Cochliomycin G, a 14-membered resorcylic acid lactone from a marine-derived fungus Cochliobolus lunatus

2019 ◽  
pp. 1-4 ◽  
Author(s):  
Wei-Feng Xu ◽  
Xiao-Jia Xue ◽  
Yue-Xuan Qi ◽  
Na-Na Wu ◽  
Chang-Yun Wang ◽  
...  
Keyword(s):  
Cochliobolus Lunatus ◽  
Acid Lactone

Metal Biosorption by Cochliobolus lunatus with High Cadmium Resistance

2013 ◽  
Vol 19 (4) ◽  
pp. 694-698 ◽  
Author(s):  
Hong FENG ◽  
Yongtao LI ◽  
Gan ZHANG ◽  
Chunling LUO
Keyword(s):  
Cadmium Resistance ◽  
Metal Biosorption ◽  
Cochliobolus Lunatus

scholarly journals Complete and efficient conversion of plant cell wall hemicellulose into high-value bioproducts by engineered yeast

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Liang Sun ◽  
Jae Won Lee ◽  
Sangdo Yook ◽  
Stephan Lane ◽  
Ziqiao Sun ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Cellulosic Biomass ◽  
Hemicellulose Hydrolysate ◽  
Acetyl Coa ◽  
Engineered Yeast ◽  
Fermentation Inhibitor ◽  
Acid Lactone

AbstractPlant cell wall hydrolysates contain not only sugars but also substantial amounts of acetate, a fermentation inhibitor that hinders bioconversion of lignocellulose. Despite the toxic and non-consumable nature of acetate during glucose metabolism, we demonstrate that acetate can be rapidly co-consumed with xylose by engineered Saccharomyces cerevisiae. The co-consumption leads to a metabolic re-configuration that boosts the synthesis of acetyl-CoA derived bioproducts, including triacetic acid lactone (TAL) and vitamin A, in engineered strains. Notably, by co-feeding xylose and acetate, an enginered strain produces 23.91 g/L TAL with a productivity of 0.29 g/L/h in bioreactor fermentation. This strain also completely converts a hemicellulose hydrolysate of switchgrass into 3.55 g/L TAL. These findings establish a versatile strategy that not only transforms an inhibitor into a valuable substrate but also expands the capacity of acetyl-CoA supply in S. cerevisiae for efficient bioconversion of cellulosic biomass.

scholarly journals Structure modification, antialgal, antiplasmodial, and toxic evaluations of a series of new marine-derived 14-membered resorcylic acid lactone derivatives

2021 ◽  
Author(s):  
Wei-Feng Xu ◽  
Na-Na Wu ◽  
Yan-Wei Wu ◽  
Yue-Xuan Qi ◽  
Mei-Yan Wei ◽  
...  
Keyword(s):  
Positive Control ◽  
Structure Modification ◽  
Inhibitory Effects ◽  
Cytotoxicity Assays ◽  
Structure Activity ◽  
Novel Drugs ◽  
Systematic Strategy ◽  
Nmr Techniques ◽  
Acid Lactone ◽  
Drug Leads

AbstractMarine natural products play critical roles in the chemical defense of many marine organisms and are essential, reputable sources of successful drug leads. Sixty-seven 14-membered resorcylic acid lactone derivatives 3–27 and 30–71 of the natural product zeaenol (1) isolated from the marine-derived fungus Cochliobolus lunatus were semisynthesized by chlorination, acylation, esterification, and acetalization in one to three steps. The structures of these new derivatives were established by HRESIMS and NMR techniques. All the compounds (1–71) were evaluated for their antialgal and antiplasmodial activities. Among them, 14 compounds displayed antifouling activities against adhesion of the fouling diatoms. In particular, 9 and 34 exhibited strong and selective inhibitory effects against the diatoms Navicula laevissima and Navicula exigua (EC50 = 6.67 and 8.55 μmol/L), respectively, which were similar in efficacy to those of the positive control SeaNine 211 (EC50 = 2.90 and 9.74 μmol/L). More importantly, 38, 39, and 69–71 showed potent antiplasmodial activities against Plasmodium falciparum with IC50 values ranging from 3.54 to 9.72 μmol/L. Very interestingly, the five antiplasmodial derivatives displayed non-toxicity in the cytotoxicity assays and the zebrafish embryos model, thus, representing potential promising antiplasmodial drug agents. The preliminary structure–activity relationships indicated that biphenyl substituent at C-2, acetonide at positions C-5′ and C-6′, and tri- or tetra-substituted of acyl groups increased the antiplasmodial activity. Therefore, combining evaluation of chemical ecology with pharmacological models will be implemented as a systematic strategy, not only for environmentally friendly antifoulants but also for structurally novel drugs.

