New abietane and tigliane diterpenoids from the roots of Euphorbia fischeriana and their cytotoxic activities.

Three new abietane and two new tigliane diterpenoids were isolated from the roots Euphorbia fischeriana. Their structures were elucidated by spectroscopic methods and quantum chemical calculation. Compounds 4 and 5 exhibited the inhibitory activities against human cancer cells HeLa and HepG2, with IC50 ranging from 3.54 to 11.45 µM.

A review: biosynthesis of plant-derived labdane-related diterpenoids.

Plant-derived labdane-related diterpenoids (LRDs) represent a large group of terpenoids. LRDs possess either a labdane-type bicyclic core structure or more complex ring systems derived from labdane-type skeletons, such as abietane, pimarane, kaurane, etc. Due to their various pharmaceutical activities and unique properties, many of LRDs have been widely used in pharmaceutical, food and perfume industries. Biosynthesis of various LRDs has been extensively studied, leading to characterization of a large number of new biosynthetic enzymes. The biosynthetic pathways of important LRDs and the relevant enzymes (especially diterpene synthases and cytochrome P450 enzymes) were summarized in this review.

Advances in biotechnological production of santalenes and santalols.

Sandalwood essential oil has been widely used not only as natural medicines but also in perfumery and food industries, with sesquiterpenoids as its major components including (Z)- α-santalol and (Z)-ß-santalol and so on. The mature heartwoods of Santalum album, Santalum austrocaledonicum and Santalum spicatum are the major plant resources for extracting sandalwood essential oil, which have been overexploited. Synthetic biology approaches have been successfully applied to produce natural products on large scale. In this review, we summarize biosynthetic enzymes of santalenes and santalols, including various santalene synthases (STSs) and cytochrome P450 monooxygenases (CYPs), and then highlight the advances of biotechnological production of santalenes and santalols in heterologous hosts, especially metabolic engineering strategies for constructing santalene- and santalol-producing Saccharomyces cerevisiae.

[Limonoids from seeds of Azadirachta indica and their antibacterial activity].

Fifteen limonoids were isolated from 95% ethanol extracts of the dry seeds of neem( Azadirachta indica) by various column chromatography techniques including silica gel,Pharmadex LH-20 gel and ODS resin. Based on spectroscopic analysis,their structures were determined as nimbocinol( 1),17ß-hydroxynimbocinol( 2),1α,3α,7α-triacetylvilasinin( 3),7α-benzoyltrichilinin( 4),1,3-diacetyl-7-tigloyl-12-hydroxyvilasinin( 5),3-deacetylsalannin( 6),1-O-acetyl-1-detigloylsalannin( 7),2'( R),3'-dihydrosalannin( 8),2'( S),3'-dihydrosalannin( 9),2,3-dihydronimbolide( 10),6-homodesacetylnimbin( 11),gedunin( 12),7-deacetyl-7-epi-dihydrogedunin( 13),7-deacetoxy-7α-hydroxygedunin( 14) and nimbinene( 15). Compound 7 is a new natural product. 4,8,9,13 and 14 are isolated from the genus Azadirachta for the first time. Compound 2 showed inhibitory activity against Escherichia coli and Staphylococcus epidermidis,with MIC values of 32 and 128 mg·L~(-1),respectively. Compound 10 showed moderate inhibitory activity against S. epidermidis with a MIC value of 64 mg·L~(-1). Compound 11 inhibited the growth of E. coli and Pseudomonas aeruginosa,both with MIC values of 128 mg·L~(-1). Compound 15 exhibited inhibitory activity against P. aeruginosa,with a MIC value of128 mg·L~(-1).

[Limonoids from seeds of Azadirachta indica and their cytotoxic activity].

Eight limonoids were isolated from 95% ethanol extracts of neem(Azadirachta indica) seeds by various chromatographic methods. By comparison of their spectroscopic data with those reported in the literatures, these limonoids were determined as salannin(1), 1-detigloyl-1-isobutylsalannin(2), salannol-3-acetate(3), salannol(4), spirosendan(5), 1-detigloyloxy-3-deacetylsalannin-1-en-3-one(6), nimbin(7) and 6-deacetylnimbin(8). Compounds 2 and 5 were firstly isolated from this genus and 5 represented the only example of its type. And 6 is a new natural product. 6 showed inhibitory activity against HeLa and HL-60 cells, with IC50 of(21.61±4.37) and(27.33±5.74) µmol·L⁻¹, respectively. Both 7 and 8 mildly inhibited the growth of HeLa cells, with IC50 of (33.15±5.24) and (38.56±6.41) µmol·L⁻¹, respectively.

Chemical constituents from branch of Fraxinus sieboldiana.

