Flavone Glycosides from Strobilanthes Formosanus

Two new flavone glycosides, 3′‐hydroxy‐5,7‐dimethoxyflavone 4′‐O‐β‐D‐apiofuranoside ( 1 ), and 5,7‐dimethoxyflavone 4′‐O‐[β‐D‐apiofuranosyl(1→5)‐ β‐D‐glucopyranoside] ( 2 ) along with four known compounds, 4′‐hydroxy‐5,7‐dimethoxyflavone ( 3 ), 2,6‐dimethoxy‐1,4‐benzoquinone ( 4 ), lupeol ( 5 ) and betulin ( 6 ) were isolated from the stem and roots of Strobilanthes formosanus. Their structures were elucidated on the basis of their spectroscopic evidence.     

Chemical Components of Seriphidium Santolium Poljak

A new biflavonoid glucoside, apigenin‐7‐O‐β‐D‐glucopyranoside‐(3′‐O‐7″)‐quercetin‐3″‐methyl ether ( 1 ) together with twenty known compounds, apigenin ( 2 ), luteolin ( 3 ), chrysoeriol ( 4 ), tricin ( 5 ), hispidulin ( 6 ), pectolinarigenin ( 7 ), eupatilin ( 8 ), 5,7‐dihydroxy‐6,3′,4′,5′‐tetramethoxyflavone ( 9 ), 5,7,4′‐trihydroxy‐6,3′,5′‐trimethoxyflavone ( 10 ), 3,6‐O‐dimethylquercetagetin‐7‐O‐β‐D‐glucoside ( 11 ), 6‐hydroxy‐5,7‐dimethoxy‐coumarin ( 12 ), taraxerol ( 13 ), taraxeryl acetate ( 14 ), a mixture of β‐sitosterol ( 15 ) and stigmasterol ( 16 ), a mixture of the n‐alkyl trans‐p‐coumarates ( 17 ), a mixture of the n‐alkyl trans‐ferulates ( 18 ), 2‐hydroxy‐4,6‐dimethoxyacetophenone ( 19 ), 4‐hydroxy‐2,6‐dimethoxyphenol‐1‐O‐β‐D‐glucopyranoside ( 20 ), and 2‐hydroxycinnamoyl‐β‐D‐glucopyranoside ( 21 ), were isolated from the whole plant of Seriphidium santolium Poljak. The structures of these compounds were determined by means of spectral and chemical studies.     

Clionasterol Glucoside and Acylated Clionasterol Glucosides from Oplismenus burmannii

A new clionasterol glucoside, clionasterol‐[(1'→3α)‐O‐β‐D]‐glucopyranoside ( 1 ), a new acylated clionasterol glucoside, clionasterol‐[6'‐O‐acyl‐(1'→3β)‐O‐b‐D]‐glucopyranoside ( 2 ) and clionasterol ( 3 ) were isolated from the aerial parts of Oplismenus burmannii. The nature and length of fatty acid acyl chains in 2 was identified by alkaline methanolysis of compound 2 . The aglycone fraction on GC‐MS analysis showed three peaks in GC at t_R 49.86 (82.1%), 51.13 (13.3%) and 56.53 (4.6%) min, which were characterized as arachidic acid methyl ester ( a ) oleic acid methyl ester ( b ) and 12‐methyltetradecanoic acid methyl ester ( c ) respectively. Thus 2 was characterized as a mixture of three new compounds, clionasterol‐[6'‐O‐eicosanoyl‐(1'→3β)‐O‐β‐D]‐glucopyranoside ( 2a ), clionasterol‐[6'‐O‐(8Z)‐octa‐deca‐9‐enoyl‐(1'→3β)‐O‐β‐D]‐glucopyranoside ( 2b ) and clionasterol‐[6'‐O‐(12‐methyltetradecanoyl)‐(1'→3β)‐O‐β‐D]‐glucopyranoside ( 2c ).     

