Composition and Antibacterial Activity of the Essential Oils of Four Commercial Grades of Omani Luban,the Oleo‐Gum Resin of Boswellia sacra Flueck.

The essential oil compositions of four botanically certified and commercially available samples of Omani lubans (oleo‐gum resins of Boswellia sacra Flueck .), locally known as Hoojri, Najdi, Shathari, and Shaabi in Jibali Arabic, obtained from plants growing in four different geographic locations of the Dhofar region of Oman, were analyzed by GC‐FID, GC/MS, and ¹³C‐NMR spectroscopy. The market price of these four grades of lubans differed considerably, according to their color, clump size, and texture. However, this study revealed that Hoojri, the first grade luban, and Shaabi, the fourth grade luban, which greatly differed in their price, closely resembled each other in their essential oil composition, yield, and physicochemical characteristics, except the color and texture. The composition, yield, and specific rotation of the oils of Najdi and Shathari, the second and the third grade lubans, respectively, were different from those of Hoojri and Shaabi, but they both had high limonene contents. Najdi oil was different from the other three oils in terms of its high myrcene content. α‐Pinene was the principal component in all the oils and can be considered as a chemotaxonomical marker that confirms the botanical and geographical source of the resins. All the oils showed pronounced activity against a panel of bacteria, and the trend in their bioactivity and their mode of action are discussed.     

Stand structure of the emergent conifer Agathis ovata in forest and maquis, Province Sud, New Caledonia

Abstract. The size structure of the endemic New Caledonian conifer Agathis ovata is reported for sample stands in forest and maquis from three areas on ultramafic substrates in the south of the main island (Grand Terre). In closed forest Agathis ovata is typically represented by a low density of emergent adult trees with only limited evidence of seedling recruitment. In maquis, Agathis ovata is represented by individuals of all sizes, with seedlings and saplings abundant in most sample stands. Preliminary evidence from tree-ring studies indicates that rings may be annual. Estimated diameter growth rate is about 2 mm y^?1 for trees ≥ 10 cm d.b.h., and ring counts suggest tree ages of up to 400 years in maquis and 500 years in forest. Agathis ovata, and three other members of the Araucariaceae found in New Caledonia (Araucaria laubenfelsii, A. montana and A. rulei), are the only tree species which regularly occur scattered in maquis in this way, creating an unusual structural assemblage. No angiosperm tree species show this behaviour. The circumstances under which the Agathis ovata– maquis stands arise and are maintained are the subject of further investigation. Preliminary evidence for tree ages indicates that these stands predate European arrival in New Caledonia and so are not the result of recent increases in the frequency and intensity of human disturbances. The presence of fire scars on many individuals, and location of most stands on slopes and spurs with outcropping laterite (cuirasse), suggests that this assemblage may owe its existence to the interplay of fire regime, topography and rockiness, and a resistance to fire in Agathis ovata which increases with plant size and age.     

Frankincense Revisited,Part I: Comparative Analysis of Volatiles in Commercially Relevant Boswellia Species

The genus Boswellia comprises many species which are famous for their production of frankincense, a fragrant gum resin. In the published literature, manifold studies on the volatiles and semivolatiles in individual samples of these gum resins exist, yet very few studies have investigated multiple samples. Contradictory results with regard to the volatile composition exist in literature. In this first part of the study, a large sample set (n = 46) of mostly commercially obtained gum resins and essential oils was investigated by solid‐phase microextraction gas chromatography/mass spectrometry. A total of 216 compounds were identified or tentatively identified from the four commercially relevant species, namely B. sacra, B. serrata, B. papyrifera, and B. frereana, and the statistical evaluation of the resulting chemical profiles allowed a clear distinction between the species by their volatile profile. With only few exceptions, the designated species was found to be in accordance with the composition reported in reliable literature sources and detected in botanically identified samples. Chemotaxonomic marker substances were suggested to facilitate the differentiation of commercial gum resins or essential oils based on their volatile profile.     

Fourier transform IR study of aggregational behavior of N-acetyl-L- and N-butyloxycarbonyl-L-glutamic acid oligomeric benzyl esters in dioxane and benzene: beta-turn --> antiparallel beta-sheet transition

Resins from several different genera are studied using Fourier transform (FT)-Raman spectroscopy. Tree resins can be broadly divided into those that contain diterpenoid components and those that contain triterpenoid components. The diterpenoid resins analyzed are from the genera Pinus, Cedrus, and Agathis (kauri resin) and the triterpenoid resins examined are samples from Pistacia, Boswellia (frankincense), and Commiphora (myrrh) genera. A protocol is developed to nondestructively distinguish diterpenoid and triterpenoid resins and to differentiate the genera within the two types. The effects of oxidation on the discrimination of the FT-Raman spectra are considered.     

