A Novel 4′-O-Diglycoside of Decarboxyrosmarinic Acid from Blepharis ciliaris

Abstract

A novel natural phenolic 1 was isolated from the hydroalcoholic extract of the aerial parts of Blepharis ciliaris (L.) B.L. Burtt (Acanthaceae), in addition to apigenin 7-O-glucoside 2 and apigenin-7-O-(3″-acetyl-6″-E-p-coumaroyl glucoside) 3. The structure of 1 was established as 3′,4′-dihydroxy-β-phenyl ethyl caffeate-4′-β-O-D-galactopyranosyl-(1′″→4″)-α-O-L-rhamnopyranoside [= 9′-decarboxy rosmarinic acid-4′-O-(1→4)-galactosyl rhanmoside]. Structures were determined by conventional methods of analysis, as well as by different MS and NMR techniques.     

A new meta-homoisoflavane from the fresh stems of dracaena cochinchinensis

A new meta-homoisoflavane, 10,11-dihydroxydracaenone C (1), together with 7,4′-dihydroxyflavone (2), 7,4′-dihydroxyflavane (3), 4,4′-dihydroxy-2-methoxychalcone (4), 4,4′-dihydroxy-2-methoxydihydrochalcone (5), 7,4′-dihydrohomoisoflavanone (6), 7,4′-homoisoflavane (7), lophenol (8), β-sitosterol (9), stigma-5, 22-diene-3-ol (10), 1-(4′-O-β-d-glucopyranosyl)benzyl-ethan-2-ol (11), 3,4-dihydoxy-1-allylbenezene-4-O-α-l-rhamnopyranosyl-(1 → 6)-O-β-d-glucopyranoside (12), 1-hydroxy-3,4,5-trimethoxybenzene-1-O-α-l-apiopyranosyl-(1 → 6)-O-β-d-glucopyranoside (13), and tachioside (14) have been isolated from the fresh stems of Dracaena cochinchinensis. Their structures have been established by spectroscopic analysis, especially by 2D NMR. This is the first time compounds 11, 13, 14 have been isolated from Dracaena.     

Chemical constituents of Isodon nervosus and their cytotoxicity

Two new ent-kaurane diterpenoids, 6,20,15α-trihydroxy-6,7-seco-1α,7-olide-ent-kaur-16-ene (1) and 7β,12α-dihydroxy-6β,15β-diacetoxy-7α,20-epoxy-ent-kaur-2,16-dien-1-one (2), together with the six known compounds, were isolated from the aerial part of Isodon nervosus. The structures of the new compounds were determined by spectral methods (1D, 2D NMR, and MS). Six compounds were assayed for their cytotoxicity against HL60, SMMC-7721, and HeLa human cell lines. Compounds 5, 7, and 8 showed significant cytotoxicity.     

New antioxidant phenylethanol glycosides from Torenia concolor

Two new phenylethanol glycosides, phenylethyl-O-α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranoside (torenoside A, 1) and 2′-O-3,4-dihydroxy-β-phenylethoxy-O-α-l-rhamnopyranosyl-(1″ → 3′)-(4′-O-caffeoyl)-β-d-glucopyranoside (torenoside B, 2), along with the 17 known compounds (3–19) were isolated from Torenia concolor. Those structures were established on the basis of spectroscopic analysis including NMR spectroscopic techniques (¹³C, ¹H, ¹H–¹H COSY, HMQC, HMBC, TOCSY, and NOESY). Moreover, phenylethanol glycosides 3–6 exhibited significant antioxidant activities in DPPH radical scavenging assay.     

Two new flavonoid glycosides from Artemisia frigida Willd.

An investigation of the n-BuOH-soluble fraction from the aerial parts of Artemisia frigida has led to the isolation of two new flavonoid glycosides, named friginoside A and friginoside B. Their structures were characterized as 5,7-dihydroxy-3′,4′,5′-trimethoxy flavone 7-O-β-d-glucuronide (1) and 5,7-dihydroxy-3′,4′,5′-trimethoxyflavone 7-O-β-d-glucuronyl-(1 → 2)O-β-d-glucuronide (2) on the basis of 1D and 2D NMR spectral analysis.     