Xanthone O‐Glycosides from the Roots of Pteris Multifida

Two new xanthone glycosides and six known compounds were isolated from the roots of Pteris multifida. Based on spectroscopic and chemical methods, the structures of the new compounds were elucidated as 1‐hydroxy‐4,7‐dimethoxy‐8‐(3‐methyl‐2‐butenyl)‐6‐O‐α‐L‐rhamnopyranosyl‐(1→2)‐[β‐D‐glucopyranosyl‐(1→3)]‐β‐D‐glucopyranosylxanthone ( 1 ), and 1,3‐dihydroxy‐7‐methoxy‐8‐(3‐methyl‐2‐butenyl)‐6‐O‐α‐L‐rhamnopyranosyl‐(1 →2)‐[β‐D‐glucopyranosyl‐(1→3)]‐β‐D‐glucopyranosylxanthone ( 2 ), respectively.     

New α‐Tetralone Galloylglucosides from the Fresh Pericarps of Juglans sigillata

Three new α‐tetralone galloylglucosides, 1 – 3 , were isolated from the fresh pericarps of Juglans sigillata (Juglandaceae), together with six known compounds. The structures of the new compounds were determined as 1,2,3,4‐tetrahydro‐7‐hydroxy‐4‐oxonaphthalen‐1‐yl 6‐O‐[(3,4,5‐trihydroxyphenyl)carbonyl]‐β‐D ‐glucopyranoside ( 1 ), (1S)‐1,2,3,4‐tetrahydro‐8‐hydroxy‐4‐oxonaphthalen‐1‐yl 6‐O‐[(3,4,5‐trihydroxyphenyl)carbonyl]‐β‐D ‐glucopyranoside ( 2 ), and 1,2,3,4‐tetrahydro‐7,8‐dihydroxy‐4‐oxonaphthalen‐1‐yl 6‐O‐[(3,4,5‐trihydroxyphenyl)carbonyl]‐β‐D ‐glucopyranoside ( 3 ), respectively, on the basis of detailed spectroscopic analyses, and acidic and enzymatic hydrolysis. The antimicrobial activities of the isolated compounds 2, 4 , and 7 – 9 were evaluated.     

1H, 13C and 15N NMR spectroscopic characterization of unexpected degradation products of the nifedipine analogue bis(2‐cyanoethyl) 2,6‐dimethyl‐4‐(2‐nitrophenyl)‐1,4‐dihydro‐3,5‐pyridinedicarboxylate

In the course of saponification experiments with bis(2‐cyanoethyl) 2,6‐dimethyl‐4‐(2‐nitrophenyl)‐1,4‐dihydro‐3,5‐pyridinedicarboxylate ( 1 ), an analogue of the calcium channel blocker nifedipine, three unexpected degradation products were isolated. The compounds were identified as 3‐(2‐acetamido‐1‐carboxy‐1‐propenyl)‐1‐hydroxy‐2‐indolecarboxylic acid ( 3 ), 9‐hydroxy‐1,3‐dimethyl‐β‐carboline‐4‐carboxylic acid ( 4 ) and 6‐hydroxy‐2,4‐dimethyl‐5‐oxo‐5,6‐dihydrobenzo[c][2,7]naphthyridine‐1‐carboxylic acid ( 6 ). The structures of these compounds were deduced from one‐ and two‐dimensional ¹H, ¹³C and natural abundance ¹⁵N NMR experiments (¹H,¹H‐COSY, gs‐HSQC, gs‐HMBC, ¹⁵N gs‐HMBC), and corroborated by comparison of their NMR data with the respective data for structurally similar compounds. Copyright © 2002 John Wiley & Sons, Ltd.     

