Neo-clerodane diterpenoids from Baccharis macraei

Two new neo-clerodane diterpenes, hautriwaic acid acetate and 4β-hydroxyisobacchasmacranone, were isolated from the aerial parts of Baccharis macraei. The structures of the new compounds were elucidated by spectroscopic methods. The structure of hautriwaic acid acetate was confirmed by correlation with its known deacetyl derivative, hautriwaic acid.     

Non-trichothecenes from baccharis megapotamica

A large scale extract of Baccharis megapotamic has yielded small quantities of several known compounds (2,6-dimethoxybenzoquinone, scopoletin and clovandiol) and a new natural product, megapodiol.     

Ent-Labdanes from Baccharis Sternbergiana

The aerial parts of Baccharis sternbergiana afforded six new ent-labdane derivatives, while those of a Baccharis tricuneata subspecies gave 12-acetoxytremetone.     

Diterpenes from Baccharis species

The aerial parts of Baccharis minutiflora afforded in addition to known compounds eight new ent-kaurane derivatives, one being a homo kaurane, while the aerial parts of B. alatemoides gave two pairs of epimeric clerodane derivatives, which, however, had to be modified chemically before they could be separated. The stereochemistry of these diterpenes could not be elucidated with certainty.     

Neo-clerodane diterpenoids from baccharis incarum

Five new neo-clerodane diterpenoids were isolated from Baccharis incarum. Their structures were established by spectroscopic methods.     

Furanediterpenes from Baccharis thymifolia

From the aerial part of Baccharis thymifolia two new furanediterpenoids have been isolated besides previously know flavonoids. The structure of thymifodioic acid and 17-acetoxymethylthymifodioic acid, were established by spectroscopic data and chemical transformations.     

Neo-clerodane diterpenoids from Baccharis incarum

A new neo-clerodane diterpenoid was isolated from the aerial parts of Baccharis incarum together with the previously known diterpenoids bacchalineol and barticulidiol.     

Kingidiol,a kolavane derivative from Baccharis kingii

The aerial parts of Baccharis kingii afforded quercetin 3,3′-dimethyl ether and a new diterpene closely related to hautriwaic acid. Structure and     

Characterization of three sect. Caulopterae species (Baccharis-Asteraceae) inferred from morphoanatomy, polypeptide profiles and spectrophotometry data

There are still controversies regarding differentiation between Baccharis species (sect. Caulopterae). In the present work, we compare three species: Baccharis articulata, Baccharis gaudichaudiana and Baccharis trimera, emphasising the importance of anatomy, polypeptide profiles and ultraviolet–visible spectrophotometry as taxonomic characters, utilizing multivariate analysis. Seventy-two populations of the three species were examined. The first two principal components of morphoanatomical data gathered relevant information to classify species (61% of the total variability), with the largest contribution from the stomata density variable (2.105). PCoorA based on protein analysis enabled separation of the species with the first two principal coordinates (67.20% of the total variability). Regarding spectrophotometrical data, the second and third principal components only separated B. trimera from the rest (22.7% of total variability).     

Batudioic acid and flavonoids from Baccharis tucumanensis

Batudioic acid, a new labdane type diterpene, was isolated from aerial parts of Baccharis tucumanensis. Its structure was determined by spectral analysis and some chemical transformations. Xan- thomicrol and scutellarein-7,4′-dimethyl ether were also isolated.     

A diterpene acid from baccharis tucumanensis

The new clerodane diterpene 1 was isolated from the aerial parts of Baccharis tucumanensis (Compositae). Its structure has been determined from spectral data combined with chemical transformations.     

Comparative responses of a non-N-fixing shrub and an actinorhizal N-fixing shrub to N fertilization

Background and aims

Variations in responses to soil N between a non-N-fixing shrub, Baccharis halimifolia L., and a N-fixing shrub, Morella cerifera (L.) Small, were tested over 12 weeks to determine whether N availability is the sole cause of persistent dominance of M. cerifera on barrier islands.

