A new natural nucleotide and other antibacterial metabolites from an endophytic Nocardia sp.

Nine compounds were isolated from Nocardia sp. YIM 64630, and their structures were elucidated as 5′-O-acetyl-2′-deoxyuridine (1), 22E,24R-5α,6α-epoxyergosta-8(14),22-diene-3β,7α-diol (2), 22E,24R-5α,6α-epoxyergosta-8,22-diene-3β,7α-diol (3), 22E,24R-ergosta-7,22-diene-3β,5α,6β-triol (4), 5α,8α-epidioxyergosta-6,22-dien-3β-ol (5), 4′,5,6-trihydroxy-7-methoxyisoflavone (6), 2,4,4′-trihydroxy-deoxybenzoin (7), methyl [4-hydroxyphenyl]acetate (8) and daidzein by extensive spectroscopic analyses. Compound 1 was isolated from natural resources for the first time. The antimicrobial and antioxidant activities of compounds 1–8 were investigated.     

Synthesis of brassinosteroids analogues from laxogenin and their plant growth promotion

Four steroid saponins (2–5) and three derivatives (6–8) were synthesised from laxogenin. Four of them were new compounds: (25R)-3β-(2,3,4,6-tetra-O-acetyl-β-d-galactopyranosyloxy)-5α-spirostan-6-one (3), (25R)-3β-(β-d-galactopyranosyloxy)-5α-spirostan-6-one (5), 3β,16-diacetyl-26-hydroxy-5α-cholestan-6,22-dione (6) and 16-acetyl-3β,26-dihydroxy-5α-cholestan-6,22-dione (7). All the compounds showed plant growth-promoting activity in the radish hypocotyl elongation and cotyledon expansion bioassay. Above all, 2 and 6 were found to be more active.     

Two new sesquiterpenes from Chloranthus japonicus Sieb

Two new sesquiterpenes, namely, 1β,10β-dihydroxy-eremophil-7(11), 8-dien-12,8-olide (1) and 8,12-epoxy-1β-hydroxyeudesm-3,7,11-trien-9-one (2), together with three known sesquiterpenoids, shizukolidol (3), 4α-hydroxy-5α(H)-8β-methoxy-eudesm-7(11)-en-12,8-olide (4), and neolitacumone B (5), and two known monoterpenes, (3R,4S,6R)-p-menth-1-en-3,6-diol (6) and (R)-p-menth-1-en-4,7-diol (7), were isolated from the whole plant of Chloranthus japonicus Sieb. Their structures were elucidated on the basis of spectroscopic data analysis and comparison with those of related known compounds. Compounds 4–7 were isolated from this plant for the first time.     

Chemical constituents from Piper wallichii

Fifteen known compounds including four triterpenoids (1–4), one sterol (5), one diketopiperazine alkaloid (6) and nine phenolics (7–15) were isolated from the stems of Piper wallichii. Their structures were elucidated by means of spectroscopic analysis, and acidic hydrolysis in case of the 2-oxo-3β,19α,23-trihydroxyurs-12-en-28-oic acid β-D-glucopyranosyl ester (1). The structure of compound 1 was fully assigned by 1D and 2D NMR experiments for the first time. All isolates were tested for their antibacterial, antifungal, anti-inflammatory and antiplatelet aggregation bioactivities.     

Two new triterpenoids from Gypsophila oldhamiana

Two new triterpenoids (1–2) were isolated and elucidated from the roots of Gypsophila oldhamiana, together with four known triterpenoids (3–6). Their structures were identified to be 3β-hydroxyolean-13(18)-ene-23, 28-dioic acid (1), 3β, 12α-dihydroxy-23-carboxyolean-28, 13β-olide (2), 3β, 16α-dihydroxy-23-oxoolean-13(18)-en-28-oic acid (3), gypsogenin (4), quillaic acid (5) and gypsogenic acid (6) by spectral methods. All compounds were tested for their cytotoxicities against human tumour cell lines (lung cancer H460 and gastric cancer SGC-7901) and for their antiangiogenic effects using a zebra fish model. All compounds showed interesting antiangiogenic activities and the significant cytotoxicities against H460.     

