Tortile Research Articles

Leptosins O—S, Cytotoxic Metabolites of a Strain of Leptosphaeria sp. Isolated from a Marine Alga.

Leptosins O (1), P (2), Q (3), R (4) and S (5) have been isolated from a strain of Leptosphaeria sp. originally separated from the marine alga Sargassum tortile. Their absolute stereostructures have been elucidated on thebasis of spectroscopic analyses of their acetate derivatives (6-10) using various ID and 2D NMR techniques and some chemical transformations. The NMR and NOE spectral analyses of 6-10 revealed that they exist in a single conformer of B type in CDCl 3 . Among these metabolites, leptosins O (1) and P (2) exhibited significant cytotoxicity against cultured P388 cells.

Biosorption of di(2-ethylhexyl)phthalate by seaweed biomass

Samples of various Sargassum species were collected in the Hong Kong marine environment and used for studies on biosorption of di(2-ethylhexyl)phthalate (DEHP). Batch adsorption experiments were carried out to determine the removal capacity and removal efficiency of the biosorbents. The DEHP removal ability was similar among beached seaweed and three freshly collected Sargassum species. Different physico-chemical factors were evaluated in order to enhance the performance of the biosorbents. Under optimized conditions (25 mg biomass, initial pH 4, 25 °C, 40 mg L−1 DEHP), the mean removal capacity of beached seaweed and Sargassum siliquastrum was 5.68 and 6.54 mg g−1, respectively. Examination of the Langmuir and Freundlich adsorption isotherms showed that the biosorption phenomenon by these biosorbents could well be described by these models. Desorption of DEHP was also assessed with methanol, which showed the most satisfactory desorbing ability. Further study in multiple adsorption–desorption of DEHP by the biosorbents demonstrated the reusability of both beached seaweed and S. siliquastrum for biosorption of DEHP.

Leptosins O-S, Cytotoxic Metabolites of a Strain of Leptosphaeria Sp. Isolated from a Marine Alga

Leptosins O (1), P (2), Q (3), R (4) and S (5) have been isolated from a strain of Leptosphaeria sp. originally separated from the marine alga Sargassum tortile. Their absolute stereostructures have been elucidated on thebasis of spectroscopic analyses of their acetate derivatives (6-10) using various ID and 2D NMR techniques and some chemical transformations. The NMR and NOE spectral analyses of 6-10 revealed that they exist in a single conformer of B type in CDCl 3 . Among these metabolites, leptosins O (1) and P (2) exhibited significant cytotoxicity against cultured P388 cells.

Seasonal variations of bromophenols in brown algae (Padina arborescens, Sargassum siliquastrum, and Lobophora variegata) collected in Hong Kong.

Distributions and seasonal variations of the key seafood flavor compounds including 2-bromophenol, 4-bromophenol, 2,4-dibromophenol, 2,6-dibromophenol, and 2,4,6-tribromophenol in three species of brown algae (Padina arborescens, Sargassum siliquastrum, and Lobophora variegata) found in Hong Kong waters were investigated. Bromophenols were extracted by simultaneous steam distillation and solvent extraction apparatus and analyzed by gas chromatography-mass spectrometry. On a dried weight basis, the total bromophenol content (TBC) determined varied widely with seasons (from 40.9 to 7030 ng/g). The TBCs detected were higher in winter and lower in summer. Except for 2-bromophenol, the rest of the bromophenols were detected in all of the algal samples. The TBC of L. variegata was generally the highest among all of the algae collected. Relatively high concentrations of bromophenols in algae supported the fact that marine algae were major producers of bromophenols in the marine environment.

Evaluation of antioxidative activity of extracts from a brown seaweed, Sargassum siliquastrum.

