Synthesis and Biological Evaluation of 3,5‐Dimethoxystilbene Analogs

In our continuing effort to discover natural product‐based pest management agents, derivatives of 3,5‐dimethoxystilbene were synthesized yielding 27 new and six known compounds. Compounds 11 and 12 showed strong Aedes aegypti larvicidal activity (LC₅₀ 45.31 and 49.93 μm , respectively). Furthermore, 11 and 12 exhibited high effectiveness against larvae of pesticide‐susceptible and pyrethroid‐resistant strains of Ae. aegypti; activity against the adult mosquitoes was low. Compounds 6f , 6g , and 6i at either 83.3 or 166.7 μg/ml reduced the mobility of second‐stage juveniles (J2) of the root‐knot nematode (Meloidogyne incognita) that hatched from eggs immersed in the test compounds for 7 days. However, there was little or no effect on J2 placed directly into these compounds, and none of the analogs suppressed M. incognita egg hatch. The compounds were tested for inhibition of some agriculturally important fungi; 6a , 7a , and 7e demonstrated strong inhibition of Colletotrichum species. Activity of the stilbenes against some human pathogens was also explored; 11 , 12 , and 16 showed moderate inhibitory activity against Cryptococcus neoformans, Staphylococcus aureus, methicillin‐resistant S. aureus, and Mycobacterium intracellulare. Except for 11 and 12 , which were active against mosquito larvae and some human pathogens, no single analog demonstrated activity in all the tests, indicating specific activities. Synthesis of the analogs and structure–activity relationships are discussed.     

Iridoids from Pedicularis verticillata and Their Anti‐Complementary Activity

Three new iridoids named as pediverticilatasin A – C ( 1 – 3 , resp.), together with five known iridoids ( 4 – 8 , resp.) were isolated from the whole plants of Pedicularis verticillata. The structures of three new compounds were identified as (1S,7R)‐1‐ethoxy‐1,5,6,7‐tetrahydro‐7‐hydroxy‐7‐methylcyclopenta[c]pyran‐4(3H)‐one ( 1 ), (1S,4aS,7R,7aS)‐1‐ethoxy‐1,4a,5,6,7,7a‐hexahydro‐7‐hydroxy‐7‐methylcyclopenta[c]pyran‐4‐carboxylic acid ( 2 ), (1S,4aS,7R,7aS)‐1‐ethoxy‐1,4a,5,6,7,7a‐hexahydro‐7‐hydroxy‐7‐methylcyclopenta[c]pyran‐4‐carbaldehyde ( 3 ). Their structures were elucidated on the basis of spectroscopic methods and compared with the NMR spectra data in the literature. All compounds were evaluated for their anti‐complementary activity on the classical pathway of the complement system in vitro. Among which, compounds 1 , 3 , and 6 exhibited anti‐complementary effects with CH₅₀ values ranging from 0.43 to 1.72 mm , which are plausible candidates for developing potent anti‐complementary agents.     

Variation in Essential Oil and Bioactive Compounds of Curcuma kwangsiensis Collected from Natural Habitats

The chemical compositions of essential oils (EOs) extracted from Curcuma kwangsiensis rhizomes collected from six natural habitats in P. R. China were evaluated using gas chromatography/mass spectrometry (GC/MS). Fifty‐seven components were identified from the six EOs, and their main constituents were 8,9‐dehydro‐9‐formyl‐cycloisolongifolene (2.37 – 42.59%), germacrone (6.53 – 22.20%), and l ‐camphor (0.19 – 6.12%). The six EOs exhibited different DPPH radical‐scavenging activities (IC₅₀, 2.24 – 31.03 μg/ml), with the activity of most of EOs being much higher than that of Trolox C (IC₅₀, 10.49 μg/ml) and BHT (IC₅₀, 54.13 μg/ml). Most EOs had potent antimicrobial effects against the tested bacteria and fungus. They also exhibited cytotoxicity against B16 (IC₅₀, 4.44 – 147.4 μg/ml) and LNCaP cells (IC₅₀, 73.94 – 429.25 μg/ml). The EOs showed excellent anti‐inflammatory action by significantly downregulating expression of pro‐inflammatory cytokines, cyclooxygenase‐2, and tumor necrosis factor‐α. This study provides insight into the interrelation among growth location, phytoconstituents, and bioactivities, and the results indicate the potential of C. kwangsiensis as natural nutrients, medicines, and others additives.     

