Cytotoxic scalarane sesterterpenes from a Korean marine sponge Psammocinia sp.

Three novel scalarane sesterterpenes were isolated from a Korean marine sponge, Psammocinia sp., along with four known derivatives. Their structures were elucidated on the basis of NMR, MS and IR spectroscopic data. The three new compounds are 12-deacetoxy-23-hydroxyscalaradial (1), 12-dehydroxy-23-hydroxyhyrtiolide (2) and 12-O-acetyl-16-deacetoxy-23-acetoxyscalarafuran (3), respectively, and the four known compounds are 12-deacetoxy-23-hydroxyheteronemin (4), 12-deacetoxy-23-acetoxy-19-O-acetylscalarin (5), 12-deacetoxy-23-O-acetoxyheteronemin (6) and 12-deacetoxyscalaradial (7). They exhibited cytotoxicity against intractable human cancer cell lines A498, ACHN, MIA-paca and PANC-1, with an IC₅₀ range of 0.4–48 μM.     

Steroid compounds from two pacific starfish of the genus <Emphasis Type="Italic">Evasterias</Emphasis>

Three new steroid glycosides (evasteriosides C, D, and E) along with six known compounds were isolated from two Pacific starfish of the genus Evasterias. Evasterioside C from E. retiferacollected from the Sea of Japan was identified as (20R, 22E)-3-O-(β-D-xylopyranosyl)-24-nor-5α-cholest-22-ene-3β,6β,15α,26-pentaol 26-sulfate sodium salt. The structures of evasteriosides D and E from E. echinosoma (collected from the Gulf of Shelichov, the Sea of Okhotsk) were established as (20R, 24S)-24-O-(β-D-glucopyranosyl)-5α-cholestane-3β,6α,8,15β,24-pentaol and (20R,24S)-3,24-di-O-(β-D-xylopyranosyl)-cholest-4-ene-3β,6β,8,15α,24-pentaol, respectively. In addition, the known compounds pycnopodiosides A and C, luridoside A, 5α-cholestane-3β,6α,8,15β,16β,26-hexaol. 5α-Cholestane-3β,6α,8,15β,24-pentaol 24-sulfate sodium saltand marthasterone sulfate sodium salt were identified in E. echinosoma. The structures of the isolated compounds were established on the basis of spectroscopic analyses, using 1D and 2D NMR techniques, mass spectrometry, and some chemical transformations.     

New acyclic sesquiterpenoid derivatives and a monoterpene disaccharide from Dichondra repens Forst.

A new highly oxygenated acyclic sesquiterpenoid (2E, 6E)-8,10,11-trihydroxyl-7,11-dimethyl-3-hydroxymethyl-2,6-dodecadienoic acid (1) and its glucoside (2), together with a new pinane monoterpene disaccharide glucoside 6,6-dimethyl-2-methlenebicyclo [3.1.1]hept-3-O-(6-O-apiofuranosyl)-β-d-glucopyranoside (3) were isolated from hydrophilic extract of Dichondra repens. Their structures were elucidated on the basis of spectroscopic analyses and chemical methods. The three compounds did not show any cytotoxic activity (IC50 > 20 μM) against two human lung cancer cell lines (NCI-H661 and A549).     

Furostanol glycosides from Trigonella foenum-graecum seeds

Two new furostanol glycosides trigofoenosides A and D have been isolated from the Trigonella foenum-graecum seeds as their methyl ethers, A-1 and D-1. Their structures have been determined as (25S)-22-O-methyl-furost-5-ene-3β,26-diol, 3-O-α-L-rhamnopyranosyl (1 → 2)-β-D-glucopyranoside; 26-O-β-D-glucopyranoside (A-1) and (25S)-22-O-methyl-furost-5-ene-3β,26-diol, 3-O-α-L-rhamnopyranosyl (1 → 2)-[β-D-glucopyranosyl (1 → 3)]-β-D-glucopyranoside; 26-O-β-D-glucopyranoside (D-1).     

Chemical constituents of Trilepisium madagascariense (Moraceae) and their antimicrobial activity

The chemical study of Trilepisium madagascariense has led to the isolation of two previously undescribed compounds, (+)-(2S)-7-hydroxy-3′,4′-dimethoxyflavan (trilepisflavan) and (E)-4-[3-(3,4-dihydroxyphenyl)prop-2-enoyloxy]-3-hydroxybenzoic acid (trilepisuimic acid), together with ten known compounds caffeic acid, catechin, erythrodiol-3-O-palmitate, 8-C-glucopyranosylapigenin, dihydrokaempferol, protocatechuic acid, 3′,7-dihydroxy-4′-methoxyflavan, isoliquiritigenin, luteolin and 1,3-dimethoxybenzene. Their structures were elucidated on the basis of spectroscopic evidence. Crude extracts, trilepisflavan, dihydrokaempferol and 8-C-glucopyranosylapigenin showed significant antimicrobial activity.     

