STRUCTURE–ACTIVITY RELATIONSHIPS OF CORTICOSTEROID FEEDBACK AT THE HYPOTHALAMIC LEVEL

1977 ◽  
Vol 74 (3) ◽  
pp. 415-424 ◽  
Author(s):  
M. T. JONES ◽  
E. W. HILLHOUSE ◽  
J. L. BURDEN
Keyword(s):  
Binding Site ◽  
Delayed Feedback ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Rat Hypothalamus ◽  
Structure Activity Relationships ◽  
Corticotrophin Releasing Factor ◽  
Structure Activity ◽  
Hypothalamic Level

SUMMARY Structure–activity studies on the corticosteroid fast and delayed feedback receptor mechanisms controlling the secretion of corticotrophin releasing factor (CRF) were carried out with the rat hypothalamus in vitro. The secretion of CRF was induced by acetylcholine (3 pg/ml). The fast feedback receptor appears highly specific, and the structure essential for efficacy involves an 11β-hydroxyl group and an unblocked 21-hydroxyl group. Several steroids showed antagonism and so the binding site is not very specific. 18-Hydroxy,11-deoxycorticosterone, progesterone, 17α-hydroxyprogesterone and 11-deoxycorticosterone were antagonists of fast feedback. The delayed feedback receptor required either an 11β- or a 21-hydroxyl group for efficacy. The binding site required a 17-hydroxyl group when the 11β- or 21-hydroxyl groups were absent. Binding also involved the 3-oxo,4,5-ene structure since steroids in which these are absent were inactive.

scholarly journals UFLC-MS-IT-TOF and Bioassay Guided Isolation of Flavonoids as Xanthine Oxidase Inhibitors from Diospyros dumetorum

2017 ◽  
Vol 12 (11) ◽  
pp. 1934578X1701201
Author(s):  
Zhen-Tao Deng ◽  
Tong-Hua Yang ◽  
Xiao-Yan Huang ◽  
Xing-Long Chen ◽  
Jian-Gang Zhang ◽  
...  
Keyword(s):  
Xanthine Oxidase ◽  
Inhibitory Activity ◽  
Folk Medicine ◽  
Hydroxyl Groups ◽  
Active Constituents ◽  
Structure Activity Relationships ◽  
Structure Activity ◽  
Pulmonary Abscess ◽  
Xanthine Oxidase Inhibitors

Diospyros dumetorum is an important folk medicine for treating pulmonary abscess and inflammation. The leaves of D. dumetorum revealed xanthine oxidase (XOD) inhibitory activity. With the guidance of UFLC-MS-IT-TOF analyses combined with bioassay in vitro, 15 flavonoids were isolated from the active parts of D. dumetorum. Except for 11 (IC50 > 200μM), all compounds showed obvious XOD inhibitory activity with IC50 values of 32.5 ± 0.7 ~ 145.0 ± 3.3 μM. The preliminary structure-activity relationships study suggested that glycosylation on C-3 was unfavorable for XOD inhibitory activity; hydroxyl groups on ring B were essential for maintaining activity; the activity was closely related with the position of galloylation. This is the first recognition of the XOD inhibitory activity and active constituents of D. dumetorum, and will provide valuable information for this plant as a new resource for treating hyperuricemia and gout.

Effect of reserpine on the structure–activity relationships for the inhibition of noradrenaline uptake in adrenergic nerves in rat and rabbit ventricle by phenethylamines

1977 ◽  
Vol 55 (2) ◽  
pp. 196-205 ◽  
Author(s):  
D. M. Paton ◽  
D. S. Golko
Keyword(s):  
Phenolic Hydroxyl ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Noradrenaline Uptake ◽  
Inhibitory Potency ◽  
Sympathomimetic Amines ◽  
Structure Activity Relationships ◽  
Structure Activity ◽  
Phenolic Hydroxyl Groups ◽  
Inhibitory Agents