Isolation,structural elucidation and cytotoxicity evaluation of a new pentahydroxy-pimarane diterpenoid along with other chemical constituents from Aerva lanata

Aervalanata possesses various useful medicinal and pharmaceutical activities. Phytochemical investigation of the plant has now led to the isolation of a new 2α,3α,15,16,19-pentahydroxy pimar-8(14)-ene diterpenoid (1) together with 12 other known compounds identified as β-sitosterol (2), β-sitosterol-3-O-β-D-glucoside (3), canthin-6-one (4), 10-hydroxycanthin-6-one (aervine, 5), 10-methoxycanthin-6-one (methylaervine, 6), β-carboline-1-propionic acid (7), 1-O-β-D-glucopyranosyl-(2S,3R,8E)-2-[(2′R)-2-hydroxylpalmitoylamino]-8-octadecene-1,3-diol (8), 1-O-(β-D-glucopyranosyl)-(2S,3S,4R,8Z)-2-[(2′R)-2′-hydroxytetracosanoylamino]-8(Z)-octadene-1,3,4-triol (9), (2S,3S,4R,10E)-2-[(2′R)-2′-hydroxytetracosanoylamino]-10-octadecene-1,3,4-triol (10), 6′-O-(4″-hydroxy-trans-cinnamoyl)-kaempferol-3-O-β-D-glucopyranoside (tribuloside, 11), 3-cinnamoyltribuloside (12) and sulfonoquinovosyldiacylglyceride (13). Among these, six compounds (8–13) are reported for the first time from this plant. Cytotoxicity evaluation of the compounds against five cancer cell lines (CHO, HepG2, HeLa, A-431 and MCF-7) shows promising IC₅₀ values for compounds 4, 6 and 12.     

Chemical constituents and biological activities of Viburnum macrocephalum f. keteleeri

Three new compounds (1–3) and seven known compounds (4–10) have been isolated from the ethanolic extract of Viburnum macrocephalum f. keteleeri using bioactivity-guided fractionation and identified as methyl (2-α-L-rhamnopyranosyloxy)acetate (1), methyl (2R-3-α-L-rhamnopyranosyloxy)glycerate (2), methyl (3R-4-α-L-rhamnopyranosyloxy-3-hydroxy)butanoate (3), bridelionoside B (4), (6S,7E,9R)-roseoside (5), linarionoside A (6), 3,7,11-trimethyl-1,6-dodecadien-3,10,11-triol (7), (+)-8-hydroxylinalool (8), β-sitosterol (9) and daucosterol (10). The structures of 1–3, including absolute configurations, were determined by spectroscopic data (¹H and ¹³C NMR, HSQC, HMBC and ORD) and chemical methods. In addition, compounds 1–8 were assayed for their insecticidal and antimicrobial activities. Compounds 7 and 8 exhibited moderately insecticidal effects against Mythimna separata with LD₅₀ values of 180 and 230 μg g^?1, respectively. Compounds 2, 3, 7 and 8 showed varying antimicrobial activities with IC₅₀ values ranging from 125 to 529 μM.     

A bioactive cycloartane triterpene from Garcinia hombroniana

The dichloromethane bark extract of Garcinia hombroniana yielded one new cycloartane triterpene; (22Z,24E)-3β-hydroxycycloart-14,22,24-trien-26-oic acid (1) together with five known compounds: garcihombronane G (2), garcihombronane J (3), 3β acetoxy-9α-hydroxy-17,14-friedolanostan-14,24-dien-26-oic acid (4), (22Z, 24E)-3β, 9α-dihydroxy-17,14-friedolanostan-14,22,24-trien-26-oic acid (5) and 3β, 23α-dihydroxy-17,14-friedolanostan-8,14,24-trien-26-oic acid (6). Their structures were established by the spectral techniques of NMR and ESI-MS. These compounds together with some previously isolated compounds; garcihombronane B (7), garcihombronane D (8) 2,3’,4,5’-tetrahydroxy-6-methoxybenzophenone (9), volkensiflavone (10), 4’’-O-methyll-volkensiflavone (11), volkensiflavone-7-O-glucopyranoside (12), volkensiflavone-7-O-rhamnopyranoside (13), Morelloflavone (14), 3’’-O-methyl-morelloflavone (15) and morelloflavone-7-O-glucopyranoside (16) were evaluated for cholinesterase enzymes inhibitory activities using acetylcholinesterase and butyrylcholinesterase. In these activities, compounds 1–9 showed good dual inhibition on both the enzymes while compounds 10–16 did not reasonably contribute to both the cholinesterases inhibitory effects.     