Steroidal Alkaloids from Veratrum dahuricum (Turcz.) Loes. f. with Genotoxicity on Brain Cell DNA in Mice

Two new steroidal alkaloids, 2β‐hydroxyverdine ( 1 ) and tomatillidine 3‐O‐β‐D ‐glucopyranoside ( 2 ), were isolated from the root and rhizome of Veratrum dahuricum (Turcz .) Loes . f., together with four known compounds, i.e., 16‐O‐(2‐methylbutyroyl)germine ( 3 ), veramitaline ( 4 ), jervine ( 5 ), and veratroylzygadenine ( 6 ). Their structures were established by extensive spectroscopic analysis, as well as by comparison with data in literature. Compounds 1 – 6 exhibited genotoxicity on brain cell DNA of the cerebellum and cerebral cortex in mice, evaluated by using single‐cell gel electrophoresis (comet assay).     

Semi‐synthesis and NMR spectral assignments of flavonoid and chalcone derivatives

Previous investigations of the aerial parts of the Australian plant Eremophila microtheca and Syzygium tierneyanum resulted in the isolation of the antimicrobial flavonoid jaceosidin ( 4 ) and 2′,6′‐dihydroxy‐4′‐methoxy‐3′,5′‐dimethyl chalcone ( 7 ), respectively. In this current study, compounds 4 and 7 were derivatized by acetylation, pivaloylation, and methylation reactions. The final products, 5,7,4′‐triacetoxy jaceosidin ( 10 ), 5,7,4′‐tripivaloyloxy jaceosidin ( 11 ), 5,7,4′‐trimethoxy jaceosidin ( 12 ), 2′,6′‐diacetoxy‐4′‐methoxy‐3′,5′‐dimethyl chalcone ( 13 ), 2′‐hydroxy‐4′‐methoxy‐6′‐pivaloyloxy‐3′,5′‐dimethyl chalcone ( 14 ), and 2′‐hydroxy‐4′,6′‐dimethoxy‐3′,5′‐dimethyl chalcone ( 15 ) were all fully characterized by NMR and MS. Derivatives 10 and 13 have been previously reported but were only partially characterized. This is the first reported synthesis of 11 and 14 . The natural products and their derivatives were evaluated for their antibacterial and antifungal properties, and the natural product, jaceosidin ( 4 ) and the acetylated derivative, 5,7,4′‐triacetoxy jaceosidin ( 10 ), showed modest antibacterial activity (32–128 µg/ml) against Staphylococcus aureus strains. Copyright © 2016 John Wiley & Sons, Ltd.     

Flavones and Cytotoxic Constituents from the Stem Bark of Muntingia Calabura

Two new flavones, 8‐hydroxy‐7,3′,4′,5′‐tetramethoxyflavone and 8,4′‐dihydroxy‐7,3′,5′‐trimethoxyflavone, together with thirteen known compounds have been isolated from the stem bark of Muntingia calabura. The structures of two new compounds were determined through spectral analyses. Among the isolates, 8‐hydroxy‐7,3′,4′,5′‐tetramethoxyflavone, 8,4′‐dihydroxy‐7,3′,5′‐trimethoxyflavone, and 3‐hydroxy‐1‐(3,5‐dimethoxy‐4‐hydroxyphenyl)propan‐1‐one exhibited effective cytotoxicities (ED₅₀ values = 3.56, 3.71, and 3.27 μg/mL, respectively) against the P‐388 cell line in vitro.     

Nonsteroidal Constituents from Solanum Incanum L.

Sixteen compounds were isolated from the aerial parts of Solanum incanum L. These compounds included ten flavonoids ( 1‐10 ), chlorogenic acid ( 11 ), adenosine ( 12 ), benzyl‐O‐β‐D‐xylopyranosyl(1→2)‐β‐D‐glucopyranoside ( 13 ), and three phenylalkanoic acids ( 14‐16 ). The structures were determined from their physical and spectral data. Among these compounds, kaempferol 3‐O‐(6″′‐O‐2,5‐dihydroxycinnamoyl)‐β‐D‐glucopyranosyl (1→2) β‐D‐glucopyranoside ( 10 ) was identified as a new compound.     