Methods

Plants were supplied increasing levels of soil N up to 200 mg kg^?1. Measurements included gas exchange and chlorophyll fluorescence parameters across treatments, species, and time. Tissues were analyzed for differences in biomass and nutrients.

Results

Baccharis halimifolia had reduced physiological responses across all treatment levels, but M. cerifera had comparatively few variations. Across all treatments B. halimifolia photosynthesis and stomatal conductance were reduced by 62 and 76 %, respectively,by week 12. Increasing foliar δ¹⁵N values across treatments for M. cerifera indicated a shift from utilizing fixed N to available soil N. Biomass was highest at 200 mg kg^?1 N for both species. Baccharis halimifolia showed indications of stress response and resource limitation based on physiological responses, nutrient contents, and isotope effects.

Conclusions

Baccharis halimifolia showed signs of co-limitation of both N and P whereas M. cerifera was limited by neither, suggesting that dominance of M. cerifera is only partially explained by actinorhizal symbiosis and N availability.     

Anti-listerial activity of plant essential oils from western region of Argentina

Listeria monocytogenes is an important foodborne pathogen due to the severity of infection with a high mortality rate. In the past few years, there has been an increase in the use of naturally derived compounds such as plant extracts or essential oils as antimicrobials in food. The objective of the present study was to determine the antimicrobial effect of theFlourensia oolepis, Baccharis salicifolia, andArtemisia echegarayi essential oils on fourteen strains ofL. monocytogenes, by the disk diffusion method. The results indicate that the essential oils tested could potentially be used to inhibitL. monocytogenes, but appropriate applications in food should be validated.     

Flavonoids from four compositae species

The isolation of umbelliferone from Eupatorium angustifolium, of alnustin, 5,7,8-trimethoxyflavone, 7-hydroxy-3,5,8-trimethoxyflavone and 3,5,7,8-tetramethoxyflavone from Achyrocline satureoides var. albicans; of cirsimaritin from Baccharis eleagnoides; and of genkwanin from Symphyopappus polystachyus is reported.     

Chemical,Antioxidant, and Antimicrobial Evaluation of Essential Oils and an Anatomical Study of the Aerial Parts from Baccharis Species (Asteraceae)

The aim of this study was to evaluate the chemical, antioxidant, and antimicrobial activity of the essential oils as well as the anatomy of the aerial parts from Baccharis aracatubaensis, Baccharis burchellii, and Baccharis organensis owing to the therapeutic potential of Baccharis. The volatile constituents were analyzed using GC/MS, the antioxidant activity was evaluated by oxygen radical absorbance capacity (ORAC_FL) and DPPH assays, and the antimicrobial activity by a microdilution technique. Of the 56 compounds identified, only seven (β‐caryophyllene, γ‐muurolene, bicyclogermacrene, β‐germacrene, spathulenol, τ‐muurolol, and α‐cadinol) were common in the three specimens studied. Of these, γ‐muurolene was found abundantly in B. aracatubaensis, while bicyclogermacrene was abundant in B. burchellii and B. organensis. The essential oils exhibited antioxidant activity in the ORAC_FL (>500.0 μmol TE g^?1) and DPPH assays. However, they did not exhibit any antimicrobial activity. Secretory ducts and flagelliform glandular trichomes were observed in the anatomical study of all the Baccharis species studied.     

Tres adiciones al genero Baccharis (Compositae) en Mexico

1. -Bigelowia pyramidata Rob. & Greenm. from Oaxaca proves to be a dioecious plant and is therefore transferred to the genusBaccharis.
2. -Baccharis matudae sp. nov. is described on the basis of material collected in Zacatecas and San Luis Potosí. The species is closely related toB. pyramidata (Rob. & Greenm.) Rzedowski.
3. -Baccharis zamoranensis sp. nov. is described on the basis of material collected on the border of Querétaro and Guanajuato. The taxon is related toB. multiflora H.B.K., known from central and southern Mexico.

     

A new dwarf shrubby species of <Emphasis Type="Italic">Baccharis</Emphasis> subg. <Emphasis Type="Italic">Baccharis</Emphasis> (Asteraceae,Astereae) from southeastern Brazil

Baccharis dichotoma, a new dwarf shrubby species, with small leaves and few heads, of high-altitude grasslands from southeastern Brazil, is described, illustrated, and assigned to subgenus Baccharis.     

