Model Vulcanization of EPDM Compounds—Part I: Structure Determination of Vulcanization Products from Ethylidene Norbornane

1984 ◽  
Vol 57 (2) ◽  
pp. 265-274 ◽  
Author(s):  
J. H. M. van den Berg ◽  
J. W. Beulen ◽  
E. F. J. Duynstee ◽  
H. L. Nelissen
Keyword(s):  
Zinc Oxide ◽  
Double Bond ◽  
Stearic Acid ◽  
Structure Determination ◽  
Epdm Rubber

Abstract Vulcanization of ENBH (C9H14), a model for ENB containing EPDM rubber, with a system consisting of zinc oxide, stearic acid, sulfur, TMTD, and MBT at 140°C for 1 h yields slightly more than 30 different crosslinked products C9H13-Sn-C9H13 where n=2,3,4, and 5. In all of the products, the original ENBH structure is maintained (no shift of the double bond) and attachment of the sulfur bridge occurs only at the two allylic positions 3 and 9. Monosulfides (n=1) are probably also formed but no structures could be determined. Only small amounts of the MBT-Sn-C9H13 coupling products and noncrosslinked cyclic sulfides are formed.

scholarly journals Structure Determination of Two New Monocillin I Derivatives

2010 ◽  
Vol 5 (5) ◽  
pp. 1934578X1000500
Author(s):  
Jixun Zhan ◽  
E. M. Kithsiri Wijeratne ◽  
A. A. Leslie Gunatilaka
Keyword(s):  
Double Bond ◽  
Acid Solution ◽  
Beauveria Bassiana ◽  
Structure Determination ◽  
Spectroscopic Data ◽  
Enzymatic Process ◽  
Acid Catalyzed ◽  
Hydrolysis Of

Biotransformation of monocillin I (1) by Beauveria bassiana ATCC 7159 was investigated. Two new derivatives 2 and 3 were isolated and identified on the basis of the spectroscopic data. Compounds 2 and 3 are synthesized by hydration at 10,11-double bond and hydrolysis of 14,15-epoxide, respectively. The R configuration of 11-OH in 2 was established by the modified 2-methoxy-2-trifluoromethylphenylacetic acid (MTPA) method. The conversion of 1 to 2 and 3 was reconstituted in an acid solution, indicating that the formation of 2 and 3 is an acid-catalyzed instead of an enzymatic process.

scholarly journals Structure Determination of a Natural Juvenile Hormone Isolated from a Heteropteran Insect

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Toyomi Kotaki ◽  
Tetsuro Shinada ◽  
Hideharu Numata
Keyword(s):  
Double Bond ◽  
Juvenile Hormone ◽  
Structure Determination ◽  
Stink Bug ◽  
Juvenile Hormone Iii ◽  
Experimental Animals ◽  
Insect Hormones ◽  
Plautia Stali

Juvenile hormone (JH), which occurs in several forms in different insects, is one of the most important insect hormones. The structure of JH in Heteroptera has not been elucidated until recently, although insects in this suborder have long been used as experimental animals for JH research. Here we review the structure determination of a novel JH in a stink bug,Plautia stali, which was named juvenile hormone III skipped bisepoxide [JHSB3: methyl (2R,3S,10R)-2,3;10,11-bisepoxyfarnesoate], based on the arrangement of two epoxides at C2,3 and C10,11 with a skipped double bond at C6,7.

Ab initio structure determination of cytochrome c6 by combined reciprocal space-real space approach

2003 ◽  
Vol 218 (1) ◽  
Author(s):  
K. Chowdhury ◽  
S. Ghosh ◽  
M. Mukherjee
Keyword(s):  
Cytochrome C ◽  
Ab Initio ◽  
Structure Determination ◽  
Direct Method ◽  
Real Space ◽  
Reciprocal Space ◽  
Cytochrome C6 ◽  
Ab Initio Structure ◽  
Space Approach

AbstractThe direct method program SAYTAN has been applied successfully to redetermine the structure of cytochrome c

STRUCTURE DETERMINATION OF 5 MEMBERED SILANE RINGS USING MICROWAVE SPECTROSCOPY

2018 ◽  
Author(s):  
Frank Marshall ◽  
G. Grubbs II ◽  
Gamil Guirgis ◽  
Theodore Carrigan-Broda ◽  
Grier Jones ◽  
...  
Keyword(s):  
Structure Determination ◽  
Microwave Spectroscopy

THE THYMOLYTIC ACTIVITY OF 6- AND 9-HALOCORTICOIDS AND RELATED STEROIDS

1965 ◽  
Vol 49 (2) ◽  
pp. 262-270 ◽  
Author(s):  
Ralph I. Dorfman ◽  
P. G. Holton ◽  
Fred A. Kind
Keyword(s):  
Double Bond ◽  
Subcutaneous Injection ◽  
Fluocinolone Acetonide ◽  
Relative Potency ◽  
Subcutaneous Route ◽  
Adrenalectomized Rats

ABSTRACT Adrenalectomized rats were used for the determination of the relative potency of various 6- and 9-halo substituted corticoids administered subcutaneously or by gavage using thymus weightas the endpoint. By subcutaneous injection, fluocinolone acetonide was the most active corticoid at 700 times that of cortisol. This compound was also the most active corticoid by the gavage route and was judged to be 570 times as active as the standard cortisol. The introduction of the 16,17-acetonide and 16,17-acetone 21-acetate groups into 17α,21-dihydroxy-9α,11β-dichloropregna-1,4-diene-3,20-dione increased the activity by a factor of 42 and 100, respectively. The introduction of the δ1 double bond into 6α-fluoroprogesterone 16,17-acetonide caused an increase of 10-fold in thymolytic activity assessed by the subcutaneous route

Isolation and Structure Determination of Antiproliferative Secondary Metabolites from the Potato Earthball Mushroom, Scleroderma bovista (Agaricomycetes)

2018 ◽  
Vol 20 (5) ◽  
pp. 411-418 ◽  
Author(s):  
Bernadett Kovacs ◽  
Zoltán Béni ◽  
Miklós Dékány ◽  
Noémi Bózsity ◽  
Istvan Zupko ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Structure Determination
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