Effect of light intensity and nutrients supply on microalgae cultivated in urban wastewater: Biomass production, lipids accumulation and settleability characteristics.

Microalgae cultivation systems fed with wastewater as source of nutrients represents the principal sustainable condition to produce microalgal biomass to be converted conveniently to biofuels. In order to optimize microalgae growth and their lipid content, the effect of light intensity and nutrients load in real wastewater was investigated through batch microalgal cultivation tests. A microalgal polyculture was used as inoculum and grown for 10 days in batch at different conditions of light intensity (i.e. 20, 50 and 100 µmol s-1m-2) and nutrients concentration in wastewater. Experimental results showed that biomass productivity decreased for rich nutrients conditions and increased for high light intensities. The highest lipid mass content (29%) was found for high light intensity condition (100 µmol s-1m-2). Furthermore, microalgae settleability tests, conducted at the end of the cultivation time, resulted in the highest biomass recovery efficiency (72%) for low light intensity and nutrients supply conditions.

Ethnobotanical study on the medicinal plants in the Mainarde Mountains (central-southern Apennine, Italy).

ETHNOPHARMACOLOGICAL RELEVANCE: New documentation of the uses of plants in the popular medicine of the Mainarde Mountain, a protected area of the central-southern Apennine characterised by a high floristic richness, is here reported. MATERIALS AND METHODS: Field data were collected through semi-structured and open interviews with native People between 2011 and 2014. The plants were identified and vouchers specimens were scanned to create a Virtual Herbarium. The Ethnobotanicity Index (EI), the Relative Importance Index (RI) and the Fidelity Level Index (FL) were calculated. The plant uses surveyed in the study area were compared with those described in medical and ethnobotanical literature. RESULTS: Seventy-one interviews were conducted, the age range of the informants was between 21 and 98 years. The inventory included 106 taxa belonging to 45 families; among these, 87 were wild species and 20 were cultivated species. The uses recorded were 429, among these, 69.1% of the uses concerned internal applications to treat digestive system disorders, infections and respiratory system disorders mainly, while 31.9% concerned external applications, especially to treat skin/subcutaneous cellular tissue disorders and injuries. In particular, 17 new uses and 16 unusual and rarely mentioned plants are documented. CONCLUSION: The data collected support evidence on traditional uses for plant in the Apennine. Findings from medical flora and from new or rare medical uses reinforce the usefulness of such research efforts.

New glycosides from Capsicum annuum L. var. acuminatum. Isolation, structure determination, and biological activity.

Investigation of polar extracts from ripe fruits of Capsicum annuum L. var. acuminatum yielded three new glycosides, capsosides A (1) and B (2) and capsianoside VII (3), along with seven known compounds (4-10). The chemical structures were elucidated mainly by extensive nuclear magnetic resonance methods and mass spectrometry, and the biological activities of icariside E(5) (4) were tested by different assays. Icariside E(5), in contrast to capsaicin, neither induces an increase in the intracellular levels of reactive oxygen species nor affects the mitochondria permeability transition, and it does not signal through the vanilloid receptor type 1. Interestingly, this compound protects Jurkat cells from apoptosis induced by the oxidative stress mediated by serum withdrawal. These results suggest that icariside E(5) may have antioxidant properties that strengthen the importance of peppers in the Mediterranean diet.

New pyridinium alkaloids from a marine sponge of the genus Spongia with a human phospholipase A(2) inhibitor profile.

Four new bioactive pyridinium alkaloids, named spongidines A-D (5-8), have been isolated from a Vanuatu sponge of the genus Spongia, together with known petrosaspongiolides D (1) and G (2). Compounds 3 and 4 are 21-hydroxy derivatives of petrosaspongiolides K and P. Structure elucidation was accomplished through extensive 2D NMR experiments (COSY, ROESY, HMBC, HMQC) and IR, UV, and FABMS data. All compounds significantly inhibited human synovial phospholipase A(2) (PLA(2)) at 10 microM, with an IC(50) value of 5.8 microM for compound 4, which is the most potent inhibitor, with a higher selectivity toward this enzyme than the reference inhibitor manoalide. Pyridinium alkaloids (5-8) mainly inhibited human synovial PLA(2). Compound 8, which contains a sulfonic acid group, is the most interesting inhibitor.

Starfish saponins. 55. Isolation, structure elucidation, and biological activity of the steroid oligoglycosides from an Antarctic starfish of the family Asteriidae.