Larvicidal Activity of Essential Oils of Five Apiaceae Taxa and Some of Their Main Constituents Against Culex quinquefasciatus

Apiaceae are aromatic herbs producing essential oils which are used on an industrial scale for various purposes. Notably, Apiaceae essential oils may replace synthetic insecticides keeping most of their efficacy and avoiding environmental pollution and human poisoning. In the present work, we explored the insecticidal potential of the essential oils from five Apiaceae taxa, namely Sison amomum, Echinophora spinosa, Heracleum sphondylium subsp. sphondylium, Heracleum sphondylium subsp. ternatum, and Trachyspemum ammi, as well as their major constituents (sabinene, p‐cymene, terpinolene, myristicin, and thymol), against the filariasis vector Culex quinquefasciatus. For the purpose, the essential oils were obtained by hydrodistillation and their composition was achieved by gas chromatography/mass spectrometry (GC/MS). Their acute toxicity on third instar larvae of C. quinquefasciatus was determined. The two most active essential oils were those from T. ammi fruits and E. spinosa roots, showing LC₅₀ below 20 μl/l and LD₉₀ below 50 μl/l. These oils were dominated by the monoterpene phenol thymol and the phenylpropanoid myristicin, respectively, which showed the strongest larvicidal activity (LC₅₀ of 15.1 and 16.3 μl/l, respectively) among the pure compounds tested. These results showed that Apiaceae may be useful as source of larvicidal compounds to be used for the development of cheap, effective and eco‐friendly insecticidal formulations.     

Uncovering Biological Application of Brazilian Green Propolis: A Phenotypic Screening against Schistosoma mansoni

The chemotherapy of schistosomiasis remains centered in the use of praziquantel, however, there has been growing resistant parasites to this drug. Thus, the aim of this work was to evaluate in vitro schistosomicidal activity of the hexanes/dichloromethane 1 : 1 extract of Brazilian green propolis (Pex), as well as its major isolated compounds artepillin C, caffeic acid, coumaric acid and drupanin against Schistosoma mansoni. The Pex was active by displaying an IC₅₀ value of 36.60 (26.26–51.13) μg mL^?1 at 72 h against adult worms of S. mansoni. The major isolated compounds were inactive with IC₅₀ values >100 μM, however, the combination of the isolated compounds (CM) in the same range found in the extract was active with an IC₅₀ value of 41.17 (39.89–42.46) μg mL^?1 at 72 h. Pex and CM induced alteration in the tegument of S. mansoni, and caffeic acid caused alteration in egg's maturation. Pex displayed in vitro activity against adult worms’ and eggs’ viability of S. mansoni, which opens new perspectives to better understand the synergistic and/or additive effects promoted by both Pex extract and CM against schistosomiasis features.     

Toxicity of Thiophenes from Echinops transiliensis (Asteraceae) against Aedes aegypti (Diptera: Culicidae) Larvae

Structure? activity relationships of nine thiophenes, 2,2′: 5′,2″‐terthiophene ( 1 ), 2‐chloro‐4‐[5‐(penta‐1,3‐diyn‐1‐yl)thiophen‐2‐yl]but‐3‐yn‐1‐yl acetate ( 2 ), 4‐(2,2′‐bithiophen‐5‐yl)but‐3‐yne‐1,2‐diyl diacetate ( 3 ), 4‐[5‐(penta‐1,3‐diyn‐1‐yl)thiophen‐2‐yl]but‐3‐yne‐1,2‐diyl diacetate ( 4 ), 4‐(2,2′‐bithiophen‐5‐yl)‐2‐hydroxybut‐3‐yn‐1‐yl acetate ( 5 ), 2‐hydroxy‐4‐[5‐(penta‐1,3‐diyn‐1‐yl)thiophen‐2‐yl]but‐3‐yn‐1‐yl acetate ( 6 ), 1‐hydroxy‐4‐[5‐(penta‐1,3‐diyn‐1‐yl)thiophen‐2‐yl]but‐3‐yn‐2‐yl acetate ( 7 ), 4‐(2,2′‐bithiophen‐5‐yl)but‐3‐yne‐1,2‐diol ( 8 ), and 4‐[5‐(penta‐1,3‐diyn‐1‐yl)thiophen‐2‐yl]but‐3‐yne‐1,2‐diol ( 9 ), isolated from the roots of Echinops transiliensis, were studied as larvicides against Aedes aegypti. Structural differences among compounds 3, 5 , and 8 consisted in differing AcO and OH groups attached to C(3″) and C(4″), and resulted in variations in efficacy. Terthiophene 1 showed the highest activity (LC₅₀, 0.16 μg/ml) among compounds 1 – 9 , followed by bithiophene compounds 3 (LC₅₀, 4.22 μg/ml), 5 (LC₅₀, 7.45 μg/ml), and 8 (LC₅₀, 9.89 μg/ml), and monothiophene compounds 9 (LC₅₀, 12.45 μg/ml), 2 (LC₅₀, 14.71 μg/ml), 4 (LC₅₀, 17.95 μg/ml), 6 (LC₅₀, 18.55 μg/ml), and 7 (LC₅₀, 19.97 μg/ml). These data indicated that A. aegypti larvicidal activities of thiophenes increase with increasing number of thiophene rings, and the most important active site in the structure of thiophenes could be the tetrahydro‐thiophene moiety. In bithiophenes, 3, 5 , and 8 , A. aegypti larvicidal activity increased with increasing number of AcO groups attached to C(3″) or C(4″), indicating that AcO groups may play an important role in the larvicidal activity.     