Triterpene saponins from the leaves of Ilex kudingcha

Three new triterpene saponins, ilekudinosides T–V (1–3), along with six known saponins were isolated from the 70% ethanolic extract of the leaves of Ilex kudingcha. The new saponins were characterized as 3-O-β-d-glucopyranosyl-(1 → 3)-[α-l-rhamnopyranosyl-(1 → 2)]-α-l-arabinopyranosyl-3β,19α-dihydroxy-urs-12(13)-en-28,20β-lactone (1), 3-O-β-d-glucopyranosyl-(1 → 3)-[α-l-rhamnopyranosyl-(1 → 2)]-α-l-arabinopyranosyl-3β,19α-dihydroxy-12-ethoxy-urs-13(18)-ene-28,20β-lactone (2), 3-O-β-d-glucopyranosyl-(1 → 3)-[α-l-rhamnopyranosyl-(1 → 2)]-α-l-arabinopyranosyl-3β,19α-dihydroxy-11-oxo-urs-13(18)-ene-28,20β-lactone (3), respectively. The structures of compounds 1–3 were elucidated on the basis of the chemical and spectroscopic evidence, and the structures of known compounds were identified by comparison of their spectroscopic data with those reported in the literature.     

Flavonoids from silkworm droppings and their promotional activities on heme oxygenase-1

A new flavane glucoside, 7,2′-dihydroxy-8-hydroxyethyl-4′-methoxyflavane-2′-O-β-d-glucopyranoside (3), along with three known flavonoids, 7,2′-dihydroxy-8-prenyl-4′-methoxyflavane (1), euchrenone a₇ (2), and 7,2′-dihydroxy-8-prenyl-4′-methoxy-2′-O-β-d-glucopyranosylflavane (4), was isolated from silkworm droppings. The structures of the compounds were elucidated on the basis of 1D and 2D NMR spectroscopic analyses and optical rotational characteristics. The compounds isolated from silkworm droppings were evaluated for their effects on heme oxygenase-1 (HO-1) activity. Compounds 1 and 3 increased the expression of HO-1 in HepG2 cells. HO-1 is an antioxidant enzyme that catabolizes heme to carbon monoxide, free iron, and biliverdin, all of which are involved in the suppression of inflammatory mediators.     

Flavonoids from the leaves of Pleioblastus argenteastriatus

A new flavonoid, 5,7,3′-trihydroxy-6-C-β-d-digitoxopyranosyl-4′-O-β-d-glucopyranosyl flavonoside (1), along with four known flavonoids 5,7,4′-trihydroxy-3′,5′-dimethoxy flavone (2), 5,3′,4′-trihydroxy-7-O-β-d-glucopyranosyl flavonoside (3), 5,4′-dihydroxy-3′,5′-dimethoxy-7-O-β-d-glucopyranosyl flavonoside (4), 5,3′,4′-trihydroxy-6-C-[β-d-glucopyranosyl-(1 → 6)]-β-d-glucopyranosyl flavonoside (5) were isolated from 95% EtOH extract of the leaves of Pleioblastus argenteastriatus. Their structures were determined on the basis of spectroscopic techniques and chemical methods.     

Two triterpenoid glycosides from the roots of Camellia oleifera and their cytotoxic activity

Two new triterpenoid saponins, oleiferoside N and oleiferoside O, were isolated from the EtOH extract from the roots of Camellia oleifera C. Abel. Their structures were elucidated as 16α-acetoxy-21β,22α-O-diangeloyloxy-23,28-dihydroxyolean-12-ene 3β-O-β-d-xylopyranosyl-(1 → 3)-α-l-arabinopyranosyl-(1 → 3)-β-d-glucuronopyranoside (1), 16α-acetoxy-21β-O-angeloyloxy-23,28-dihydroxy-22α-O-(2-methylbutanoyloxy)olean-12-ene 3β-O-β-d-xylopyranosyl-(1 → 3)-α-l-arabinopyranosyl-(1 → 3)-β-d-glucuronopyranoside (2), on the basis of spectroscopic analyses (IR, ESI-MS, HR-ESI-MS, 1D and 2D NMR) and acid hydrolysis. Both were characterized to be oleanane-type saponins with sugar moieties linked to C-3 of the aglycone. Cytotoxic activities of two saponins were evaluated against four human tumor cell lines (A549, B16, BEL-7402, and MCF-7) by using the MTT in vitro assay. Compounds 1 and 2 showed moderate cytotoxic activities toward the tested cell lines.     

