Simple brominated phenols in red algae

By using TLC and GLC-MS techniques, 23 species of red algae, representing nine orders, were analyzed for the presence of simple bromophenols. Ten bromophenols were detected, five of which might be artefacts. Furthermore, lanosol was identified in sea water from the Polysiphonia Brodiaei—zone. Bromophenols were detected in species from the families Ceramiaceae, Delesseriaceae, Bonnemaisoniaceae, Rhodophyllaceae, Corallinaceae and Rhodomelaceae.     

Taxonomic notes on Laurencia mariannensis (Rhodomelaceae, Rhodophyta)

The marine red alga Laurencia mariannensis Yamada (Rhodomelaceae, Ceramiales) is characterized by pale rose-red, softly fleshy, slender, terete axes (up to 600 μm in diameter), arising from a loosely entangled, stoloniferous basal system among species that have the following combination of features: the presence of longitudinally orientated secondary pit-connections between contiguous superficial cortical cells; the presence of projecting superficial cortical cells at the upper portions of branches; and the presence of lenticular thickenings in the walls of medullary cells, Furthermore, the presence of two or three corps en cerise per superficial cortical cell and one per trichoblast cell may characterize the species.     

Bromophenols of Rhodomela larix: Chemotaxonomy of morphological forms

The bromophenols of two morphological forms of Rhodomela larix were examined. GLC-MIS analyses revealed five bromophenols in a low intertidal form of the alga and four of the same compounds in a tidepool form. The results are discussed in relation to the chemotaxonomy of the species.     

Effect of dietary terpenes on glucuronic acid excretion and ascorbic acid turnover in the brushtail possum (Trichosurus vulpecula)

1. Glucuronic acid was excreted in the urine of the brushtail possum, Trichosurus vulpecula, in response to dietary terpenes (essential oils found in Eucalyptus foliage). 2. The relationship between urinary glucuronic acid and the estimated terpene content of the diet was not equimolar, but varied from 1-17%, with levels of 5-39% found in animals maintained on terpenes or eucalypt leaves for several weeks. 3. Blood levels of ascorbate and the turnover rate of ascorbate were increased in the brushtail possum in response to dietary terpenes. 4. The presence of an active glucuronic acid pathway and associated glucose-ascorbate-glucose cycle was postulated for the brushtail possum and the other arboreal marsupials, Pseudocheirus peregrinus (common ringtail possum) and Petauroides volans (greater glider). 5. By means of these pathways these animals may utilise the high ascorbate content of Eucalyptus leaves to conserve glucose required for synthesis of glucuronic acid used for conjugation of dietary terpenes.     

Synthesis and carbonic anhydrase inhibitory properties of novel bromophenols including natural products

(2-Bromo-3,4-dimethoxyphenyl) (3,4-dimethoxyphenyl)methanone (10) and its derivatives with Br, one dibromide and isomeric three tribromides, were synthesized. Demethylation of these compounds afforded a series of new bromophenols. Inhibition of human cytosolic carbonic anhydrase II (hCA II) isozyme by these new bromophenols and naturally occurring 3,4,6-tribromo-5-(2,5-dibromo-3,4-dihydroxybenzyl)benzene-1,2-diol (3), and 5,5'-methylenebis(3,4,6-tribromo-benzene-1,2-diol) (4) was investigated. The synthesized compounds showed carbonic anhydrase inhibitory capacities with IC(50) values in the range of 0.7-372 μM against hCA II. Some bromophenols investigated here showed effective hCA II inhibitory activity and might be used as leads for generating novel carbonic anhydrase inhibitors which are valuable drug candidates for the treatment of glaucoma, epilepsy, gastric and duodenal ulcers, neurological disorders, or osteoporosis.     