Variation on Composition and Bioactivity of Essential Oils of Four Common Curcuma Herbs

Chemical compositions, antioxidative, antimicrobial, anti‐inflammatory, and cytotoxic activities of essential oils extracted from four common Curcuma species (Curcuma longa, Curcuma phaeocaulis, Curcuma wenyujin, and Curcuma kwangsiensis) rhizomes in P. R. China are comparatively studied. In total, 47, 49, 35, and 30 compounds are identified in C. longa, C. phaeocaulis, C. wenyujin, and C. kwangsiensis essential oils by GC/MS, and their richest compounds are ar‐turmerone (21.67%), elemenone (19.41%), curdione (40.23%) and (36.47%), respectively. Moreover, C. kwangsiensis essential oils display the strongest DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) radical‐scavenging activity (IC₅₀, 3.47 μg/ml), much higher than ascorbic acid (6.50 μg/ml). C. phaeocaulis oils show the best antibacterial activities against Escherichia coli (MIC, 235.54 μg/ml), Pseudomonas aeruginosa (391.31 μg/ml) and Staphylococcus aureus (378.36 μg/ml), while C. wenyujin and C. kwangsiensis oils show optimum activities against Candida albicans (208.61 μg/ml) and Saccharomyces cerevisiae (193.27 μg/ml), respectively. C. phaeocaulis (IC₅₀, 4.63 μg/ml) and C. longa essential oils (73.05 μg/ml) have the best cytotoxicity against LNCaP and HepG2, respectively. C. kwangsiensis oils also exhibit the strongest anti‐inflammatory activities by remarkably down‐regulating expression of COX‐2 and TNF‐α. Therefore, due to their different chemical compositions and bioactivities, traditional Chinese Curcuma herbs should be differentially served as natural additives for food, pharmaceutical, and cosmetic.     

Phytochemical Study of the Genus Salpichroa (Solanaceae), Chemotaxonomic Considerations,and Biological Evaluation in Prostate and Breast Cancer Cells

Twelve Salpichroa taxa have been phytochemically analyzed. From the aerial parts of S. scandens, four known salpichrolides A, C, I, S, and an unreported withanolide named salpichrolide V ( 1 ), were isolated. In S. dependens, S. gayi, S. glandulosa subsp. glandulosa, S. glandulosa subps. weddellii, S. leucantha, S. micrantha, S. microloba, S. proboscidea, S. ramosissima, S. tristis var. tristis, and S. weberbauerii, no withanolides were found. The chemical content of ca. 85% of the Salpichroa taxa is in agreement with molecular studies, which suggest that Salpichroa and Jaborosa, a genus considered morphologically close to Salpichroa, are distant in the systematic of the Solanoideae subfamily. Moreover, the in vitro cytotoxic activity of a set of natural salpichrolides and derivatives was examined against two prostate carcinoma cell lines (PC3 and LNCaP) and two human breast cancer cell lines (MCF‐7 and T47D). Several compounds showed moderate activity (IC₅₀ = 64.91 – 29.97 μm ).     