Steroidal saponins from the leaves of Beaucarnea recurvata

Thirteen steroidal saponins were isolated from the leaves of Beaucarnea recurvata Lem. Their structures were established using one- and two-dimensional NMR spectroscopy and mass spectrometry. Six of them were identified as: 26-O-β-d-glucopyranosyl (25S)-furosta-5,20(22)-diene 1β,3β,26-triol 1-O-α-l-rhamnopyranosyl-(1 → 2) β-d-fucopyranoside, 26-O-β-d-glucopyranosyl (25S)-furosta-5,20(22)-diene 1β,3β,26-triol 1-O-α-l-rhamnopyranosyl-(1 → 2)-4-O-acetyl-β-d-fucopyranoside, 26-O-β-d-glucopyranosyl (25R)-furosta-5,20(22)-diene-23-one-1β,3β,26-triol 1-O-α-l-rhamnopyranosyl-(1 → 2) β-d-fucopyranoside, 26-O-β-d-glucopyranosyl (25S)-furosta-5-ene-1β,3β,22α,26-tetrol 1-O-α-l-rhamnopyranosyl-(1 → 4)-6-O-acetyl-β-d-glucopyranoside, 26-O-β-d-glucopyranosyl (25S)-furosta-5-ene-1β,3β,22α,26-tetrol 1-O-α-l-rhamnopyranosyl-(1 → 2) β-d-fucopyranoside, and 24-O-β-d-glucopyranosyl (25R)-spirost-5-ene-1β,3β,24-triol 1-O-α-l-rhamnopyranosyl-(1 → 2)-4-O-acetyl-β-d-fucopyranoside. The chemotaxonomic classification of B. recurvata in the family Ruscaceae was discussed.     

Three oxanthrones from Aloe littoralis

The leaf exudate of Aloe littoralis yielded, in addition to the known 10-hydroxyaloin B, two new C-glucoside oxanthrones namely 10-hydroxy-15-O-(2R,3S-nilyl)(6′-O-acetyl)aloin B (littoraloin) and 10-hydroxy-15-O-(2R,3S- nilyl)aloin B (deacetyllittoraloin). Their structures were determined by spectroscopic methods as well as by conversion to the known 10-hydroxyaloin B and nilic acid.     

Steroidal saponins of Asparagus curillus

Three spirostanol and two furostanol glycosides were isolated from a methanol extract of the roots of Asparagus curillus and characterized as 3-O-[α-l-arabinopyranosyl (1→4)- β-d-glucopyranosyl]-(25S)-5β-spirostan-3β-ol, 3-O-[{α-l-rhamnopyranosyl (1→2)} {α-l-arabinopyranosyl (1→4)}-β-d-glucopyranosyl]-(25S)-5β-spirostan- 3β-ol, 3-O-[{β-d-glucopyranosyl (1→2)} {α-l-arabinopyranosyl (1→4)}-β- d-glucopyranosyl]-(25S)-5β-spirostan-3β-ol, 3-O-[{β-d-glucopyranosyl (1→2)} {α-l-arabinopyranosyl (1→4)}-β-d-glucopyranosyl]-26-O-[β-d-glucopyranosyl]- 22α-methoxy-(25S)-5β-furostan-3β, 26-diol and 3-O-[{β-d-glucopyranosyl (1→2)} {α-l-arabinopyranosyl (1→4)}-β-d-glucopyranosyl]-26-O-[β-d-glucopyranosyl]- (25S)-5β-furostan-3β, 22α, 26-triol respectively.     

Sesquiterpenoids and flavonoids from Pteris multifida Poir.

Phytochemical research of Pteris multifida Poir. led to the isolation of fifteen compounds, including six flavonoids (1–6) and nine sesquiterpenoids (7–15). Their structures were characterized by NMR, MS, ORD and CD data. Compounds kaempferol 3-O-α-L-rhamnoside-7-O-β-D-glucoside (1), myricetin 3-O-β-D-glucoside (2), kaempferol 3-O-β-D-glucoside (4), luteolin-7-O-β-D-rutinoside (5), quercetin-3-O-α-L-rhamnopyranoside (6), (2S,3S)-12-hydroxypterosin Q (7), (2S,3S)-pterosin Q (8), 2-hydroxypterosin C (9) and (2S)-12-hydroxypterosin A (10) were first isolated from P. multifida, and compounds 1–2 and 10 were first isolated from the family Pteridaceae. Furthermore, the chemotaxonomic significance of the isolates was discussed.     