13C NMR and IR analyses of structure,aging and botanical origin of Dominican and Mexican ambers

¹³C NMR analysis of Oligocene amber from the Dominican Republic, Oligo-Miocene amber from Mexico and trunk resins from certain extant species of Hymenaea, suggests a polylabdane structure for all and gives insights into structural changes during aging. Additionally, IR spectra, some aspects of the ¹³C NMR spectra and paleobotanical data suggest a close relationship between Dominican amber and H. verrucosa. By contrast, spectral evidence shows that Mexican amber differs, not only from the former polymers, but from the H. courbaril polymer.     

Pollen analysis of Atlantic forest honey from the Vale do Ribeira Region,state of São Paulo,Brazil

The pollen contents of 34 Apis mellifera honey samples from the Quilombola Community of Porto Velho (Vale do Ribeira, state of São Paulo, Brazil) were studied in order to identify their botanical and geographical origin. A total number of 114 pollen types distributed in 43 families were identified. Fabaceae pollen types were the most diverse (20). Dominant pollen was observed in 27 samples. The dominant type Piper was found in 21 samples and Zanthoxylum, Mikania cordifolia, Cupania oblongifolia, Cecropia, Attalea and Poaceae only in one sample. The quantitative analysis revealed a predominance of very-high pollen concentrations in the samples (Category IV, 35.3%). A second frequency of occurrence analysis revealed 67 pollen types from 26 botanical families from nectariferous species. Fabaceae was also the family with the largest number of nectariferous pollen types (15), followed by Sapindaceae, Asteraceae (six pollen types each), and Euphorbiaceae (five types). Dominant pollen occurred in 19 samples. The main nectariferous sources of pollen in the present study were: Arecaceae (Attalea and Euterpe/Syagrus), Asteraceae (Mikania cordifolia), Fabaceae (Machaerium), Rutaceae (Zanthoxylum), and Sapindaceae (Cupania oblongifolia). The honey was classified as predominantly heterofloral (67.6%). Monofloral honey from Mikania cordifolia, Machaerium, Zanthoxylum, Cupania oblongifolia, Euterpe/Syagrus and Attalea were also identified. The geographical origin demonstrates Apis mellifera using nectariferous sources available from the Atlantic Rainforest in the south and southeast of Brazil, as well as in the brushwood, secondary forest and field plants. This is one of the first works about melissopalynology in the Vale do Ribeira Region.     

Biosynthèse de la cellulose bacterienne deutériée: étude par R. M. N. du taux d'incorporation et de la localisation du deutérium

The use of the NMR spectra (250 MHz) of cellulose triacetate allows the determination of the percentage of deuterium bonded to each of the six carbon atoms of the monomer residue (except for H_?1 and one of the protons bonded to C₆ where the signals overlap). Deuterated derivatives of D -glucose and/or deuterated water were used for the biosynthesis of bacterial cellulose by Acetobacter xylinum. Analysis of NMR spectra of acetylated samples gives the following results. About 90% of the protons linked to C₁ and C₆ come from the D -glucose used in the nutrition medium, whereas 10% are exchanged with other sources of protons. Over 40% of the protons linked to C₂, C₃, C₄, and C₅ arise from the water of the nutrition medium. Discrepancies between results of biosynthesis from deuterated water and from deuterated D -glucose can only be explained if more than one enzymatic process is involved in the biosynthesis of bacterial cellulose.     

Antifungal effects of selected botanicals on fungal pathogens of watermelon fruit

This study investigates the use of botanical extracts (Piper guineense, Xylopia aethiopica and Bambusa vulgaris at 5, 10 and 15% concentration levels) for controlling deteriorating fungal pathogens in vitro. Identification of the fungal pathogens after pathogenicity test reaffirm isolates identity as Fusarium oxysporum, Fusarium solani, Macrophomina phaseolina, Fusarium verticillioides and Botryodiplodia theobromae. All the fungal pathogens induced rot in the watermelon fruit. The botanical extracts were best effective at high concentration levels (10 and 15%), though varied in their inhibitory activity. P. guineense and X. aethiopica were observed to be more effective than B. vulgaris. This study showed the efficacy of the botanical extracts on deteriorating fungal pathogens of watermelon fruit. Thus, the botanical extracts can be employed as antideteriorating biological-based fungicides for watermelon fruits.     

