What's the difference between natural and racemic?

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.

Racemic


Definition:

  • (a.) Pertaining to, or designating, an acid found in many kinds of grapes. It is also obtained from tartaric acid, with which it is isomeric, and from sugar, gum, etc., by oxidation. It is a sour white crystalline substance, consisting of a combination of dextrorotatory and levorotatory tartaric acids.

Example Sentences:

  • (1) These results indicate that both racemic and L-baclofen inhibit trigeminal transmission in man, probably because they interfere with excitatory transmission through the interneurons of the lateral reticular formation.
  • (2) In contrast to the enantiomeric discrimination observed with racemic amine, the individual isomers were metabolized at approximately the same rate.
  • (3) Routine enantiomeric analyses were successfully carried out on samples taken from animals dosed orally with the racemic drugs, providing important data on the possible levels of exposure to individual enantiomers during toxicity testing.
  • (4) Racemic verapamil and the L- and D-isomer increased cellular vincristine accumulation to the same extent.
  • (5) By this method, about 5.0 mg of racemic HCZ could be resolved completely in one run.
  • (6) The racemization-suppressing effect of other compounds were also evaluated by employing one of these model couplings to be at best only limitedly effective.
  • (7) The antihypertensive and pulse-slowing effects of racemic propranolol, oxprenolol, pindolol, practolol and d-propranolol were assessed in 54 hypertensive patients.
  • (8) The assay is reliable to 0.1% racemate with a detection limit of approximately 100 pmol.
  • (9) The allene oxide also opens to a zwitterion, which undergoes charge delocalization to form a planar intermediate; this structure is the achiral precursor of the stable end product of pericyclic ring closure, viz., racemic cis-12-oxo-PDA.
  • (10) Decreasing the water concentration in the reaction medium by adding methanol at 0 degrees C drastically reduces the rate of racemization without affecting the rate of transamination.
  • (11) Racemization of aspartic acid in dentin protein during the human lifetime progresses with age.
  • (12) Five diammine-Pt(II) or Pt(IV) coordination compounds, namely cis-diammine-dichloro-platinum (II) "cis-DDP", transdihydroxy-cis-diammine-dichloro-platinum (IV) "trans-ODDP", and derived substitution products of lactic acid (racemates or L-forms) with diminished toxicity in comparison to cis-DDP have been tested against mouse leukemia P388, and partly on melanoma B16 for antineoplastic activity.
  • (13) The racemic drug has unusual pharmacokinetic properties because of its concentration-dependent binding to plasma proteins in the therapeutic plasma concentration range.
  • (14) The vasodilating potency of d-alprenolol and d-propranolol was not significantly different from that of the respective racemic mixtures.
  • (15) High-pressure liquid chromatographic (HPLC) methods have been developed for the determination of drug content, racemate A and related compounds in nadolol raw materials.
  • (16) The effects of the d- and l-isomers of pentazocine were compared to that of racemic pentazocine on contractions of the mouse isolated vas deferens.
  • (17) Our results indicate that racemic EM 12 as well as its enantiomers are chemically and metabolically more stable than thalidomide; however, extensive racemisation occurs both in vivo and in vitro.
  • (18) These data, coupled with the equilibrium fractionation factor for the 2-position of proline (which has been determined to be 1.17), provide the transition-state factors for each of the in-flight protons, and delineate the nature of the transition state(s) for the enzyme-catalyzed racemization.
  • (19) Consequently, racemic compounds showed approximately half potency of the corresponding enantiomers.
  • (20) S(+)-ibuprofen and R(-)-ibuprofen given alone more rapidly reached significantly higher maximal plasma concentrations than after the same doses of the racemic compound.

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