(n.) A substance of a resinous nature, obtained from the outer bark of the common European birch (Betula alba), or from the tar prepared therefrom; -- called also birch camphor.
Example Sentences:
(1) Based on spectroscopic data and chemical transformations, the structures of the new constituents were determined as 3-epi-betulinic acid 3-O-beta-D-glucopyranoside 28-O-[alpha-L-rhamnopyranosyl(1----4)-O-beta-D-glucopyranosyl(1----6)]-b eta- D-glucopyranoside and alpha-L-rhamnopyranosyl(1----4)-O-beta-D-glucopyranosyl(1----6)-beta-D- glucopyranose.
(2) The structures of the glycosides have been determined as 28-O-[alpha-L-rhamnopyranosyl(1----4)-O-beta-D-glucopyranosyl(1----6)-be ta-D- glucopyranosides of 3 alpha-hydroxy-lup-20(29)-ene-23,28-dioic acid, 3 alpha,11 alpha- dihydroxy-lup20(29)-ene-23,28-dioic acid and 3-epi-betulinic acid by spectroscopic data and chemical transformations.
(3) In addition to 3-epi-betulinic acid, three triterpene glycosides were isolated from leaves of Schefflera octophylla.
(4) On the basis of spectrometric analysis and physico-chemical constants they were identified as oleanolic acid, betulin and beta-sitosterol-D-glucoside respectively.
(5) A new triterpene saponin was isolated from the roots of Ampelozizyphus amazonicus together with the known 3-O-beta-D-glucopyranosyl-20-O-alpha-L-rhamnopyranosyljujubogenin and the known triterpenes melaleucic acid, 3 beta,27 alpha-dihydroxylup-20(29)-en-28 beta-oic acid, betulinic acid, betulin, lupeol.
(6) The constituents responsible for this activity were identified as uvaol, ursolic acid, and betulinic acid.
(7) From spectroscopic data and chemical transformations the structure of the new constituent was determined as 3-epi-betulinic acid 3-O-sulphate 28-O-[alpha-L-rhamnopyranosyl(1----4)-O-beta-D-glucopyranosyl (1----6)]-beta-D-glucopyranoside.
(8) A phytochemical investigation of Grewia bicolor gave the following results: the petroleum ether extract afforded beta-sitosterol and beta-sitosterol- and triterpene esters, and the triterpenes lupeol and betulin.
(9) megaphyllum gave (E)-betulin-3-p-coumarate [20] and (Z)-betulin-3-p-coumarate [21], both of which appear to be novel.
(10) beta-Sitosterol, betulinic acid, ursolic acid, 2alpha-hydroxyursolic acid, 2alpha,3alpha-dihydroxyurs-12-en-28-oic acid and a new triterpene acid, jacarandic acid, were also isolated.
(11) A new acetylated bidesmosidic triterpenoid saponin has been isolated from the leaves of Schefflera octophylla and structurally elucidated as 3-epi-betulinic acid 3-O-beta-D-6'-acetylglucopyranoside 28-[alpha-L-rhamnopyranosyl(1----4)-O-beta-D-glucopyranosyl(1----6)]-bet a-D-0-glucopyranoside [1].
(12) In addition, 5 mumol betulinic acid markedly inhibited the promoting effect of 2.5 micrograms TPA applied twice weekly on skin tumor formation in mice initiated with 50 micrograms of 7,12-dimethylbenz[a]anthracene, and 5 mumol of sitosterol caused slight suppression.
Isolate
Definition:
(v. t.) To place in a detached situation; to place by itself or alone; to insulate; to separate from others.
(v. t.) To insulate. See Insulate.
(v. t.) To separate from all foreign substances; to make pure; to obtain in a free state.
Example Sentences:
(1) A series of human cDNA clones of various sizes and relative localizations to the mRNA molecule were isolated by using the human p53-H14 (2.35-kilobase) cDNA probe which we previously cloned.
(2) On the other hand, human IL-9, which is a homologue to murine P40, was cloned from a cDNA library prepared with mRNA isolated from PHA-induced T-cell line (C5MJ2).
(3) Open field behaviors and isolation-induced aggression were reduced by anxiolytics, at doses which may be within the sedative-hypnotic range.
(4) The ability of azelastine to influence antigen-induced contractile responses (Schultz-Dale phenomenon) in isolated tracheal segments of the guinea-pig was investigated and compared with selected antiallergic drugs and inhibitors of arachidonic acid metabolism.
(5) One thing seems to be noteworthy in their opinion: the bacterial resistance of the germs isolated from the urine is bigger than the one of the germs isolated from the respiratory apparatus.
(6) Thus, saponin and ammonium chloride can be used to isolate whole infected erythrocytes, depleted of hemoglobin, by selective disruption of uninfected cells.
(7) Detergent-solubilized HLA antigens were isolated from a human lymphoblastoid cell using an anti-beta2-microglobulin immunoaffinity column.
(8) A phytochemical investigation of an ethanolic extract of the whole plant of Echites hirsuta (Apocynaceae) resulted in the isolation and identification of the flavonoids naringenin, aromadendrin (dihydrokaempferol), and kaempferol; the coumarin fraxetin; the triterpene ursolic acid; and the sterol glycoside sitosteryl glucoside.
(9) The present findings indicate that the deafferented [or isolated] hypothalamus remains neuronally isolated from the environment if the operation is carried out later than the end of the first week of life.
(10) Proliferation assays using F3 showed that 15 (14 CD4+ and 1 CD8+) of the 18 isolated clones were specific for T. gondii.
(11) Similar to intact crayfish, animals with an isolated protocerebrum-eyestalk complex, exhibit competent circadian rhythms in the electroretinogram (ERG).
(12) Reiteration VII (within protein coding regions of genes US10 and US11) and reiteration IV (within introns of genes US1 and US12) were stable between the isolates (group 1).
(13) The role of O2 free radicals in the reduction of sarcolemmal Na+-K+-ATPase, which occurs during reperfusion of ischemic heart, was examined in isolated guinea pig heart using exogenous scavengers of O2 radicals and an inhibitor of xanthine oxidase.
(14) The agent present in the serum which causes dissolution of the fibrin clot was isolated and identified as pepsinogen.
(15) Completeness of isolation of the coronary and systemic circulations was shown by the marked difference in appearance times between the reflex hypotensive responses from catecholamine injections into the isolated coronary circulation and the direct hypertensive response from a similar injection when the circulations were connected as well as by the marked difference between the pressure pulses recorded simultaneously on both sides of the aortic balloon separating the two circulations.4.
(16) At the same time the duodenum can be isolated from the stomach and maintained under constant stimulus by a continual infusion at regulated pressure, volume and temperature into the distal cannula.
(17) Only the approximately 2.7 kb mRNA species was visualized in Northern blots of total cellular and poly(A+) RNA isolated from cardiac ventricular muscle.
(18) These major departmental transformations are being run in isolation from each other.
(19) This postulate is supported by a limited study of the serovars present among the isolates.
(20) Plasma membranes were isolated from rat kidney and their transport properties for sodium, calcium, protons, phosphate, glucose, lactate, and phenylalanine were investigated.