New furostanol glycosides from the rhizomes of Dioscorea futschauensis R. Kunth

Two new furostanol glycosides, 26-O-β-D-glucopyranosyl-3β,26-dihydroxy-23(S)-methoxyl-25(R)-furosta-5,20(22)-dien-3-O-α-L-rhamnopyranosyl(1→2)-[β-D-glucopyranosyl(1→3)]-β-D-glucopyranoside (dioscoreside E, 1) and 26-O-β-D-glucopyranosyl-3β,26-dihydroxy-25(R)-furosta-5,20(22)-dien-3-O-α-L-rhamnopyranosyl(1→2)-[β-D-glucopyranosyl (1→3)]-β-D-glucopyranoside (prtotogracillin, 2), together with 11 known furostanol glycosides were isolated from the rhizomes of Dioscorea futshauensis R. Kunth. Their structures were elucidated on the basis of spectroscopic analysis (NMR and FABMS). Their anti-fungal activity against the plant pathogenic fungus Pyricularia oryzae and cytotoxic activity on K562 cancer cell line were evaluated in vitro.     

Three triterpenoid saponins acylated with monoterpenic acid from Gymnocladus chinensis

A new triterpenoid saponin acylated with monoterpenic acid, together with two known triterpenoid saponins, has been isolated from the fruit of Gymnocladus chinensis Baill. Their structures were elucidated as 2β,23-dihydroxy-3-O-α-L-rhamnopyranosyl-21-O-{(6S)-2-trans-2,6-dimethyl-6-O-[3-O-(β-D-glucopyranosyl)-4-O-((6S)-2-trans-2,6-dimethyl-6-hydroxy-2,7-octadienoyl)-β-L-arabinopyranosyl]-2,7-octadienoyl}-acacic acid 28-O-β-D-xylopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-[α-L-rhamnopyranosyl-(1 → 6)]-β-D-glucopyranosyl ester (1), gymnocladus saponin E (2), and gymnocladus saponin F₂ (3).     

Stilbenoids isolated from the roots of Rheum lhasaense under the guidance of the acetylcholinesterase inhibition activity

Four unknown stilbenoids, including one dimer, namely 4′-methoxy-scirpusin A (5) and three monomeric stilbene glycosides, namely piceatannol-3′-O-[2′′-(3,5-dihydroxy-4-methoxybenzoyl)]-β-d-glucopyranoside (13), piceatannol-3′-O-(2′′-galloyl)-β-d-glucopyranoside (14) and piceatannol-3′-O-(6″-p-coumaroyl)-β-d-glucopyranoside (16) together with 15 described compounds, were isolated from the ethyl acetate fraction of the ethanol extract of roots of Rheum lhasaense based on the guidance of the inhibitory effect on acetylcholinesterase. The structures of the unknown compounds were established by combined spectroscopic analysis and comparing their spectral data with compounds with similar structures. Some selected components were also investigated for their inhibitory abilities on acetylcholinesterase (AChE), indicating that compound 13 may be responsible for higher inhibitory activity of the ethyl acetate fraction on AChE.

     

Two new isoflavone triglycosides from the small branches of Sophora japonica

Two new isoflavone triglycosides, genistein 4′-O-(6″-O-α-l-rhamnopyranosyl)-β-sophoroside (1), and genistein 4′-O-(6?-O-α-l-rhamnopyranosyl)-β-sophoroside (2), together with five known compounds, namely, sophorabioside, genistin, rutin, quercetin 3-O-β-d-glucopyranoside, and kaempferol 3-O-β-d-glucopyranoside, were isolated from the small branches of Sophora japonica L. Their structures were elucidated on the basis of spectroscopic analyses and chemical evidence.     

Three new flavonoid glycosides from Urena lobata

Three new flavonoid glycosides, kaempferol-3-O-β-d-apiofuranosyl(1 → 2)-β-d-glucopyranosyl-7-O-α-l-rhamnopyranoside (1), kaempferol-4′-O-β-d-apiofuranosyl-3-O-β-d-glucopyranosyl-7-O-α-l-rhamnopyranoside (2), and 5,6,7,4′-tetrahydroxy-flavone-6-O-β-d-arabinopyranosyl-7-O-α-l-rhamnopyranoside (3), were isolated from the aerial parts of Urena lobata L., along with 10 known compounds (4–13). Their structures were determined based on spectroscopic methods including 1D and 2D NMR spectroscopy as well as HR-ESI-MS.     

