effective as this antimonial drug in the liver.

Psychoneuropharmacological activities and chemical composition of essential oil of fresh fruits of Piper guineense (Piperaceae) in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Piper guineense Schum & Thonn (Piperaceae) is a medicinal plant used in the Southern States of Nigeria to treat fever, mental disorders and febrile convulsions.

AIMS OF THE STUDY

This study aims at determining the chemical composition and the central nervous system (CNS) activities of the essential oil obtained from the plant׳s fresh fruits in order to rationalize its folkloric use.

MATERIALS AND METHODS

Essential oil of P. guineense (EOPG) obtained by hydrodistillation was analysed by GC/MS. EOPG (50-200mg/kg, i.p.) was evaluated for behavioural, hypothermic, sedative, muscle relaxant, anti-psychotic and anticonvulsant activities using standard procedures.

RESULTS AND DISCUSSION

Analysis of the oil reveals 44 compounds of which 30 compounds constituting 84.7% were identified. The oil was characterized by sesquiterpenoids (64.4%) while only four monoterpeneoids (21.3%) were found present in the oil. Major compounds identified were β-sesquiphellandrene (20.9%), linalool (6.1%), limonene (5.8%), Z-β-bisabolene (5.4%) and α-pinene (5.3%). The EOPG (50-200mg/kg, i.p.) caused significant (p<0.01) inhibition on rearing {F(4,20)=43}, locomotor {F(4,20)=22} activity and decreased head dips in hole board {F(4,20)=7} indicating CNS depressant effect; decreased rectal temperature {F(4,20)=7-16}, signifying hypothermic activity; decreased ketamine-induced sleep latency {F(4,20)=7.8} and prolonged total sleeping time {F(4,20)=8.8}, indicating sedative effect; reduced muscular tone on the hind-limb grip test {F(4,20)=22}, inclined board {F(4,20)=4-49} and rota rod {F(4,20)=13-106}, implying muscle relaxant activity; induced catalepsy {F(4,20)=47-136}, inhibited apomorphine-induced climbing behaviour {F(4,20)=9} and inhibited apomorphine-induced locomotor {F(4,20)=16}, suggesting anti-psychotic effect; and protected mice against pentylenetetrazole-induced convulsions, indicating anticonvulsant potential.

CONCLUSION

The most abundant component of the fresh fruits essential oil of P. guineense was β-sesquiphellandrene (20.9%); and the oil possesses CNS depressant, hypothermic, sedative, muscle relaxant, antipsychotic and anticonvulsant activities, thus providing scientific basis for its ethnomedicinal applications.

Chemical Composition and Insecticidal Activity of Essential Oils from Zanthoxylum dissitum Leaves and Roots against Three Species of Storage Pests

This work aimed to investigate chemical composition of essential oils obtained from Zanthoxylum dissitum leaves and roots and their insecticidal activities against several stored product pests, namely the cigarette beetle (Lasioderma serricorne), red flour beetle (Tribolium castaneum) and black carpet beetle (Attagenus piceus). The analysis by GC-MS of the essential oils allowed the identification of 28 and 22 components, respectively. It was found that sesquiterpenoids comprised a fairly high portion of the two essential oils, with percentages of 74.0% and 80.9% in the leaves and roots, respectively. The main constituents identified in the essential oil of Z. dissitum leaves were δ-cadinol (12.8%), caryophyllene (12.7%), β-cubebene (7.9%), 4-terpineol (7.5%) and germacrene D-4-ol (5.7%), while humulene epoxide II (29.4%), caryophyllene oxide (24.0%), diepicedrene-1-oxide (10.7%) and Z,Z,Z-1,5,9,9-tetramethyl-1,4,7-cycloundecatriene (8.7%) were the major components in the essential oil of Z. dissitum roots. The insecticidal activity results indicated that the essential oil of Z. dissitum roots exhibited moderate contact toxicity against three species of storage pests, L. serricorne, T. castaneum and A. piceus, with LD₅₀ values of 13.8, 43.7 and 96.8 µg/adult, respectively.

