Pubescone, a Novel 11(7→6)Abeo‐14‐norcarabrane Sesquiterpenoid from Siegesbeckia pubescens

Abstract

The phytochemical investigation of the aerial parts of Siegesbeckia pubescens L. yielded 16 sesquiterpenoids, including a novel 11(7 ! 6)abeo-14-norcarabrane sesquiterpenoid, pubescone (1), and a new germacrane sesquiterpene, 5. The molecular structures of the isolated compounds were elucidated on the basis of extensive spectroscopic analysis, including 1D-and 2D-NMR.

Kalshinoids A–F, Anti-inflammatory Sesquiterpenes from Kalimeris shimadae

“…The structures of 1 – 6 were assigned from spectroscopic evidence, and the absolute configurations of kalshinoids A, B, E, and F were determined by electronic circular dichroism (ECD) calculations. The 21 known compounds were identified as 4α,7α-epoxyguaiane-10α,11-diol ( 7 ), ent -4­(15)-eudesmene-1β,6α-diol ( 8 ), pubescone ( 9 ), schensianol A ( 10 ), hydroxylindestenolide ( 11 ), lβ-hydroxy-β-cyperone ( 12 ), 10-hydroxy-15-oxo-α-cadinol ( 13 ), 1-patchoulene-4α,7α-diol ( 14 ), 10β,15-hydroxy-α-cadinol ( 15 ), cosmosoic acid ( 16 ), 4(15)-eudesmene-1β,7,11-triol ( 17 ), 3-eudesmene-1β,7,11-triol ( 18 ), 4α,7β,11-trihydroxy-1β H ,5α H -guai-10­(14)-ene ( 19 ), grasshopper ketone ( 20 ), 11-oxo-13-nor-alismol ( 21 ), ( S )-3-hydroxy-β-ionone ( 22 ), (3 R ,6 R ,7 E )-3-hydroxy-4,7-megastigmadien-9-one ( 23 ), 3-hydroxy-β-ionone ( 24 ), 9-hydroxy-4-megastigmen-3-one ( 25 ), alismorientol B ( 26 ), and 4α,10α,11-trihydroxy-1β H ,5β H -guai-7­(8)-ene ( 27 ), by comparison with literature data.…”

Sesquiterpenoids with Various Carbocyclic Skeletons from the Flowers of Chrysanthemum indicum

“…On the basis of the literature and spectroscopic data, the known sesquiterpenoids were defined as 11(7→6)­abeo-14-norcarbrane-4,7-dione ( 11 ), 6,8-cycloeudesm-4(15)-en-1-ol ( 12 ), (4 R ,5 R )-4,5-dihydroxycaryophyll-8­(13)-ene ( 13 ), 11-hydroxy-1-oxo-4α,5α,7β,10β-eremophilane ( 14 ), spathulenol ( 15 ), chrysanthediol A ( 16 ), 1β-hydroxy-4(15),5 E ,10­(14)-germacratriene ( 17 ), 5α-hydroxy-β-eudesmol ( 18 ), ligucyperonol ( 19 ), intermedeol ( 20 ), eudesm-4(15)-ene-1β,6α-diol ( 21 ), angeloylcumambrin B ( 22 ), cumambrin A ( 23 ), 11,13-dehydrodesacetylmatricarin ( 24 ), and matricarin ( 25 ) …”

“…This plant is an important heat-clearing and detoxifying herb used to treat inflammation, headache, and vertigo and for the preparation of a bitter tea used for antibacterial, antioxidant, and anti-inflammatory purposes . Over the past years, studies on selected TCM herbs led to the identification of several bioactive terpenoids. − As part of this program, an investigation of an aqueous EtOH extract of the flowers of C. indicum afforded 10 new sesquiterpenoids, i.e., chrysanthemumins A–J ( 1 – 10 ), which included six eudesmane ( 1 – 6 ), an iphionane ( 7 ), two germacrane ( 8 and 9 ), a guaiane ( 10 ), and 15 known sesquiterpenoids ( 11 – 25 ). Herein, the isolation and structure determination of these isolates, as well as their inhibitory activities against porcine epidemic diarrhea virus (PEDV) replication, are described.…”

Sesquiterpenoids from the Rhizomes of Homalomena occulta

“…Our research group has considerably focused on phytochemical investigations of TCM [7][8][9][10]. As part of our continuing efforts to obtain novel compounds with exquisite structural architectures, we initiated a chemical investigation of H. occulta, which has thus far led to the isolation and structural elucidation of six oplopanane sesquiterpenoids (1)(2)(3)(4)(5)(6), including four new (1-4) and one 3,5-seco-oplopanane (6), together with three previously reported sesquiterpenoids (7-9).…”