Megastigmane and 7,9′-dinorlignan glycosides from the tubers of Stephania kaweesakii

Two isomers of megastigmane glycosides, (6R, 9S)-blumenol C 9-O-gentibioside (2) and (6S, 9S)-blumenol C 9-O-gentiobioside (3), and a new 7,9′-dinorlignan glycoside, stepdonorlignoside (4) were isolated from the tubers of Stephania kaweesakii. The structure determinations were considered based on the physical data and spectroscopic evidence. The absolute configurations of two megastigmanes were determined for the first time. Additionally, ten known compounds were isolated: (6R, 9S)-blumenol C 9-O-β-D-glucopyranoside, (+)-isolariciresinol 3a-O-β-D-glucopyranoside, salidroside, N-trans-caffeoyltyramine, (R)-isococlaurine, (R)-isococlaurine 4′-O-β-glucopyranoside, (−)-oblongine, (+)-magnocurarine, fordianoside, and (−)-cyclanoline.     

Neuroprotective metabolites from the endophytic fungus Penicillium citrinum of the mangrove Bruguiera gymnorrhiza

Two new compounds, named as (Z)-7,4′-dimethoxy-6-hydroxy-aurone-4-O-β-glucopyranoside (1), and (1S,3R,4S)-1-(4′-hydroxyl-phenyl)-3,4-dihydro-3,4,5-trimethyl-1H-2-benzopyran-6,8-diol (2), were isolated from the endophytic fungus Penicillium citrinum of Bruguiera gymnorrhiza. Their structures were elucidated on the basis of spectroscopic analysis. Additionally, compound 1 exhibited potent neuroprotective activity in 1-methyl-4-phenylpyridinium-induced oxidative damage in PC12 cells.     

Two new phenolic glucosides and an ellagitannin from the leaves of Castanopsis sclerophylla

In the course of a chemotaxonomical study of Castanopsis species (Fagaceae), detailed investigation of the leaves of C. sclerophylla led to isolation of three new phenolic compounds together with 62 known compounds. The structures of the new compounds were elucidated as 2-O-galloyl-O-4,6-(S)-valoneoyl-d-glucose (1), 6-O-galloyl-1-O-vanilloyl-β-d-glucose (2), and 4″-O-galloylchestanin (3) by means of spectroscopic analyses and enzymatic hydrolysis with tannase. Comparison with other Castanopsis species indicated that C. sclerophylla characteristically accumulates chlorogenic acid and a dimeric ellagitannin, rugosin E. Triterpene hexahydroxydiphenoyl esters, which are major constituents of C. cuspidata var. sieboldii, C. hystrix, and C. fissa were not detected.     

Steroidal saponins of Asparagus adscendens

From the methanol extract of the fruits of Asparagus adscendens sitosterol-β-d-glucoside, two spirostanol glycosides (asparanin A and B) and two furostanol glycosides (asparoside A and B) were isolated and characterized as 3-O-[β-d-glucopyranosyl (1→2)-β-d-glucopyranosyl]-(25S)-5β-spirostan-3β-ol, 3-O-{[β-d-glucopyranosyl(1→2)][α-l-rhamnopyranosyl(1→4)]-β-d-glucopyranosyl}-(25S)-5β-spirostan-3β-ol,3-O-{[β-d-glucopyranosyl(1→2)][α-l-rhamnopyranosyl(1→4)]-β-d-glucopyranosyl|} -26-O-(β- d-glucopyranosyl)-22α-methoxy-(25S)-5β-furostan-3β,26-diol and 3-O-{[β-d-glucopyranosyl(1→2)][α-l-rhamnopyranosyl(1→4)]-β-d-glucopyranosyl}-26-O-(β-d-glucopyranosyl)- 25S)-5β-furostan-3β,22α, 26-triol, respectively.     

