Five new ent-kaurane diterpenes from Annona squamosa L. pericarps

Abstract

In the present study, five new ent-kaurane diterpenes including 4α-hydroxy-17,19-dinor-ent-kaurane-16-one (1), 4β-hydroxy-16β-H-18-nor-ent-kaurane-17-oic acid (2), 4β,17-dihydroxy-16α-acetoxy-18-nor-ent-kaurane (3), Annosquamosin Z (4) and 16α-H-ent-kaurane-17,18-dioic acid, 17-methy ester (5) were isolated from Annona squamosa L. pericarp. The compounds were also evaluated for their cytotoxic activities against SMMC-7721 and HepG2 cell lines, among which compound 3 exhibited potent cytotoxicity with IC₅₀ value of less than 20?μM.     

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.     

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.     

A new sesquiterpene from Kalimeris integrifolia

A new sesquiterpene kalinturoside A (1), and 17 known compounds friedelan-3-ol (2), 24-ethyl-5a-cholesta-7, 22(E)-dien-3-one (3), friedelin (4), syringaresinol (5), α-spinasterol (6), ciwujiatone (7), syringic acid (8), scopoletin (9), apocynin (10), 1-(3-hydroxy-4, 5-dimethoxyphenyl)ethan-1-one (11), apigenin (12), 5-hydroxymethylfurfural (13), stigmasterol-3-O-β-d-glucopy-ranoside (14), bidenoside C (15), citrusin (16), irioresinol A (17) and syringaresinol-4-O-β-d-glucopyranoside (18) were isolated from the herbs of Kalimeris integrifolia. The structures of these compounds were elucidated using spectroscopic techniques such as NMR and MS. All of the compounds were isolated from this genus for the first time.     

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).     

Lignans and Kauranes from the Stems of Annona cherimola

Four lignans and six kauranes, (+)-epi-syringaresinol ( 1 ), annocherin A (16β-hydroxy-17,19-diacetoxy-ent-kaurane) ( 2 ), (+)-syringaresinol ( 3 ), (+)-dia-syringaresinol ( 4 ), liriodendrin[(+)-syringaresinol-di-O-β-D-glucopyranoside] ( 5 ), 16α-hydro-17-acetoxy-ent-kauran-19-oic acid ( 6 ), 16β-hydro-17-hydroxy-ent-kauran-19-al ( 7 ), 16α-hydro-17-hydroxy-ent-kauran-19-al ( 8 ), 16β-hydro-17-hydroxy-ent-kauran-19-oic acid ( 9 ) and 16α-hydro-17-hydroxy-ent-kauran-19-oic acid ( 10 ) were isolated from the stems of Annona cherimola. Among them, 1 is obtained for the first time from natural sources and 2 is a new compound. The structures of these compounds were characterized and identified by spectral analyses.     

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.     

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.     

Two new triterpenoids from Nauclea officinalis

Two new triterpenoids and three 27-nor-triterpenoids were isolated from the stems (with bark) of Nauclea officinalis. Their structures were identified to be 2β,3β,19α,23-tetrahydroxy-urs-12-en-28-oic acid (1), 2β,3β,19α,23-tetrahydroxy-urs-12-en-28-O-[β-d-glucopyranosyl (1-2)-β-d-glucopyranosyl] ester (2), pyrocincholic acid 3β-O-α-l-rhamnopyranoside (3), pyrocincholic acid 3β-O-α-l-rhamnopyranosy1-28-O-β-d-glucopyranosyl ester (4), pyrocincholic acid 3β-O-α-l-rhamnopyranosy1-28-O-β-d-glucopyranosyl-(1-6)-β-d-glucopyranosyl ester (5) by spectroscopic methods including 1D, 2D NMR and HR-MS analyses. The cytotoxic activity of 1–5 against lung cancer A-549 cells was also investigated.     

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.     

