(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.
Natural
Definition:
(a.) Fixed or determined by nature; pertaining to the constitution of a thing; belonging to native character; according to nature; essential; characteristic; not artifical, foreign, assumed, put on, or acquired; as, the natural growth of animals or plants; the natural motion of a gravitating body; natural strength or disposition; the natural heat of the body; natural color.
(a.) Conformed to the order, laws, or actual facts, of nature; consonant to the methods of nature; according to the stated course of things, or in accordance with the laws which govern events, feelings, etc.; not exceptional or violent; legitimate; normal; regular; as, the natural consequence of crime; a natural death.
(a.) Having to do with existing system to things; dealing with, or derived from, the creation, or the world of matter and mind, as known by man; within the scope of human reason or experience; not supernatural; as, a natural law; natural science; history, theology.
(a.) Conformed to truth or reality
(a.) Springing from true sentiment; not artifical or exaggerated; -- said of action, delivery, etc.; as, a natural gesture, tone, etc.
(a.) Resembling the object imitated; true to nature; according to the life; -- said of anything copied or imitated; as, a portrait is natural.
(a.) Having the character or sentiments properly belonging to one's position; not unnatural in feelings.
(a.) Connected by the ties of consanguinity.
(a.) Begotten without the sanction of law; born out of wedlock; illegitimate; bastard; as, a natural child.
(a.) Of or pertaining to the lower or animal nature, as contrasted with the higher or moral powers, or that which is spiritual; being in a state of nature; unregenerate.
(a.) Belonging to, to be taken in, or referred to, some system, in which the base is 1; -- said or certain functions or numbers; as, natural numbers, those commencing at 1; natural sines, cosines, etc., those taken in arcs whose radii are 1.
(a.) Produced by natural organs, as those of the human throat, in distinction from instrumental music.
(a.) Of or pertaining to a key which has neither a flat nor a sharp for its signature, as the key of C major.
(a.) Applied to an air or modulation of harmony which moves by easy and smooth transitions, digressing but little from the original key.
(n.) A native; an aboriginal.
(n.) Natural gifts, impulses, etc.
(n.) One born without the usual powers of reason or understanding; an idiot.
(n.) A character [/] used to contradict, or to remove the effect of, a sharp or flat which has preceded it, and to restore the unaltered note.
Example Sentences:
(1) The results indicated that neuropsychological measures may serve to broaden the concept of intelligence and that a brain-related criterion may contribute to a fuller understanding of its nature.
(2) In Patient 2 they were at first paroxysmal and unformed, with more prolonged metamorphopsia; later there appeared to be palinoptic formed images, possibly postictal in nature.
(3) We conclude that the priming effect is not a clinically significant phenomenon during natural pollen exposure in allergic rhinitis patients.
(4) Quantitative determinations indicate that the amount of PBG-D mRNA is modulated both by the erythroid nature of the tissue and by cell proliferation, probably at the transcriptional level.
(5) The severity and site of hypertrophy is important in determining the clinical picture and the natural history of hypertrophic cardiomyopathy (HCM).
(6) Here, we review the nature of the heart sound signal and the various signal-processing techniques that have been applied to PCG analysis.
(7) To investigate the immunomodulating properties of cis-diamminedichloroplatinum (II) (CDDP), we studied the drug's effects on natural killer (NK) lymphocyte cytotoxicity.
(8) Examined specific relationships, as they occur in nature, between particular dietary variables or groups of variables and specific MMPI subscales.
(9) Natural tubulin polymerization leads to the formation of hooks on microtubular structures.
(10) Trichostatin C is presumably the first example of a glucopyranosyl hydroxamate from nature.
(11) The present study was undertaken to find out the nature of enzymes responsible for the processing of DV antigen in M phi.
(12) The cyclical nature of pyromania has parallels in cycles of reform in standards of civil commitment (Livermore, Malmquist & Meehl, 1958; Dershowitz, 1974), in the use of physical therapies and medications (Tourney, 1967; Mora, 1974), in treatment of the chronically mentally ill (Deutsch, 1949; Morrissey & Goldman, 1984), and in institutional practices (Treffert, 1967; Morrissey, Goldman & Klerman (1980).
(13) The nature of the putative autoantigen in Graves' ophthalmopathy (Go) remains an enigma but the sequence similarity between thyroglobulin (Tg) and acetylcholinesterase (ACHE) provides a rationale for epitopes which are common to the thyroid gland and the eye orbit.
(14) Further exploration of these excretory pathways will provide interesting new insights on the numerous cholestatic and hyperbilirubinemic syndromes that occur in nature.
(15) In this way they offer the doctor the chance of preventing genetic handicaps that cannot be obtained by natural reproduction, and that therefore should be used.
(16) The nature, intracellular distribution, and role of proteins synthesized during meiotic maturation of mouse oocytes in vitro have been examined.
(17) Natural killer cells (CD8+CD57+) as well as activated T cells (CD3+HLA-DR+) were significantly increased in patients with sarcoidosis.
(18) In certain cases, the effects of these substances are enhanced, in others, they are inhibited by compounds that were isolated from natural sources or prepared by chemical synthesis.
(19) Analysis of 156 records relating to patients at the age of 15 to 85 years with extended purulent peritonitis of the surgical and gynecological genesis (the toxic phase, VI category ASA) showed that combination of programmed sanitation laparotomy and intensive antibacterial therapy performed as short-term courses before, during and after the operation with an account of the information on the nature of the microbial associations and antibioticograms was an efficient procedure in treatment of severe peritonitis.
(20) There is no convincing evidence that immunosuppression is effective, also because the natural history of the disease is characterised by a spontaneous disappearance of the factor VIII-C inhibitor.