Engineering dithiobenzoic acid lactone-decorated Si-rhodamine as a highly selective near-infrared HOCl fluorescent probe for imaging drug-induced acute nephrotoxicity

2019 ◽  
Vol 55 (73) ◽  
pp. 10916-10919 ◽  
Author(s):  
Jinping Wang ◽  
Dan Cheng ◽  
Longmin Zhu ◽  
Peng Wang ◽  
Hong-Wen Liu ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Near Infrared ◽  
Drug Induced ◽  
Acid Lactone ◽  
First Time

A NIR fluorescent probe based on Si-rhodamine dithiobenzoic acid lactone was used to selectively visualize HOCl during GEN-induced nephrotoxicity for the first time.

Application of response surface methodology for rapid chrysene biodegradation by newly isolated marine-derived fungus Cochliobolus lunatus strain CHR4D

2014 ◽  
Vol 52 (11) ◽  
pp. 908-917 ◽  
Author(s):  
Jwalant K. Bhatt ◽  
Chirag M. Ghevariya ◽  
Dushyant R. Dudhagara ◽  
Rahul K. Rajpara ◽  
Bharti P. Dave
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Cochliobolus Lunatus

The effect of the microbial flora on the flavour and free fatty acid composition of cheddar cheese

1967 ◽  
Vol 34 (3) ◽  
pp. 257-272 ◽  
Author(s):  
B. Reiter ◽  
T. F. Fryer ◽  
A. Pickering ◽  
Helen R. Chapman ◽  
R. C. Lawrence ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Acetic Acid ◽  
Fatty Acid Composition ◽  
Milk Fat ◽  
Gluconic Acid ◽  
Bacterial Flora ◽  
Single Strain ◽  
Acid Lactone ◽  
Aseptic Conditions ◽  
Higher Fatty Acids

SummaryComparisons were made of the flavour, free fatty acids and bacterial flora of commercial cheese made at different factories and experimental cheese made under aseptic conditions: (i) with δ-gluconic acid lactone instead of starter, (ii) with starter only, (iii) with starter and added floras derived from the curd of the commercial cheeses (reference flora cheeses).Comparison of the bacterial flora of commercial and reference flora cheeses showed that replication of organisms was better with some reference floras than with others. In all the cheeses the lactobacilli increased in numbers during maturation, whilst other groups of organisms died out.The amount of acetic acid present was influenced by the starter and by the lactobacilli. Single-strain starters produced some acetic acid, most of which was lost in the whey; commercial starters produced considerably more, due to the presence in them of Streptococcus diacetilactis. Later in maturation lactobacilli increased the acetic acid content, a greater increase being observed with homo-than with heterofermentative strains.The initial levels of butyric and higher fatty acids in the milk varied with source of the milk and with the season, summer milk having higher levels than winter milk. During cheese-making a slight increase of these acids occurred in every cheese made with starter and a further small increase occurred during ripening. However, there was no increase in the content of these acids in the cheese made with δ-gluconic acid lactone, indicating that lactic acid bacteria were weakly hydrolysing the milk fat.Flavour trials showed that Cheddar flavour was present not only in the reference flora and commercial cheese, but also in the cheese made with starter only. Different starters produced different intensities of flavour; one strain produced an intense fruity off-flavour. Cheeses made with δ-gluconic acid lactone were devoid of cheese flavour.