Antioxidative activities of the extracts from Sargassum siliquastrum were determined using the inhibition of red blood cell (RBC) hemolysis induced by 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) radicals, suppression of lipid peroxidation using rat brain homogenate, and scavenging activity of superoxide radicals. The dichloromethane fraction isolated from the methanol crude extract by differential solvent extractions exhibited the strongest antioxidant activity in both RBC hemolysis and lipid peroxidation assays. This fraction was further fractionated into four subfractions F1-F4 by silica gel column chromatography. F1 was found to be most effective in protecting RBC against AAPH radicals and in inhibiting lipid peroxidation. On the basis of thin-layer chromatography and UV and IR spectra analyses, all subfractions contained phenolic compounds. However, there was no correlation between the above antioxidant potency and total phenolic compounds estimated by using the Folin-Ciocalteau method.

Leptosins M–N 1, cytotoxic metabolites from a Leptosphaeria species separated from a marine alga. Structure determination and biological activities

Leptosins M ( 4 ), M 1 ( 5 ) N ( 6 ) and N 1 ( 7 ) have been isolated from a strain of Leptosphaeria sp. originally separated from the marine alga Sargassum tortile. Their absolute stereostructures have been elucidated by spectral analyses and some chemical transformations. Their NMR and NOE spectral analyses revealed that 4– 7 exist in a single conformer of B type in acetone- d 6. All the compounds exhibited significant cytotoxicity against cultured P388 cells. In addition, leptosin M ( 4 ) proved to exhibit significant cytotoxicity against human cancer cell lines, and to inhibit specifically two protein kinases, PTK and CaMKIII, and human topoisomerase II.

COMPARISON OF GROWTH AND REPRODUCTION BETWEEN TWO POPULATIONS OF SARGASSUM SILIQUASTRUM IN PING CHAU, HONG KONG

In Ping Chau Island of Hong Kong, two populations of Sargassum siliquastrum are present. One is in the shallow water of about 1 to 3 m Chart Datum (CD), and the other one in deeper water of 5 to 10 m CD. These two populations are separated by an extensive sand patch. Individuals of the “shallow” water population increased their size from a mean length of 8.3 ± 3.6 (SD) cm in Aug 1998 to a maximum of 48.2 ± 29.9 cm in early Jan 1999 before they started to die back. In the following year, they attained a minimum of 6.1 ± 3.8 cm in May 1999 and a maximum of 56.1 ± 23.6 cm in Dec 1999. Their reproductive period lasted for two to three months from Jan to Feb 1999, and again from Nov 1999 to Jan 2000. The “deep” water individuals increased their size to a maximum of 123 ± 50.8 cm at the end of Jan 1999 and started to die back in Feb, 1999. They again reached their maximum mean length in Jan 2000. Their reproductive period lasted for five to six months from Sept 1998 to Feb 1999 and again from Sept 1999 to Jan 2000. The “deep” water individuals tended to be longer in size and they attained their maximum growth a month later than the “shallow” water individuals. Their reproductive season tended to start earlier and lasted longer than those in the “shallow” water. These differences in the phenology of the two populations may be related to the temperature differences (up to 5° C difference in summer) between the two depths. Sargassum siliquastrum is likely to be a cold adapted species such that warmer temperature in the shallow water has compressed and shortened their rapid growth and reproductive period to within the few colder months in fall and winter.

Potent cytotoxic metabolites from a Leptosphaeria species. Structure determination and conformational analysis

New cytotoxic epipolysulfanyldioxopiperazine dimers, leptosins K ( 4), K 1 ( 5) and K 2 ( 6), have been isolated from a strain of Leptosphaeria sp. originally isolated from the marine alga Sargassum tortile. Their stereostructures, with a different configuration from that of leptosins A-C, have been elucidated by spectral and X-ray analyses and some chemical transformations. X-Ray and NMR and NOE spectral analyses of 4 revealed that it exists in a mixture of four conformers, of which two each closely resemble, in a single crystal, and in a single conformer in solution. NOE experiments of 5 and 6 demonstrated that they exist in a mixture of two conformers slowly exchanging in CDCl 3.

