Dihydrophenanthrenes from Bletilla formosana

Abstract

Bletilla formosana HAYATA (Orchidaceae) is a perennial herb with rhizomes, corms, or root-stem tuberoids. It is the only variable species of Bletilla in Taiwan. 1) The tubers of Bletilla striata REICHB. FIL. has attracted much attention during the Severe Acute Respiratory Syndrome (SARS) prevalent period due to its use in treating pneumonophthisis and pneumonorrhagia in traditional Chinese medicine.2) To the best of our knowledge, there has been no phytochemical investigation on B. formosana. As part of our effort to search for bioactive components from local indigenous herbs, we describe herein the isolation of three new dihydrophenanthrenes, along with seven known phenanthrene derivatives, six known flavonoids, a bibenzyl and three phenolic compounds from the whole herb of B. formosana. Results and DiscussionThe ethanolic extract of the whole herbs was successively partitioned with ethyl acetate and n-butanol. The ethyl acetate and n-butanol-soluble fractions were separatedly subjected to silica gel column chromatography. Fractions rich in polyphenolic compounds were combined and purified by Sephadex LH-20 column to give three new dihydrophenanthrenes, 4-methoxy-9,10-dihydrophenanthrene-1,2,7-triol (1), 1-(4-hydroxybenzyl)-4,7-dimethoxy-9,10-dihydrophenanthrene-2-ol (2), and 1,3,6-tri(4-hydroxylbenzyl)-4-methoxydihydrophenanthrene-2,7-diol (3), along with seven known phenanthrene derivatives, 1-(4-hydroxybenzyl)-4-methoxy-9,10-dihydrophenanthrene-2,7-diol (4),3) 1,6-di(4-hydroxylbenzyl)-4-methoxy-9,10-dihydrophenanthrene-2,7-diol (5), 4) 1,3-di(4-hydroxybenzyl)-4-methoxy-9,10-dihydrophenanthrene-2,7-diol (6), 3,4) 1-(4-hydroxybenzyl)-4-methoxyphenanthrene-2,7-diol (7), 4) 1-(4-hydroxybenzyl)-4,8-di-methoxyphenanthrene-2,7-diol (8), 5) 1,8-bi(4-hydroxybenzyl)-4-methoxyphenanthrene-2,7-diol (9), 6) and blestriarene B (10), , 4-methoxy-9,10-dihydrophenanthrene-1,2,7-triol (1), 1-(4-hydroxybenzyl)-4,7-dimethoxy-9,10-dihydrophenanthrene-2-ol (2), and 1,3,6-tri(4-hydroxybenzyl)-4-methoxydihydrophenanthrene-2,7-diol (3) together with seven known phenanthrene derivatives, six known flavonoids, a bibenzyl and three phenolic compounds were isolated from the whole plant of Bletilla formosana. Their structures were elucidated by spectroscopic, mainly 2D NMR spectrometry and chemical methods.

Antimicrobial Activity of Necklace Orchids is Phylogenetically Clustered and can be Predicted With a Biological Response Method

“…Yang et al (2012) successfully isolated bletilin A, bletilin B and other phenanthrenes from Bletilla ochracea tuber extracts that showed antibacterial activities against S. aureus, S. epidermis and B. subtilis. The fibrous roots and tubers from Bletilla striata contain biphenanthrenes and stilbenoids, which possess antibacterial activity (Kovács et al, 2008;Qian et al, 2015), Additionally, dihydrophenanthrenes, phenanthrene, flavonoids, bibenzyl and phenolic compounds were isolated from entire plants of B. formosana by Lin et al (2005). These research findings support the results of our bioprospecting analyses and show that the biological response classification method is more effective in uncovering potential clades with high medicinal potential as compared with the EBDCS classification method.…”

Studies on the constituents of bulbs of the orchid Prosthechea michuacana and antioxidant activity

“…The IR spectrum showed absorptions at 3400 (OH), 1699, and 1458 cm -1 (aromatic ring). The degree of protonation of each carbon was determined by DEPT experiments, and the assignment of the carbon chemical shifts was made by comparison with the G C values of structurally related compounds [14,15]. Since 4 contains a total of 20 shifts, each of these signals corresponds to double the number of protons given by the respective integral ratios.…”

Cocktail Method: Effect of the Bletilla striata Extracts on CytochromeP450 Activity in Rat

“…3 It has pharmacological effects such as hemostasis, antibacterial, antitumor, etc. 4 However, the published literature mainly focuses on the separation and identification of its chemical components as well as the preliminary exploration of various crude extracts of therapeutic substances, there have been few reports on the interaction between B striata and other drugs. Therefore, this study aims to evaluate its effect on cytochrome P450 (CYP) activity in rat by using a Cocktail approach, as well as evaluate its safety, and predict its interaction with other drugs.…”