Chemical Components of Anaphalis Sinica Hance

Twenty components (including a new flavanone) were isolated and identified from the whole plant of Anaphalis sinica Hance. Their structures were determined on the basis of spectral analysis and chemical transformation. These components are 6‐[(5‐methyl‐6‐ethyl‐4‐hydroxy‐pyrone‐3‐yl)‐methylene]glabranine ( 1 ), kaempferol ( 2 ), tiliroside ( 3 ), quercetin ( 4 ), quercetin‐3‐O‐β‐D‐glucoside ( 5 ), scutellarin ( 6 ), 5,7‐dihydroxy‐8‐methoxyflavone ( 7 ), 5,7‐dihydroxy‐4′‐methoxy‐flavone‐7‐O‐α‐L‐rhamnopyranosyl(1→6)‐β‐D‐glucopyranoside ( 8 ), helipyrone ( 9 ), 4′‐hydroxydehydrokawain ( 10 ), panamin ( 11 ), ursolic acid ( 12 ), pomolic acid ( 13 ), 3‐acetyloleanolic acid ( 14 ), a mixture of N‐(2‐hydroxy‐acyl)‐4‐hydroxy‐8(E)‐ene‐sphingenine ( 15 ), O‐methyl‐D‐inositol ( 16 ), a mixture of β‐sitosterol ( 17 ) and stigmasterol ( 18 ) and a mixture of daucosterol ( 19 ) and stigmasterol‐β‐D‐glucoside ( 20 ). Among them, 6‐[(5‐methyl‐6‐ethyl‐4‐hydroxy‐pyrone‐3‐yl)‐methylene]glabranine ( 1 ) is a new compound, and ¹³C NMR data of panamin ( 11 ) is reported for the first time.     

Three Novel Compounds from the Flowers of Bombax malabaricum

Two unusual 9′‐norneolignans, bombasin ( 1 ) and bombasin 4‐O‐β‐glucoside ( 2 ), and a novel D ‐gulono‐γ‐lactone derivative, bombalin ( 3 ), were isolated from the flowers of Bombax malabaricum, together with the three known compounds dihydrodehydrodiconiferyl alcohol 4‐O‐β‐D ‐glucopyranoside ( 4 ), trans‐3‐(p‐coumaroyl)quinic acid ( 5 ), and neochlorogenic acid ( 6 ). Their structures were elucidated by extensive spectroscopic methods as well as chemical transformation. Compounds 1 – 3 were evaluated against the HGC‐27 gastrointestinal and Hela cervical human cancer cell lines, but all were inactive in both lines (IC₅₀>50 μM ).     

New Lignans from the Roots of Taiwania cryptomerioides Hayata

The five new lignans designated 3′,4′‐de‐O‐methylenehinokinin ( 1 ), taiwaninolide ( 2 ), 8′‐hydroxysavinin ( 3 ), isoguamarol ( 4 ), and 4′‐O‐methylsalicifolin ( 5 ), as well as the new 4‐(3,4‐dimethoxybenzyl)dihydro‐3‐(4‐hydroxybenzyl)furan‐2(3H)‐one ( 6 ) were isolated from the roots of Taiwania cryptomerioides, besides the three known compounds hinokinin ( 8 ), savinin ( 9 ), and 3,4‐de‐O‐methylenehinokinin ( 7 ). The structures of the new constituents were elucidated through chemical and spectral studies. A compound previously isolated from the heartwood of Chamaecyparis obtusa var. formosana was assigned structure 1 ; however, this structure has now been revised to be 3,4‐de‐O‐methylenehinokinin ( 7 ).     

Cytotoxic Activity of Capnellene‐8β, 10α‐Diol Derivatives from a Taiwanese Soft Coral Capnella sp.