This paper reports an analysis of the chemical constituents from an Antarctic starfish of the family Asteriidae. Different steroid glycoside types are represented among its constituents, including the five hexaglycoside steroidal sulfates ("asterosaponins") asteriidosides A-E (1-5), differing in their oligosaccharide chain, and the two nonsulfated diglycosides asteriidoside F (6) and G (7), in which 6 is the 26-methyl analogue of 7. Also present are the two sulfated diglycosides asteriidoside H (8) and I (9) and one sulfated monoglycoside asteriidoside L (10). Eight of the compounds were tested against human nonsmall-cell lung carcinoma cells (NSCLC-L16) and found to be moderately cytotoxic.

Isolation, structure elucidation, and biological activity of the steroid oligoglycosides and polyhydroxysteroids from the Antarctic starfish Acodontaster conspicuus.

A total of 19 steroids, of which 13 steroidal oligoglycosides (nine new and four known) and six polyhydroxylated steroids (four new and two known), has been isolated from the Antarctic starfish Acodontaster conspicuus. The mixture is dominated by glycosides composed of steroidal aglycons having the hydroxyl groups typically disposed on one side of the tetracyclic nucleus, i.e., 3 beta,4 beta,6 alpha,8,15 beta-, with some having a sulfate at C-6, and differing in the side chains and/or in the disaccharide moieties that are usually attached at C-26, with some at C-28 and C-29. Those compounds are accompanied by minute amounts of glycosides with a delta 8(14)-double bond in the steroid, which is a structural feature not previously found among polyhydroxysteroids derived from starfish. Small amounts of six related unglycosidated polyhydroxysteroids and three higher-molecular-weight asterosaponins complete the composition of the mixture. The structures of the new compounds were determined by interpretation of their spectral data and by comparison with spectral data of known compounds. Eighteen of these compounds were evaluated for their ability to inhibit growth in Antarctic marine bacteria isolated from either the water column or the surfaces of benthic marine invertebrates. Of these compounds, 50% were active against at least one Antarctic marine bacterium. This suggests that these compounds may play an important role in deterring microbial fouling.

Isolation of 20 glycosides from the starfish Henricia downeyae, collected in the Gulf of Mexico.

Thirteen new (1-13) and seven known (14-20) steroid glycosides were isolated from Henricia downeyae, collected from the offshore waters of the northern Gulf of Mexico. Ethanolic extracts of these starfish caused growth inhibition in bacteria and fungi, potent antifouling activity against barnacle and bryozoan larvae, and feeding deterrent activity against a marine fish. The known compounds are typical glycosides found in several species of the family Echinasteridae, i.e., Echinaster sp. and Henricia laeviuscola. One of the new compounds belongs to this group, whereas the remaining 12 new compounds represent a novel series of steroid glycosides which have aglycons with structural similarities to the "asterosaponins". They possess a delta 9(11) 3 beta, 6 alpha-dihydroxysteroidal aglycon with 23-oxo or 22,23-epoxy functionalities and often a 20-hydroxyl group in the side chain. The sulfate is located at C-6 and the saccharide moiety at C-3, in contrast with the asterosaponins which have the sulfate at C-3 and the oligosaccaride moiety at C-6. All the new compounds contain a glucuronic acid unit, which is uncommon among steroid glycosides from echinoderms. The structures of the new compounds, isolated in amounts ranging from 3.4 to 0.9 mg, were determined by interpretation of their spectral data and by comparison with spectral data of known compounds.

Steroid and triterpenoid oligoglycosides of marine origin.

Saponins have been considered for a long time typical metabolites of plant origin. It has been only in the last two decades that the world-wide investigation of marine organisms as sources of new bioactive metabolites disclosed the wide distribution of these molecules also among marine animals. Today saponins are recognized as the most common characteristic metabolites in two classes of the phylum Echinodermata (Holothuroidea and Asteroidea). Furthermore, several steroid and triterpenoid oligoglycosides have been isolated from different species of marine sponges, more rarely Anthozoans, and also from fishes of the genus Pardachirus, where they have been shown to act as shark repellents. This communication offers a general view of the distribution of steroid and triterpenoid oligoglycosides among marine organisms and focuses on a number of recent examples to discuss structural characteristics, biological activities, and methods of investigation.

Chemical and biological investigation of the polar constituents of the starfish Luidia clathrata, collected in the Gulf of Mexico.