The transcriptome of sesquiterpenoid biosynthesis in heartwood xylem of Western Australian sandalwood (Santalum spicatum)

The fragrant heartwood oil of West Australian sandalwood (Santalum spicatum) contains a mixture of sesquiterpene olefins and alcohols, including variable levels of the valuable sesquiterpene alcohols, α- and β-santalol, and often high levels of E,E-farnesol. Transcriptome analysis revealed sequences for a nearly complete set of genes of the sesquiterpenoid biosynthetic pathway in this commercially valuable sandalwood species. Transcriptome sequences were produced from heartwood xylem tissue of a farnesol-rich individual tree. From the assembly of 12,537 contigs, seven different terpene synthases (TPSs), several cytochromes P450, and allylic phosphatases were identified, as well as transcripts of the mevalonic acid and methylerythritol phosphate pathways. Five of the S. spicatum TPS sequences were previously unknown. The full-length cDNA of SspiTPS4 was cloned and the enzyme functionally characterized as a multi-product sesquisabinene B synthase, which complements previous characterization of santalene and bisabolol synthases in S. spicatum. While SspiTPS4 and previously cloned sandalwood TPSs do not explain the prevalence of E,E-farnesol in S. spicatum, the genes identified in this and previous work can form a basis for future studies on natural variation of sandalwood terpenoid oil profiles.

Antitumor Properties of the leaf essential oil of Zornia brasiliensis

Zornia brasiliensis, popularly known as "urinária", "urinana", and "carrapicho", is a medicinal plant used in Brazilian northeast folk medicine as a diuretic and against venereal diseases. The aim of this study was to investigate the chemical composition and antitumor potential of the leaf essential oil of Z. brasiliensis. The essential oil was obtained by hydrodistillation using a Clevenger-type apparatus and analyzed by GC-MS and GC-FID. Its composition was characterized by the presence of trans-nerolidol, germacrene D, trans-caryophyllene, α-humulene, and farnesene as major constituents. In vitro cytotoxicity of the essential oil and some of its major constituents (trans-nerolidol, trans-caryophyllene, and α-humulene) was evaluated for tumor cell lines from different histotypes using the Alamar blue assay. The essential oil, but not the constituents tested, presented promising cytotoxicity. Furthermore, mice inoculated with B16-F10 mouse melanoma were used to confirm its in vivo effectiveness. An in vivo antitumor study showed tumor growth inhibition rates of 1.68-38.61 % (50 and 100 mg/kg, respectively). In conclusion, the leaf essential oil of Z. brasiliensis presents trans-nerolidol, germacrene D, trans-caryophyllene, α-humulene, and farnesene as major constituents and is able to inhibit cell proliferation in cultures as well as in tumor growth in mice.

[Analysis of Volatile Oils from Different Processed Products of Zingiber officinale Rhizome by GC-MS]

OBJECTIVE

To analyze the volatile components in different processed products of Zingiber officinale rhizome, and to make clear the effect of different heating degree on them.

METHODS

The volatile components were extracted from four kinds of processed products by applying steam distillation, and then were analyzed by GC-MS.

RESULTS

There were totally 43 components of volatile oil identified from four kinds of processed products of Zingiber officinale rhizome. Fresh product, dried product, and charcoal product of Zingiber officinale rhizome each had 27 components of volatile oil, while sand fried product contained 24 components. Fresh Zingiber officinale rhizome contained 22. 59% of zingiberene, 20. 87% of a-citral and 11. 01% of β-phellandrene, respectively. After processing in different heating degree, the volatile components changed greatly in both of their quantity and quality, For instance, dried Zingiber officinale rhizome contained 40. 48% of α-citral and 8-phellandrene content was slightly lower at 10. 38%. 32.73% of 3,7,11-trimethyl-l, 6, 10-dodecatriene,16. 38% of murolan-3, 9 (11)-diene-10-peroxy and 3. 36% of cubebene newly emerged in the sand fried Zingiber officinale rhizome, and eudesm-4 (14) and β-bisabolol, etc. However, β-phellandrene content was only 1. 95%. The zingiberene and β-sesquiphellandrene were the highest in charcoal product, besides, new components such as α-cedrene, decanal and γ-elemene appeared.

CONCLUSION

Volatile components in different processed products of Zingiber officinale rhizome were different in both of their kinds and contents. This method is suitable for the analysis of volatile components in Zingiber officinale rhizome, and this study can provide the experimental evidence for quality evaluation and clinical application for ginger processed products.