Using a combination of various chromatographic techniques including column chromatography over silica gel, Sephadex LH-20, macroporous adsorbent resin, and reversed-phase HPLC, 115 compounds including diterpenes, sesquiterpenes, treterpenes, coumarins, lignans, fatty acid derivatives, and simple aromatic derivatives were isolated from an ethanol extract of branch of Fraxinus sieboldiana (Oleaceaue), and their structures of the compounds were elucidated by spectroscopic methods including 1 D, 2D NMR and MS techniques. Among them, 41 compounds were new. In previous reports, we have been described the isolation, structure elucidation, and bioactivities of the 41 new compounds and 22 known orii including 8 coumarins, 4 phenolic and 12 phenylethanoidal glycosides. As a consequence, we herein reported the isolation and structure elucidation of the remaining 50 known compounds including 8- hydroxy-12-oxoabieta-9(11),13-dien-20-oic 8, 20-lactone(1), 6beta-hydroxyfcrruginol(2),(+)-pisiferic acid(3), (+)-pisiferal(4),(+)-7-dehydroabiet6none(5), 1-oxomiltirone(6), subdigitatone(7), linarionoside B(8), (9S)-linarionoside B(9), (3R,9R)-3-hydroxy-7,8-dihydro-beta-ionol 9-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside(10), ursolic acid(11), betulinic acid(12), euscaphic acid(13), (+)-syringaresinol(14), (+)-fraxiresinol(15), (+)-1-hydroxysyringaresinol(16), pinoresinol(17), medioresinol(18), 8-acetoxypinoresinol(19), epipinoresinol(20), (-)-olivil(21), (+)-cyclo-olivil(22), 3,3'-dimethoxy-4,4',9-trihydroxy-7,9'-epoxylignan-7'-one(23),(+)-1-hydroxypinoresinol 4'-O-beta-D-glucopyranoside (24), (+)-1-hydroxypinoresinol 4"-O-beta-D-glucopyranoside(25),(+)-syringaresinol O-beta-D-glucopyranoside (26), liriodendrin (27), ehletianol D(28), icariside E5(29) (-)-(7R, 8R)-threo-1-C-syringylglycerol(30),(-)-(7R, 8S)-erythro-guaiacylglycerol (31),(-)-(7R, 8R)-threo-guaiacylglycerol(32), 3-(4-beta-D-glucopyranosyloxy-3-methoxy)-phenyl-2E-propenol(33),2,3-dihydroxy-l-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanone(34), 2,3-dihydroxy-1-(4-hydroxy-3-methoxyphenyl)-1-propanone (35), 3-hydroxy-l-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanone(36), omega-hydroxypropioguaiacone(37), sinapyladehyde(38), trans-p-hydroxycinnamaldehyde(39), syringic acid(40), vanilic acid(41), vanillin(42), 4-hydroxy-benzaldehyde (43), (24R)-24-ethyl-5alpha-cholestane-3beta,5,6beta-triol(44), beta-sitosterol(45), daucosterol(46), 2,6-dimethoxy-I,4-benzoquinone(47), 2,6-dimethoxy-pyran-4-one(48), 1-(beta-D-ribofuranosyl)uracil(49), and mannitol(50). Compouds 1-7,12,18,28-37,44 and 48 were obtained from the genus Fraxinus for the first time.

Butanolide derivatives from the bark of Machilus yaoshansis.

Six new butanolide derivatives with long aliphatic side chains (1-6), together with 23 known lipophilic constituents, were isolated from the bark of Machilus yaoshansis. Their structures were elucidated by spectroscopic and chemical methods. All the isolates were evaluated for cytotoxic and anti-inflammatory activities.

Methoxylated fatty acids from the bark of Fraxinus sieboldiana.

Nine new fatty acid derivatives, including seven methoxylated (1, 2, and 4-8) and two hydroxylated (3 and 9) fatty acids, have been isolated from the ethanol extract of the stem bark of Fraxinus sieboldiana. Their structures were determined by spectroscopic methods including IR, MS, 1D, and 2D NMR experiments. The 3- or 9-methoxylated fatty acids are reported for the first time in nature.

Minor constituents from the tubers of Gymnadenia conopsea.

Four new minor constituents including two cyclodipeptides (1 and 2) and two cyclopentene derivatives (3 and 4), together with four known cyclodipeptides, have been isolated from an ethanolic extract of the tubers of Gymnadenia conopsea. Their structures including absolute configurations were determined by spectroscopic data interpretation combined with chemical methods. Among them, compound 1 contains an abnormal S-(4''-hydroxybenzyl)cysteine residue, 3 and 4 possess [(4-methylcyclopentyl)methyl]benzene and (4-hydroxymethylcyclopentyl)benzene carbon skeletons, respectively, both of which are first found from the natural source.