Cardiovascular protective flavonolignans and flavonoids from Calamus quiquesetinervius

Tricin-type flavonolignans, (2S)-dihydrotricin 4′-O-(erythro-β-guaiacylglyceryl) ether, (2S)-dihydrotricin 4′-O-(threo-β-guaiacylglyceryl) ether, (2S)-dihydrotricin 4′-O-(threo-β-4-hydroxyphenylglyceryl) ether, tricin 4′-O-(erythro-β-4-hydroxyphenylglyceryl) ether, tricin 4′-O-(threo-β-4-hydroxylphenylglyceryl) ether, and (2S)-dihydrotricin 4′-O-(β-6′′-methoxy-4′′-oxo-chroman-3′′-yloxy) ether namely calquiquelignan A–F, respectively, were isolated and characterized from the EtOAc extract of Calamus quiquesetinervius. Additionally, six known phenolic compounds, including dihydrotricin, tricin, salcolin A, p-hydroxybenzoic acid, (2S, 3S)-trans-dihydrokapempferol and (2S)-naringenin, were also obtained and identified from the extract. Structures of the flavonolignans were assigned based on spectroscopic analyses that included 1D and 2D NMR spectroscopic techniques, such as HMQC, HMBC, and NOESY. Bioassay results showed that calquiquelignan A, dihydrotricin and (2S)-naringenin exhibited significant vasodilatory potencies, as indicated by 60.3%, 80.3% and 60.9% relaxations, respectively, at 100 μM. Salcolin A showed potent platelet aggregation inhibition, compared with aspirin. Most of the tricin-type derivatives (calquiquelignan A–B, dihydrotricin and tricin) also exhibited more potent hydroxyl radical (OH) scavenging activity than trolox as characterized by the ultraweak chemiluminescence assay.     

(2S)-Prenylflavanones and taraxerane triterpenoids from Mallotus mollissimus

Three prenylflavanones, (2S)-5,7-dihydroxy-4′-methoxy-8-(3″,3″-dimethylallyl)flavanone (3), (2S)-5,4′-dihydroxy-7-methoxy-6-(3″,3″-dimethylallyl)flavanone (6), 8-prenylnaringenin (11), and a new epimeric pair (2″S/2″R)-(2S)-5,7-dihydroxy-4′-methoxy-6-(2″-hydroxy-3″-methylbut-3″-enyl)flavanones (4a/4b) were isolated together with taraxerone, taraxerol, epitaraxerol, β-sitosterol, oleanolic acid, 1-O-docosanoyl glycerol, apigenin, and apigenin 7-O-β-D-glucopyranoside from the MeOH extract of the leaves of Mallotus mollissimus. The structures of the isolated compounds were determined on the basis of 1D/2D NMR and HR-MS spectroscopic data; the 2S configuration of the prenylflavanones 3, 4, and 6 was deduced from CD spectroscopic data. The presence of three taraxerane triterpenoids reinforces the inclusion of M. mollissimus (syn. Croton mollissimus) in Mallotus genus. Among species of Mallotus the occurrence of the (2S)-prenylflavanones 3, 4, and 6 is confined to M. mollissimus.     

Oligofuro- and spiro-stanosides of Asparagus adscendens

Two oligofurostanosides and two spirostanosides, isolated from a methanol extract of Asparagus adscendens (leaves), were characterized as 3-O-[{α-l-rhamnopyranosyl (1 → 4)} {α-l-rhamnopyranosyl (1 → 6)}-β-d-glucopyranosyl]-26-O-[β-d-glucopyranosyl]-22α-methoxy-(25S)-furost-5-en-3β,26-diol (Adscendoside A), 3-O-[{α-l-rhamnopyranosyl (1 → 4)} {α-l-rhamnopyranosyl (1 → 6)}-β-d-glucopyranosyl]-26-O-[β-d-glucopyranosyl]-(25S)-furost-5-en-3β,22α,26-triol-(Adscendoside B), 3-O-[{α-l-rhamnopyranosyl (1 → 6)}-β-d-glucopyranosyl]-(25S)-spirostan-5-en-3β-ol (Adscendin A) and 3-O-[{α-l-rhamnopyranosyl (1 → 4)} {α-l-rhamnopyranosyl (1 → 6)}-β-d-glucopyr anosyl]-(25S)-spirostan-5-en-3β-ol (Adscendin B), respectively. Adscendin B and Adscendoside A are the artefacts of Adscendoside B formed through hydrolysis and methanol extraction respectively.bl]     