Elevated CO2 did not affect the hydrological balance of a mature native Eucalyptus woodland

Elevated atmospheric CO₂ concentration (eC_a) might reduce forest water‐use, due to decreased transpiration, following partial stomatal closure, thus enhancing water‐use efficiency and productivity at low water availability. If evapotranspiration (E_t) is reduced, it may subsequently increase soil water storage (ΔS) or surface runoff (R) and drainage (D_g), although these could be offset or even reversed by changes in vegetation structure, mainly increased leaf area index (L). To understand the effect of eC_a in a water‐limited ecosystem, we tested whether 2 years of eC_a (~40% increase) affected the hydrological partitioning in a mature water‐limited Eucalyptus woodland exposed to Free‐Air CO₂ Enrichment (FACE). This timeframe allowed us to evaluate whether physiological effects of eC_a reduced stand water‐use irrespective of L, which was unaffected by eC_a in this timeframe. We hypothesized that eC_a would reduce tree‐canopy transpiration (E_tree), but excess water from reduced E_tree would be lost via increased soil evaporation and understory transpiration (E_floor) with no increase in ΔS, R or D_g. We computed E_t, ΔS, R and D_g from measurements of sapflow velocity, L, soil water content (θ), understory micrometeorology, throughfall and stemflow. We found that eC_a did not affect E_tree, E_floor, ΔS or θ at any depth (to 4.5 m) over the experimental period. We closed the water balance for dry seasons with no differences in the partitioning to R and D_g between C_a levels. Soil temperature and θ were the main drivers of E_floor while vapour pressure deficit‐controlled E_tree, though eC_a did not significantly affect any of these relationships. Our results suggest that in the short‐term, eC_a does not significantly affect ecosystem water‐use at this site. We conclude that water‐savings under eC_a mediated by either direct effects on plant transpiration or by indirect effects via changes in L or soil moisture availability are unlikely in water‐limited mature eucalypt woodlands.     

Chemical Components from Phaeanthus vietnamensis and Their Inhibitory NO Production in BV2 Cells

Phaeanthus vietnamensis Bân is a well‐known medicinal plant which has been used for the treatment of various inflammatory diseases in traditional medicine. Using various chromatographic methods, three new compounds, (7S,8R,8′R)‐9,9′‐epoxy‐3,5,3′,5′‐tetramethoxylignan‐4,4′,7‐triol ( 1 ), 8α‐hydroxyoplop‐11(12)‐en‐14‐one ( 5 ), and (1R,2S,4S)‐4‐acetyl‐2‐[(E)‐(cinnamoyloxy)]‐1‐methylcyclohexan‐1‐ol ( 12 ) along with twelve known compounds were isolated from the leaves of P. vietnamensis. Their chemical structures were elucidated by physical and chemical methods. All compounds were evaluated for the inhibitory activities of nitric oxide production in LPS‐stimulated BV2 cells. As the results, compound 6 showed the most potent inhibitory activity on LPS‐stimulated NO production in BV2 cells with the IC₅₀ values of 15.7 ± 1.2 μm . Compounds 2 , 7 , and 8 significantly inhibited inflammatory NO production with IC₅₀ values ranging from 22.6 to 25.3 μm .     

Chemical Composition and Behavioral Effects of Five Plant Essential Oils on the Green Pea Aphid Acyrthosiphon pisum (Harris) (Homoptera: Aphididae)

Essential oils (EOs) from Schinus molle, Helichrysum gymnocephalum, Cedrelopsis grevei and Melaleuca viridiflora, four aromatic and medicinal plants, are commonly used in folk medicine. EOs were characterized by gas chromatography/mass spectrometry (GC/MS) and quantified by gas chromatography‐flame ionization detection (GC‐FID); then evaluated for their behavioral effects on adults of the green pea aphid Acyrthosiphon pisum (Harris ) using a Perspex four‐armed olfactometer in order to test the compatibility of their use as phytoinsecticides to control this insect pest. Our results showed that the EOs from the leaves of S. molle, M. viridiflora and C. grevei did not change aphids’ behavior. However, S. molle fruits EO seemed to be attractive while H. gymnocephalum leaves EO exhibited repellency towards aphids at a dose of 10 μl. The major compounds in S. molle fruits EO were 6‐epi‐shyobunol (16.22%) and d ‐limonene (15.35%). While, in H. gymnocephalum leaves EO, 1,8‐cineole was the main compound (47.4%). The difference in aphids’ responses to these two EOs could be attributed to the differences in their compositions. Our findings suggest that these two EOs have potential applications for the integrated pest management of A. pisum (Harris ).     

