[Dynamic control of ERG20 expression to improve production of monoterpenes by engineering Saccharomyces cerevisiae].

Monoterpenes are widely used in cosmetics, food, medicine, agriculture and other fields. With the development of synthetic biology, it is considered as a potential way to create microbial cell factories to produce monoterpenes. Engineering Saccharomyces cerevisiae to produce monoterpenes has been a research hotspot in synthetic biology. In S. cerevisiae, the production of geranyl pyrophosphate(GPP) and farnesyl pyrophosphate(FPP) is catalyzed by a bifunctional enzyme farnesyl pyrophosphate synthetase(encoded by ERG20 gene) which is inclined to synthesize FPP essential for yeast growth. Therefore, reasonable control of FPP synthesis is the basis for efficient monoterpene synthesis in yeast cell factories. In order to achieve dynamic control from GPP to FPP biosynthesis in S. cerevisiae, we obtained a novel chassis strain HP001-pERG1-ERG20 by replacing the ERG20 promoter of the chassis strain HP001 with the promoter of cyclosqualene cyclase(ERG1) gene. Further, we reconstructed the metabolic pathway by using GPP and neryl diphosphate(NPP), cis-GPP as substrates in HP001-pERG1-ERG20. The yield of GPP-derived linalool increased by 42.5% to 7.6 mg·L~(-1), and that of NPP-derived nerol increased by 1 436.4% to 8.3 mg·L~(-1). This study provides a basis for the production of monoterpenes by microbial fermentation.

neo-Clerodane Diterpenoids from the Aerial Parts of Scutellaria barbata with Anti-Inflammatory Activity.

The bioactivity-guided isolation on the Scutellaria barbata extract resulted in the purification of four undescribed neo-clerodane diterpenoids, scuttenlines A-D (1-4), alone with 20 known diterpenoids (5-24). The chemical structures of them were elaborated by extensive spectroscopic means, including 1D, 2D-NMR and HR-MS. The anti-inflammatory potential ability of 1-24 was screened in lipopolysaccharide-stimulated mouse RAW 264.7 cells. Scuttenline C (IC50 =1.9 µM) and 18 (IC50 =3.7 µM) exhibited potent activity to inhibit NO production.

Phenolic constituents with neuroprotective activities from Hypericum wightianum.

Five undescribed phenolic compounds, inclusing a depsidone derivative, hyperwightin A, a flavone derivative, hyperwightin B, and three benzophenone glycosides, hyperwightins C-E, along with four known ones were isolated from the 95% EtOH extract of the whole plants of Hypericum wightianum. Structures of the obtained compounds were elucidated by spectroscopic analyses. The protective effects of the isolates against corticosterone-induced PC12 cell injury were assessed. Hyperwightin E, petiolin G and hyperxanthone exhibited noticeable neuroprotection at 10 µM.

[Chemical Constituents of Inula japonica].

Objective: To study the chemical constituents of Inula japonica. Methods: Silica gel, Sephadex LH-20,MCI and semipreparative HPLC were used to isolate and purify the constituents of Inula japonica,and the chemical structures were elucidated by chemical properties, MS and NMR analysis. Results: 14 compounds were isolated and their structures were identified as ivangustin( 1),1-acetoxy-6α-hydroxyeriolanolide( 2), 1ß-hydroxyalantolactone( 3),tomentosin( 4),11,13-dihydroinuchinenolide B( 5), britanlin A( 6),vomifoliol( 7), 17-hydroxy-16α-ent-kauran-19-oic acid( 8), 12-hydroxygeranylgeraniol ( 9), dihydroquercetin( 10), kaempferol( 11), quercetin( 12), dihydroconiferyl alcohol( 13) and fareanol( 14). Conclusion: Compounds 5,6,9,13 and 14 are isolated from this plant for the first time.

Hupehenols A-E, selective 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) inhibitors from Viburnum hupehense.