The diterpene acids in the bled resins of three pacific kauri, Agathis vitiensis, A. Lanceolata and A. Macrophylla

The composition of the diterpene acids in the bled resins of three kauri pines, Agathis vitiensis from Fiji, A. lanceolata from New Caledonia, and A. macrophylla from the Solomon Islands has been determined by extraction, methylation and chromatography. The results are compared with Agathis species from Australia and New Zealand.     

Dimethylbutyrylated Dibenzocyclooctadiene Lignans from the Fruits of Schisandra cauliflora Inhibit NO Production in LPS-Activated RAW264.7 Cells

From the fruits of Schisandra cauliflora, five new dimethylbutyrylated dibenzocyclooctadiene lignans, named schisandracaurins A−E, were isolated using separation and chromatographic techniques. Their structures were determined by extensive analyses of HR-ESI-MS, NMR, and ECD spectra. The schisandracaurins A−E potentially inhibited NO production in LPS-activated RAW264.7 cells with their IC₅₀ values from 21.4 to 30.3 μM.     

Fully automated sequence-specific resonance assignments of hetero- nuclear protein spectra

Full automation of the analysis of spectra is a prerequisite for high-throughput NMR studies in structural or functional genomics. Sequence-specific assignments often form the major bottleneck. Here, we present a procedure that yields nearly complete backbone and side chain resonance assignments starting from a set of heteronuclear three-dimensional spectra. Neither manual intervention, e.g., to correct lists obtained from peak picking before feeding these to an assignment program, nor protein-specific information, e.g., structures of homologous proteins, were required. By combining two earlier published procedures, AUTOPSY [Koradi et al. (1998) J. Magn. Reson., 135, 288–297] and GARANT [Bartels et al. (1996) J. Biomol. NMR, 7, 207–213], with a new program, PICS, all necessary steps from spectra analyses to sequence-specific assignments were performed fully automatically. Characteristic features of the present approach are a flexible design allowing as input almost any combination of NMR spectra, applicability to side chains, robustness with respect to parameter choices (such as noise levels) and reproducibility. In this study, automated resonance assignments were obtained for the 14 kD blue copper protein azurin from P. aeruginosa using five spectra: HNCACB, HNHA, HCCH-TOCSY, ¹⁵N-NOESY-HSQC and ¹³C-NOESY-HSQC. Peaks from these three-dimensional spectra were filtered and calibrated with the help of two two-dimensional spectra: ¹⁵N-HSQC and ¹³C-HSQC. The rate of incorrect assignments is less than 1.5% for backbone nuclei and about 3.5% when side chain protons are also considered.     

Pollen analysis of honeys from Caatinga vegetation of the state of Bahia,Brazil

Based on pollen analysis, 17 honey samples collected in the Caatinga area from Nova Soure city were classified by botanical origin to identify the most important floral sources. Most of the honey samples were obtained in August and September. A total of 73 pollen types were identified belonging to 30 families, 64 genera and 30 species. The families best represented by their number of pollen types were Mimosaceae (11), Caesalpiniaceae (9), Rubiaceae and Fabaceae (5 each). Predominant pollen types were: Mimosa arenosa in four samples, M. sensitiva and M. tenuiflora in one sample. Pollen from Mimosa ursina was registered for the first time in the pollen spectrum of the Caatinga vegetation. The correspondence analysis showed a similarity among the honey samples based on pollen composition. The high representation of pollen from native species such as Chamaecrista nictitans, C. ramosa, C. swainsonii and Copaifera martii (Caesalpiniaceae); Aeschynomene martii and Zornia sericea (Fabaceae); Herissantia tiubae (Malvaceae); Mimosa arenosa, M. quadrivalvis, M. sensitiva, M. tenuiflora, M. ursina, Piptadenia moniliformis and Plathymenia reticulata (Mimosaceae), and Ziziphus joazeiro (Rhamnaceae) supports the origin of these honeys from Caatinga vegetation.     

