University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
3
1
1992
06
01
STUDIES ON PHOSPHOLIPASE C FROM MELIA
AZADIRACHTA SEEDS
-
31197
EN
Journal Article
1970
01
01
The activity of phospholipase C in crude enzymatic preparation of Melia
azadiracht seeds (Neem seeds) was studied by the use of lecithin as a substrate in
aqueous medium. The enzyme activity was found optimum at pH 2.5 and
temperature 35?C. The phospholipase C was found heat labile, being inactivated
88% within 10 minutes at 90°C
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
3
1
1992
06
01
PARTIAL PURIFICATION AND PROPERTIES OF
L-GLUTAMINE: D-FRUCTOSE 6-P
AMIDOTRANSFERASE FROM HUMAN
PLACENTA
-
31198
EN
Journal Article
1970
01
01
The first enzyme of the pathway for uridine diphosphate N-acetyl-D-glucosamine
(UDPAG) biosynthesis i.e. L-glutamine: D-fructose 6-P amidotransferase (E.C.
2.6.1.16) was purified 52-fold from human placenta using methanol fractionation
and column chromatography on DEAE-Sephadex A-50. The enzyme showed
optimal activity in a broad range of pH from 5.8 to 7.8 in both phosphate and
cacodylate buffers. Its K m value for D-fructose 6-P was found to be 2.14 mM. The
enzyme was inhibited up to 76% in the presence of 0.12mM UDPAG. A K value
of 6.6 ?M was obtained for the feedback inhibition of this enzyme by UDPAG
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
3
1
1992
06
01
THE EFFECT OF IONIC STRENGTH ON THE
BINDING OF SODIUM N-DODECYL SULPHATE
TO ASPERGILLUS NIGER CATALASE
-
31199
EN
Journal Article
1970
01
01
The binding of sodium n-dodecyl sulphate (SDS) to Aspergillus niger catalase in
various ionic strengths at pH 6.4 and a temperature of 27? and 37?C has been
studied over a range of SDS concentrations using equilibrium dialysis and
fluorescence spectroscopy techniques. The binding data were used and interpreted in
terms of theoretical models (Scatchard Equation and Wyman Binding Potential). The
cationic ionizable residues were estimated and have been compared with data from
amino acid analysis
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
3
1
1992
06
01
FAST ATOM BOMBARDMENT MASS
SPECTROMETRY (FABMS) ANALYSIS OF AN
N- TERMINAL - BLOCKED PEPTIDE
-
31200
EN
Journal Article
1970
01
01
FABMS analysis of T-lb peptide before and after one cycle of Edman
degradation indicated an unblocked N-terminal Thr residue for this tryptic peptide.
In contrast , our data showed a molecular protonated ion, MH + for T- la peptide at
655 mass units (mu) which is 42 mu higher than the MH ion of T- 1b peptide. In
addition, T- la peptide was not amenable to one cycle of manual Edman degradation.
These observations suggest that the N-terminal residue of T- 1 a peptide is blocked by
a chemical group having a mass of 42 mu. This observation is consistent with the
presence of an N-terminal acetyl group. This prediction was further investigated by
complete characterization of the gas phased fragment ions, originated from the
individual peptides, using link-scanning approach. The fragment ions again suggest
an acetyl group attached to an N-terminal threonine. In addition, the fragment ions
provide evidence that the two peptides (T-la and T-lb) have identical structures
except for the N-acetyl group
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
3
1
1992
06
01
STEREOSELECTIVE SYNTHESIS OF METHYL
TETRA-0-METHYL a-AND P-D-GLUCO-AND
MANNOPYRANOSIDES
-
31201
EN
Journal Article
1970
01
01
Methyl tetra - 0-methyl- ?-D- glucopyranoside is stereoselectively prepared
from tetramethyl-D- glucopyranose by using (MeI+NaH) in toluene (86%) or
cyclohexane (85%), while its ?- isomer is best synthesized in hexamethyl
phosphoramide (64%). Similarly, methyl tetra-o-methyl-?- D-mannopyranoside is
synthesized in cyclohexane (80%), while its ?- isomer is predominantly prepared
by (MeI+n-BuLi) in cyclohexane (98%). The ?-and ?- isomers of these glycosides
were identified and quantified by G.C
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
3
1
1992
06
01
STUDIES ON PHOSPHOLIPASE C FROM MELIA
AZADIRACHTA SEEDS
-
31202
EN
Journal Article
1970
01
01
3,5- dinitrobenzoyl chloride-pyridine system has been used for dehydration of
aldoximes and carboxamides at room temperature
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
3
1
1992
06
01
STUDIES ON SPIROHETEROCYCLES :
SYNTHESIS OF NEW SPIRO 4-
THIAZOLIDINONES AS POSSIBLE
BIODYNAMICS
-
31203
EN
Journal Article
1970
01
01
Spiro-4- thiazolidinones have been synthesized by the cyclocondensation of
phthalazinyl hydrazones with cyclic ketones and substituted mercapto acetic acids.