[Volatile Oil Analysis of Piper hongkongense form Different Hatbitats by GC-MS]

OBJECTIVE

To analyze the volatile oil in Piper hongkongense from five different habitats.

METHODS

The volatile oil was analyzed by GC-MS.

RESULT

The volatile components oil of each sample varied significantly. Caryophyllene, α-caryophyllene and nerolidol 2 were common constituents of five samples. The volatile oil and chemical constituent contents of fresh sample were higher than that of the old sample.

CONCLUSION

The volatile oil and chemical constituent contents of Piper hongkongense from different habitats have sig- nificant differences, which are affected by habitats, harvest season, storage time and so on.

Morphological Changes in the Overall Mycobacterium tuberculosis H37Ra Cell Shape and Cytoplasm Homogeneity due to Mutellina purpurea L. Essential Oil and Its Main Constituents

OBJECTIVE

The aim of this study was to evaluate the antimycobacterial activity of the essential oil (EO) of Mutellina purpurea L. and its main constituents against the M. tuberculosis H37Ra strain.

MATERIALS AND METHODS

The M. purpurea EO was obtained by hydrodistillation, while its main constituents were purchased. The minimal inhibitory concentration values were determined by the log2 dilution method. Visualization of the effects of the tested substances on M. tuberculosis was performed using a transmission electron microscope (TEM). Mathematical shape descriptors such as area, circularity, aspect ratio and roundness were calculated to describe morphological changes in bacterial cell shape.

RESULTS

The EO of M.purpurea and all substances tested in this experiment showed a significant antimycobacterial activity. The most active was α-pinene followed by bisabolol and myrcene (8, 16 and 32 µg/ml, respectively). The EO and limonene exhibited the same antimicrobial activity (64 µg/ml). The TEM images and shape descriptors showed significant changes in the overall tuberculosis cell shape and cytoplasm homogeneity (uniformity and consistency)

CONCLUSIONS

In this study, the low molecular weight compounds of mono- and sesquiterpenes penetrated/destabilized the complex mycobacterial cell wall and decreased its viability. There is a need for further experiments to explain the mechanism of action of these small particles.

[Cloning, prokaryotic expression, and functional identification of a sesquiterpene synthase gene (AsSS4) from Aquilaria sinensis]

A sesquiterpene synthase (AsSS4) full-length open reading frame (ORF) cDNA was cloned from wounded stems of Aquilaria sinensis by RT-PCR method. The result showed that the ORF of AsSS4 was 1,698 bp encoding 565 amino acids. Prokaryotic expression vector pET28a-AsSS4 was constructed and transformed into E. coli BL21 (DE3) pLysS. Recombinant AsSS4 protein was obtained after induction by IPTG and SDS-PAGE analysis with a MW of 64 kD. Enzymatic reactions using farnesyl pyrophosphate showed that recombinant AsSS4 protein purified by Ni-agarose gel yielded five sesquiterpene compounds, cyclohexane, 1-ethenyl-1-methyl-2, 4-bis(1-methylethenyl)-, β-elemene, α-guaiene, α-caryophyllene and δ-guaiene. This paper reported the first cloning and functional characterization of AsSS4 gene from A. sinensis, which will establish a foundation for future studies on the molecular mechanisms of wound-induce agarwood formation in A. sinensis

Compositional variability and antifungal potentials of ocimum basilicum, O. tenuiflorum, O. gratissimum and O. kilimandscharicum essential oils against Rhizoctonia solani and Choanephora cucurbitarum