Acetylcholinesterase inhibitory active metabolites from the endophytic fungus Colletotrichum sp. YMF432

An endophytic fungus, Chaetomium sp. YMF432, was isolated from Huperzia serrata (Thunb. ex Murray) Trev. and subjected to phytochemical investigation based on its special environment. From the extracts of fermentation solid of strain YMF 432, eight compounds including 1-O-methylemodin (1), 5-methoxy-2-methyl-3-tricosyl-1,4-benzoquinone (2), 4,8-dihydroxy-1-tetralone (3), (3β,5α,6α, 22E)-3-hydroxy-5,6-epoxy-7-one-8(14),22-dien-ergosta (4), ergosta-4,6,8(14),22-tetraen-3-one (5), β-sitostenone (6), β-sitosterol (7) and (22E,24R)-ergosta-5,7,22 -trien-3β-ol (8) were obtained. Their structures were elucidated on the basis of their spectroscopic data. These compounds were evaluated for acetylcholinesterase inhibitory activities in vitro. Compounds 1, 2, and 4 showed moderate acetylcholinesterase inhibitory activities (IC₅₀ from 37.7 ± 1.5 to 370.0 ± 2.9 μM).     

A new tetracyclic saponin from Astragalus glycyphyllos L. and its neuroprotective and hMAO-B inhibiting activity

Abstract

A new tetracyclic saponin, 17(R),20(R)-3β,6α,16β-trihydroxycycloartanyl-23-carboxylic acid 16-lactone 3-O-β-D-glucopyranoside (1) together with one known flavonoid, camelliaside A (2) were isolated from the aerial parts of Astragalus glycyphyllos L. Their structures were determined by chemical, HRESIMS and NMR methods. On 6-hydroxydopamine in vitro model on isolated rat brain synaptosomes, compounds 1–2 had statistically significant neuroprotective activity similar to that of Silibinin, tested at 100?μM. Saponin 1 possessed the most prominent neuroprotective and antioxidant effects in this in vitro model. On human recombinant monoamine oxidase type B enzyme compound 1 displayed strong inhibiting activity, compared to Selegiline (1?μM). It could be concluded that the new epoxycycloartane saponin 1 could be a promising leading structure in respect of neurodegenerative diseases.     

Microbial hydroxylation and glycosidation of oleanolic acid by Circinella muscae and their anti-inflammatory activities

Biotransformation of oleanolic acid (OA) by Circinella muscae AS 3.2695 was investigated. Nine hydroxylated and glycosylated metabolites (1–9) were obtained. Their structures were elucidated as 3β,7β-dihydroxyolean-12-en-28-oic acid (1), 3β,7β,21β-trihydroxyolean-12-en-28-oic acid (2), 3β,7α,21β-trihydroxyolean-12-en- 28-oic acid (3), 3β,7β,15α-trihydroxyolean-12-en-28-oic acid (4), 7β,15α-dihydroxy- 3-oxo-olean-12-en-28-oic acid (5), 7β-hydroxy-3-oxo-olean-12-en-28-oic acid (6), oleanolic acid-28-O-β-D-glucopyranosyl ester (7), 3β,21β-dihydroxyolean-12-en-28- oic acid-28-O-β-D-glucopyranosyl ester (8), and 3β,7β,15α-trihydroxyolean-12-en- 28-oic acid-28-O-β-D-glucopyranosyl ester (9) by spectroscopic analysis. Among them, compounds 4 and 9 were new compounds. In addition, anti-inflammatory activities were assayed and evaluated for the isolated metabolites. Most of the metabolites exhibited significant inhibitory activities on lipopolysaccharides-induced NO production in RAW 264.7 cells.     

