Moulting Hormones. LIII. the Synthesis and Biological Activity of Some Ecdysone Analogues

1981 ◽  
Vol 34 (12) ◽  
pp. 2607 ◽  
Author(s):  
M Galbraith ◽  
DS Horn ◽  
B Kelly ◽  
J Kinnear ◽  
M Martin ◽  
...  
Keyword(s):  
Biological Activity ◽  
Hydroxy Group ◽  
Structural Changes ◽  
Mosquito Larvae ◽  
Moulting Hormones

A number of ecdysone analogues were prepared to study the effect of structural changes on biological activity. It was found that analogues with the 5α-configuration or a 3,5-cyclo structure were inactive, that a 3β-hydroxy group enhances activity but is not essential for activity, and that 3β-substituents decrease activity as follows: OMe (60%), OAc (25%) and OEt (10%). The keto diol (3), keto alcohol (9) and amide (36) were found to be highly toxic to mosquito larvae.

scholarly journals Tandem MS-Based Metabolite Profiling of 19,20-Epoxycytochalasin C Reveals the Importance of a Hydroxy Group at the C7 Position for Biological Activity

ACS Omega ◽  
2021 ◽  
Vol 6 (5) ◽  
pp. 3717-3726
Author(s):  
Manoj Kushwaha ◽  
Arem Qayum ◽  
Shreyans K. Jain ◽  
Jasvinder Singh ◽  
Amit Kumar Srivastava ◽  
...  
Keyword(s):  
Biological Activity ◽  
Hydroxy Group ◽  
Metabolite Profiling ◽  
Tandem Ms

scholarly journals Structural control of fibrin bioactivity by mechanical deformation

2020 ◽  
Author(s):  
Sachin Kumar ◽  
Yujen Wang ◽  
Manuel K. Rausch ◽  
Sapun H. Parekh
Keyword(s):  
Biological Activity ◽  
Conformational Changes ◽  
Structural Control ◽  
Structural Changes ◽  
Tensile Deformation ◽  
Mechanical Strain ◽  
Fibrous Protein ◽  
Binding Partners ◽  
Blood Clots ◽  
Β Sheet

AbstractFibrin is a fibrous protein network that entraps blood cells and platelets to form blood clots following vascular injury. As a biomaterial, fibrin acts a biochemical scaffold as well as a viscoelastic patch that resists mechanical insults. The biomechanics and biochemistry of fibrin have been well characterized independently, showing that fibrin is a hierarchical material with numerous binding partners. However, comparatively little is known about how fibrin biomechanics and biochemistry are coupled: how does fibrin deformation influence its biochemistry at the molecular level? In this study, we show how mechanically-induced molecular structural changes in fibrin affect fibrin biochemistry and fibrin-platelet interaction. We found that tensile deformation of fibrin lead to molecular structural transitions of α-helices to β-sheets, which reduced binding of tissue plasminogen activator (tPA), an enzyme that initiates fibrinolysis, at the network and single fiber level. Moreover, binding of tPA and Thioflavin T (ThT), a commonly used β-sheet marker, was primarily mutually exclusive such that tPA bound to native (helical) fibrin whereas ThT bound to strained fibrin. Finally, we demonstrate that conformational changes in fibrin suppressed the biological activity of platelets on mechanically strained fibrin due to attenuated αIIbβ3 integrin binding. Our work shows that mechanical strain regulates fibrin molecular structure and fibrin biological activity in an elegant mechano-chemical feedback loop, which likely influences fibrinolysis and wound healing kinetics.

Synthesis and Biological Activity of New 16,17-Secoestrone Derivatives

2000 ◽  
Vol 65 (1) ◽  
pp. 77-82 ◽  
Author(s):  
Suzana Jovanović-Šanta ◽  
Silvana Andrić ◽  
Radmila Kovačević ◽  
Vjera Pejanović
Keyword(s):  
Biological Activity ◽  
Hydroxy Group ◽  
Sodium Borohydride ◽  
Estrogenic Activity ◽  
Complete Loss ◽  
Borohydride Reduction ◽  
Experimental Animals ◽  
Biological Tests ◽  
Sodium Borohydride Reduction

Starting from estrone 3-benzyloxy-17β-hydroxyestra-1,3,5(10)-trien-16-one oxime (3b) was synthesized, which underwent Beckmann fragmentation giving the 3-benzyloxy-17-oxo- 16,17-secoestra-1,3,5(10)-triene-16-nitrile (4b). Sodium borohydride reduction of this compound afforded 3-benzyloxy-17-hydroxy-16,17-secoestra-1,3,5(10)-triene-16-nitrile (5b). The deprotection of the 3-hydroxy group was achieved by action of hydrogen upon derivatives 4b and 5b in presence of Pd/C as a catalyst, yielding 3-hydroxy-17-oxo-16,17-secoestra- 1,3,5(10)-triene-16-nitrile (4a) and 3,17-dihydroxy-16,17-secoestra-1,3,5(10)-triene-16-nitrile (5a). In biological tests on experimental animals, compounds 4a, 4b, 5a and 5b showed virtually a complete loss of estrogenic activity, whereas compounds 4a, 5a and 5b exhibited moderate antiestrogenic effect.