The composition of hydrodistilled essential oils of Ocimum basilicum L. (four chemovariants), O. tenuiflorum L., O. gratissimum L., and O. kilimandscharicum Guerke were analyzed and compared by using capillary gas chromatography (GC/FID) and GC-mass spectrometry (GC/MS). Phenyl propanoids (upto 87.0%) and monoterpenoids (upto 83.3%) were prevalent constituents distributed in the studied Ocimum taxa. The major constituents of the four distinct chemovariants of O. basilicum were methyl chavicol (86.3%), methyl chavicol (61.5%)/linalool (28.6%), citral (65.9%); and linalool (36.1%)/citral (28.8%). Eugenol (66.5% and 78.0%) was the major constituent of O. tenuiflorum and O. gratissimum. Eugenol (34.0%), β-bisabolene (15.4%), (E)-α-bisabolene (10.9%), methyl chavicol (10.2%) and 1,8-cineole (8.2%) were the major constituents of O. kilimandscharicum. In order to explore the potential for industrial use, the extracted essential oils were assessed for their antifungal potential through poison food technique against two phytopathogens, Rhizoctonia solani and Choanephora cucurbitarum, which cause root and wet rot diseases in various crops. O. tenuiflorum, O. gratissimum, and O. kilimandscharicum exhibited complete growth inhibition against R. solani and C. cucurbitarum after 24 and 48 h of treatment. O. basilicum chemotypes showed variable levels of growth inhibition (63.0%-100%) against these two phytopathogens.

The First Humulene Type Sesquiterpene from Lactarius hirtipes

A new sesquiterpene of humulene type, named 2β, α-epoxy-6Z, 9Z-humuladien-8α-ol (1) together with a known compound lactarinic acid was isolated from the fruiting bodies of Lactarius hirtipes. Their structures were established on the basis of spectral evidence (MS, IR, NMR, HMBC, HMQC, 1H-1H COSY, ROSEY experiments). Compound 1 was found as the first humulene-type sesquiterpene in higher fungi.

Zerumbone Suppresses Phorbol Ester-Induced Expression of Multiple Scavenger Receptor Genes in THP-1 Human Monocytic Cells

Unregulated uptake of oxidized low-density lipoproteins (ox-LDL) via macrophage scavenger receptors (SRs), such as lectin-like ox-LDL receptor-1 (LOX-1), is a key event in atherosclerosis. In the present study, we used differentiated Caco-2 cells as a model of the human small intestine to evaluate the suppressive effects of 16 traditional food items selected from Okinawa on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced LOX-1 mRNA expression in THP-1 human monocyte-like cells. Three Zingiberaceae plants, Curcuma aromatica Salisbury, Curcuma longa L., and Zingiber zerumbet Smith, markedly suppressed that expression. When added to the apical sides of Caco-2 monolayers, zerumbone, a sesquiterpene from Z. zerumbet Smith, was found to permeate into the basolateral medium as an intact structure in a time-dependent manner. alpha-Humulene, a structural analog of zerumbone lacking the alpha,beta-unsaturated carbonyl group, did not suppress LOX-1 mRNA expression, indicating that its electrophilic moiety might play pivotal roles in its activities. Further, zerumbone attenuated the expression of SR-A, SR-PSOX, and CD36, but not that of CD68 or CLA-1, leading to a blockade of DiI-acLDL uptake, while it also inhibited the transcriptional activities of activator protein-1 and nuclear factor-kappaB. Together, our results indicate that zerumbone is a potential phytochemical for regulating atherosclerosis with reasonable action mechanisms.

Analysis of Perilla nankinensis decne essential oil using gas chromatography coupled with time-of-flight mass spectrometry

Perilla is the genus of herbaceous plants of Lamiaceae family. The essential oil of Perilla is believed to be essential part of the herb. It was claimed to have anti-inflammatory, anti-hyperlipidemia, antioxidative and antimicrobial activities. Apart from pharmaceutical and nutrition purposes, It is an edible plant frequently used as a fresh vegetable. It was also applied to produce perfume and cosmetics. Due to the importance of the essential oil from the P. nanakinensis and the lack of detailed studies of them, our work aimed investigation of contents of essential compositions by GC- TOF/MS method. The materials of the study were the aerial parts of P. nankinesis collected at full flowering stage, Guria Region, Georgia. A qualitative analysis of the individual compounds in P. nankinensis essential oil performed by gas chromatography (GC) coupled with time-of-flight mass spectrometer (TOF/MS) for the identification of the resolved peaks. 28 components, which accounted for 77,7% of the oil, were identified. The main components of this essential oil were 1,3,6,10-Dodecatetraene, 3,7,11-trimethyl-, (Z,E)- (α-Farnesene) (34.3%), Caryophyllene oxide (10.2%), 1,6-Octadien-3-ol, 3,7-dimethyl- (linalool) (10.2%). Essential oil also contained humulene (3.9%),caryophyllene (1.9%), methyl salicilate (1.15%), 2-hexanoylfuran (1.0%), gernacrene (1.1%). Based on the results of our experimental data and literature reviews, Perilla essential oil can represent special interest and can be used as an important natural substance for obtaining medicinal and preventive products with the several biological activities.