Two new dammarane-type triterpene sapogenins from Chinese red ginseng

Two new dammarane-type triterpene sapogenins were isolated from the Chinese red ginseng. The new sapogenins were named as 24,26-dihydroxy-panaxdiol (1) and 24-hydroxy-panaxdiol (2). Their structures were elucidated by the combined analysis of NMR and mass spectrometry as 20(S),25(R)-epoxydammarane-3β,12β,24β,26-tetraol (1) and 20(S),25-epoxydammarane-3β,12β,24α-triol (2). The complete signal assignments of the two compounds were carried out by 2D NMR spectral and NOE differential spectroscopy analysis.     

Lignans from the seeds of Chinese hawthorn (Crataegus pinnatifida var. major N.E.Br.) against β-amyloid aggregation

Phytochemical investigation on the seeds of hawthorn (Crataegus spp.) led to the isolation of a new compound, (7′R, 8′R, 8S)-isolariciresinol (1), along with six known compounds (2–7). The structures of all compounds were determined based on spectroscopic data interpretation. The Aβ_1–42 inhibition activity of all isolated compounds was evaluated in vitro. As a result, compounds 5 and 6 showed stronger inhibition of Aβ_1–42 aggregation than curcumin, with inhibition rates of 70.59 and 68.14% at 20 μM. The possible mechanism of interaction between Aβ_1–42 and the active compounds 5 and 6 was also investigated by molecular docking.     

Isolation and identification of a new neo-clerodane diterpenoid from Teucrium chamaedrys L.

Teucrium chamaedrys L. is an aromatic and medicinal plant used as traditional medicine. Aerial parts of the plant material were dried and extracted with hexane–dichloromethane (extract 1), ethyl acetate–dichloromethane (extract 2) and methanol–dichloromethane (extract 3) in a ratio of 1:1 at rt successively. The solvents were evaporated to give crude extracts. Extract 1 was suspended in water at 60°C then partitioned successively with hexane and ethyl acetate to give hexane and ethyl acetate portions. After the column chromatography (silica gel) of ethyl acetate extract, one new and four known compounds were isolated. The new compound was named as 1(12S,18R)-15,16-epoxy-2β,6β-dihydroxy-neo-cleroda-13(16),14-dien-20,l2-olide-l8,l9-hemiacetal (teuchamaedryn D) (4). The known compounds were teucrin A (1), dihydroteugin (2), teucroxide (3), syspirensin A (5). The chromatographic methods were also applied for extract 3 to isolate verbascoside (6) and teucrioside (7). The structure of isolated compounds was elucidated by spectroscopic methods including LC-TOF/MS, 1D NMR and 2D NMR.     

Two new labdane diterpenoids from the rhizomes of Isodon yuennanensis

Two new labdane diterpenoids, s-trans-8(17),12E,14-labdatrien-20-oic acid (1), s-trans-12E,14-labdadien-20,8β-olide (2), along with 10 known compounds, hinokiol (3), ursonic acid (4), 2α,3α-dihydroxyolean-12-en-28-oic acid (5), 2α,3β,23-trihydroxyolean-12-en-28-oic acid (6), ethyl 3-(3,4-dihydroxyphenyl)lactate (7), ethyl rosmarinate (8), (Z,E)-2-(3,4-dihydroxyphenyl)ethenyl caffeic ester (9), tridecanoic acid (10), β-sitosterol (11) and daucosterol (12), were isolated from the 70% acetone extract of the rhizomes of Isodon yuennanensis. Their structures were elucidated based on the analyses of extensive spectroscopic data and physicochemical properties.     

Dhasingreoside: new flavonoid from the stems and leaves of Gaultheria fragrantissima

A new flavonoid, dhasingreoside (1) and seven known compounds, quercetin 3-O-β-d-galacturonopyranoside (2), quercetin 3-O-β-d-galactopyranoside (3), quercetin 3-O-β-d-glucuronopyranoside (4), quercetin 3-O-α-l-rhamnopyranoside (5), (–)-epicatechin (6), salicylic acid (7) and gaultherin (8), have been isolated from the shade-dried stems and leaves of Gaultheria fragrantissima, commonly known as ‘Dhasingre’ in Nepal. The structures were elucidated on the basis of physical, chemical and spectroscopic methods. Among known compounds, five compounds (3–6 and 8) were isolated for the first time from G. fragrantissima. In vitro antioxidant activity of all the isolated compounds was evaluated by 1,1-diphenyl-2-picrylhydrazyl free radical-scavenging assay. Dhasingreoside (1) and other compounds (2–6) showed significant free radical-scavenging activity.     