Five selective 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) competitive inhibitors, hupehenols A-E (1-5), were isolated from Viburnum hupehense. The structure elucidation indicated that compounds 1-5 are new 20,21,22,23,24,25,26,27-octanordammarane triterpenoids. Their structures were established on the basis of NMR spectroscopic and mass spectrometric analysis. Hupehenols A-E (1-5) showed inhibition against human 11ß-HSD1, with hupehenols B (2) and E (5) having IC50 values of 15.3 and 34.0 nM, respectively. Moreover, hupehenols C (3) and D (4) are highly selective inhibitors of human 11ß-HSD1 when compared to murine 11ß-HSD1.

Polycyclic polyprenylated acylphloroglucinols and cytotoxic constituents of Hypericum androsaemum.

Two new polycyclic polyprenylated acylphloroglucinols (PPAPs), androforin A and hyperandrone A, together with twelve known compounds, were isolated from the aerial parts of Hypericum androsaemum. Their structures were established by detailed spectral analysis. In the cytotoxic assay, 1,4-O-diferuloylsecoisolariciresinol showed activities comparable with those of cisplatin, and acetyloleanolic acid exhibited moderate inhibitory effects against HL-60, SMMC-7721, A-549, MCF-7, and SW480 cancer cell lines.

Spirocyclic acylphloroglucinol derivatives from Hypericum beanii.

Four new acylphloroglucinols with an unusual 6/6/5 spirocyclic skeleton, hyperbeanols A-D (1-4), were isolated from the methanol extract of Hypericum beanii along with 16 known compounds. Their structures were established on the basis of spectroscopic and X-ray diffraction analysis. Hyperbeanols A-C were three stereoisomers different only at the relative configuration of C-4 and C-13, which were distinguished by the nuclear Overhauser effect spectroscopy (NOESY) spectroscopic data in combination with the single X-ray analysis of hyperbeanol A (1). The cytotoxic activity of hyperbeanols A-D against the cancer cell lines SK-BR-3, HL-60, SMMC-7721, PANC-1, MCF-7, and K562 was also evaluated.

Macrophyllionium and macrophyllines A and B, oxindole alkaloids from Uncaria macrophylla.

An unusual oxindole alkaloid inner salt, macrophyllionium (1), and a pair of new tetracyclic oxindole alkaloids, macrophyllines A (2) and B (3), together with six known alkaloids, were isolated from the aerial parts of Uncaria macrophylla. Corynantheidine (8) exhibited moderate cytotoxicity against HL-60 and SW480 cells with IC(50) values of 13.96 and 23.28 µM, respectively. Dihydrocorynantheine (9) exhibited significant vasodilating activity against phenylephrine-induced contraction in rat thoracic aorta rings (IC(50) = 6.73 µg/mL). In addition, compounds 2, 6, and 9 showed weak inhibitory action on KCl-induced contraction.

Polycyclic polyprenylated acylphloroglucinols and chromone O-glucosides from Hypericum henryi subsp. uraloides.

Two new C(30)-epimeric polycyclic polyprenylated acylphloroglucinols (PPAPs), named uralodins B and C (1 and 2, resp.), were isolated from the aerial parts of Hypericum henryi subsp. uraloides together with two new chromone glucosides, urachromones A and B (3 and 4, resp.), as well as 16 known compounds. Their structures were established by extensive NMR techniques and MS analysis. The epimers 1 and 2 always behaved like a single compound when examined by TLC, and were separated by HPLC. Their configuration was distinguished by comparative analysis of the NMR data with known analogues together with the ROESY experiment. All the isolated PPAPs were evaluated for their cytotoxic activities against HepG2, SGC7901, HL-60, and K562 cell lines. Compound 1 showed modest cytotoxic activities against SGC7901 and HL-60 cell lines, and 2 showed modest cytotoxic activities against HepG2, SGC7901, HL-60, and K562 cell lines.

Four new lignans from Viburnum foetidum var. foedidum.

The 70% aqueous acetone extract of the aerial part of Viburnum foetidum var. foedidum afforded four new lignans (1-4) together with six known ones. The structures of the four new compounds were elucidated on the basis of 1D (dimensional), 2D-NMR, and mass spectral analysis. The structure of compound 1, with a novel spirocyclic moiety, was also confirmed by X-ray diffraction analysis. Compounds 1-10 were evaluated for their cytotoxic activity. However, none of the compounds showed significant cytotoxic activity.