Seventeen new lathyrane diterpenoids (1-17) and two known analogues have been isolated from an ethanolic extract of Euphorbia micractina roots. Their structures including absolute configurations were determined by spectroscopic data interpretation and single-crystal X-ray crystallography. Compound 10 showed activity against HIV-1 replication in vitro, with an IC50 value of 8.2 μM. Compounds 6, 7, 11, 14, 15, and 18, at 10(-6) M, showed significant vascular-relaxing activities against phenylephrine-induced vasoconstriction with relaxation rates of 48%, 41%, 42%, 48%, 50%, and 53%, respectively.

Eleven new metabolites, butanolides 1-6, lignan derivatives 7-9, sesquiterpene 10, and 3',4'-seco-flavane derivative 11, have been isolated from an ethanol extract of Machilus wangchiana. Twenty known compounds, including ginkgolides A and B (16 and 17), were also isolated. Their structures and absolute configurations were determined by spectroscopic and chemical methods. Compounds 7, 8a, 8b, 9, 11, (+)-guaiacin (12), meso-dihydroguaiaretic acid (13), and hamabiwalactone A (15) showed potent in vitro activities against the release of beta-glucuronidase in rat polymorphonuclear leukocytes (PMNs) induced by platelet-activating factor (PAF), with 42.5-75.6% inhibition at 10(-5) M. Compounds 8, 8a, 8b, 9, and 11 reduced dl-galactosamine (GalN)-induced hepatocyte (WB-F344 cells) damage with 39.4 +/- 6.3% to 53.6 +/- 3.5% inhibition at 10(-4) M. Isomahubannolide-23 (14) was cytotoxic against human stomach cancer (BGC-823) and ovarian cancer (A2780) cell lines, with IC(50) values of 0.13 and 2.66 muM, respectively.

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Sandalwood oil has been widely used in perfumery industries and aromatherapy. Santalols are its major components. Herein, we attempted to construct santalol-producing yeasts. To alter flux from predominant triterpenoid/ steroid biosynthesis to sesquiterpenoid production, expression of ERG9 (encoding yeast squalene synthase) was depressed by replacing its innate promotor with P HXT1 and fermenting the resulting strains in galactose-rich media. And the genes related to santalol biosynthesis were overexpressed under control of GAL promotors, which linked santalol biosynthesis to GAL regulatory system. GAL4 (a transcriptional activator of GAL promotors) and PGM2 (a yeast phosphoglucomutase) were overexpressed to overall promote this artificial santalol biosynthetic pathway and enhance galactose uptake. 1.3 g/L santalols and 1.2 g/L Z-α-santalol were achieved in the strain WL17 expressing SaSS (α-santalene synthase from Santalum album) and WL19 expressing SanSyn (α-santalene synthase from Clausena lansium) by fed-batch fermentation, respectively. This study constructed the microbial santalol-producing platform for the first time.

Nine minor new tirucallane (1-7) and euphane (8 and 9) triterpenoids including five hydroperoxides, together with 18 known compounds, have been isolated from an ethanolic extract of the roots of Euphorbia micractina. Their structures including absolute configurations were elucidated by spectroscopic and chemical analysis. In the in vitro assays, betulin (10) showed a selective cytotoxic activity against A2780 ovarian cells with an IC(50) value of 6.1 microM and inhibitory activity against protein tyrosine phosphatase 1B (PTP1B) with an IC(50) value of 15.3 microM. Jolkinol B (11) showed a potent activity against HIV-1 replication with an IC(50) value of 12.6 muM. However, compounds 1-9 and the other known compounds were inactive in the three assays used.

Twelve new minor diterpenoids, possessing 5/6/8 (1 and 2), 5/6/7/3 (3-9), and 5/6/6/4 (10-12) fused-ring skeletons, as determined by spectroscopic analysis, were isolated from an ethanol extract of the roots of Euphorbia micractina, together with 25 known compounds. The structures of the diterpene skeletons are rare and have been found only in compounds isolated from Euphorbia micractina and Euphorbia villosa. On the basis of the octant rule for cyclohexanones, the absolute configurations of 1-12, as well as of the known euphactins A-D and euphoractins A-D (13-15), could be assigned by circular dichroism spectroscopy. In addition, the co-occurring jolkinol B (16) was chemically transformed to euphoractin E (17), supporting the absolute configuration assignment and the biogenetic relationship between the different types of diterpenes. Compound 9 showed activity against HIV-1 replication in vitro, with an IC50 value of 8.8 ± 0.6 μM.

A novel diterpenoid with an unprecedented 6/5/7/3 fused-ring skeleton, euphorbactin (1), was isolated from an ethanol extract of the roots of Euphorbia micractina. The structure was determined by extensive spectroscopic studies, especially by 2D NMR and CD data analysis. A proposed biosynthetic pathway and preliminary investigations of the biological activity of compound 1 are also discussed.

Eleven new compounds including two sesquiterpenes with an unusual 2,2,5,9-tetramethylbicyclo[6.3.0]undecane carbon skeleton (1 and 2), five phytane-type diterpene dilactones (3-7), an ent-clerodane diterpene dilactone (8), and three phenylpropenol esters (9-11), together with a diacylphenol (12) and 38 known compounds, have been isolated from an ethanolic extract of Heteroplexis micocephala. Their structures including absolute configurations were elucidated by spectroscopic and chemical analyses. In the in vitro assays, compound 6 showed a selective cytotoxic activity against A2780 with an IC(50) value of 4.37 microM, while sinapyl diangelate (13) showed a potent activity inhibiting HIV-1 replication with an IC(50) value of 4.04 microM.