New humulenes from Hyptis incana (Labiatae)

Two new humulene-type sesquiterpenes, named hyptishumulene I (1) and II (2), have been isolated, together with eight known compounds, a humulene-type sesquiterpene (3), a monoterpene (4) and six abietane-type diterpenoids (5-10) from the aerial parts of Hyptis incana (Labiatae). The cytotoxic activity of the isolated compounds against mouse leukemia cells (L1210) was examined. The abietane-type diterpenoids (5-10) showed rather potent growth inhibitory activity (IC50<15 microM), while the new humulene-type compounds (1 and 2) exhibited moderate activity (IC50>50 microM).

Synthesis, photostability and bioactivity of 2,3-cyclopropanated abscisic acid

The plant hormone abscisic acid (ABA) plays a central role in the regulation of plant development and adaptation to environmental stress. The isomerization of ABA to the biologically inactive 2E-isomer by light considerably limits its applications in agricultural fields. To overcome this shortcoming, an ABA analogue, cis-2,3-cyclopropanated ABA, was synthesized, and its photostability and biological activities were investigated. This compound showed high photostability under UV light exposure, which was 4-fold higher than that of (±)-ABA. cis-2,3-cyclopropanated ABA exhibited high ABA-like activity, including the ability to effectively inhibit seed germination, seedling growth and stomatal movements of Arabidopsis. In some cases, its bioactivity approaches that of (±)-ABA. trans-2,3-cyclopropanated abscisic acid was also prepared, an isomer that was more photostable but which showed weak ABA-like activity.

Isolation and characterization of terpene synthases in cotton (Gossypium hirsutum)

Cotton plants accumulate gossypol and related sesquiterpene aldehydes, which function as phytoalexins against pathogens and feeding deterrents to herbivorous insects. However, to date little is known about the biosynthesis of volatile terpenes in this crop. Herein is reported that 5 monoterpenes and 11 sesquiterpenes from extracts of a glanded cotton cultivar, Gossypium hirsutum cv. CCRI12, were detected by gas chromatography-mass spectrometry (GC-MS). By EST data mining combined with Rapid Amplification of cDNA Ends (RACE), full-length cDNAs of three terpene synthases (TPSs), GhTPS1, GhTPS2 and GhTPS3 were isolated. By in vitro assays of the recombinant proteins, it was found that GhTPS1 and GhTPS2 are sesquiterpene synthases: the former converted farnesyl pyrophosphate (FPP) into β-caryophyllene and α-humulene in a ratio of 2:1, whereas the latter produced several sesquiterpenes with guaia-1(10),11-diene as the major product. By contrast, GhTPS3 is a monoterpene synthase, which produced α-pinene, β-pinene, β-phellandrene and trace amounts of other monoterpenes from geranyl pyrophosphate (GPP). The TPS activities were also supported by Virus Induced Gene Silencing (VIGS) in the cotton plant. GhTPS1 and GhTPS3 were highly expressed in the cotton plant overall, whereas GhTPS2 was expressed only in leaves. When stimulated by mechanical wounding, Verticillium dahliae (Vde) elicitor or methyl jasmonate (MeJA), production of terpenes and expression of the corresponding synthase genes were induced. These data demonstrate that the three genes account for the biosynthesis of volatile terpenes of cotton, at least of this Upland cotton.

