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1.
In our ongoing investigation of the bioactive compounds from the extract of the roots of Sophora flavescens, two novel prenylated flavanones, named sophoflavanones A (1) and B (2), each with an unusual pyran ring were isolated. Their structures, as well as their absolute configurations, were elucidated based on spectroscopic data including a comparison of their experimental and calculated electronic circular dichroism (ECD) spectra. Additionally, compounds 1 and 2 showed moderate antioxidant activities against Fe2+/cysteine-induced toxicity at a concentration of 0.1 µM (inhibition values of 71.65% and 72.49%, respectively, using vitamin C as a positive control (87.83%)). 相似文献
2.
Dai‐Chun Li Yan Yang Bing Zhang Xiao‐Jian Liao Zhi‐Hui Jiang Shi‐Hai Xu Bing‐Xin Zhao 《化学与生物多样性》2020,17(5)
Three new butenolides, caulerpalide A and a pair of enantiomers, (+)‐caulerpalide B and (?)‐caulerpalide B, together with seven known compounds, have been isolated from the green alga Caulerpa racemosa var. turbinata. All these structures were determined by spectroscopic techniques. The absolute configurations of caulerpalide A, (+)‐caulerpalide B and (?)‐caulerpalide B were elucidated by the method of ECD calculation. This is the first separation of butenolides from the algae of genus Caulerpa. Additionally, the antibacterial activities of the nine isolated compounds were also evaluated. 相似文献
3.
《Saudi Journal of Biological Sciences》2022,29(4):2772-2781
The green silver nanoparticles (green AgNPs) exhibit an exceptional antimicrobial property against different microbes, including bacteria and fungi. The current study aimed to compare the antifungal activities of both the crude aqueous extract of Portulaca oleracea or different preparations of green AgNPs biosynthesized by mixing that aqueous extract with silver nitrate (AgNO3). Two preparations of the green AgNPs were synthesized either by mixing the aqueous extract of P. oleracea with silver nitrate (AgNO3) (normal AgNPs) or either irradiation of the AgNPs, previously prepared, under 60Co γ-ray using chitosan (gamma-irradiated AgNPs). Characterization of different AgNPs were tested by Zeta potential analyzer, Ultraviolet (UV) Visible Spectroscopy, and Fourier-Transform Infrared (FTIR) spectrometry. Three different plant pathogenic fungi were tested, Curvularia spicifera, Macrophomina phaseolina, and Bipolaris sp. The antifungal activities were evaluated by Transmission Electron Microscope (TEM) for either the crude aqueous extract of P. oleracea at three doses (25%, 50%, and 100%) or the newly biosynthesized AgNPs, normal or gamma-irradiated. With a few exceptions, the comparative analysis revealed that the irradiated green AgNPs at all three concentrations showed a relatively stronger antifungal effect than the normal AgNPs against all the three selected fungal strains. UV–visible spectroscopy of both preparations showed surface plasmon resonance at 421 nm. TEM results showed that both AgNPs were aggregated and characterized by a unique spherical shape, however, the gamma-irradiated AgNPs were smaller than the non-irradiated AgNPs (0.007–0.026 µM vs. 0.009–0.086 µM). TEM photographs of the fungal strains treated with the two AgNPs preparations showed flaccid structures, condensed hyphae, and shrunken surface compared with control cells. The data suggested that the biosynthesized P. oleracea AgNPs have antifungal properties against C. spicifera, M. phaseolina, and Bipolaris sp. These AgNPs may be considered a fungicide to protect different plants against phytopathogenic fungi. 相似文献
4.
Two new triterpene glycosides, patagonicosides B and C (2 and 3, resp.), together with the known patagonicoside A (1), have been isolated from the EtOH extract of the sea cucumber Psolus patagonicus. The structures of the new compounds were established on the basis of extensive NMR spectroscopic analysis ((1)H- and (13)C-NMR, (1)H,(1)H-COSY, HMBC, HSQC, TOCSY, and NOESY), HR-ESI-MS data, and chemical transformations. Compounds 1-3 and their desulfated analogs showed antifungal activities against the phytopathogenic fungus Cladosporium cladosporoides in a dose-dependent fashion. 相似文献
5.