土佐湾の外海域に設置した人工礁上に着生する海藻類の遷移

A total of 18 artificial reefs (3 tons each of concrete trapezoid blocks) were placed in Ecklonia and Sargassum community on the gravelly patch about 7m in depth on the coast of Tosa Bay. The quantitative survey of seaweed community was carried out on the artificial reefs for 3 years. Colpomenia sinuosa dominated 1 month after their placement, but disappeared 3 months later. A total number of 19 species including Sargassum siliquastrum and S. micracanthum, Ecklonia cava and Corallina spp. were identified after 11 months and then the number of species was stabilized. The average of seaweed biomass was about 4, 000g wet weight m-2 from 17 months to 28 months and then about 7, 000g wet weight m-2 until 36 months on the blocks. The dominant species through the succession changed from Colpomenia sinuosa into Ecklonia cava as follows: Colpomenia sinuosa→Zonaria diesingiana→Sargassum spp.→Ecklonia cava. It took one and half years for this community on the artificial reefs to achieve the climax phase, which were well comparable to the neighboring area.

Cytotoxic metabolites from a fungal adherent of a marine alga

Leptosins G, G 1, G 2 and H, belonging to a series of dimeric epipolythiodioxopiperazines, were isolated from the mycelium of a strain of Leptosphaeria sp. stuck on the marine alga Sargassum tortile. Their stereostructures were elucidated by chemical and spectral evidence.

Leptosins, antitumour metabolites of a fungus isolated from a marine alga

Leptosins A B, C, D, E and F, chaetocin derivatives, have been isolated from the mycelium of a strain of Leptosphaeria sp. attached to the marine alga Sargassum tortile. Their stereostructures, with a different configuration from that of related compounds, have been elucidated by spectroscopic analyses using various 1D and 2D NMR techniques and some chemical transformations. All the compounds showed potent cytotoxicity against cultured P388 cells, and leptosins A and C exhibited significant antitumour activity against Sarcoma 180 ascites.

Growth of Main Branches of Sargassum siliquastrum at Tsuyazaki, Japan.

Growth of Main Branches of Sargassum siliquastrum at Tsuyazaki, Japan.

Antibacterial activity of crinitol and its potentiation.

An acyclic diterpene alcohol, crinitol [1], was identified in a marine brown alga, Sargassum tortile, as the principal antibacterial agent against Gram-positive bacteria, among which Propionibacterium acnes was most sensitive and, Staphylococcus aureus was least. To enhance its activity, crinitol was combined with several antioxidants, which presumably retard oxidative destruction of this molecule which possesses two easily oxidizable allylic alcohol groups. Two synthetic antioxidants, BHA (butylated hydroxyanisole) and BHT (butylated hydroxytoluene), significantly enhanced the activity of crinitol, especially against Streptococcus mutans. Interestingly, crinitol also synergized BHT and BHA against this cariogenic bacterium.

A cytotoxic principle of the brown alga Sargassum tortile and structures of chromenes

Bioassay-directed fractionation of a methanolic extract of the marine alga Sargassum tortile has led to the isolation and characterization of eight compounds which include the new chromenes sargaol, sargasal-II, and sargadiols-I and -II in addition to sargasal-I, hydroxysargaquinone, kjellmanianone, and fucosterol. Among them, hydroxysargaquinone and sargasals-I and -II demonstrated significant and marginal cytotoxicity against cultured P-388 lymphocytic leukemia cells, respectively.

Cytotoxic activity of marine algae and a cytotoxic principle of the brown alga Sargassum tortile.

Partition fractions of hexane, CCl4 and CHCl3 from methanolic extracts of marine algae were each examined for cytotoxic activities against cultured P-388 lymphocytic leukemia cells. Cytotoxic activities were found for partition fractions of 21 species of seaweed. Bioactivity-guided fractionation of the CCl4 partition fraction from Sargassum tortile, exhibiting the most prominent activity, afforded dihydroxysargaquinone (1) and sargatriol (2) previously isolated from this alga. The former was evaluated as a cytotoxic principle, and the latter, showing moderate activity, was suggested to be an artifact derived from 1 during the isolation procedure.

