New eudesmane‐type sesquiterpenoids and other volatile constituents from the roots of Gynura bicolor DC.

Abstract

Diethyl ether extracts from fresh, field-grown plant roots and the thin roots of the cultured plantlet were analysed by gas chromatography (GC) and GC-mass spectrometry (GC-MS), and their constituents were compared. Of the components identified, major components of the field-grown plant roots were revealed to be sesquiterpene hydrocarbons such as (E)-caryophyllene, a-humulene, and germacrenes A, B, and C. (E)-b-Farnesene and germacrene C were predominant in the roots of the cultured plantlet. Three new sesquiterpenoids, gynuradienol (1), hydroperoxy-gynuradiene (2), and gynurenol (3) were isolated from the field-grown plant roots and their chemical structures were elucidated by nuclear magnetic resonance (NMR) spectra together with five known sesquiterpenoids, eudesm-11-en-4a-ol (4), intermedeol (5), alismol (6), alismoxide (7), (2E,6E)-3-isopropyl-6-methyl-10-oxoundeca-2,6-dienal (8), and a polyacetylenic compound, 1-tridecene-3,5,7,9,11-pentayne (9). Furthermore, characteristic green, moldy, and earthy aromas of the field-grown plant roots, which were remarkably different from those of the thin roots of the cultured plantlet, were revealed to be contributed by four methoxypyrazines, 2-methoxy-3-isopropylpyrazine (10), 2-methoxy-3-sec-butylpyrazine (11), 2-methoxy-3-isopropyl-5-methylpyrazine (12), and 2-methoxy-3-sec-butyl-5-methoxypyrazine (14) using a combination of GC-MS and GC-olfactometry (GC-O).

Two New Monoterpene Glycosides from Qing Shan Lu Shui Tea with Inhibitory Effects on Leukocyte-Type 12-Lipoxygenase Activity

“…The 13 C resonances of the monoterpene unit of 1 were close to those of 3 , except for C-7 (δ 80.6 for 1 and δ 71.1 for 3 ) and the tertiary methyl (C-8 and 9) (δ 24.1 for 1 and δ 30.0 for 3 ) carbon signals [ 11 ] ( Table 2 ). The remarkable downfield shift of C-7 and upfield shift of C-8 and C-9 resonances implied that the hydroxyl group of C-7 position in 3 for 1 is replaced by the hydroperoxy group [ 12 , 13 ]. The molecular formula of 1 calculated by HRESIMS analysis supports this suggestion.…”

Peroxy natural products

“…182 Another two compounds of this type 323 and 324 were discovered from Xylopia emarginata and Ecdysanthera rosea, respectively. 183,184 Two novel eudesmene-type sesquiterpene peroxides, kandenols C 325 and D 326, have been reported from Streptomyces sp.…”

Steroid Compounds From Gynura pseudochina (Lour) DC

“…The plant is a well-known traditional herbs in South East Asia, and it is widely used to treat eruptive fever, ulcer, detoxification, bleeding, rash, diabetes melitus, herves and cancer (Lemmens & Bunyapraphatsara, 2003;Hew, Ko & Gam, 2013). This genus contains some bioactive compounds such as pyrrolizidine and pyrazine alkaloids (Siriwatanametanon & Heinrich, 2011;Shimizu, et al, 2010), flavonoid, chlorogenic acid and terpenoid (Shimizu, et al, 2011). Some extract of this genus have been reported as antioxidant , antihyperglycemia, antihypertension (Wu et al, 2011), antiangiogenic (Seow, et al, 2011), NF-KB inhibitory (Siriwatanametanon & Heinrich, 2011) and antidiabetic (Hassan, Yam, Ahmad, & Yusof, 2010;Algarii, et al, 2013).…”