Ten new [1-10] and three known [11-13] polyhydroxysteroids were isolated, along with four known asterosaponins [14-17], from the starfish Luidia clathrata, collected from the offshore waters of the northern Gulf of Mexico. The EtOH extracts of this starfish showed feeding-deterrent properties against marine fish, and inhibited the settlement of larvae of barnacles and bryozoans, as well as the growth of several bacteria. The structures of the new compounds were determined by interpretation of their nmr spectral data and by comparison with the spectral data of known compounds. The assignment of the configurations of the side-chain stereogenic centers of compounds 1 and 3-10 were based on the comparison of their nmr data with those of the stereoisomeric model compounds after derivatization with the chiral auxiliary MTPA reagent. Larval settlement assays conducted on ten isolated compounds revealed they are all potent inhibitors of settlement. Two of these isolated compounds inhibited the growth of several bacteria.

Starfish saponins, Part 53. A reinvestigation of the polar steroids from the starfish Oreaster reticulatus: isolation of sixteen steroidal oligoglycosides and six polyhydroxysteroids.

A reinvestigation of the starfish Oreaster reticulatus has led to the isolation of sixteen steroidal oligoglycosides and six polyhydroxysteroids. One steroidal monoglycoside has been identified as asterosaponin-1 [5], previously isolated from the same organism, and one pentaglycoside steroidal sulfate has been identified with the known ophidianoside F [1], previously isolated from starfish species of the family Ophidiasteridae. The novel pentaglycoside steroidal sulfates reticulatosides A [3] and B [4] represent the second examples of asterosaponins containing the 5 alpha-cholesta-9(11)-en-3 beta,6 alpha,20,22-tetraol aglycone. Of the remaining new steroidal oligoglycosides, the majority are characterized by the common (24S)-5 alpha-cholesta-3 beta,6 alpha,8,15 alpha,24-pentaol aglycone, with some having a sulfate group at C-6, and differing in the sugar moiety. Compounds 11, 12, 15, and 16 represent major departures from the more common structural features encountered in steroidal glycosides from starfish with the presence in 11 and 12 of a rare 5-O-methylgalactofuranosyl unit and in 15 and 16 of a 3-O-methyl-2-O-sulfate-xylopyranosyl unit. The latter was shown by nmr data combined with molecular dynamics calculations to exist in an 8:2 equilibrium mixture of the 1C4 and 4C1 conformations.

Starfish saponins, Part 2. Steroidal oligoglycosides from the starfish Cosmasterias lurida.

Four new sulfated asterosaponins, designated as cosmasterosides A [1], B [2], C [4], and D [5], have been isolated from the Atlantic starfish Cosmasterias lurida along with large amounts of the pentaglycoside ophidianoside F [3] and the minor component forbeside H [6], previously isolated from Ophidiaster ophidianus and Asterias forbesi, respectively. Cosmasteroside A [1] contains the same oligosaccharide chain as ophidianoside F [3] and a (20S)-5 alpha-cholesta-9(11),24-diene-3 beta,6 alpha,20-triol-3 beta-sulfated aglycone. Cosmasterosides B [2], C [4], and D [5] are based on the known aglycone, thornasterol A, and differ in the number and type of monosaccharide components of the carbohydrate chain. Cosmasteroside B [2] contains a novel oligosaccharide chain that differs from that of ophidianoside F [3] by the replacement of the quinovose unit attached to C-6 of the steroidal aglycone by glucose. The tetraglycosides cosmasterosides C [4] and D [5] are structurally related to ophidianoside F [3] and cosmasteroside B [2], respectively, by the loss of a terminal fucose unit.

HIV-inhibitory natural products. 11. Comparative studies of sulfated sterols from marine invertebrates.

A total of 22 sulfated sterols isolated from marine sponges, ophiuroids (brittle stars), and asteroids (sea stars) were comparatively evaluated for their antiviral activity against HIV-1 and HIV-2. In general, sterols with sulfate groups at position 2, 3, or 6 were the most active, with EC50 values of 3-13 microM against HIV-1 (RF) and 2-8 microM against HIV-2 (CBL20). Those compounds which were sulfated on the sterol D ring were completely inactive against both HIV-1 and HIV-2. Overall, sulfated sterols active against HIV-1 were also active against HIV-2.

Starfish saponins, 52. Chemical constituents from the starfish Echinaster brasiliensis.