Orientations and Locations of Local Anesthetics Benzocaine and Butamben in Phospholipid Membranes as Studied by 2H NMR Spectroscopy

This paper presents experimental evidence that an aromatic compound that has a quadrupole moment locates in a polar headgroup region in the lipid membranes, but not in a membrane interior hydrophobic region, and discusses correlation to the site of action of benzocaine and butamben on sodium channels. The ²H NMR spectra of benzocaine-d₄, benzocaine-d₅, butamben-d₄, and butamben-d₉ in the model membranes were observed. The ²H NMR spectra of perdeuterated palmitic acid and selectively deuterated palmitic acids at C2, C3, C5, C6, C9, or C10, which were inserted into the lipid membranes, were also observed. The phosphatidylserine (PS), phosphatidylcholine (PC), and liquid mixtures composed of PS, PC, and phosphatidylethanolamine (PE), which contain or do not contain cholesterol, were employed. A moment analysis was applied to the ²H NMR spectra of palmitic-d₃₁ acid. An order parameter, S _CD , for each carbon segment was calculated from the observed quadruple splitting. We concluded that in the lipid mixture containing cholesterol, the aromatic rings of benzocaine and butamben locate around the glycerol moiety of the lipids and that when there exists no cholesterol, they locate a little more inside from the headgroup region, directing, in both cases, their amino groups upward (polar region) and the ethyl and butyl groups downward (hydrophobic region). These data cast a question on the site of action of the neutral local anesthetics in the sodium channels. Received: 22 March 2000/Revised: 20 June 2000     

Chemotaxonomic Profiling Through NMR1

A metabolite screening of cyanobacteria was performed by nuclear magnetic resonance (NMR) analysis of the soluble material obtained through sequential extraction of the biomass with three different extractive ability solvents (hexane, ethyl acetate, and methanol). Twenty-five strains from the Coimbra Collection of Algae (ACOI) belonging to different orders in the botanical code that represent three subsections of the Stainer-Rippka classification were used. The ¹H NMR spectra of hexane extracts showed that only two strains of Nostoc genus accumulated triacylglycerols. Monogalactosyldiacylglycerols and digalactosyldiacylglycerols were the major components of the ethyl acetate extracts in a mono- to digalactosyldiacylglycerols ratio of 4.5 estimated by integration of the signals at δ 3.99 and 3.94 ppm (sn3 glycerol methylene). Oligosaccharides of sucrose and mycosporine-like amino acids, among other polar metabolites, were detected in the methanolic extracts. Strains of Nostocales order contained heterocyst glycolipids, whereas sulphoquinovosyldiacylglycerols were absent in one of the studied strains (Microchaete tenera ACOI 1451). Phosphathidylglycerol was identified as the major phospholipid in the methanolic extracts together with minor amounts of phosphatidylcholine based on ¹H, ³¹P 2D correlation experiments. Chemotaxonomic information could be easily obtained through the analysis of the δ 3.0–0.5 ppm (fatty acid distribution) and δ 1.2–1.1 ppm (terminal methyl groups of the aglycons in heterocyst glycolipids) regions of the ¹H NMR spectra of the ethyl acetate and methanol extracts, respectively.     

Production of a New Ammonucleoside, 9-(2′-Amino-2′-deoxypentofuranosyl) Guanine,by Aerobacter sp.

A species of Aerobacter KY 3071 isolated from soil was found to produce a guanosine analog. It was isolated in a crystalline form from the broth culture through chromatographies on ion-exchange resins and porous resin, and characterized as 9-(2′-amino-2′-deoxypentofuranosyl) guanine by paper chromatographies, UV, NMR, IR spectra and chemical analysis.

This compound inhibited the growth of E. coli KY 8323 but not of other bacteria including most of the other strains of E. coli. It also showed antitumor activity against HeLa cell and Sarcoma 180.     

31P NMR for the study of P metabolism and translocation in arbuscular mycorrhizal fungi

³¹P nuclear magnetic resonance (NMR) spectroscopy was used to study phosphate (P) metabolism in mycorrhizal and nonmycorrhizal roots of cucumber (Cucumis sativus L) and in external mycelium of the arbuscular mycorrhizal (AM) fungus Glomus intraradices Schenck & Smith. The in vivo NMR method allows biological systems to be studied non-invasively and non-destructively. ³¹P NMR experiments provide information about cytoplasmic and vacuolar pH, based on the pH-dependent chemical shifts of the signals arising from the inorganic P (P_i) located in the two compartments. Similarly, the resonances arising from α, β and γ phosphates of nucleoside triphosphates (NTP) and nucleoside diphosphates (NDP) supply knowledge about the metabolic activity and the energetic status of the tissue. In addition, the kinetic behaviour of P uptake and storage can be determined with this method. The ³¹P NMR spectra of excised AM fungi and mycorrhizal roots contained signals from polyphosphate (PolyP), which were absent in the spectra of nonmycorrhizal roots. This demonstrated that the P_i taken up by the fungus was transformed into PolyP with a short chain length. The spectra of excised AM fungi revealed only a small signal from the cytoplasmic P_i, suggesting a low cytoplasmic volume in this AM fungus. This revised version was published online in June 2006 with corrections to the Cover Date.     