Synthesis and characterization of novel bromophenols: Determination of their anticholinergic,antidiabetic and antioxidant activities

In this paper, a series of novel bromophenol derivatives were synthesized and evaluated for their acetylcholinesterase and α-glycosidase enzymes inhibition properties and antioxidant activity. Diarylmethanones were synthesized and their bromination was carried out. During bromination, some compounds gave new bromophenols via regioselective O-demethylation. Demethylation of brominated diarylmethanones was also performed with BBr₃ to give novel bromophenols. In addition, we examines the antioxidant capacity of novel bromophenol derivatives using several in vitro bioanalytical methodologies such as 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS⋅⁺) and 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) radical scavenging activity, Fe³⁺ and Cu²⁺ reducing activities and ferrous (Fe²⁺) ions chelating activities. Also, novel bromophenols and methoxylated bromophenols derivatives were tested against acetylcholinesterase and α-glycosidase, which associated with some metabolic diseases. The novel bromophenols showed Ki values in range of 8.94 ± 0.73–59.45 ± 14.97 nM against AChE and 4.31 ± 1.93–44.14 ± 2.19 nM against α-glycosidase.     

Monoterpenes affect chlorodiazepoxide-micelle interaction through micellar dipole potential modifications

The ability of several natural terpenes to affect benzodiazepine (BZD)-micelle interaction through the membrane dipolar organization was investigated. The acid-base equilibrium of chlorodiazepoxide (CDX) and the spectroscopic behavior of the electrochromic dye merocyanine were tested in the presence and in the absence of Triton X-100 micelles (used to mimic a membrane environment) containing or not cineole, menthol, geraniol or camphor. CDX's apparent pK increased in the environment of terpene-containing micelles compared with pure Triton X-100 micelles. Decrements in electric potentials (between -111 and -128 mV with respect to pure detergent) were calculated from Boltzmann equation. This result suggested, that in the presence of terpenes, the tendency of CDXH(+) to remain in the membrane phase increased. The dielectric constant (D) of the microenvironment sensed by merocyanine within Triton X-100 micelles, determined from lambda(max,2) of merocyanine monomer, was D=9 and increased in the presence of all the terpenes assayed (D congruent with 11). The decrease in merocyanine partitioning (A(peak1)/A(peak2) increased) also reflected an increment in the negative dipole potential. The present results suggest that terpenes contributed to the whole dipolar arrangement of the micelle with a dipole moment vector which had an intense component oriented parallel to the intrinsic dipole of the Triton X-100 molecules in the micelles. This led to a more negative environment of the interface region where CDX was located, and increased the net polarity of the deepest micelle regions sensed by merocyanine.     

Adaptation mechanisms of bacteria during the degradation of polychlorinated biphenyls in the presence of natural and synthetic terpenes as potential degradation inducers

In this study, we examined the effect of polychlorinated biphenyls (PCBs) in the presence of natural and synthetic terpenes and biphenyl on biomass production, lipid accumulation, and membrane adaptation mechanisms of two PCB-degrading bacterial strains Pseudomonas stutzeri and Burkholderia xenovorans LB400. According to the results obtained, it could be concluded that natural terpenes, mainly those contained in ivy leaves and pine needles, decreased adaptation responses induced by PCBs in these strains. The adaptation processes under investigation included growth inhibition, lipid accumulation, composition of fatty acids, cis/trans isomerization, and membrane saturation. Growth inhibition effect decreased upon addition of these natural compounds to the medium. The amount of unsaturated fatty acids that can lead to elevated membrane fluidity increased in both strains after the addition of the two natural terpene sources. The cells adaptation changes were more prominent in the presence of carvone, limonene, and biphenyl than in the presence of natural terpenes, as indicated by growth inhibition, lipid accumulation, and cis/trans isomerization. Addition of biphenyl and carvone simultaneously with PCBs increased the trans/cis ratio of fatty acids in membrane fractions probably as a result of fluidizing effects of PCBs. This stimulation is more pronounced in the presence of PCBs as a sole carbon source. This suggests that PCBs alone have a stronger effect on bacterial membrane adaptation mechanisms than when added together with biphenyl or natural or synthetic terpenes.     

Dehalogenation and biodegradation of brominated phenols and benzoic acids under iron-reducing, sulfidogenic, and methanogenic conditions.