The sesquiterpene capnellene‐8β, 10α‐diol ( 1 ) was isolated from non‐polar extract of the soft coral Capnella sp. Ten acylation products of capnellene‐8β, 10α‐diol were prepared: 10α‐hydroxy‐8β‐O‐benzoylcapnellene ( 2 ), 10α‐hydroxy‐8β‐O‐p‐toluoylcapnellene ( 3 ), 10α‐hydroxy‐8β‐O‐4‐chlorobenzoyl‐capnellene ( 4 ), 10α‐hydroxy‐8β‐O‐2‐furoylcapnellene ( 5 ), 10α‐hydroxy‐8β‐O‐2‐thiophenoylcapnellene ( 6 ), 10α‐hydroxy‐8β‐O‐4‐fluorobenzoylcapnellene ( 7 ), 10α‐hydroxy‐8β‐O‐4‐propylbenzoylcapnellene ( 8 ), 10α‐hydroxy‐8β‐O‐cinnamoylcapnellene ( 9 ), 10α‐hydroxy‐8β‐O‐4‐nitrobenzoylcapnellene ( 10 ), and 10α‐hydroxy‐8β‐O‐4‐anisoylcapnellene ( 11 ). The structures of capnellene‐8β, 10α‐diol as well as its derivatives were established through standard spectroscopic analysis. The in vitro cytotoxic activities of the eleven compounds were evaluated against Hela, KB, Daoy, and WiDr human tumor cell lines.     

Five Aromatics Bearing a 4‐O‐Methylglucose Unit from Cordyceps cicadae

Five new aromatics bearing a 4‐O‐methylglucose unit, namely 3‐methoxy‐1,4‐hydroquinone 1‐(4′‐O‐methyl‐β‐glucopyranoside) (=4‐hydroxy‐3‐methoxyphenyl 4‐O‐methyl‐β‐glucopyranoside; 1 ), 3‐methoxy‐1,4‐hydroquinone 4‐(4′‐O‐methyl‐β‐glucopyranoside) (=4‐hydroxy‐2‐methoxyphenyl 4‐O‐methyl‐β‐glucopyranoside; 2 ), vanillic acid 4‐(4′‐O‐methyl‐β‐glucopyranoside) (=3‐methoxy‐4‐[(O‐methyl‐β‐glucopyranosyl)oxy]benzoic acid; 3 ), 5‐methoxycinnamic acid 3‐O‐(4′‐O‐methyl‐β‐glucopyranoside) (=(2E)‐3‐{3‐methoxy‐5‐[(4‐O‐methyl‐β‐glucopyranosyl)oxy]phenyl}prop‐2‐enoic acid; 4 ), and naphthalene‐1,8‐diol 1,8‐bis(4′‐O‐methyl‐β‐glucopyranoside) (=naphthalene‐1,8‐diyl bis(4‐O‐methyl‐β‐glucopyranoside; 5 ), were isolated from the cultivated Cordyceps cicadae mycelia, together with thirteen known compounds. Their structures were determined by spectroscopic methods. The absolute configurations of the sugar units were not determined.     

β‐Carboline alkaloids from the stems of Picrasma quassioides

Five new β‐carboline alkaloids, 6,12‐dimethoxy‐3‐(2‐hydroxylethyl)‐β‐carboline (1), 3,10‐dihydroxy‐β‐carboline (2), 6,12‐dimethoxy‐3‐(1‐hydroxylethyl)‐β‐carboline (3), 6,12‐dimethoxy‐3‐(1,2‐dihydroxylethyl)‐β‐carboline (4), and 6‐methoxy‐3‐(2‐hydroxyl‐1‐ethoxylethyl)‐β‐carboline (5), and two new natural products, 6‐methoxy‐12‐hydroxy‐3‐methoxycarbonyl‐β‐carboline (6) and 3‐hydroxy‐β‐carboline (7) were isolated from the stems of Picrasma quassioides along with 16 known β‐carboline alkaloids (8–23). The structures of new compounds were determined by extensive spectroscopic analyses, and the 1D and 2D NMR data of compounds 6, 7 and 10 were reported for the first time. The bioassays showed that only compounds 14 and 16 could enhance the differentiation of 3T3‐L1 preadiocytes accompanied by secretion of adiponectin proteins among these 23 compounds. Copyright © 2010 John Wiley & Sons, Ltd.     