Identification and characterization of (E)-β-caryophyllene synthase and α/β-pinene synthase potentially involved in constitutive and herbivore-induced terpene formation in cotton

Cotton (Gossypium hirsutum L.) plants damaged by insects emit a blend of volatiles, including monoterpenes and sesquiterpenes, which can directly repel herbivores and/or indirectly protect the plant by attracting natural enemies of the herbivores. To understand the molecular basis of terpene biosynthesis and regulation in cotton, two terpene synthase genes, GhTPS1 and GhTPS2, were heterologously expressed and characterized. Recombinant GhTPS1 accepted farnesyl pyrophosphate as substrate and produced (E)-β-caryophyllene and α-humulene. GhTPS2 was characterized as a monoterpene synthase which formed α-pinene and β-pinene using geranyl pyrophosphate as substrate. Quantitative real-time PCR analysis revealed that GhTPS1 and GhTPS2 gene expression was elevated after methyl jasmonate (MeJA) treatment in cotton leaves. Moreover, feeding of the green plant bug Apolygus lucorum, a major cotton pest in northern China, resulted in increased GhTPS2 expression in young leaves, suggesting that GhTPS2 might be involved in plant defense in cotton.

Hydroxylated bisabolol oxides: evidence for secondary oxidative metabolism in Matricaria chamomilla

German chamomile (Matricaria chamomilla) is one of the most popular medicinal plants used in Western herbal medicine. Among the various phytochemicals present in the essential oil of the flowers of German chamomile, bisabolol and its oxidized metabolites are considered as marker compounds for distinguishing different chemotypes. These compounds are influential in mediating the aroma of the essential oil of M. chamomilla and contribute to the therapeutic properties (anti-inflammatory, antibacterial, insecticidal, and antiulcer) of this species. In order to find other possible bisabolol derivatives as marker compounds for authentication of German chamomile in botanical and commercial products, an in-depth investigation using a GC-assisted fractionation procedure was performed on nonpolar fractions. As a result of this approach, three new hydroxylated derivatives of bisabolol oxides A and B (1-3) have been isolated from M. chamomilla. Plausible biogenetic pathways are presented.

Chemical composition and biological activities of essential oils of Eremanthus erythropappus (DC) McLeisch (Asteraceae)

The chemical composition of the essential oils obtained by hydrodistillation of different parts of Eremanthus erythropappus, including leaves, branches and inflorescences, was investigated by Gas Chromatography and Gas Chromatography/Mass Spectrometry. The antimicrobial activity of the oils was assessed by the disc diffusion and microdilution methods, while the antioxidant activity was evaluated by DPPH and reducing power tests. The main compounds found in the essential oils derived from the inflorescences and leaves were β-caryophyllene, germacrene-D, α-copaene and β-pinene. α-Bisabolol was the major component in the branches. The oils were active against Staphylococcus aureus, Streptococcus pyogenes and fungi, but not Escherichia coli and Pseudomonas aeruginosa. The MIC values ranged from 0.01 to 0.50 mg/mL. Using the DPPH test, the IC₅₀ values ranged from 38.77 ± 0.76 to 102.24 ± 1.96 μg/mL, while the reducing power test produced IC₅₀ values between 109.85 ± 1.68 and 169.53 ± 0.64 μg/mL. The results revealed that the E. erythropappus oils are new promising potential sources of antimicrobial and antioxidant compounds with good future practical applications for human health.

Use of hydrodistillation and headspace solid-phase microextraction to characterize the volatile composition of different hop cultivars

BACKGROUND

Hop cones, the immature inflorescences of the female plant of Humulus lupulus L., have been used for centuries to improve the flavor of beer and can be also used for a great variety of other products. Four samples of hop, belonging to three different cultivars (Nugget, Saaz and Perle), were studied in the present work. Headspace solid-phase microextraction and hydrodistillation techniques were used to obtain the volatile profiles of the samples.

RESULTS

Independent of the technique employed, over 40 volatile compounds were detected in the hop pellet samples (esters, monoterpenes, monoterpenoids, sesquiterpenes and sesquiterpenoids). Sesquiterpenes and sesquiterpenoids represented the majority of the total aromatic compounds. The main compounds for all cultivars were myrcene, β-caryophyllene and humulene, but the presence of high amounts of β-farnesene in Saaz cultivar was highlighted.

CONCLUSION

Both techniques were suitable for studying qualitatively the volatile composition of hop pellets, but some differences were shown when studying the proportion of the main constituents of the volatile profiles. Understanding these differences may help researchers design future studies to advise the industry how to exploit the potential of each hop cultivar.

