China
Africa
Explore chapters and articles related to this topic
Sensory and Inflammatory Peptide Receptors in Airways
Published in Devendra K. Agrawal, Robert G. Townley, Inflammatory Cells and Mediators in Bronchial Asthma, 2020
Nonpeptide receptor antagonists are likely to be more useful. Recently, a very potent and highly selective antagonist was developed for the cholecystokinin octapeptide peripheral receptor (CCK-A receptor).115 This drug, L 334,526, was developed as a modification of a naturally occurring chemical, asperlicin, which was discovered to have CCK-antagonist activity by routine screening of broths. This drug, which has a benzodiazepine-related structure, is extremely potent on CCK-A receptors in human and guinea pig airway smooth muscle, with a PA2 value of almost 10,116 which makes it one of the most potent antagonists of any receptor. It is hoped that similarly effective drugs will be developed in the future for tachykinins, bradykinin, and anaphylatoxins.
Hormonal Effects on Gastrointestinal Cancer Growth
Published in Jean Morisset, Travis E. Solomon, Growth of the Gastrointestinal Tract: Gastrointestinal Hormones and Growth Factors, 2017
Courtney M. Townsend, Singh Pomila, James C. Thompson
The relative binding affinity (RBA) of four analogs of gastrin, for inhibition of binding of 125I-gastrin to GR on MC-26 cells, was investigated.82 Removal of even one N-terminal amino acid resulted in a significant loss (to 15%) in the binding affinity of the analog (gastrin 2-17) for binding to GR on MC-26 cells. A further reduction of N-terminal amino acids (beyond position 8 — pentagastrin) resulted in a significant loss of RBA to only 0.3%. Proglumide (a gastrin and CCK-receptor antagonist) had a low RBA (0.0003%). No specific binding sites for CCK could be measured on MC-26 cells, and CCK did not inhibit gastrin binding to MC-26 cells. Asperlicin, a specific CCK-receptor antagonist, did not inhibit gastrin binding. From these studies we conclude that GR on normal and neoplastic gut tissue in mice are different. We have recently found by use of cross-linking techniques that there are different molecular species of GR on normal mouse fundic mucosa and MC-26 cells.83
Quinazoline and quinazolinone as important medicinal scaffolds: a comparative patent review (2011–2016)
Published in Expert Opinion on Therapeutic Patents, 2018
Abdul Hameed, Mariya Al-Rashida, Maliha Uroos, Syed Abid Ali, Marium Ishtiaq, Khalid Mohammed Khan
Febrifugine and isofebrifugine are naturally occurring quinazoline alkaloids (first isolated from a Chinese herb Dichroa febrifuga), and these compounds were found to possess excellent antimalarial activity. Many quinazoline/quinazolinone containing natural products have been isolated and structurally modified to modulate their biological potential against various targets. Benzomalvin A and sclerotigenin were isolated from Penicillium sp during the lead discovery for neurokinin receptor antagonists. The fungal quinazolines, such as asperlicin, were isolated from Aspergillus alliaceus and found to act as potent cholecystokinin (CCK) antagonist. Luotonin A alkaloid was isolated from the aerial part of Peganum nigellastrum possessing biological potential among isolated compounds (Figure 7) [46].