Ochnaflavone, a secondary plant secondary metabolite of the

Biflavonoid Biflavonoids are a type of flavonoids with the general formula scheme (C6-C3-C6)2. Examples * Amentoflavone (bis-apigenin coupled at 8 and 3' positions) * Lophirone L and lophirone M found in ''Lophira alata'' * Sulcatone A, a naturally occur ...

family, has been widely investigated in past decades due to its unique ability to mediate biological activities, such as inhibition of

phospholipase A2 The enzyme phospholipase A2 (EC 3.1.1.4, PLA2, systematic name phosphatidylcholine 2-acylhydrolase) catalyse the cleavage of fatty acids in position 2 of phospholipids, hydrolyzing the bond between the second fatty acid “tail” and the glyce ...

and lymphocyte proliferation. It was first isolated from '' Ochna squarrosa'' Linn, a member of

Ochnaceae Ochnaceae is a family of flowering plants in the order Malpighiales.Vernon H. Heywood, Richard K. Brummitt, Ole Seberg, and Alastair Culham. ''Flowering Plant Families of the World''. Firefly Books: Ontario, Canada. (2007). . In the APG III syst ...

family, in 1973.

Synthesis

The first total synthesis of ochnaflavone derivatives was achieved by Kawano group in 1973, followed by the Heerden group for the first time reporting the total synthesis the ochnaflavone by constructing a diaryl ether intermediate and assemble the two flavone nuclei through ring cyclization. To date, the field of biochemistry of biflavonoids is still wide open. Little is known about Ochnaflavone of its natural occurrence and biosynthesis.

Activity

Although Ochnaflavone has not been fully studied in the past decades, its protective role in plants and human body already attract scientists’ much attention, such as anti-atherogenic activity and anti-inflammatory activity. Anti-atherogenic activity:

Atherogenesis Atherosclerosis is a pattern of the disease arteriosclerosis in which the wall of the artery develops abnormalities, called lesions. These lesions may lead to narrowing due to the buildup of atheromatous plaque. At onset there are usually no sy ...

refers to the formation of atheromas on arteries’ walls. It is believed that atherogenesis may be caused by an infection of the vascular smooth muscle cells. Find molecules that possess anti-proliferation activity of vascular smooth muscle cells seems a good strategy to treat Atherogenesis. In 2006, a research group from Korea found Ochnaflavone could inhibit tumor necrosis factor (TNF)-a-induced human vascular smooth muscle cells proliferation. It was achieved by the ability of Ochnaflavone to regulate the

extracellular signal-regulated kinase In molecular biology, extracellular signal-regulated kinases (ERKs) or classical MAP kinases are widely expressed protein kinase intracellular signalling molecules that are involved in functions including the regulation of meiosis, mitosis, and p ...

1/2,

matrix metalloproteinase Matrix metalloproteinases (MMPs), also known as matrix metallopeptidases or matrixins, are metalloproteinases that are calcium-dependent zinc-containing endopeptidases; other family members are adamalysins, serralysins, and astacins. The MMPs b ...

-9 and cell cycle. Anti-inflammatory activity:

Inflammation Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...

is a biological response to certain harmful stimuli.

Phospholipase A2 The enzyme phospholipase A2 (EC 3.1.1.4, PLA2, systematic name phosphatidylcholine 2-acylhydrolase) catalyse the cleavage of fatty acids in position 2 of phospholipids, hydrolyzing the bond between the second fatty acid “tail” and the glyce ...

(PLA2) is important in many inflammatory processes as it catalyses the release of arachidonic acid, which could generate lipid mediators of inflammation. Ochnaflavone is found to inhibit PLA2 by directly binding this enzyme irreversibly.Chang, H. W.; Baek, S. H.; Chung, K. W.; Son, K. H.; Kim, H. P.; Kang, S. S., Inactivation of Phospholipase A2 by Naturally Occurring Biflavonoid, Ochnaflavone. Biochemical and Biophysical Research Communications 1994, 205, 843–849.

References

{{Flavones Flavones Natural phenol dimers