The anaerobic biodegradation of monobrominated phenols and benzoic acids by microorganisms enriched from marine and estuarine sediments was determined in the presence of different electron acceptors [i.e., Fe(III), SO4(2-), or HCO3-]. Under all conditions tested, the bromophenol isomers were utilized without a lengthy lag period whereas the bromobenzoate isomers were utilized only after a lag period of 23 to 64 days. 2-Bromophenol was debrominated to phenol, with the subsequent utilization of phenol under all three reducing conditions. Debromination of 3-bromophenol and 4-bromophenol was also observed under sulfidogenic and methanogenic conditions but not under iron-reducing conditions. In the bromobenzoate-degrading cultures, no intermediates were observed under any of the conditions tested. Debromination rates were higher under methanogenic conditions than under sulfate-reducing or iron-reducing conditions. The stoichiometric reduction of sulfate or Fe(III) and the utilization of bromophenols and phenol indicated that biodegradation was coupled to sulfate or iron reduction, respectively. The production of phenol as a transient intermediate demonstrates that reductive dehalogenation is the initial step in the biodegradation of bromophenols under iron- and sulfate-reducing conditions.     

Red algal exotics on North Sea coasts

A total of ten red seaweed species are recognized as introduced into the North Sea from other parts of the world. These areAsparagopsis armata andBonnemaisonia hamifera (Bonnemaisoniales),Grateloupia doryphora (Halymeniales),Antithamnionella spirographidis, Antithamnionella ternifolia, Anotrichium furcellatum, Dasya baillouviana, ?Dasysiphonia sp.,Polysiphonia harveyi andPolysiphonia senticulosa (Ceramiales). The oldest of these isB. hamifera, introduced prior to 1890, while the most recent,?Dasysiphonia sp., was first found in 1994 and still requires taxonomic investigation. A variety of distribution patterns is seen, with geographical ranges varying from general within the North Sea to very restricted. The diversity of introduced red algae on eastern coasts of the North Sea is much greater than in the west. The most likely explanation for this pattern is that French coasts were the initial site of introduction for many of the seaweeds, which were then distributed northwards by the residual surface currents. Their increasing success in the Netherlands has probably been promoted by the drastically changed local hydrodynamic conditions which have also permitted the recent introduction of many native European species. Of the biological features of species that may favour their success as introductions, clonal vegetative propagation, often with specialized propagules or fragmentation mechanisms, is almost ubiquitous. Low-temperature tolerances can be inferred, but data are sparse. Many of the alien red algae in the North Sea contain anti-grazing compounds such as bromophenols, which may contribute to their invasive potential by deterring grazing sufficiently to permit establishment of an inoculum.     

Antimicrobial activities of the bromophenols from the red alga Odonthalia corymbifera and some synthetic derivatives

A series of bromophenols was obtained by isolation from red alga Odonthalia corymbifera and by reactions of bis(hydroxyphenyl)methanes with bromine. New bromophenols including 3,3',5,5'-tetrabromo-2,2',4,4'-tetrahydroxydiphenylmethane (10), a regioisomer of the potent antimicrobial natural product, together with known derivatives were synthesized in high yield. All of the isolated and synthesized compounds were tested for antimicrobial activity against gram-negative, gram-positive bacteria and fungi. The preliminary structure-activity relationship, to elucidate the essential structure requirements for antimicrobial activity, has been described. Among the isolated natural products 2,2',3,3'-tetrabromo-4,4',5,5'-tetrahydroxydiphenylmethane (4) was found to be the most active derivative against Candida albicans, Aspergillus fumigatus, Trichophyton rubrum, and Trichophyton mentagrophytes. The synthetic bromophenols 3,3'-dibromo-6,6'-dihydroxydiphenylmethane (13) and 3,3',5,5'-tetrabromo-6,6'-dihydroxydiphenylmethane (14) showed potent antibacterial effect against Staphylococcus aureus, Bacillus subtilis, Micrococcus luteus, Proteus vulgaris, and Salmonella typhimurium.     