Lannang AM Komguem J Ngninzeko FN Tangmouo JG Lontsi D Ajaz A Choudhary MI Ranjit R Devkota KP Sondengam BL 《Phytochemistry》2005,66(19):2351-2355
Two xanthones, bangangxanthone A (1) [1,5,8-trihydroxy-6'-methyl-6'-(4-methylpent-3-enyl)- pyrano[2',3':3,4]xanthone] and B (2) [1,4,8-trihydroxy-2-prenylxanthone], along with two known xanthones, 1,5-dihydroxyxanthone, 2-hydroxy-1,7-dimethoxyxanthone and the pentacyclic triterpenoids, friedelin, oleanolic acid and lupeol were isolated from the chloroform extract of the stem bark of Garcinia polyantha. The structures of these compounds were assigned by spectroscopic analysis. Compounds 1-4 showed antioxidant DPPH radical scavenging activities. 相似文献
6.
Protoplasts have been obtained from vegetative thallus of the green seaweed Enteromorpha following enzymic digestion with driselase and pectinase. The viability of purified protoplast fractions was assessed by staining and measurements of O2 uptake and evolution.Abbreviations MES
2-(N-morpholino) ethanesulphonic acid
- TES
N-tris(hydoxymethyl) methyl-2 aminoethanesulphonic acid 相似文献
7.
Jin‐Yan Dong Li‐Mei Wang Hong‐Chuang Song Kai‐Ze Shen Yong‐Ping Zhou Le Wang Ke‐Qin Zhang 《化学与生物多样性》2009,6(8):1216-1223
Two novel diastereoisomeric bicyclic ketals, colomitides A and B ( 1 and 2 , resp.), together with the known (4RS)‐3,4‐dihydro‐4,8‐dihydroxynaphthalen‐1(2H)‐one ( 3 ) and preussomerin E ( 4 ), were isolated from liquid cultures of an unidentified freshwater fungus YMF 1.01029. Colomitides possess an unusual 2,7‐dioxabicyclo[3.2.1]octane skeleton. The chemical structures and relative configurations of compounds 1 and 2 were elucidated by spectroscopic means, including 2D‐NMR (HMBC, HMQC, TOCSY, ROESY, and 1H,1H‐COSY). Compounds 1, 2 , and 4 showed noticeable antifungal and antibacterial activities. 相似文献
8.
Shui-Chun Mao Ding-Quan Liu Xiao-Qing Yu Xiao-Ping Lai 《Biochemical Systematics and Ecology》2011,39(4-6):253-257
A new polyacetylenic fatty acid, (8E,12Z,15Z)-10-hydroxy-8,12,15-octadecatrien-4,6-diynoic acid (1), together with five known metabolites, including two linear diterpenes (3 and 4) and three sterols (5–7), has been isolated from the Chinese green alga Caulerpa racemosa. Its structure was determined on the basis of extensive spectroscopic analysis. Compound 1 represents the first example of polyacetylenic lipids from marine algae up to now, while compound 4 is characterized for the first time in the Caulerpaceae. Furthermore, the chemotaxonomic significance of these compounds was also summarized. 相似文献
9.
Two new monoterpenoid indole alkaloids, melohenryines A and B (1 and 2), along with six known indole alkaloids, were isolated from the twigs and leaves of Melodinus henryi. Structures of the new alkaloids were established by extensive spectroscopic techniques including NMR spectroscopy and mass spectrometry. Melohenryine A (1) represents the first example of monoterpenoid indole alkaloids characterized an ester carbonyl group at C-19 position. All of the new compounds were evaluated for in vitro cytotoxicity against several human cancer cell lines. 相似文献
10.
Kozhiparambil K. Purushothaman Mathuram Venkatanarasimhan Ayyappath Sarada 《Phytochemistry》1985,24(4):773-776
Two new iridoid glucosides, arbortristoside A and B have been isolated from the seeds of Nyctanthes arbortristis. The structures of the two new compounds were determined by spectroscopic methods and chemical reactions. 相似文献
11.
Kiminori Matsubara Masaharu Mori Hiroaki Matsumoto Kanji Hori Keisuke Miyazawa 《Journal of applied phycology》2003,15(1):87-90
An anticoagulant sulfated galactan isolated from the marine green alga, Codium cylindricum, was shown to have antiangiogeinic activity. This galactan suppressed microvessel formation in an ex vivo serum-free matrix culture model using rat aortic ring. It also inhibited human umbilical vein endothelial cells (HUVEC) tube formation on reconstituted basement membrane gel. These results show the value of algal sulfated galactans in the design of antiangiogenic agents. 相似文献
12.