Chemotaxonomic Considerations of the n‐Alkane Composition in Pinus heldreichii,P. nigra,and P. peuce

The n‐alkane composition in the leaf cuticular waxes of natural populations of Bosnian pine (Pinus heldreichii), Austrian pine (P. nigra), and Macedonian pine (P. peuce) was compared for the first time. The range of n‐alkanes was wider in P. nigra (C₁₆ – C₃₃) than in P. heldreichii and P. peuce (C₁₈ – C₃₃). Species also diverged in abundance and range of dominant n‐alkanes (P. heldreichii: C₂₃, C₂₇, and C₂₅; P. nigra: C₂₅, C₂₇, C₂₉, and C₂₃; P. peuce: C₂₉, C₂₅, C₂₇, and C₂₃). Multivariate statistical analyses (PCA, DA, and CA) generally pointed out separation of populations of P. nigra from populations of P. heldreichii and P. peuce (which were, to a greater or lesser extent, separated too). However, position of these species on the basis of n‐alkane composition was in accordance neither with infrageneric classification nor with recent molecular and terpene investigations.     

Cis-diastereoselectivity in pictet-spengler reactions of L-tryptophan and electronic circular dichroism studies

The diastereoselective synthesis of optically active 1,3‐disubstituted tetrahydro‐β‐carbolines using polar protic Pictet–Spengler cyclization of (S)‐tryptophan methyl ester with five aldehydes RCHO (R═CH₃, C₂H₅, C₃H₇, C₄H₉, and C₆H₅) was studied. As an alternate route, the cyclization of (S)‐tryptophan with the same aldehydes and subsequent methylation of the resulting tetrahydro‐β‐carboline carboxylic acids were also performed for comparison. ¹³C NMR and electronic circular dichroism (ECD) studies and time‐dependent density functional theory ECD calculations data established the relative 1,3 cis/trans and the absolute configuration (1S,3S/ 1R,3S) of the synthesized compounds. The solid‐state and solution ECD study of the prepared compounds, supported by ECD calculation and X‐ray data, afforded a reliable ECD method for the configurational assignment of 1,3‐disubstituted tetrahydro‐β‐carbolines and revealed the stereochemical factors that determine the characteristic ECD data. Chirality 24:789–795, 2012. © 2012 Wiley Periodicals, Inc.     

Chemical Composition,Antibacterial, Schistosomicidal,and Cytotoxic Activities of the Essential Oil of Dysphania ambrosioides (L.) Mosyakin & Clemants (Chenopodiaceae)

We have investigated the chemical composition and the antibacterial activity of the essential oil of Dysphania ambrosioides (L.) Mosyakin & Clemants (Chenopodiaceae) (DA‐EO) against a representative panel of cariogenic bacteria. We have also assessed the in vitro schistosomicidal effects of DA‐EO on Schistosoma mansoni and its cytotoxicity to GM07492‐A cells in vitro. Gas chromatography (GC) and gas chromatography‐mass spectrometry (GC/MS) revealed that the monoterpenes cis‐piperitone oxide (35.2%), p‐cymene (14.5%), isoascaridole (14.1%), and α‐terpinene (11.6%) were identified by as the major constituents of DA‐EO. DA‐EO displayed weak activity against Streptococcus sobrinus and Enterococcus faecalis (minimum inhibitory concentration (MIC) = 1000 μg/ml). On the other hand, DA‐EO at 25 and 12.5 μg/ml presented remarkable schistosomicidal action in vitro and killed 100% of adult worm pairs within 24 and 72 h, respectively. The LC₅₀ values of DA‐EO were 6.50 ± 0.38, 3.66 ± 1.06, and 3.65 ± 0.76 μg/ml at 24, 48, and 72 h, respectively. However, DA‐EO at concentrations higher than 312.5 μg/ml significantly reduced the viability of GM07492‐A cells (IC₅₀ = 207.1 ± 4.4 μg/ml). The selectivity index showed that DA‐EO was 31.8 times more toxic to the adult S. mansoni worms than GM07492‐A cells. Taken together, these results demonstrate the promising schistosomicidal potential of the essential oil of Dysphania ambrosioides.     