Synthesis of Some Di- and Tridepsipeptides Containing Hydroxy-methylbutyric Acid Involved in the Structure of a Depsipeptide Isolated from the Mushroom Sarcodon scabrosus

Some di- and tridepsipeptides containing hydroxymethylbutyric acid were synthesized. A comparison of their NMR spectra with those of the degradation products from the Sarcodon scarbrosus depsipeptide enabled assigning the natural compound preferentially to be cyclo-Hmb-Ile-Hmb-Ala-Thr-. The configuration of the residue of Hmb-Ile is postulated to be L-L, although it could possibly be D–D.     

Preparation of chitin butyrate by using phosphoryl mixed anhydride system

Acylation of chitin with butyric acid was performed in the presence of trifluoroacetic anhydride/phosphoric acid mediated system. The products were characterized by ¹H NMR and FT-IR spectroscopy and their solubility was tested in different organic solvents. Inclusion of butyric acid moieties into the parent molecule was confirmed from the ¹H NMR and FT-IR spectra. FT-IR analysis revealed that the degree of acid substitution (DS) of the products was in a range of 1.9–2.38, which increased with increasing the amounts of butyric acid added to the reaction system. Degree of N-deacetylation (DD) of the products, as determined by ¹H NMR was between 54.2% and 65.6%. The products with DS >2.0 were soluble in dimethyl sulfoxide, N,N-dimethylformamide, tetrahydrofuran, methanol, acetone, chloroform, and acetic acid.     

Antimicrobial activity and structure of a consensus human β-defensin and its comparison to a novel putative hBD10

The spread of multidrug resistant bacteria owing to the intensive use of antibiotics is challenging current antibiotic therapies, and making the discovery and evaluation of new antimicrobial agents a high priority. The evaluation of novel peptide sequences of predicted antimicrobial peptides from different sources is valuable approach to identify alternative antibiotic leads. Two strategies were pursued in this study to evaluate novel antimicrobial peptides from the human β-defensin family (hBD). In the first, a 32-residue peptide was designed based on the alignment of all available hBD primary structures, while in the second a putative 35-residue peptide, hBD10, was mined from the gene DEFB110. Both hBDconsensus and hBD10 were chemically synthesized, folded and purified. They showed antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Mycobacterium tuberculosis, but were not hemolytic on human red blood cells. The NMR-based solution structure of hBDconsensus revealed that it adopts a classical β-defensin fold and disulfide connectivities. Even though the mass spectrum of hBD10 confirmed the formation of three disulfide bonds, it showed limited dispersion in ¹H NMR spectra and structural studies were not pursued. The evaluation of different β-defensin structures may identify new antimicrobial agents effective against multidrug-resistant bacterial strains.     

THE ROLE OF RESIN IN ANGIOSPERM POLLINATION: ECOLOGICAL AND CHEMICAL CONSIDERATIONS

Members of at least two unrelated genera of plants, Dalechampia (Euphorbiaceae) and Clusia (Guttiferae), attract pollinators by secreting resins from floral structures. Bees that pollinate these flowers collect and use the resin in nest construction; these include Euglossa, Eulaema, Eufriesea, Trígona and, Hypanthidium in the neotropics, and Heriades in Africa. Floral resins are slow in hardening as compared with many other plant resins; this facilitates collection and storage by bees, hence probably enhancing the attractiveness of the flowers. Floral resins are probably of great utility and dependability and may be an especially important resource to certain bees, which in turn are major pollinators of many species of tropical plants. Bees appear to forage floral resin using a “strategy” of energy efficiency; large bees collect resin only from copious sources, smaller bees collect resin from sources with small amounts as well as from sources with large amounts of resin. Resin secretion in flowers may have originated as defense against herbivores and secondarily assumed the role of pollinator reward.