Four new ursane‐type saponins from Morina nepalensis var. alba

Four new ursane‐type saponins, monepalosides C–F, together with a known saponin, mazusaponin II, were isolated from Morina nepalensis var. alba Hand.‐Mazz. Their structures were determined to be 3‐O‐α‐L ‐arabinopyranosyl‐(1 → 3)‐&[alpha;‐L ‐rhamnopyranosyl‐(1 → 2)]‐α‐L ‐arabinopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranoside (monepaloside C, 1 ), 3‐O‐α‐L ‐arabinopyranosyl‐(1 → 3)‐&[alpha;‐L ‐rhamnopyranosyl‐(1 → 2)]‐β‐D ‐xylopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranoside (monepaloside D, 2 ), 3‐O‐α‐L ‐arabinopyranosyl‐(1 → 3)‐&[beta;‐D ‐glucopyranosy‐(1 → 2)]‐α‐L ‐arabinopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranoside (monepaloside E, 3 ) and 3‐O‐β‐D ‐xylopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranoside (monepaloside F, 4 ) on the basis of chemical and spectroscopic evidence. 2D NMR techniques, including ¹H–¹H COSY, HMQC, 2D HMQC‐TOCSY, HMBC and ROESY, and selective excitation experiments, including SELTOCSY and SELNOESY, were utilized in the structure elucidation and complete assignments of ¹H and ¹³C NMR spectra. Copyright © 2002 John Wiley & Sons, Ltd.     

Bioassay Guided Isolation and Identification of a Cytotoxic Compound from Azadirachta indica Leaves

This study aimed to investigate the structural features of the isolated flavonol glycoside, which might behave as a cytotoxic compound. The hexane, chloroform, ethyl acetate, and aqueous fractions of an 80% methanol solution of Neem (Azadirachta indica) (Family: Meliaceae) leaves were subjected to a cytotoxicity bioassay against brine shrimp, Artemia salina. The ethyl acetate fraction exhibited the highest cytotoxic effect, supported by the lowest lethal concentration, a LC₅₀ value of 1.35±0.40 ppm. A compound, Quercetin 3‐O‐β‐D‐glucopyranoside, was isolated from the most toxic fraction of the ethyl acetate via preparative liquid chromatography and then identified via ultraviolet‐visible (UV‐Vis), infrared (IR), mass spectrum (MS) and nuclear magnetic resonance (NMR) analyses. The compound was further confirmed by physical state, color, solubility, and melting point determination. The cytotoxic results suggest that the leaf ethyl acetate fraction consists of toxic compounds, which point towards the isolation of Quercetin 3‐O‐β‐D‐glucopyranoside.     

An Ethylenedioxy Flavonoid Carboxylic Acid from Limnophila Indica

The hexane extract of the aerial parts and roots of Limnophila indica yielded a new flavone, 3′,4′‐ethylenedioxy‐5‐hydroxy‐3‐(1‐hydroxy‐1‐methylethyl)‐6,7‐dimethyl‐5′‐methoxyflavone‐8‐carboxylic acid ( 1 ), characterized by spectral studies.     

New Prenylated Flavones from the Roots of Ficus Beecheyana

Two new prenylated flavanones, ficubee A and ficubee B, respectively, as 7,8‐(2,2‐dimethylpyrano)‐6‐prenyl‐5,3′,4′‐trihydroxyflavone and 6,7‐(2,2‐dimethylpyrano)‐8‐prenyl‐5,3′,4′‐trihydroxyflavone were isolated from the roots of Ficus beecheyana together with twelve known compounds: β‐sitosterol, 5‐stigmasten‐3β,7α‐diol, 5‐stigmasten‐3β,7β‐diol, 3β‐hydroxystigmast‐5‐en‐7‐one, 4‐hydroxybenzaldehyde, 4‐hydroxy‐3‐methoxybenzaldehyde, 1‐(4‐hydroxyphenyl)‐ethanone, 4‐hydroxy‐3‐methoxybenzoic acid, 4‐hydroxy‐cinnamic acid, seseline, xanthyletin, and psoralene. The structures of these secondary metabolites were determined by spectroscopic means and in comparison with published data.