Bromophenol accumulation and sediment contamination by the marine annelids Notomastus lobatus and Thelepus crispus

The occurrence of bromophenols in Notomastus lobatus and Thelepus crispus and associated sediment and porewater was determined. 4-Bromophenol, 2,4-dibromophenol, and 2,4,6-tribromophenol were identified in N. lobatus with the highest concentrations occurring in the anterior and posterior abdomen and substantially less in the thorax (345, 209, and 6.6 μg/ml of worm, respectively). The concentration of dibromobenzyl alcohol was highest in the tail (last 15 setigers) of T. crispus (1.02 mg/ml of worm), but did not differ among body parts as the bromophenols did in N. lobatus. Concentrations in sediments were significantly reduced from those in the worms and decreased from the inner burrow lining out to 5 cm from N. lobatus burrows. Similarly for T. crispus, concentrations of dibromobenzyl alcohol in the surrounding sediments and porewater were low and increased with proximity to the burrow. For both species, concentrations in surface sediment (upper 1 cm) did not differ from those at 6 cm depth. Several lines of evidence indicate that these compounds are produced by the worms and hence their presence in sediments is derived from the worms. The contamination of sediment by these bromophenols has important implications for the structure and activities of benthic-associated communities.     

The function of terpene natural products in the natural world

As the largest class of natural products, terpenes have a variety of roles in mediating antagonistic and beneficial interactions among organisms. They defend many species of plants, animals and microorganisms against predators, pathogens and competitors, and they are involved in conveying messages to conspecifics and mutualists regarding the presence of food, mates and enemies. Despite the diversity of terpenes known, it is striking how phylogenetically distant organisms have come to use similar structures for common purposes. New natural roles undoubtedly remain to be discovered for this large class of compounds, given that such a small percentage of terpenes has been investigated so far.     

PHYLOGENETIC RELATIONSHIPS AMONG LINEAGES OF THE CERAMIACEAE (CERAMIALES,RHODOPHYTA) BASED ON NUCLEAR SMALL SUBUNIT rDNA SEQUENCE DATA1

Phylogenetic relationships among 69 species of the Ceramiales (51 Ceramiaceae, six Dasyaceae, seven Delesseriaceae, and five Rhodomelaceae) were determined based on nuclear SSU rDNA sequence data. We resolved five strongly supported but divergent lineages among the included Ceramiaceae: (i) the genus Inkyuleea, which weakly joins other orders of the Rhodymeniophycidae rather than the Ceramiales in our analyses; (ii) the tribe Spyridieae, which is sister to the remainder of the included ceramialean taxa; (iii) the subfamily Ceramioideae, weakly including the tribe Warrenieae; (iv) the subfamily Callithamnioideae; and (v) the subfamily Compsothamnioideae, which emerges as sister to the Dasyaceae/Delesseriaceae/Rhodomelaceae complex, thus rendering the Ceramiaceae sensu lato unequivocally paraphyletic, as has been argued separately on anatomical grounds by Kylin and Hommersand. Our data support a restricted concept of the Ceramiaceae that includes only one of the five lineages (Ceramioideae) that we have resolved. In addition to failing to ally with the Ceramiales in our molecular analyses, species of Inkyuleea differ substantially from other Ceramiaceae sensu lato in details of pre‐ and postfertilization development. The genus Inkyuleea is here assigned to the Inkyuleeaceae fam. nov., which we provisionally retain in the Ceramiales. Species of Spyridia also differ from the remaining Ceramiaceae in their postfertilization development, and, in light of our molecular data, the genus Spyridia is assigned to the Spyridiaceae. The Callithamnioideae is strongly monophyletic (100% in all analyses), which, in combination with key anatomical differences, supports elevation to family status for this lineage as the Callithamniaceae. Similarly, the Compsothamnioideae is solidly monophyletic in our molecular trees and has a unique suite of defining anatomical characters that supports family status for a complex that we consider to include the tribes Compsothamnieae, Dasyphileae, Griffithsieae, Monosporeae, Ptiloteae, Spermothamnieae, Sphondylothamnieae, Spongoclonieae, and Wrangelieae, for which the reinstated family name Wrangeliaceae is available.     