This paper reports an analysis of the chemical constituents from the Caribbean starfish Echinaster brasiliensis collected at Grand Bahama Island. This species is completely devoid of cyclic steroidal glycosides, previously isolated from two species of the genus Echinaster in place of the more common penta- and hexa-glycoside steroidal sulfates ("asterosaponins"). Two typical "asterosaponins" and ten glycosides of polyhydroxysteroids were instead isolated in relatively large amounts from E. brasiliensis. The asterosaponins include the known marthasteroside A1 [1] and the new brasiliensoside [2], while the glycosides of polyhydroxysteroids include seven new compounds (six monoglycosides and one diglycoside). The known echinasteroside A, previously found in Echinaster sepositus and in the related Henricia laeviuscula (both belonging to the family Echinasteridae), and laeviusculosides C and I from H. laeviuscula were also isolated. Most of the glycosides from E. brasiliensis are 3-O-beta-xylopyranosides of delta 4-3 beta,6 beta,8,15 alpha,16 beta pentahydroxysteroid aglycones, having different side chains and sometimes a sulfate group at C-15, structural features which are typical of steroidal glycosides from starfishes of the family Echinasteridae. Continuing the analysis of the constituents of E. brasiliensis, we have also isolated a series of anthraquinones, known animal pigments found only in echinoderms and particularly in Crinoidea and in the Echinasteridae family of Asteroidea.

Starfish saponins, Part 51. Steroidal oligoglycosides from the starfish Distolasterias nipon.

A reinvestigation of the extracts from the starfish Distolasterias nipon, collected at Mutsu Bay, Japan, has led to the isolation of six glycosides of polyhydroxysteroids and six asterosaponins. Four steroidal glycosides have been identified as distolasterosides D1 [1] and D2 [2] (previously isolated from the same organism), and pycnopodioside C [5] and pisasteroside A [6], previously found in the related species Pycnopodia helianthoides and Pisaster ochraceus (family Asteridae), respectively. Two asterosaponins have been identified as the common versicoside A [7] and thornasteroside A [7a]. The two remaining glycosides of polyhydroxysteroids, named distolasterosides D4 [3] and D5 [4], and four asterosaponins designated nipoglycosides A [8], B [9], C [10], and D [11] are new compounds, and their structures have been elucidated mainly by interpretation of spectral data and comparison with known compounds.

Starfish saponins, 48. Isolation of fifteen sterol constituents (six glycosides and nine polyhydroxysteroids) from the starfish Solaster borealis.

This paper reports a complete steroid glycoside and polyhydroxysteroid analysis of the starfish Solaster borealis, collected at Mutsu Bay, Japan. The glycosides include a new pentaglycoside steroid sulfate ("asterosaponin"), designated solasteroside A [1], two new sulfated 24-O-diglycosides, both with the common 5 alpha-cholesta-3 beta,6 alpha,8,15 alpha, 24-pentaol aglycone, borealosides A [2] and B [3], two new 24-O-(3-O-methyl)xylosides, borealosides C [4] and D [5], having the same aglycone with an additional hydroxy group at 4 beta-position in 5, and the known amurensoside B, previously isolated from Asterias amurensis. Among the polyhydroxysteroid constituents, four (7-10) are new, and five (11-15) have previously been isolated from starfishes.

Distribution of tetrodotoxin, 6-epitetrodotoxin, and 11-deoxytetrodotoxin in newts.

Tetrodotoxin was detected in all nine species of newts tested, 6-epitetrodotoxin in six species, and 11-deoxytetrodotoxin in five species. Only one species lacked the analogues, thus suggesting that the analogues were common metabolites among newts. Toxin levels were high in Taricha granulosa and Notophthalmus viridescens followed by Cynops spp. Distinct differences in toxin contents and profiles existed among species and tissues.

Biological activity of saponins and saponin-like compounds from starfish and brittle-stars.

Twenty-four saponins and saponin-like compounds, isolated from starfish and brittle-stars, have been tested in four in vitro tests, based upon bacterial and cell tissue cultures. Saponin-like compounds from brittle-stars have previously not been tested for biological activity. In an antibacterial test based on an agar diffusion test, the Gram positive bacterium S. aureus was affected by the polyhydroxylated steroidal glycosides, polyhydroxylated sterols and disulfated sterols. However, none of the 21 compounds tested were active against the Gram negative bacterium E. coli. In a cytotoxicity test all 21 compounds tested influenced the cells at a concentration of 100 micrograms/ml, while the cells were unaffected at 1 microgram/ml. In an antitumor test, 16 compounds were tested on two lymphoma cell lines. Inhibition of cell growth, at a concentration of 5 ng/ml, was seen for three polyhydroxylated sterols, in one cell line. Weak activity was seen in an antiviral test at a concentration of 10 micrograms/ml.