New cytotoxic bufadienolides from the roots and rhizomes of Helleborus thibetanus Franch

Abstract

Three new bufadienolides 14β, 16β-dihydroxy-3β-[β-D-glucopyranosyl-(1→6)-(β-D-glucopyranosyl)oxy]-5α-bufa-20, 22-dienolide (1), 14β-hydroxy-3β-[β-D-glucopyranosyl-(1→4)-(β-D-glucopyranosyl)oxy]-5α-bufa-20, 22-dienolide (2) and hellebrigenin-3-O-β-D-glucosyl-(1→4)-β-D-glucoside (3), together with eight known bufadienolides (4–11) were isolated from the roots and rhizomes of Helleborus thibetanus. Their structures were elucidated by extensive spectroscopic methods and acid hydrolysis. Compounds 1–7 were evaluated for their cytotoxic activity against HCT116, A549 and HepG2 tumor cell lines. Compound 1 exhibited moderate cytotoxicity against HepG2 cells with IC₅₀ value of 15.1?±?1.72?μM. Compounds 5 and 6 exhibited moderate cytotoxicity against HCT116 cells with IC₅₀ values of 15.12?±?0.58?μM and 13.17?±?2.34?μM, respectively.     

大叶橐吾中三个新的艾里莫芬型倍半萜

从大叶橐吾的根部分离得到三个新的艾里莫芬型倍半萜(1, 2和3), 经多种波谱方法和单晶X射线衍射确定它们的结构分别为: 6α,15β-环氧-8β-羟基-艾里莫芬-7(11)-烯-8α,12-内酯(1), 7-乙酰基-13β-羧酸-6(7)-烯-降-艾里莫芬烷(2), 艾里莫芬-7(11)-烯-6α,15β-内酯(3). 此外, 对化合物1进行了抗菌和抗癌活性测试.     

New ent-kaurane diterpenoid dimer from Pulicaria inuloides

A new naturally occurring ent-kaurane diterpenoid dimer, 15β, 15′β-oxybis (ent-kaur-16-en-19-oic acid) (1) along with six known compounds, 15β-hydroxy-ent-kaur-16-en-19-oic acid (2), 15β-hydroxy-ent-kaur-16-en-19-oate-β-d-glucopyranoside (3), 6-hydroxykaempferol-3, 7-dimethyl ether (4), quercetagetin 3, 7, 3′-trimethyl ether (5), β-sitosterol (6) and β-sitosterol glucoside (daucosterol) (7) were isolated from the aerial parts of Pulicaria inuloides DC. Compounds 2–5 were isolated for the first time from genus Pulicaria. The structures of compounds 1–7 were established on the basis of extensive 1D and 2D NMR spectroscopic techniques in combination with ESI-MS. The antimicrobial activity of the isolated compounds was evaluated against Staphylococcus aureus, Escherichia coli and Candida albicans. Sulphorhodamine B cytotoxic assay against HepG2 (liver cancer) cell line and ABTS antioxidant assay were carried out.     

Three new sesquiterpenes from Ainsliaea glabra

Three new sesquiterpenes: 4-acrylic-6-methyl-α-tetralone (1), ainsliaea acid A (2) and ainsliaea acid B (3), together with 8 known compounds (4-11) were isolated from the whole herb of Ainsliaea glabra and their structures were established by means of 1D and 2D NMR spectroscopy and HR-ESIMS. Compounds 1–6 were tested for the inhibition of nuclear factor kappa B (NF-κB) in the 293-NF-κB-luciferase reporter cell line induced by lipopolysaccharide (LPS), and compound 2 was further tested for the production of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6 and IL-10 in RAW264.7 macrophages induced by LPS. The isolated compound 2 exhibited significant anti-inflammatory activity.     

Chemical Constituents of a Formosan Soft Coral Sinularia sp.