Statistical optimization of antifungal iturin A production from Bacillus amyloliquefaciens RHNK22 using agro-industrial wastes 总被引:1,自引:0,他引:1
《Saudi Journal of Biological Sciences》2017,24(7):1722-1740
Biosurfactants are secondary metabolites with surface active properties and have wide application in agriculture, industrial and therapeutic products. The present study was aimed to screen bacteria for the production of biosurfactant, its characterization and development of a cost effective media formulation for iturin A production. A total of 100 bacterial isolates were isolated from different rhizosphere soil samples by enrichment culture method and screened for biosurfactant activity. Twenty isolates were selected for further studies based on their biosurfactant activity [emulsification index (EI%), emulsification assay (EA), surface tension (ST) reduction] and antagonistic activity. Among them one potential isolate Bacillus sp. RHNK22 showed good EI% and EA with different hydrocarbons tested in this study. Using biochemical methods and 16S rRNA gene sequence, it was identified as Bacillus amyloliquefaciens. Presence of iturin A in RHNK22 was identified by gene specific primers and confirmed as iturin A by FTIR and HPLC. B. amyloliquefaciens RHNK22 exhibited good surface active properties and antifungal activity against Sclerotium rolfsii and Macrophomina phaseolina. For cost-effective production of iturin A, 16 different agro-industrial wastes were screened as substrates, and Sunflower oil cake (SOC) was favouring high iturin A production. Further, using response surface methodology (RSM) model, there was a 3-fold increase in iturin A production (using SOC 4%, inoculum size 1%, at pH 6.0 and 37 °C temperature in 48 h). This is the first report on using SOC as a substrate for iturin A production. 相似文献
13.
The green algae of the genus Codium have recently been demonstrated to be an important source of sulfated galactans from the marine environment. Here, a sulfated galactan was isolated from the species Codium isthmocladum and its structure was studied by a combination of chemical analyses and NMR spectroscopy. Two fractions (SG 1, approximately 14 kDa, and SG 2, approximately 20 kDa) were derived from this highly polydisperse and heterogeneous polysaccharide. Both exhibited similar structures in (1)H 1D NMR spectra. The structural features of SG 2 and its desulfated derivative were analyzed by COSY, TOCSY, DEPT-HSQC, HSQC, and HMBC. This sulfated galactan is composed preponderantly of 4-sulfated, 3-linked beta-D-galactopyranosyl units. In minor amounts, it is sulfated and glycosylated at C-6. Pyruvate groups are also found, forming five-membered cyclic ketals as 3,4-O-(1'carboxy)-ethylidene-beta-D-galactose residues. A comparison of sulfated galactans from different marine taxonomic groups revealed similar backbones of 3-beta-D-Galp-1. 相似文献
14.
Despite the well-characterized function of the green-algal eyespot apparatus as a combined absorption/reflection screen for
the photoreceptor for phototaxis, little is known about the proteins involved in the formation of this complex organelle.
We therefore purified the carotenoid-rich lipid globules, which are the most conspicuous component of the eyespot sensu strictu
from Spermatozopsis similis Preisig et Melkonian. Electron microscopy and an average carotenoid:chlorophyll ratio of 51, confirmed the high purity of
the fraction. The diameter of isolated globules (approx. 112 nm) fell within their in vivo range (90–120 nm). Absorption spectra
in aqueous media peaked at 535 nm. The predominant carotenoids were β,ψ-, β, β- and δ-carotene. Freeze-fracture studies with
cells and whole-mount electron microscopy of isolated globules demonstrated regularly arranged particles at the globule surface.
Sodium dodecyl sulfate–polyacrylamide gel electrophresis revealed specific enrichment of 10 tightly bound major proteins and
several minor proteins with the globules. Proteases were used to analyze their topology and function. Upon treatment with
thermolysin, globules were released from a fraction enriched in isolated eyespot apparatuses. Major proteins of these globules,
and those treated with thermolysin after isolation, were identical. However, the purified proteins were sensitive to thermolysin,
indicating that domains of them are normally hidden in the globule matrix. In contrast, pronase degraded all globule-associated
proteins in situ. These globules were not stable and easily fused, whereas thermolysin-treated globules were relatively stable.