Elevated CO2 affects photosynthetic responses in canopy pine and subcanopy deciduous trees over 10 years: a synthesis from Duke FACE

Leaf responses to elevated atmospheric CO₂ concentration (C_a) are central to models of forest CO₂ exchange with the atmosphere and constrain the magnitude of the future carbon sink. Estimating the magnitude of primary productivity enhancement of forests in elevated C_a requires an understanding of how photosynthesis is regulated by diffusional and biochemical components and up‐scaled to entire canopies. To test the sensitivity of leaf photosynthesis and stomatal conductance to elevated C_a in time and space, we compiled a comprehensive dataset measured over 10 years for a temperate pine forest of Pinus taeda, but also including deciduous species, primarily Liquidambar styraciflua. We combined over one thousand controlled‐response curves of photosynthesis as a function of environmental drivers (light, air C_a and temperature) measured at canopy heights up to 20 m over 11 years (1996–2006) to generate parameterizations for leaf‐scale models for the Duke free‐air CO₂ enrichment (FACE) experiment. The enhancement of leaf net photosynthesis (A_net) in P. taeda by elevated C_a of +200 μmol mol^?1 was 67% for current‐year needles in the upper crown in summer conditions over 10 years. Photosynthetic enhancement of P. taeda at the leaf‐scale increased by two‐fold from the driest to wettest growing seasons. Current‐year pine foliage A_net was sensitive to temporal variation, whereas previous‐year foliage A_net was less responsive and overall showed less enhancement (+30%). Photosynthetic downregulation in overwintering upper canopy pine needles was small at average leaf N (N_area), but statistically significant. In contrast, co‐dominant and subcanopy L. styraciflua trees showed A_net enhancement of 62% and no A_net–N_area adjustments. Various understory deciduous tree species showed an average A_net enhancement of 42%. Differences in photosynthetic responses between overwintering pine needles and subcanopy deciduous leaves suggest that increased C_a has the potential to enhance the mixed‐species composition of planted pine stands and, by extension, naturally regenerating pine‐dominated stands.     

Four New Tirucallane Triterpenoids from the Fruits of Melia azedarach and Their Cytotoxic Activities

Four new tirucallane triterpenoids, (21S,23R,24R)‐21,23‐epoxy‐21,24‐dihydroxy‐25‐methoxytirucall‐7‐en‐3‐one ( 2 ), (3S,21S,23R,24S)‐21,23‐epoxy‐21,25‐dimethoxytirucall‐7‐ene‐3,24‐diol ( 8 ), (21S,23R,24R)‐21,23‐epoxy‐24‐hydroxy‐21‐methoxytirucalla‐7,25‐dien‐3‐one ( 11 ), and (21S,23R,24R)‐21,23‐epoxy‐21,24‐dihydroxytirucalla‐7,25‐dien‐3‐one ( 12 ), along with 16 known analogues, 1 , 3  –  7 , 9  –  10 , and 13  –  20 , were isolated from the fruits of Melia azedarach. Their structures were elucidated by spectroscopic methods including 1D‐ and 2D‐NMR techniques and mass spectrometry. These compounds were evaluated for their cytotoxicities against HepG2 (liver), SGC7901 (stomach), K562 (leukemia), and HL60 (leukemia) cancer cell lines. Compound 20 exhibited potent cytotoxicity against HepG2 and SGC7901 cancer cells with the IC₅₀ values of 6.9 and 6.9 μm , respectively.     

Insecticidal Activity of the Leaf Essential Oil of Peperomia borbonensis Miq. (Piperaceae) and Its Major Components against the Melon Fly Bactrocera cucurbitae (Diptera: Tephritidae)

The essential oil from the leaves of Peperomia borbonensis from Réunion Island was obtained by hydrodistillation and characterized using GC‐FID, GC/MS and NMR. The main components were myristicin (39.5%) and elemicin (26.6%). The essential oil (EO) of Peperomia borbonensis and its major compounds (myristicin and elemicin), pure or in a mixture, were evaluated for their insecticidal activity against Bactrocera cucurbitae (Diptera: Tephritidae) using a filter paper impregnated bioassay. The concentrations necessary to kill 50% (LC₅₀) and 90% (LC₉₀) of the flies in three hours were determined. The LC₅₀ value was 0.23 ± 0.009 mg/cm² and the LC₉₀ value was 0.34 ± 0.015 mg/cm² for the EO. The median lethal time (LT₅₀) was determined to compare the toxicity of EO and the major constituents. The EO was the most potent insecticide (LT₅₀ = 98 ± 2 min), followed by the mixture of myristicin and elemicin (1.4:1) (LT₅₀ = 127 ± 2 min) indicating that the efficiency of the EO is potentiated by minor compounds and emphasizing one of the major assets of EOs against pure molecules.     