STUDIES ON THE DISSIPATION OF DIFLUBENZURON AND METHOPRENE FROM SHALLOW PRAIRIE POOLS

1980 ◽  
Vol 112 (2) ◽  
pp. 173-177 ◽  
Author(s):  
D. J. Madder ◽  
W. L. Lockhart
Keyword(s):  
Biological Activity ◽  
Liquid Chromatography ◽  
Growth Regulator ◽  
Mosquito Control ◽  
Parent Compound ◽  
Gas Liquid Chromatography ◽  
Mosquito Larvae ◽  
Canadian Prairie ◽  
Repeated Applications

AbstractA series of sod-lined pools were constructed and used to monitor repeated applications of diflubenzuron as Dimilin WP-25 and mefhoprene as Altosid SR-10. Diflubenzuron and methoprene "disappeared" rapidly from the pool water as determined by bioassays using Aedes aegypti (L.) (Culicidae) larvae and by gas-liquid chromatography (GLC). Chemical assays for a diflubenzuron derivative were positive for several days; bioassay indicated the presence of diflubenzuron (or at least growth regulator activity) at levels toxic to mosquito larvae for up to 16 days. In contrast methoprene "fell" below GLC detection within 2 days although biological activity persisted for approximately a week after treatment. Neither parent compound should cause a long-term persistence hazard when used for mosquito control in Canadian prairie waters.

scholarly journals Molecular-Level Understanding of the Influence of Ions and Water on HMGB1 Adsorption Induced by Surface Hydroxylation of Titanium Implants

2021 ◽  
Author(s):  
Dineli Ranathunga ◽  
Alexandra Arteaga ◽  
Claudia C. Biguetti ◽  
Danieli C. Rodrigues ◽  
Steven O. Nielsen
Keyword(s):  
Biological Activity ◽  
Structural Changes ◽  
High Mobility ◽  
Titanium Implant ◽  
Water Layer ◽  
Titanium Implants ◽  
Surgical Trauma ◽  
Hmgb1 Protein ◽  
Implant Surface ◽  
Surface Hydroxylation

<div><div><div><p>Due to its excellent chemical and mechanical properties, titanium has become the material of choice for orthopedic and dental implants to promote rehabilitation via bone anchorage and osseointegration. Titanium osseointegration is partially related to its capability to form a TiO<sub>2</sub> surface layer and its ability to interact with key endogenous proteins immediately upon implantation, establishing the first bone-biomaterial interface. Surgical trauma caused by implantation results in the release of High Mobility Group Box 1 (HMGB1) protein, which is a prototypic DAMP (Damage Associated Molecular Pattern) with multiple roles in inflammation and tissue healing. To develop different surface strategies that improve the clinical outcome of titanium-based implants by controlling their biological activity, a molecular-scale understanding of HMGB1-surface interactions is desired. Here, we use molecular dynamics (MD) computer simulations to provide direct insight into the HMGB1 interactions and the possible molecular arrangements of HMGB1 on fully hydroxylated and non-hydroxylated rutile (110) TiO<sub>2</sub> surfaces. The results establish that HMGB1 is most likely to be adsorbed directly onto the surface regardless of surface hydroxylation, which is undesirable because it could affect its biological activity by causing structural changes to the protein. The hydroxylated TiO<sub>2</sub> surface shows a greater affinity for HMGB1 than the non-hydroxylated surface. The water layer on the non-hydroxylated TiO<sub>2</sub> surface prevents ions and the protein from directly contacting the surface. However, it was observed that if the ionic strength increases, the total number of ions adsorbed on the two surfaces increases, and the protein’s direct adsorption ability decreases. These findings will help to understand the HMGB1-TiO<sub>2</sub> interactions upon implantation, as well as the development of different surface strategies by introducing ions or ionic materials to the titanium implant surface to modulate its interactions with HMGB1 to preserve biological function.</p></div></div></div>

Biological activity as an effect of structural changes in aryl N-methylcarbamates

1968 ◽  
Vol 16 (4) ◽  
pp. 605-607 ◽  
Author(s):  
R. P. Miskus ◽  
Melvin. Look ◽  
T. L. Andrews ◽  
R. L. Lyon
Keyword(s):  
Biological Activity ◽  
Structural Changes
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