Combining directed evolution with high cell permeability for high-level cadaverine production in engineered Escherichia coli.

The biosynthesis of cadaverine from lysine is an environmentally promising technology, that could contribute to a more sustainable approach to manufacturing bio-nylon 5X. However, the titer of biosynthesized cadaverine has still not reached a sufficient level for industrial production. A powerful green cell factory was developed to enhance cadaverine production by regulating lipopolysaccharide (LPS) genes and improving membrane permeability.

Scapaundulin C, a novel labdane diterpenoid isolated from Chinese liverwort Scapania undulate, inhibits acetylcholinesterase activity.

In the present study, scapaundulin C (1), a new labdane diterpenoid, and four related known compounds scapaundulin A (2), 5α, 8α, 9α-trihydroxy-13E-labden-12-one (3), 5α, 8α-dihydroxy-13E-labden-12-one (4), and (13S)-15-hydroxylabd-8 (17)-en-19-oic acid (5), were isolated from the Chinese liverwort Scapania undulate (L.) Dum., using column chromatography.

Polyacetylated labdane-type diterpenoids, ptychantins P-R from Chinese liverwort Ptychanthus striatus.

Three new polyacetylated labdane diterpenoids ptychantins P-R (1-3) and four known compounds (4-7) were isolated from an EtOH extract of the Chinese liverwort Ptychanthus striatus (Lehm. & Lindenb.) Nees.

Notolutesins A-J, dolabrane-type diterpenoids from the Chinese liverwort Notoscyphus lutescens.

Ten new dolabrane-type diterpenoids, notolutesins A-J (1-10), were isolated from the Chinese liverwort Notoscyphus lutescens, along with four known compounds. The structures of the new compounds were established on the basis of extensive spectroscopic data, and that of 1 was confirmed by single-crystal X-ray crystallography. The absolute configuration of 1 was determined by comparing its experimental and calculated electronic circular dichroism spectra.

Cembrane-type diterpenoids from the Chinese liverworts Chandonanthus hirtellus and C. birmensis.

Six new cembrane-type diterpenoids (1-6) were isolated from two species of Chandonanthus: Chandonanones A, B, and D-F (1, 2, and 4-6) were isolated from C. hirtellus, and chandonanones B, C, E, and F (2, 3, 5, and 6) from C. birmensis.

[Studies on the chemical constituents from the antithrombus activity extract of Radix Aerio Fici Microcarpae].

Objective: To study the chemical constituent from the antithrombus activity extract of Radix Aerio Fici Microcarpae.

Methods: The isolation and purification of the extract were conducted by means of silica gel column chromatography, polyamide column chromatography and recrytallization. The structures of these compounds were elucidated based on the physicochemical properties and spectroscopic analysis.

[A new flavonol glycoside from Baeckea Frutescens L].

To study the chemical constituents of the traditional Chinese herb Baeckea Frutescens L., a new flavonol glycoside, named 6, 8-dimethylkaempferol-3-O-alpha-L-rhamnoside (1), together with seven known compounds: quercetin (2), quercetin-3-O-alpha-L-rhamnoside (3), myricetin (4), myricetin-3-O-alpha-L-rhamnoside (5), gallic acid (6), ursolic acid (7) and 1,3-dihydroxy-2-(2'-methoxylpropionyl)-5-methoxy-6-methylbenzene (8) were isolated by using silica gel column chromatography, polyamide column chromatography and recrytallization. Their structures were identified on the basis of physicochemical properties and spectroscopic analysis.