Flavonoids are nearly ubiquitous in plants and are recognized as the pigments responsible for the colors of leaves, especially in autumn. They are rich in seeds, citrus fruits, olive oil, tea, and red wine. They are low molecular weight compounds composed of a three-ring structure with various substitutions. This basic structure is shared by tocopherols (vitamin E). Flavonoids can be subdivided according to the presence of an oxy group at position 4, a double bond between carbon atoms 2 and 3, or a hydroxyl group in position 3 of the C (middle) ring. These characteristics appear to also be required for best activity, especially antioxidant and antiproliferative, in the systems studied. The particular hydroxylation pattern of the B ring of the flavonoles increases their activities, especially in inhibition of mast cell secretion. Certain plants and spices containing flavonoids have been used for thousands of years in traditional Eastern medicine. In spite of the voluminous literature available, however, Western medicine has not yet used flavonoids therapeutically, even though their safety record is exceptional. Suggestions are made where such possibilities may be worth pursuing.

The Effects of Plant Flavonoids on Mammalian Cells:Implications for Inflammation, Heart Disease, and Cancer

https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

Genistein, a specific inhibitor of tyrosine-specific protein kinases.

The biochemistry and medical significance of the flavonoids.

A. Primary Alcohols as Nucleophiles 2931 B. Carboxylates as Nucleophiles 2931 C. Alkylations with Phenols 2932 IV. Nitrogen Nucleophiles in AAA Total Synthesis 2935 A. Alkylamines as Nucleophiles 2935 B. Azides as a Nucleophile 2936 C. Sulfonamide Nucleophiles 2937 D. Imide Nucleophiles 2938 E. Heterocyclic Amine Nucleophiles 2940 V. Sulfur Nucleophiles 2941 VI. Summary and Conclusions 2941 VII. Acknowledgment 2941 VIII. References 2942 I. Considerations for Enantioselective Allylic Alkylation

http://athena.uwindsor.ca/users/j/jlichaa/reference.nsf/54ef3e94e5fe816e85256d6e0063d208/10ff8b04ff3a317885256d88005720f6/$file/cr-2003-103-2921-trost-allylpd.pdf

Asymmetric transition-metal-catalyzed allylic alkylations: applications in total synthesis.

papain, chymotrypsin, elastase, acid protease and thermolysin have been found in culture filtrates of actinomycetes. Recently we found that exopeptidases have a strong effect on mammalian cell surfaces compared to endopeptidases°). It is possible that the action of hydrolytic enzymes on cell surfaces is involved in various cellular phenomena. We thought that exopeptidase inhibitors would be useful in the analysis of biological functions. So, we started screening of actinomycetes culture filtrates for activity against aminopeptidase B, and found a new compound bestatin, the discovery and isolation of which are reported herein. As described by Hopsu et a1.10', aminopeptidase B (EC 3.4.11.6) is an exopeptidase which can be obtained from rat liver. It hydrolyses an N-terminal peptide bond containing N-terminal arginine or lysine. In order to obtain quantitative values for antiaminopeptidase B activity, we established the following method. The reaction mixture was

Bestatin, an inhibitor of aminopeptidase b, produced by actinomycetes

/pdf/pepstatin-a-new-pepsin-inhibitor-produced-by-agtinomygetes-8a13kfwz8q.pdf

Pepstatin, a new pepsin inhibitor produced by agtinomygetes

https://www.jstage.jst.go.jp/article/antibiotics1968/22/6/22_6_283/_pdf

Hamao Umezawa

Papers

Bestatin, an inhibitor of aminopeptidase b, produced by actinomycetes

Pepstatin, a new pepsin inhibitor produced by agtinomygetes

Leupeptins, new protease inhibitors from Actinomycetes.

Studies on a new epidermal growth factor-receptor kinase inhibitor, erbstatin, produced by MH435-hF3.

New antitumor antibiotics aclacinomycins A and B.