Steroidal saponins from Tribulus terrestris

Five new steroidal saponins were isolated from the fruits of Tribulus terrestris. Their structures were fully established by spectroscopic and chemical analysis as (23S,25S)-5α-spirostane-24-one-3β,23-diol-3-O-{α-l-rhamnopyranosyl-(1 → 2)-O-[β-d-glucopyranosyl-(1 → 4)]-β-d-galactopyranoside} (1), (24S,25S)-5α-spirostane-3β,24-diol-3-O-{α-l-rhamnopyranosyl-(1 → 2)-O-[β-d-glucopyranosyl-(1 → 4)]-β-d-galactopyranoside} (2), 26-O-β-d-glucopyranosyl-(25R)-5α-furostan-2α,3β,22α,26-tetraol-3-O-{β-d-glucopyranosyl-(1 → 2)-O-β-d-glucopyranosyl-(1 → 4)-β-d-galactopyranoside} (3), 26-O-β-d-glucopyranosyl-(25R)-5α-furostan-20(22)-en-2α,3β,26-triol-3-O-{β-d-glucopyranosyl-(1 → 2)-O-β-d-glucopyranosyl-(1 → 4)-β-d-galactopyranoside} (4), and 26-O-β-d-glucopyranosyl-(25S)-5α-furostan-12-one-22-methoxy-3β,26-diol-3-O-{α-l-rhamnopyranosyl-(1 → 2)-O-[β-d-glucopyranosyl-(1 → 4)]-β-d-galactopyranoside} (5). The isolated compounds were evaluated for cytostatic activity against HL-60 cells.     

Thiophenes,polyacetylenes and terpenes from the aerial parts of Eclipata prostrata

One new bithiophenes, 5-(but-3-yne-1,2-diol)-5′-hydroxy-methyl-2,2′-bithiophene (2), two new polyacetylenic glucosides, 3-O-β-d-glucopyranosyloxy-1-hydroxy-4E,6E-tetradecene-8,10,12-triyne (8), (5E)-trideca-1,5-dien-7,9,11-triyne-3,4-diol-4-O-β-d-glucopyranoside (9), six new terpenoid glycosides, rel-(1S,2S,3S,4R,6R)-1,6-epoxy-menthane-2,3-diol-3-O-β-d-glucopyranoside (10), rel-(1S,2S,3S,4R,6R)-3-O-(6-O-caffeoyl-β-d-glucopyranosyl)-1,6-epoxy menthane-2,3-diol (11), (2E,6E)-2,6,10-trimethyl-2,6,11-dodecatriene-1,10-diol-1-O-β-d-glucopyranoside (12), 3β,16β,29-trihydroxy oleanane-12-ene-3-O-β-d-glucopyranoside (13), 3,28-di-O-β-d-glucopyranosyl-3β,16β-dihydroxy oleanane-12-ene-28-oleanlic acid (14), 3-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl oleanlic-18-ene acid-28-O-β-d-glucopyranoside (15), along with fifteen known compounds (1, 3–7, and 16–24), were isolated from the aerial parts of Eclipta prostrata. Their structures were established by analysis of the spectroscopic data. The isolated compounds 1–9 were tested for activities against dipeptidyl peptidase IV (DPP-IV), compound 7 showed significant antihyperglycemic activities by inhibitory effects on DPP-IV in human plasma in vitro, with IC₅₀ value of 0.51 μM. Compounds 10–24 were tested in vitro against NF-κB-luc 293 cell line induced by LPS. Compounds 12, 15, 16, 19, 21, and 23 exhibited moderate anti-inflammatory activities.     

Steroidal saponins of Yucca filamentosa: Yuccoside C and protoyuccoside C

Two new saponins, yuccoside C and protoyuccoside C, have been isolated from the methanolic extract of Yucca filamentosa root and their structures elucidated. Yuccoside C is 3-O-[α-d-galactopyranosyl-(1 → 2)-β-d-glucopyranosyl-(1 → 4)-β-d-glucopyranosyl]-(25S)-5β-spirostan-3β-ol, whereas protoyuccoside C is 3-O-[α-d-galactopyranosyl-(1 → 2)-β-d-glucopyranosyl-(1 → 4)-β-d-glucopyranosyl]-26-O-[β-d-glucopyranosy]-(25S)-5β-furostan-3β,22α,26-triol.     

Cytotoxic pterosins from Pteris multifida roots against HCT116 human colon cancer cells

Two new pterosin glycosides, (2S,3S)-pterosin C 3-O-β-d-(4′-(E)-caffeoyl)-glucopyranoside (1) and (2S,3S)-pterosin C 3-O-β-d-(6′-(E)-p-coumaroyl)-glucopyranoside (2), were isolated from Pteris multifida (Pteridaceae) roots along with ten known pterosin compounds (3–12). The chemical structures of the isolated compounds were elucidated by extensive analysis of the 1D, 2D NMR, HRESIMS, and CD spectroscopic data. The cytotoxicities of 1–12 against HCT116 human colorectal cancer cell line were evaluated. Among the isolates, compound 1 showed moderate antiproliferative activity in HCT116 cells with an IC₅₀ value of 8.0 ± 1.7 μM. Additionally, 1 induced the upregulation of the caspase-9 and procaspase-9 levels in Western blots and increased the annexin V/propidium iodide (PI)-positive cell population in flow cytometry.