Ventricular tissue from the hearts of normal and reserpine-pretreated rats and rabbits were exposed to pargyline, tropolone, and hydrocortisone to inhibit monoamine oxidase (EC 1.4.3.4), catechol-O-methyltransferase (EC 2.1.1.6), and extraneuronal uptake, respectively. To examine the structure–activity relationships for inhibition of noradrenaline uptake, the inhibition of the 10-min uptake of (−)-[3H]noradrenaline by sympathomimetic amines was determined and ID50 values calculated. In reserpine-pretreated tissues, the most potent inhibitory agents studied were amines lacking phenolic hydroxyl groups (i.e., β-phenethylamine, (+)- and (−)-amphetamine). Addition of one or two phenolic hydroxyl groups, a β-hydroxyl group, or an N-methyl group generally decreased inhibitory potency, while α-methylation had little effect. Amines with large N-substitution and phenolic O-methyl groups were the least potent inhibitory agents. The stereoisomers of amphetamine, noradrenaline, and metaraminol did not differ in potency. However, the stereoisomers of ephedrine did, the order of potency being (−)-ephedrine > (±)-ephedrine > (+)-ψ-ephedrine > (−)-ψ-ephedrine. These structure–activity relationships are the same as those previously found for the acceleration of efflux of extragranular noradrenaline. Amines also released (−)-[3H]noradrenaline from reserpine-pretreated tissues. Results obtained using ventricles from nonreserpinized rats and rabbits showed two important differences. Firstly, sympathomimetic amines were much less potent releasers of (−)-[3H]noradrenaline from such tissues. Secondly, amines lacking phenolic hydroxyl groups were, on the average, five- to seven-fold less potent as inhibitors of (−)-[3H]-noradrenaline uptake. However, the inhibitory potencies of phenolethylamines and catecholamines were generally similar to those found in reserpine-pretreated tissues. These studies have demonstrated that reserpine pretreatment potentiates the inhibitory potency of phenethylamines and phenylethanolamines.

Structure-activity relationships of anti-tyrosinase and antioxidant activities of cinnamic acid and its derivatives

2021 ◽  
Author(s):  
Jianmin Chen ◽  
Mengnan Ran ◽  
Meixia Wang ◽  
Xinying Liu ◽  
Siwan Liu ◽  
...  
Keyword(s):  
Cinnamic Acid ◽  
Phenyl Ring ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Structure Activity Relationships ◽  
Structure Activity ◽  
Ic50 Value

Abstract The related structure-activity relationships (SARs) of cinnamic acid and its derivates have not been studied in details yet. Herein, anti-tyrosinase and antioxidant activities of 18 compounds were evaluated. The results demonstrated that the substituents on the phenyl ring of cinnamic acid led to the enhancement of the inhibition on monophenolase and the weakening of the inhibition on diphenolase. Among these tested compounds, 9 was firstly discovered as a tyrosinase inhibitor in a reversible competitive manner with IC50 value of 68.6 ± 4.2 μM. Docking results demonstrated 9 located into the catalytic center of tyrosinase. Antioxidant assay indicated that only one hydroxyl group on the phenyl ring was not enough to possess the radical scavenging activity, and the number of hydroxyl groups may be more important. This study will be helpful for development of new cinnamic acid derivates as tyrosinase inhibitors and antioxidants with higher efficacy.

scholarly journals Enhancement of Antioxidant and Hydrophobic Properties of Alginate via Aromatic Derivatization: Preparation, Characterization, and Evaluation

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2575
Author(s):  
Smaher M. Elbayomi ◽  
Haili Wang ◽  
Tamer M. Tamer ◽  
Yezi You
Keyword(s):  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Benzoyl Group ◽  
Antioxidant Evaluation ◽  
Thermo Stability

The preparation of bioactive polymeric molecules requires the attention of scientists as it has a potential function in biomedical applications. In the current study, functional substitution of alginate with a benzoyl group was prepared via coupling its hydroxyl group with benzoyl chloride. Fourier transform infrared spectroscopy indicated the characteristic peaks of aromatic C=C in alginate derivative at 1431 cm−1. HNMR analysis demonstrated the aromatic protons at 7.5 ppm assigned to benzoyl groups attached to alginate hydroxyl groups. Wetting analysis showed a decrease in hydrophilicity in the new alginate derivative. Differential scanning calorimetry and thermal gravimetric analysis showed that the designed aromatic alginate derivative demonstrated higher thermo-stability than alginates. The aromatic alginate derivative displayed high anti-inflammatory properties compared to alginate. Finally, the in vitro antioxidant evaluation of the aromatic alginate derivative showed a significant increase in free radical scavenging activity compared to neat alginate against DPPH (2,2-diphenyll-picrylhydrazyl) and ABTS free radicals. The obtained results proposed that the new alginate derivative could be employed for gene and drug delivery applications.

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