A novel spinosin derivative from Semen Ziziphi Spinosae

A novel spinosin derivative, 6?-(4?′-O-β-d-glucopyranosyl)-vanilloyl spinosin (1) was isolated from the methanol extract of Semen Ziziphi Spinosae, together with five known flavonoids, swertish (2), spinosin (3), 6?-feruloylspinosin (4), isospinosin (5) and kaempferol 3-O-α-l-rhamnopyranosyl-(1 → 2)-O-[O-α-l-rhamnopyranosyl-(1 → 6)]-β-d-glucopyranoside (6), and two alkanoids, zizyphusine (7) and 6-(2′,3′-dihydroxyl-4′-hydroxymethyl-tetrahydro-furan-1′-yl)-cyclopentene[c]pyrrole-1,3-diol (8). The structure of compound 1 was elucidated by spectroscopic methods including UV, IR, ESI-TOF-MS, 1D, and 2D NMR techniques.     

New flavonol glycosides and new xanthone from Polygala japonica

Three new flavonol glycosides and a new xanthone were isolated from Polygala japonica HOUTT. with eight known compounds. Their structures were identified as 1,7-dihydroxy-3,4-dimethoxy-xanthone (1), kaempferol-7,4′-dimethyl ether (2), physcion (3), guazijinxanthone (4), rhamnetin (5), polygalin A (6), 3,5,7-trihydroxy-4′-methoxy-flavone-3-O-β-d-galactopyranoside (7), 3,5,3′-trihydoxy-7,4′-dimethoxy-flavone-3-O-β-d-galactopyranoside (8), 3,5,3′,4′-tetrahydroxy-7-methoxy-flavone-3-O-β-d-galactopyranoside (9), 3,5,3′,4′-tetrahydroxy-7-methoxy-flavone-3-O-β-d-glucopyranoside (10), polygalin B (11), polygalin C (12). Among them, compound 4 is a new xanthone, and 6, 11 and 12 are new flavonol glycosides. Compounds 1, 4, 7 and 8 were tested for cytotoxic activity with MTT assays on five human tumor cell lines, K562, A549, PC-3M, HCT-8 and SHG-44. Compound 4 showed cytotoxic activity against all the five cell lines.     

Two new compounds from Comastoma pedunlulatum

Two new compounds, a xanthonoid and a flavonoid C-glycoside, were isolated from the ethyl acetate extract of the dried herb of Comastoma pedunlulatum. The structures of the new compounds were elucidated, respectively, as 1,8-dihydroxy-3,5-dimethoxyxanthone 1-O-[2-(4′-hydroxy-3′,5′-dimethoxy-E-cinnamoyl)]-β-d-xylopyranosyl-(1-6)-β-d-glucopyranoside (1) and 6″-O-acetylisoorientin (2) on the basis of their spectroscopic and physicochemical properties.     

Antibacterial sesquiterpene lactone glucoside from seed pods of Bauhinia retusa

From the seed pods of Bauhinia retusa, a new eudesmane sesquiterpene glucoside, 1-O-β-D-glucopyranosyl-9β,15-dihydroxy-5α,6βH-eudesma-3-ene-6α,12-olide (1), has been isolated together with three known compounds, 4′-hydroxy-7-methoxy flavane (2), β-sitosterol (3), and stigmasterol (4). The structures of isolated compounds were verified with the help of 1D, 2D NMR, and HR-ESI-MS spectroscopies. Compound 1 showed moderate antibacterial activity against Pseudomonas aeruginosa and Escherichia coli when a disc diffusion method is used.     

Two new constituents from Rheum sublanceolatum

The chemical investigation of Rheum sublanceolatum has led to the isolation of two new constituents, the structures of which were identified on the basis of physical and spectroscopic analysis as 2-acetyl-3-methyl-6,8-dihydroxy-2,3,4,4-tetrahydronaphthalene-1-one-6-O-β-d-glucopyranoside (1) and 2,5-dimethyl-7-hydroxychromone-7-O-β-d-(6′-O-galloyl)-glucopyranoside (2).     

Two new acetylated flavan glycosides from rhizomes of the fern Abacopteris penangiana

Two new acetylated flavan glycosides (2S,4R)-4,5,7-trihydroxy-4′-methoxy-6,8-dimethylflavan-5-O-β-D-6-acetylglucopyranoside-7-O-β-D-glucopyranoside (1) and (2S,4R)-5,7-dihydroxy-4,4′-dimethoxy-6,8-dimethylflavan-5-O-β-D-6-acetylglucopyranoside-7-O-β-D-glucopyranoside (2) were isolated from the rhizomes of Abacopteris penangiana. Their structures were elucidated on the basis of spectroscopic methods including IR, HR-ESI-MS, 1D and 2D NMR, and chemical evidences.