다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

The role of flavonoids as the major red, blue, and purple pigments in plants has gained these secondary products a great deal of attention over the years. From the first description of acid and base effects on plant pigments by Robert Boyle in 1664 to the characterization of structural and

Flavonoid Biosynthesis. A Colorful Model for Genetics, Biochemistry, Cell Biology, and Biotechnology

Flavonoids, a group of natural substances with variable phenolic structures, are found in fruits, vegetables, grains, bark, roots, stems, flowers, tea and wine. These natural products are well known for their beneficial effects on health and efforts are being made to isolate the ingredients so called flavonoids. Flavonoids are now considered as an indispensable component in a variety of nutraceutical, pharmaceutical, medicinal and cosmetic applications. This is attributed to their anti-oxidative, anti-inflammatory, anti-mutagenic and anti-carcinogenic properties coupled with their capacity to modulate key cellular enzyme function. Research on flavonoids received an added impulse with the discovery of the low cardiovascular mortality rate and also prevention of CHD. Information on the working mechanisms of flavonoids is still not understood properly. However, it has widely been known for centuries that derivatives of plant origin possess a broad spectrum of biological activity. Current trends of research and development activities on flavonoids relate to isolation, identification, characterisation and functions of flavonoids and finally their applications on health benefits. Molecular docking and knowledge of bioinformatics are also being used to predict potential applications and manufacturing by industry. In the present review, attempts have been made to discuss the current trends of research and development on flavonoids, working mechanisms of flavonoids, flavonoid functions and applications, prediction of flavonoids as potential drugs in preventing chronic diseases and future research directions.

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Flavonoids: an overview

Dietary phenolics: chemistry, bioavailability and effects on health.

Biosynthesis of flavonoids and effects of stress.

Summary
Isoflavonoids are distributed predominantly in leguminous plants, and play pivotal roles in the interaction of host plants with biological environments. Isoflavones in the diet also have beneficial effects on human health as phytoestrogens. The isoflavonoid skeleton is constructed by the CYP93C subfamily of cytochrome P450s in plant cells. The reaction consists of hydroxylation of the flavanone molecule at C-2 and an intramolecular 1,2-aryl migration from C-2 to C-3 to yield 2-hydroxyisoflavanone. In this study, with the aid of alignment of amino acid sequences of CYP93 family P450s and a computer-generated putative stereo structure of the protein, candidates for key amino acid residues in CYP93C2 responsible for the unique aryl migration in 2-hydroxyisoflavanone synthase reaction were identified. Microsomes of recombinant yeast cells expressing mutant proteins of CYP93C2 were prepared, and their catalytic activities tested. The reaction with the mutant in which Ser 310 in the centre of the I-helix was converted to Thr yielded increased formation of 3-hydroxyflavanone, a by-product of the 2-hydroxyisoflavanone synthase reaction, in addition to the major isoflavonoid product. More dramatically, the mutant in which Lys 375 in the end of β-sheet 1–4 was replaced with Thr produced only 3-hydroxyflavanone and did not yield the isoflavonoid any longer. The roles of these amino acid residues in the catalysis and evolution of isoflavonoid biosynthesis are discussed.

https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-313X.2002.01378.x

Key amino acid residues required for aryl migration catalysed by the cytochrome P450 2‐hydroxyisoflavanone synthase

Four new triterpenoids with various skeletons, maytefolins A−C (1−3) and uvaol-3-caffeate (4), were isolated from the leaves of a Brazilian medicinal plant, Maytenus ilicifolia, together with five known triterpenoids. Of these triterpenoids only erythrodiol exhibited significant cytotoxicity against KB/S, KB/VJ300, and KU 19-20 cells.

Four new triterpenoids from Maytenus ilicifolia.

Biosynthesis of triterpenoids in cultured cells, and regenerated and wild plant organs of Taraxacum officinale

Sterols, essential eukaryotic constituents, are biosynthesized through either cyclic triterpenes, lanosterol (fungi and animals) or cycloartenol (plants). The cDNA for OSC7 of Lotus japonicus was shown to encode lanosterol synthase (LAS) by the complementation of a LAS-deficient mutant yeast and structural identification of the accumulated lanosterol. A double site-directed mutant of OSC7, in which amino acid residues crucial for the reaction specificity were changed to the cycloartenol synthase (CAS) type, produced parkeol and cycloartenol. The multiple amino acid sequence alignment of a conserved region suggests that the LAS of different eukaryotic lineages emerged from the ancestral CAS by convergent evolution.

Plant Lanosterol Synthase : Divergence of the Sterol and Triterpene Biosynthetic Pathways in Eukaryotes

Differential screening by PCR-select subtraction was carried out for cDNAs from leaves of red and green perilla, two chemovarietal forms of Perilla frutescens regarding anthocyanin accumulation. One hundred and twenty cDNA fragments were selected as the clones preferentially expressed in anthocyanin-accumulating red perilla over the nonaccumulating green perilla. About half of them were the cDNAs encoding the proteins related presumably to phenylpropanoid-derived metabolism. The cDNAs encoding glutathione S-transferase (GST), PfGST1, and chalcone isomerase (CHI), PfCHI1, were further characterized. The expression of PfGST1 in an Arabidopsis thaliana tt19 mutant lacking the GST-like gene involved in vacuole transport of anthocyanin rescued the lesion of anthocyanin accumulation in tt19, indicating a function of PfGST1 in vacuole sequestration of anthocyanin in perilla. The recombinant PfCHI1 could stereospecifically convert naringenin chalcone to (2S)-naringenin. PfGST1 and PfCHI1 were preferentially expressed in the leaves of red perilla, agreeing with the accumulation of anthocyanin and expression of other previously identified genes for anthocyanin biosynthesis. These results suggest that the genes of the whole anthocyanin biosynthetic pathway are regulated in a coordinated manner in perilla.

https://febs.onlinelibrary.wiley.com/doi/epdf/10.1111/j.1742-4658.2008.06496.x

Differential gene expression profiles of red and green forms of Perilla frutescens leading to comprehensive identification of anthocyanin biosynthetic genes

Shin-ichi Ayabe

Papers

Key amino acid residues required for aryl migration catalysed by the cytochrome P450 2‐hydroxyisoflavanone synthase

Four new triterpenoids from Maytenus ilicifolia.

Biosynthesis of triterpenoids in cultured cells, and regenerated and wild plant organs of Taraxacum officinale

Plant Lanosterol Synthase : Divergence of the Sterol and Triterpene Biosynthetic Pathways in Eukaryotes

Differential gene expression profiles of red and green forms of Perilla frutescens leading to comprehensive identification of anthocyanin biosynthetic genes