A new marine sterol 7β-hydroperoxy-24-methylenecholesterol ( 1 ) along with five known compounds sarcophytol A ( 2 ), (Z)-N-[2-(4-hydroxyphenyl)ethyl]-3-methyldodec-2-enamide ( 3 ), 5α,7αH-eduesm-11(13)en-4α-ol ( 4 ), 24-methylenecholesterol ( 5 ) and 1β-hydroxy-α-cyperone ( 6 ) have been isolated from a Formosan soft coral Sinularia sp. The structures of the above compounds were determined by spectral analyses. Cytotoxicity of compounds 1–6 toward various cancer cell lines also is reported.     

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.     

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.     

New chalcanonol glycoside from the seeds of saw palmetto: antiproliferative and antioxidant effects

A new chalcanonol glycoside dimer, bis-O-[(I-4′) → (II-6′)]-α-hydroxyphloretin-2′-O-β-glucoside (1), in addition to six known compounds, namely ( ? )-epicatechin (2) and ( ? )-epiafzelechin (3), 4-hydroxybenzoic acid (4), protocatechuic acid (5), methylgallate (6), β-sitosterol (7) and β-sitosterol-3-O-glucoside (8), was isolated from the seeds of saw palmetto. The structures of the isolated compounds were established from the analysis of their MS and 1D and 2D NMR spectroscopic data. The antiproliferative activities of the isolated compounds towards PC3, the human prostate cancer cells were investigated. Amongst the isolated compounds, the new compound and the sterolic derivatives showed antiproliferative effects. Screening of the antioxidant effects of the isolated compounds by 2,2′-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid radical assay revealed that the isolated phenolics were active free radical scavengers.     

Stereoselective Synthesis of a Tetrameric Fragment of Streptococcus Pneumoniae Type 1 Containing an α-Linked 2-Acetamido-4-amino-2,4,6-trideoxy-D-galactopyranose (SUGp) Unit

Abstract

Block condensation of fully protected donor ethyl 1,2,3,4-tetra-O-benzyl-D-Rib-(5→P→6)-2,3,4-tri-O-benzoyl-l-thio-β-D-Glcp (2), having a (5→6)-phosphotriester union between the ribitol and the glucopyranosyl moieties, with the free 3′-OH group in the acceptor methyl 2-acetamido-4-O-(2-acetamido-4-(benzyloxycarbonyl)amino-2,4,6-trideoxy-α-D-Galp)-3,6-di-O-benzyl-2-deoxy-α-D-Galp (3), under the agency of N-iodosuccinimide and triflic acid, gave the fully protected tetrameric fragment 22. Elimination of the 2-cyanoethyl group from the phosphotriester and subsequent debenzoylation, followed by hydrogenolysis of the benzyl and benzyloxycarbonyl groups provided the target tetramer methyl D-Rib-(5→P→6)-D-Glcp-β(1→3)-Sugp-α(1→4)-α-D-GalpNAc (1).     

Benzopyran derivatives from endophytic Daldinia eschscholzii JC-15 in Dendrobium chrysotoxum and their bioactivities

Five new benzopyran derivatives (2–6) and a new natural product (1) were isolated from endophytic Daldinia eschscholzii in Dendrobium chrysotoxum and determined as (R)-2,3-dihydro-2,5-dihydroxy-2-methylchromen-4-one (1), (2R, 4S)-2,3-dihydro-2-methyl-benzopyran-4,5-diol (2), (R)-3-methoxyl-1-(2,6-dihydroxy phenyl)-butan-1-one (3), 7-O-α-d-ribosyl-5-hydroxy-2-methyl-4H-chromen-4-one (4), 7-O-α-d-ribosyl-2,3-dihydro-5-hydroxy-2-methyl-chromen-4-one (5), daldinium A (6). These compounds were evaluated for their antimicrobial activity, anti-acetylcholinesterase, nitric oxide inhibition, anticoagulant, photodynamic antimicrobial activities and glucose uptake of adipocytes. Some compounds showed photoactive antimicrobial activities and glucose uptake stimulating activities.