Phytochemical,antimicrobial and antiquorum-sensing studies of pulicaria undulata L.: a revision on the structure of 1β,2α,3β,19α,23-pentahydroxy-urs-12-en-28-oic acid

Abstract

Phytochemical study of the aerial part of Pulicaria undulata L. led to the isolation of nine compounds. The structure of 1β,2α,3β,19α,23-pentahydroxy-urs-12-en-28-oic acid (4) was revised and confirmation of the stereochemical configuration of the hydroxyl groups was established using NOESY and selective decoupling experiments. The other compounds were identified as 1,2-dehydro-1,10α-dihydropseudoivalin (1), axillarin (2), grandifloric acid-15-β-glucoside (3), myrianthic acid (5), caffeic acid (6), quercetin (7), paniculoside IV (8) and caffeic anhydride (9). The structures were characterized by 1?D, 2?D NMR spectroscopy and confirmed with HRMS. Antimicrobial and antiquorum-sensing activities of the different extracts and isolated compounds of the plant were investigated. Generally, the phenolic rather than the terpenoidal compounds exhibited remarkable antimicrobial and antiquorum-sensing activity.

     

A new ent-kaurane diterpenoid from Ixora amplexicaulis

A new ent-kaurane diterpenoid, 6α,16α-dihyroxy-ent-kaurane (1), was isolated from the stems of Ixora amplexicaulis, together with (24R)-6β-hydroxy-24-ethyl-cholest-4-en-3-one (2), 7β-hydroxysitosterol (3), maslinic acid (4), 3,3′-bis(3,4-dihydro-4-hydroxy-6-methoxy-2H-1-benzopyran) (5) and protocatechuric acid (6). Their structures were established by extensive spectroscopic analysis, including 2D NMR techniques. Compounds 2–5 were isolated from the genus Ixora for the first time and 6 obtained originally from I. amplexicaulis.     

Triterpenoids and lignans from the stems of Schisandra glaucescens

Two new triterpenoids, 24(E)-3α,12α-dihydroxyl-lanost-9(11),24-dien-26-oid acid (1) and 3,4-seco-24(Z)-6α,7β-dihydroxyl-cycloart-4(28),24-dien-3,26-dioic-3-methyl ester (2), and ten known ones (3–12), together with eight lignans (13–20), were isolated from the stems of Schisandra glaucescens. Their structures were established on the basis of extensive spectroscopic analyses. Compounds 1–3, 5–7, 9, 11–13 and 15–18 were isolated from this species for the first time. 1 and 2 were evaluated for their in vitro cytotoxicities against the mouse cancer B16 cell line, human cancer HepG2 and MCF7 cell lines by MTT assay.     

A new antimicrobial sesquiterpene isolated from endophytic fungus Cytospora sp. from the Chinese mangrove plant Ceriops tagal

Abstract

Chemical examination of Chinese mangrove Ceriops tagal endophytic Cytospora sp., yielded a new biscyclic sesquiterpene seiricardine D (1), and eight known metabolites, xylariterpenoid A (2a), xylariterpenoid B (2b) and regiolone (3) 4-hydroxyphenethyl alcohol (4), (22E, 24R)5, 8-epidioxy-5α, 8α-ergosta-6,22E-dien-3ß-ol (5), (22E, 24R)5, 8-epidioxy-5α, 8α-ergosta-6,9(11), 22-trien-3 ß-ol (6), ß-sitosterol (7) and stigmast-4-en-3-one (8). These structures were unambiguously elucidated on the basis of extensive NMR spectroscopic and mass spectrometric analyses. The antimicrobial activities of compounds 1–8 and their effects on a panel of plant and human pathogens were evaluated.