Structure and absolute configuration of sargatriol, a new isoprenoid chromenol from a brown alga, Sargassum tortile C. Agardh.

The structure of sargatriol, a new phenolic compound containing an oxygenated isoprenoid component isolated from a brown alga Sargassum tortile, was elucidated to be 3 on the basis of spectral and chemical evidence. The absolute stereochemistry was established from the circular dichroism (CD) of sargatriol (3) and the shift reagent-induced CD of the methyl ether (4).

NEW GERANYLGERANYLBENZOQUINONE DERIVATIVES FROM SARGASSUM TORTILE

Abstract From the brown alga, Sargassum tortile, seven new benzoquinones and hydroquinones bearing diterpenoid side chains were isolated. 2-Geranylgeranyl-6-methylbenzoquinone, which is likely to be a basic substance of the diterpenoid-substituted benzoquinones distributed in many Sargassum species, was also obtained.

Structure of sargatriol, a new isoprenoid chromenol from a marine alga: Sargassum tortile.

The ether extract of Sargassum tortile, a marine alga, was examined and a new isoprenoid chromenol was isolated. The structure of this compound was determined to be Ia on the basis of the chemical and spectroscopic evidence.

Canine basilar arterial flow and effects of common carotid occlusion.

ARTICLESCanine basilar arterial flow and effects of common carotid occlusionGS Fukuyama, and WA HimwichGS Fukuyama, and WA HimwichPublished Online:01 Aug 1970https://doi.org/10.1152/ajplegacy.1970.219.2.525MoreSectionsPDF (783 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByVasodilatation effect of farnesylacetones, active constituents of Sargassum siliquastrum, on the basilar and carotid arteries of rabbitsBioorganic & Medicinal Chemistry Letters, Vol. 18, No. 24Comparative effects of unilateral and bilateral carotid artery ligation in the spontaneously hypertensive rat.Stroke, Vol. 11, No. 1Comparison of blood flow and patency in arterial and vein grafts to the basilar arteryComparison of Blood Flow and Patency in Arterial and Vein Grafts to Basilar ArteryStroke, Vol. 6, No. 4Mammary-vertebral microsurgical anastomosisJournal of Surgical Research, Vol. 18, No. 5Exposure of the anterior part of the circle of Willis in the dogJournal of Neurosurgery, Vol. 41, No. 1Basilar Arterial Flow Changes Elicited by Hydralazine Hydrochloride, Isoxsuprine Hydrochloride and Nylidrin HydrochlorideStroke, Vol. 3, No. 3Effects of Betahistine HCl, Nicotinic Acid, and Histamine on Basilar Blood Flow in Anesthetized DogsStroke, Vol. 2, No. 4 More from this issue > Volume 219Issue 2August 1970Pages 525-527 Copyright & PermissionsCopyright © 1970 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1970.219.2.525PubMed5448086History Published online 1 August 1970 Published in print 1 August 1970 Metrics

ホンダワラ類の受精に就いて

1. The fertilization was studied on living materials of the following fucaceous algae: Sargassum enerve, S. tortile, S. Ringgoldianum, S. serratifolium, S. Horneri, Cystophyllum sisymbrioides and Hijikia fusiforme.2. The spermatozoids penetrate into the thick mucilaginous coat of the discharged oosphere at the portion characteristic to each species.3. The mode of penetration in these species is the same as in Sargassum Horneri (Kunieda and Suto in 1940).4. The spermatozoids dissolve the inner oogonial membrane as they pass through it.5. The socalled“fertilization cone”is observed only in Sargassum tortile, not in others.6. No parthenogenesis was observed.