The synthesis of norbornanes with functionalized carbon substituents at a bridgehead. 1-(3-Oxonorborn-1-yl)ethanone and 1-(3-oxonorborn-1-yl)-2-propanone

1992 ◽  
Vol 70 (5) ◽  
pp. 1492-1505 ◽  
Author(s):  
Peter Yates ◽  
Magdy Kaldas
Keyword(s):  
Acetic Acid ◽  
Carboxylic Acid ◽  
Hydrogen Bromide ◽  
Tertiary Alcohol ◽  
Ethyl Bromoacetate ◽  
Second Molar ◽  
Molar Equivalent ◽  
Acid Lactone ◽  
Basic Hydrolysis ◽  
Hydrolysis Of

Treatment of 2-norobornene-1-carboxylic acid (7) with one equivalent of methyllithium in ether followed by a second molar equivalent after dilution with tetrahydrofuran gave 1-(norborn-2-en-lyl)ethanone (10) and only a trace of the tertiary alcohol 11. Reaction of 7 with formic acid followed by hydrolysis gave a 4:3 mixture of exo-3- and exo-2-hydroxynorbornane-1-carboxylic acid (16 and 17), whereas oxymercuration–demercuration gave only the exo-3-hydroxy isomer 16. Oxidation of 16 and 17 gave 3- and 2-oxonorbornane-1-carboxylic acid (27 and 29), respectively. Oxymercuration–demercuration of 10 gave exclusively 1-(exo-3-hydroxynorborn-1-yl)ethanone (30), which was also prepared by treatment of 16 with methyllithium in analogous fashion to that used for the conversion of 7 to 10. Oxidation of 30 gave 1-(3-oxonorborn-1-yl)ethanone (1). Dehydrobromination of exo-2-bromonorbornane-1-acetic acid and dehydration of 2-hydroxy-norbornane-2-acetic acid derivatives gave 1-(norborn-2-ylidene) acetic acid derivatives to the exclusion of norborn-2-ene-1 -acetic acid derivatives. Treatment of exo-5-acetyloxy-2-norobornanone (52) with ethyl bromoacetate and zinc gave ethyl exo-5-acetyloxy-2-hydroxynorbornane-(exo- and endo-2-acetate (53 and 54). Reaction of 53 with hydrogen bromide gave initially ethyl endo-3-acetyloxy-exo-6-bromonorbornane-1-acetate (59), which was subsequently converted to a mixture of 59 and its exo-3-acetyloxy epimer 61. Catalytic hydrogenation of this mixture gave a mixture of ethyl endo- and exo-3-acetyloxynorbornane-1 -acetate (62 and 63). Basic hydrolysis of this gave a mixture of the corresponding hydroxy acids, 70 and 71; the former was slowly converted to the latter at pH 5. Oxidation of the mixture of 70 and 71 gave 3-oxonorbornane-1-acetic acid (72). Treatment of the mixture with methyllithium as for 16 gave a mixture of 1-(endo- and exo-3-hydroxynorborn-1-yl)-2-propanone (73 and 74), which was oxidized to 1-(3-oxo-norborn-1-yl)-2-propanone (2). Reaction of exo-2-hydroxynorbornane-1-acetic acid lactone (75) with methyllithium in ether gave (1-(exo-2-hydroxynorborn-1-yl)-2-propanone (76), which on oxidation gave the 2-oxo isomer 78 of 2.

scholarly journals Incorporation of dl-[2−14C]mevalonic acid lactone into β-carotene and the phytol side chain of chlorophyll in cotyledons of four species of pine seedlings

1967 ◽  
Vol 105 (1) ◽  
pp. 89-92 ◽  
Author(s):  
S. Wieckowski ◽  
T W Goodwin
Keyword(s):  
Mevalonic Acid ◽  
Side Chain ◽  
Pinus Silvestris ◽  
Pine Seedlings ◽  
Acid Lactone ◽  
Β Carotene

1. The incorporation of dl-[2−14C]mevalonic acid lactone into β-carotene and the phytol side chain of chlorophyll has been investigated in cotyledons of four species of pine seedlings (Pinus silvestris, P. contorta, P. radiata and P. jeffrei) grown in darkness and in light. 2. The relative incorporation of label into β-carotene and the phytol side chain of chlorophyll is similar to that observed in experiments on monocotyledons and dicotyledons. 3. The relative incorporation of 14CO2 into β-carotene and phytol is much higher than the incorporation of [2−14C]mevalonic acid.

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