Compounds were screened for their antibacterial, antifungal and antihypertensive
activity. The combined elemental analyses and spectroscopic data prove the
authenticity of the synthesized compounds
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
3
1
1992
06
01
LINEAR ALIPHATIC UNSATURATED
POLYESTERS BASED ON CIS
-2- BUTENE -1,4-DIOL: SYNTHESIS AND CHARACTERIZATION
-
31204
EN
Journal Article
1970
01
01
A new homologous series of linear aliphatic polyesters, such as poly (cis-2-
butenylene carboxylate)S, PBms (m is the number of methylene groups in the acid
component, m=2-8 have been synthesized by direct polyesterification reactions in
anisole, as solvent. FT-IR, 400 MHz H- NMR, C-NMR and elemental
analysis were used to establish the structure of polyesters. Molecular weight
distributions were studied by GPC. The most narrow distributions were found to
be for PB2 and PB8, whereas, the average molecular weight for all polyesters,
except PB6, was about 3000-400
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
3
1
1992
06
01
6P- TIGLOYLOXYGLECHOMAFURAN A NEW
FURANOSESQUITERPENE FROM SALVIA
GLUTINOSA
-
31205
EN
Journal Article
1970
01
01
The aerial parts of Salvia glutinosa afforded in addition to lupeol, a - and ? -
amyrin a furanosesquiterpene, its structure being established by high field NMR
techniques. The relative configuration at C-1, C-10, C-4, C-5 and C-6 of 6?tigloyloxyglechomafuran
1 was determined by the observed NOE'S
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
3
1
1992
06
01
PETROLOGICAL AND GEOCHEMICAL STUDY
OF CRUSTAL XENOLITHS FROM 1961
ERUPTION OF CALBUCO VOLCANO, CHILE
(LATITUDE 41 20 S )
-
31206
EN
Journal Article
1970
01
01
Twenty four samples of xenoliths and country rocks from the 1961 lava flow of
Calbuco volcano have been studied. Fourteen samples have been analyzed for major
elements and P, Ni, Ba, Cr, V, Zr, Sc, Y, and Sr. Five of these samples were
further analyzed for Sm, Nd, Sr, and Pb isotope ratios. Seventeen samples were
analyzed under the microscope and three samples were analyzed by microprobe for
their pyroxene composition. Based on petrograghic studies xenoliths were divided
into three groups. Fine grained xenoliths (groups I and II) probably formed from
metamorphosed MORB-like basalts , whereas coarse grained xenoliths (group III)
were apparently derived from cumulate minerals that crystallized from the Calbuco
magma. The fine grained xenoliths were probably entrained in magma at
intermediate levels of the crust, near the stability limit of amphibole to form
pyroxene and plagioclase. In the coarse grained xenoliths amphibole that form at
depth dehydrated as the xenoliths were brought to the surface. The country rocks are
apparently unrelated to the xenoliths.
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
3
1
1992
06
01
AN EFFICIENT PRESENTATION FOR THE
GROUP SL (2,121)
-
31207
EN
Journal Article
1970
01
01
In this paper we give a 2-generator 2-relation presentation for the group
SL(2,121). This proves that SL(2,121), the covering group of PSL(2,121), is
efficient
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
3
1
1992
06
01
AXIAL FLOW IN A ROTATIONAL COAXIAL
RHEOMETER SYSTEM 11: HERSCHEL
BULKLEY MODEL
-
31208
EN
Journal Article
1970
01
01
Following recent works of several authors like Huilgol, Bhattacharya etd. and
Javadpour et al., this paper is to contribute further to the literature of axial flow in a
rotational coaxial rheometer. We consider axial flow of Herschel Bulkley mode1
between two concentric cylinders with the inner one rotating, while the outer
cylinder is held stationary. An attempt has been made to direct the analysis toward
an examination of the relationship between moment (M) and angular velocity ( ) at
the inner cylinder. The radial dependence of the shear stress and viscosity follows
directly by our mathematical analysis with a simple numerical procedure. We
describe the relationship between shear stress and shear rate and the dependence of
these on axial flow rate in the annular region, for power law and Herschel Bulkley
fluids
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
3
1
1992
06
01
SUBSTRATUM RADIATION AND CASIMIR
EFFECT
-
31209
EN
Journal Article
1970
01
01
A heuristic way to calculate the approximate value of the Casimir force is
introduced