What's the difference between lactone and phthalein?
Lactone
Definition:
(n.) One of a series of organic compounds, regarded as anhydrides of certain hydroxy acids. In general, they are colorless liquids, having a weak aromatic odor. They are so called because the typical lactone is derived from lactic acid.
Example Sentences:
(1) These compounds were tentatively identified as two epimers at C-23 of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestano-26,23-lactone, which were probably artifacts formed from the corresponding tetrahydroxycholestanoic acids during the procedures for extraction after hydrolysis.
(2) Second, both lovastatin and simvastatin are administered as prodrugs in their lactone forms.
(3) The method involves the selective joining of two synthetic fragments, namely residues 1-65 of the apopeptide with Met65 replaced by homoserine lactone and residues 66-104 of the protein in the presence of fragment 1-25 of the native heme-containing peptide.
(4) Two new isomeric delta-lactones 2 and 3 have been isolated from the marine fungus Helicascus kanaloanus (ATCC 18591).
(5) Our data do not support the possibility of hydrogen bonding between the 16 beta-hydroxyl of gitoxigenin and the lactone ring, previously suggested to account for the decreased activity of gitoxigenin vis à vis digitoxigenin, but, rather, suggest that the decreased activity may be due to an intramolecular hydrogen bond between the hydroxyls on C-14 and C-16 and an unusual D-ring conformation which combine to alter the carbonyl oxygen of the lactone ring away from the putative active position.
(6) Status epilepticus was provoked in 10 rats by embedding coriaria lactone particle into the left cerebral motor cortex.
(7) Preliminary results indicate that chloride is eliminated during subsequent lactonization of the 2,3-dichloro-cis,cis-muconate, followed by hydrolysis to form 5-chloromaleylacetic acid.
(8) This ester, on standing, gradually formed the corresponding lactone.
(9) Studies were made on the ultraviolet difference-spectra of glucoamylase from Rhizopus niveus [EC 3.2.1.3] specifically produced by the substrate maltose and the inhibitors, glucose, glucono-1: 5-lactone (gluconolactone), methyl beta-D-glucoside, cellubiose, and cyclohexa-, and cyclohepta-amyloses.
(10) Pharmacokinetics of digitoxin (DGT) and its derivative hydrogenated at the unsaturated lactone ring have been studied using the 3H-labelled compounds in cats.
(11) The enzyme hydrolyzes aldonate lactones, such as D-galactono-gamma-lactone and L-mannono-gamma-lactone, stereospecifically.
(12) Since furanoses in the envelope form are analogous (in some ways) to half-chair or sofa conformations and since lactones with six-membered rings probably have half-chair or sofa conformations, the results indicate that beta-galactosidase probably destabilizes its substrate into a planar conformation of some type and that the galactose in the transition state may, therefore, also be quite planar.
(13) An unusual change in absorbance from 300 to 310-320 nm, obtained only with the valienamine-derived inhibitors or when D-glucono-1,5-lactone and maltose are combined, is concluded to arise when subsite 2 is occupied in a transition-state-type of complex.
(14) These studies showed that neither the strained trans-fused alpha-methylene lactone 12 nor the hydroxy-alpha-methylene lactones 5 and 6 reacted with cysteine with rates comparable to elephantopin.
(15) Relative to that of glucagon, biological activity and affinity of [des-Asn-28,Thr-29](homoserine lactone-27)-glucagon, prepared by CNBr treatment of glucagon, were reduced equally by 40- to 50-fold.
(16) These data indicate that PGF2alpha, 1-15 lactone decreases menstrual cycle lengths in non-pregnant rhesus monkeys.
(17) The metabolic pathway from 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25-(OH)2D3] to 1 alpha,25-dihydroxyvitamin D3-26,23-lactone includes the formation of 1 alpha,23,25-26-tetrahydroxyvitamin D3 [1 alpha,23,25,26-(OH)4D3].
(18) The macrocyclic lactone ring is necessary for antibiotic activity.
(19) The lactones were treated with benzyl mercaptide anion to form 4-(benzylthio)butyric acid, which, on treatment with trifluoroacetic acid, cyclized to yield thiololactones.
(20) Thapsigargin is a potent skin irritating sesquiterpene lactone isolated from the roots of Thapsia garganica L. (Apiaceae).
Phthalein
Definition:
(n.) One of a series of artificial organic dyes made as condensation products of the phenols with phthalic acid, and well represented by phenol phthalein. Their alkaline solutions are fluorescent.
Example Sentences:
(1) There is no compelling explanation for this observation, but two facts are known: fluorescein is a derivative of phthalein, a pH indicator, and ischemic tissues become acidotic, with the pH falling below 7.0.
(2) In our pursuit for liver functional diagnosis, development of bifunctional radiopharmaceutical containing iminodiacetic acid (IDA), as the technetium chelating site along with phthalein or fluorescein structure, the skeleton of BSP and Rose Bengal, long used for the assessment of liver function is considered.
(3) To investigate the molecular requirements and mechanisms for the hepatic uptake of phthaleins, the transport of tetrabromosulfonephthalein (TBS) was investigated in basolateral rat liver plasma membrane vesicles.
(4) The functionality of the various technetium labeled phthalein and fluorescein IDA derivatives was evaluated by competitive BSP binding studies and by comparative binding with the hepatocyte specific protein, ligandin.
(5) The hepatobiliary transport of three structurally related phthaleins was compared in the rat, and found to differ to a large extent in three experimental conditions: 1) after a 72-h fast; 2) after a 4-day phenobarbital treatment; and 3) during infusion of bile salts: sodium dehydrocholate or taurocholate.
(6) A measured absorption increase of the Ca2+-indicator phthalein purple (10 degrees C, 562 nm, pH 9.3) occurs apparently simultaneously with the formation of metarhodopsin ii in ROS.
(7) Bilirubin and phthalein dyes are taken up by the liver via a carrier-mediated mechanism operated at least in part by bilitranslocase (BTL).
(8) Gadolinium-phthalein complexone (Gd-PC) was developed as a hepatobiliary magnetic resonance (MR) contrast agent.
(9) Moreover, inhibitions by rifamycin-SV and bilirubin suggest that there exists a common uptake system for bilirubin, phthaleins and other anions.
(10) It is, therefore, concluded that the phthalein structure recognized for transport is the quinoid molecule, with the dissociated acidic function on the benzene ring.
(11) The minimum requirement for this electrogenic process has been investigated in rat liver plasma membrane vesicles by using Thymol blue, a pH-indicator phthalein occurring either as a neutral, phenolic molecule or as a quinoid, monovalent anion.
(12) 111In has been complexed to a series of metal-complexing phthaleins and sulfonphthaleins, and the hepatobiliary excretion of the compounds were compared in rats.
(13) Phthalein complexone is one of the iminodiacetic acid derivatives and a structural analogue of bromosulfophthalein.
(14) Four Hg-203-mercurated phthaleins were prepared, purified, and compared with [203Hg] mercuric nitrate, [3H] phenolphthalein [203Hg] hydroxymercurifluorescein and Tc-99m-pyrophosphate in a rat model of myocardial necrosis to determine their specificities for damaged myocardium.
(15) Both the hydroxymercuri- functional group and the phthalein moiety are required for selectivity.