Lipase did not affect globule stability. These results indicate that the five thermolysin-resistant proteins (apparent M
r values: 56, 52, 32, 29, 27 kDa) are close to the surface and might be crucial for globule stabilization, whereas the thermolysin-accessible
proteins are probably involved in globule/globule interactions and/or globule/eyespot-membrane interactions.
Received: 19 June 2000 / Accepted: 4 October 2000 相似文献
15.
Caulerpicin from the green alga Caulerpa racemosa is shown to consist of a mixture of ceramides derived from 2S, 3R-sphinganine with C18 (32%), C20(2%), C22(6%), C24(35%) and C26(25%) saturated fatty acid 相似文献
16.
Daniel Obando Namfon Pantarat Rosemary Handke Yasuko Koda Fred Widmer Julianne T. Djordjevic David H. Ellis Tania C. Sorrell Katrina A. Jolliffe 《Bioorganic & medicinal chemistry》2009,17(17):6329-6339
A series of bis(alkylpyridinium)alkanes with a twelve carbon spacer between the positive charges was synthesised and their antifungal activity has been investigated. Compounds with 2-pentyl, 4-pentyl, 4-hexyl, 4-octyl, 4-propylbenzene, 3,4-dipentyl, 4-(5′-nonyl) and 3-methyl,4-pentyl head groups were the most potent antifungal agents with MICs in the range of 1.4–2.7 μM against reference strains of both Cryptococcus neoformans and Candida albicans. 相似文献
17.
Two new long-chain secobutanolides, illigerones A (1) and B (2), together with five known compounds, actinodaphnine (3), cryptodorine (4), β-sitosterol (5), daucosterol (6), and stigmasterol (7) were isolated from Illigera henryi W. W. Sm. The structures of 1 and 2 were identified by HRESIMS, EIMS, 1D/2D NMR, and electronic circular dichroism (ECD) spectra. Compound 1 exhibited the moderate cytotoxic activities against five tumour cells. This is the first report of secobutanolides isolated from plants of Hernandiaceae. 相似文献
18.
The re-investigation of Montanoa tomentosa afforded, in addition to known diterpenoids of the kaurene class, two new sesquiterpene lactones, zoapatanolide A and B, of the heliangolide type. 相似文献
19.
Gao SS Li XM Li CS Proksch P Wang BG 《Bioorganic & medicinal chemistry letters》2011,21(10):2894-2897
Two new polyoxygenated steroids, namely, penicisteroids A and B (1 and 2), were obtained from the culture extract of Penicillium chrysogenum QEN-24S, an endophytic fungus isolated from an unidentified marine red algal species of the genus Laurencia. In addition, seven known steroids (3-9) were also isolated and identified. The structures of these compounds were established on the basis of extensive spectroscopic analysis. The absolute configuration for compound 1 was determined by application of the modified Mosher’s method. Penicisteroid A (1), which is a structurally unique steroid having tetrahydroxy and C-16-acetoxy groups, displayed potent antifungal and cytotoxic activity in the preliminary bioassays. Preliminary structure-activity relationships are discussed. 相似文献
20.
《Cryptogamie Algologie ☆》2001,22(4):459-466
Caulerpa taxifolia and C. racemosa are tropical green algae now found in the Mediterranean, where the former was accidentally introduced and the latter presumably also introduced; both species have spread rapidly and invaded a variety of habitats. Since 1996, the two algae have co-inhabited a region along the Tuscan coast near Livorno. The present study has been carried out to evaluate the invasive capacity of the two species. After one year, the increase in surface area was 67.5 % for C. taxifolia and 284.8 % for C. racemosa, while the increase in patch number was 11.4 % and 121.4 % respectively. The stolon growth of the two algae followed a similar trend, as is showing the same temporal variations with the maximum growth rate between August and October. At the end of the study period, the increase in stolon length and number was significantly higher in C. racemosa than in C. taxifolia. The results of the present study show a higher invasive potential in C. racemosa than in C. taxifolia, although further studies are necessary to evaluate the competition between the two algae and the effect of their simultaneous presence on the benthic community. 相似文献