Cytosolic monoterpene biosynthesis is supported by plastid-generated geranyl diphosphate substrate in transgenic tomato fruits

Geranyl diphosphate (GPP), the precursor of most monoterpenes, is synthesized in plastids from dimethylallyl diphosphate and isopentenyl diphosphate by GPP synthases (GPPSs). In heterodimeric GPPSs, a non-catalytic small subunit (GPPS-SSU) interacts with a catalytic large subunit, such as geranylgeranyl diphosphate synthase, and determines its product specificity. Here, snapdragon (Antirrhinum majus) GPPS-SSU was over-expressed in tomato fruits under the control of the fruit ripening-specific polygalacturonase promoter to divert the metabolic flux from carotenoid formation towards GPP and monoterpene biosynthesis. Transgenic tomato fruits produced monoterpenes, including geraniol, geranial, neral, citronellol and citronellal, while exhibiting reduced carotenoid content. Co-expression of the Ocimum basilicum geraniol synthase (GES) gene with snapdragon GPPS-SSU led to a more than threefold increase in monoterpene formation in tomato fruits relative to the parental GES line, indicating that the produced GPP can be used by plastidic monoterpene synthases. Co-expression of snapdragon GPPS-SSU with the O. basilicum α-zingiberene synthase (ZIS) gene encoding a cytosolic terpene synthase that has been shown to possess both sesqui- and monoterpene synthase activities resulted in increased levels of ZIS-derived monoterpene products compared to fruits expressing ZIS alone. These results suggest that re-direction of the metabolic flux towards GPP in plastids also increases the cytosolic pool of GPP available for monoterpene synthesis in this compartment via GPP export from plastids.

The active natural anti-oxidant properties of chamomile, milk thistle, and halophilic bacterial components in human skin in vitro

The number of skin cancers continues to rise, accounting for approximately 40% of all cancers reported in the United States and approximately 9,500 deaths per year. Studies have shown reactive oxygen species (ROS) type free radicals are linked to skin cancer and aging. Therefore, it is important for us to identify agents that have anti-oxidant properties to protect skin against free radical damage. The purpose of this research is to investigate the anti-oxidant properties of bisabolol, silymarin, and ectoin that are components from chamomile, milk thistle, and halophilic bacteria, respectively. We measured the ability of bisabolol, silymarin, and ectoin to modulate the hydrogen peroxide (H2O2)-induced upregulation of ROS free radicals in normal human skin fibroblasts in vitro. Using a flow cytometry-based assay, we demonstrated that varying concentrations of these natural components were able to inhibit upregulation of H2O2-generated free radicals in human skin fibroblasts in vitro. Our results indicate components of chamomile, milk thistle, and halophilic bacteria exhibit anti-oxidant capabilities and warrant further study in clinical trials to characterize their anti-cancer and anti-aging capabilities.

Genetically engineered maize plants reveal distinct costs and benefits of constitutive volatile emissions in the field

Genetic manipulation of plant volatile emissions is a promising tool to enhance plant defences against herbivores. However, the potential costs associated with the manipulation of specific volatile synthase genes are unknown. Therefore, we investigated the physiological and ecological effects of transforming a maize line with a terpene synthase gene in field and laboratory assays, both above- and below ground. The transformation, which resulted in the constitutive emission of (E)-β-caryophyllene and α-humulene, was found to compromise seed germination, plant growth and yield. These physiological costs provide a possible explanation for the inducibility of an (E)-β-caryophyllene-synthase gene in wild and cultivated maize. The overexpression of the terpene synthase gene did not impair plant resistance nor volatile emission. However, constitutive terpenoid emission increased plant apparency to herbivores, including adults and larvae of the above ground pest Spodoptera frugiperda, resulting in an increase in leaf damage. Although terpenoid overproducing lines were also attractive to the specialist root herbivore Diabrotica virgifera virgifera below ground, they did not suffer more root damage in the field, possibly because of the enhanced attraction of entomopathogenic nematodes. Furthermore, fewer adults of the root herbivore Diabrotica undecimpunctata howardii were found to emerge near plants that emitted (E)-β-caryophyllene and α-humulene. Yet, overall, under the given field conditions, the costs of constitutive volatile production overshadowed its benefits. This study highlights the need for a thorough assessment of the physiological and ecological consequences of genetically engineering plant signals in the field to determine the potential of this approach for sustainable pest management strategies.