Two New Ergosterol Derivatives from the Basidiomycete Cortinarius glaucopus

Two new sterols 1 and 2 and five known ones 3 – 7 were isolated for the first time from the fruiting bodies of Cortinarius glaucopus. Their structures were established by 1‐ and 2D‐NMR spectra and HR‐FABS‐MS. The relative configuration of 1 was firmly determined by comparison of the observed ¹H–¹H couplings and NOESY correlations, with those predicted for the computed geometries of the conformers. Calculations were performed by means of DFT with the B3LYP functional at 6‐31 + G(d,p) level of theory, in CHCl₃ as the solvent. The structures of the new ergosterol derivatives, called glaucoposterol A ( 1 ) and B ( 2 ), were thus established as (3S,5R,7R,10R,13R,17R,20S,22R,23R,24R)‐5,6‐epoxy‐3,7,23‐trihydroxystrophast‐8‐en‐14‐one and (22E,3S,5S,9S,10R,13R,17R,20R,24R)‐3,5‐dihydroxyergosta‐6,8(14),22‐trien‐15‐one, respectively. Moreover, the configuration of known strophasterol C ( 3 ) was determined as (3S,5R,6S,7R,10R,13R,17R,20S,22S,24R). Glaucoposterol A ( 1 ) and strophasterol C ( 3 ) represent the second finding in nature of steroids with the rare strophastane skeleton.     

Geographically Related Variation in Epicuticular Wax Traits of Pinus nigra Populations from Southern Carpathians and Central Balkans – Taxonomic Considerations

The chemical composition of epicuticular waxes of nine populations from three Pinus nigra J. F. Arnold subspecies (namely subsp. nigra, subsp. banatica (Borbás ) Novák , and subsp. pallasiana (Lamb .) Holmboe ) from Southern Carpathians and central Balkan Peninsula were analyzed using GC/MS and GC/FID chromatography, and multivariate statistical techniques with respect to biogeography and taxonomy. In the needle waxes, four primary alcohols and 14 n‐alkanes ranging from C₂₁ to C₃₃ were identified, and the most abundant compounds were the four odd‐numbered n‐alkanes C₂₇, C₂₅, C₂₃, and C_29. Multivariate statistical analyses (CDA and CA) have shown existence of three P. nigra groups and suggested clinal differentiation as a mechanism of genetic variation across a geographic area: the first group consisted of the southernmost populations of subsp. pallasiana from Macedonia, the second consisted of the northernmost subsp. banatica populations from Romania, while all populations in Serbia described as three different subspecies (nigra, banatica, and pallasiana) formed the third group together with subsp. nigra population from Bosnia and Herzegovina. According to simple linear regression, geographic latitude and four bioclimatic parameters were moderately correlated with the contents of epicuticular wax compounds that are important in population discrimination, while stepwise multiple regression showed that latitude participated in most of the regression models for predicting the composition of the epicuticular waxes. These results agree with CDA and CA analysis, and confirmed the possibility of recognition of fine geographic differentiation of the analyzed P. nigra populations.     

Chemical Constituents of the Rare Cliff Plant Oresitrophe rupifraga and Their Antineuroinflammatory Activity

Four new ( 1 – 4 ) and thirteen known ( 5 – 17 ) compounds were isolated from a rare cliff plant, Oresitrophe rupifraga. Based on spectroscopic evidence, the new structures were established to be [(2S,3R,4R)‐4‐(4‐methoxybenzyl)‐2‐(4‐methoxyphenyl)‐tetrahydrofuran‐3‐yl]methanol ( 1 ), (3α)‐23‐(acetyloxy)‐3‐hydroxyolean‐12‐en‐29‐oic acid ( 2 ), 3α,23‐(isopropylidenedioxy)olean‐12‐en‐29‐oic acid ( 3 , artifact of isolation), and (3β,15β)‐3‐hydroxycholest‐5‐en‐15‐yl β‐d ‐glucopyranoside ( 4 ), respectively. Among the isolates, compounds 1 , 4 , epieudesmin ( 7 ), and 1‐O‐(9Z,12Z,15Z‐octadecatrienoyl)glycerol ( 17 ) were found to show significant antineuroinflammatory effects by inhibiting the NO production in lipopolysaccharide (LPS)‐stimulated murine BV‐2 microglial cells, with IC₅₀ values of 7.21, 9.39, 4.96, and 8.51 μm , respectively.