Unipartite and bipartite mycorrhizal networks of Abies religiosa forests: Incorporating network theory into applied ecology of conifer species and forest management

Abies religiosa's forests are severely endangered as a result of climate change; to save this species and its biological interactions, population assisted migration is discussed in forest management, but not in the microbial ecology field. Our objectives were to analyze its mycorrhizal networks; and, with this data, to identify potential facilitator plants and it's most important mycorrhizal fungal links. This information could be used together in assisted migration programs to connect Abies religiosa saplings to their mycorrhizal network and improve their field establishment. We collected 47 rhizosphere samples from 19 plant species and sequenced their fungal ITS2 region by Illumina. In the whole fungal community, 464 species were mycorrhizal fungi with assigned guild (32%). In this subset, 85 fungi are arbuscular, 365 ectomycorrhizal and 14 from orchid-mycorriza. The Abies religiosa bipartite network is low nested and highly modular, and has a scale-free architecture. Besides Abies religiosa, the plants with the largest degree and the lowest average shortest path were Salix paradoxa, Muhlenbergia spp., and Baccharis conferta. The most important fungal nodes are species of Cortinarius, Genea, Rhodoscypha, Russula, and Tomentella. We suggest to evaluate the Abies' future establishment in the following scheme: in the first year reintroduce Muhlenbergia spp., and Baccharis conferta, in the second year Salix paradoxa, and in the third year–once the mycorrhizal network is reestablished– Abies religiosa' saplings in close proximity of these plants. This scheme is proposed using the data and network analyses of the present study.     

New C9-polyacetylenes from the essential oil of the highly endangered species Baccharis palustris Heering (Asteraceae)

The essential oil composition of the aerial parts from Baccharis palustris Heering (Asteraceae), a highly endangered species, was analyzed by GC/qMS, GC/HRMS-TOF, FT-IR, UV–vis and NMR spectroscopy using 1D and 2D techniques. To our knowledge, this is the first report on the essential oil composition of B. palustris, as well as the first phytochemical study on this plant species. The volatile extracts were obtained from different phenologicals stages of plant, at flowering stage (FS) and vegetative stage (VS), where 51 components were identified accounting for 96.3 % and 99.0 % of the oil, respectively. The oil was rich in polyacetylene compounds (> 75 %), being the main components identified the new natural C₉-polyacetylenes 1-nonene-3,5-diyne (1, here named as baccharisdiyne) (52.7–65.0 %), 1,7(Z)-nonadiene-3,5-diyne [2, 7(Z)-dehydro-baccharisdiyne] (14.4–17.8 %), and 1,7(E)-nonadiene-3,5-diyne [3, 7(E)-dehydro-baccharisdiyne] (1.5–2.4 %). In addition, the known polyacetylenic compounds (Z)-lachnophyllum acid methyl ester (4) (4.3–5.3 %) and (E)-lachnophyllum acid methyl ester (5) (0.2 %) were also identified. Moreover, GC/qMS analysis allowed the identification of other 46 components in the essential oil samples, mainly mono- and sesquiterpenoids. In B. palustris, C₉-polyacetylenes probably derive biogenetically from a C₁₀ precursor: baccharisdiyne (1) would be derived from either or both lachnophyllum methyl ester geometric isomers (4 or 5), by enzymatic hydrolysis followed by decarboxylation. Dehydro-baccharisdiynes (2 and 3) could be produced by a similar pathway starting from the corresponding matricaria acid methyl ester isomers, one of which was tentatively identified at trace-level in B. palustris essential oil.     

Antifungal properties of a plant extract I. Source and spectrum of antimicrobial activity

Batamote (Baccharis glutinosa Pers.), a plant native to the south-western desert of the United States has been recommended in local folklore for the therapy of athlete's foot (tinea pedis). An aqueous extract of the dried powdered leaves of this plant has been shown to inhibit dermatophytesin vitro. Further purification studies are in progress.