Monoterpenes affect chlorodiazepoxide-micelle interaction through micellar dipole potential modifications

The ability of several natural terpenes to affect benzodiazepine (BZD)-micelle interaction through the membrane dipolar organization was investigated. The acid-base equilibrium of chlorodiazepoxide (CDX) and the spectroscopic behavior of the electrochromic dye merocyanine were tested in the presence and in the absence of Triton X-100 micelles (used to mimic a membrane environment) containing or not cineole, menthol, geraniol or camphor. CDX's apparent pK increased in the environment of terpene-containing micelles compared with pure Triton X-100 micelles. Decrements in electric potentials (between −111 and −128 mV with respect to pure detergent) were calculated from Boltzmann equation. This result suggested, that in the presence of terpenes, the tendency of CDXH⁺ to remain in the membrane phase increased. The dielectric constant (D) of the microenvironment sensed by merocyanine within Triton X-100 micelles, determined from λ_max,2 of merocyanine monomer, was D=9 and increased in the presence of all the terpenes assayed (D≅11). The decrease in merocyanine partitioning (A_peak1/A_peak2 increased) also reflected an increment in the negative dipole potential. The present results suggest that terpenes contributed to the whole dipolar arrangement of the micelle with a dipole moment vector which had an intense component oriented parallel to the intrinsic dipole of the Triton X-100 molecules in the micelles. This led to a more negative environment of the interface region where CDX was located, and increased the net polarity of the deepest micelle regions sensed by merocyanine.     

Taxonomic notes on Laurencia brongniartii (Rhodomelaceae, Rhodophyta)

The red alga Laurencia brongniartii J. Agardh (Rhodomelaceae, Ceramiales) is characterized by: (i) the production of four periaxial cells from each vegetative axial segment; (ii) the presence of two or three corps en cerise per superficial cortical cell and one per trichoblast cell; (iii) the production of a single tetrasporangium-bearing periaxial (fourth) cell per fertile segment; (iv) a tetrasporangial arrangement that is intermediate between perpendicular and parallel types; (v) procarps produced from the last-formed (fifth) periaxial cell of the terminal segment of a two-celled female trichoblast; and (vi) distally positioned spermatangial nuclei, in addition to known features. The production of a single tet-rasporangium-bearing periaxial cell per fertile segment allies this species to Laurencia similis Nam et Saito.     

Sulfated xylomannans isolated from red seaweeds Chondrophycus papillosus and C. flagelliferus (Ceramiales) from Brazil

Sulfated xylomannans were isolated from two species of genus Chondrophycus by aqueous extraction followed by KCl fractionation. Structural determination of the native, desulfated and Smith-degraded KCl-precipitated polysaccharides carried out by composition and methylation analysis and NMR spectroscopy (1D and 2D experiments) showed the following general structure: [see text] These xylomannans present different degrees of branching (15-25%) by beta-D-Xylp (70-80%) and beta-D-Manp-2-S (20-30%) and molecular weights (33-222kDa). This is the first report of the presence of a sulfated xylomannan in species of order Ceramiales.     

The n-hexane-soluble components of Pseudotsuga menziesii bark

β-Sitosterol and campesterol were identified in the n-hexane-soluble fraction of Douglas-fir bark and the presence of other 'steroid-like' compounds was demonstrated. GLC and MS showed the presence of terpenes.     

Evidence for a Terpene-Based Food Chain in the Gulf of Alaska

A mixture of ¹⁴C-terpenes was prepared from conifer seedlings and introduced into fresh seawater samples taken near Seward, Alaska. Initial rates of oxidation by the indigenous bacteria were linear and faster than the rates of toluene oxidation. Turnover times were 4 to 19 days. Autoradiographic measurements with ³H-terpenes indicated that at least 10% of the 0.6 × 10⁹ to 2.7 × 10⁹ bacteria per liter present could catabolize terpenes. The rate of terpene oxidation, 24 μg of terpenes per g of cells per h with 3 μg of terpenes added per liter, was a constant function of bacterial biomass. The specific affinity of the process was estimated to be between 8.1 and 81 liters/g of cells per h, indicating a high state of induction and the probable presence of terpenes. Terpene-oxidizing bacteria were grown on [¹⁴C]alanine and added to fresh seawater samples. Transfer of the bacterial radioactivity into larger particles at a rate of 146 pg/liter per h from the 2.3 × 10⁹ organisms added indicated that any terpenes present would participate in the food chain.     

Concise review of the genus Vertebrata S.F. Gray (Rhodophyta: Ceramiales)

Journal of Applied Phycology - The red algal genus Vertebrata (Ceramiales, Rhodophyta) comprises 30 species of rather small filamentous algae, differing in morphology, distribution, and ecological...