[Effects of shading intensity on growth and quality of Artemisia stolonifera].

The purpose of this study was to analyze the effects of shading intensity on the growth, yield, and quality of Artemisia stolonifera so as to provide references for the artificial cultivation of A. stolonifera. The seedlings of A. stolonifera with consistent growth underwent shading treatment at four shading intensity levels(0, 55%, 85%, and 95%) with different layers of black shading nets. The agronomic indexes, yield, moxa yield, total ash, quality characteristics of moxa during combustion and pyrolysis, main volatile components, flavonoids, and phenolic acids were measured. The results showed that under shading conditions, the stem diameter, leaf width, 5-leaf spacing, branch number, and yield of A. stolonifera decreased significantly, while the plant height, leaf length, leaf number, chlorophyll content, and moxa yield increased first and then decreased with the increase in shading intensity. The burning performance of moxa under natural light was better than that under moderate and severe shading conditions. The content of eucalyptol first increased and then decreased with the increase in shading intensity. The humulene content was negatively correlated with shading intensity. Other major volatile components showed no significant difference under various shading conditions. The content of neochlorogenic acid, cryptochlorogenic acid, isoschaftoside, and isochlorogenic acid B was positively correlated with shading intensity, while the content of chlorogenic acid, isochlorogenic acid A, and isochlorogenic acid C decreased first and then increased with the increase in shading intensity. To sum up, A. stolonifera is a light-loving plant, and shading can greatly reduce the yield, the content of internal components, and the burning performance of moxa. It is the main reason why A. stolonifera is mainly distributed in the forest edge, open forest, roadside, and wasteland grass in the middle and high mountains in the wild. For artificial domestication and cultivation of A. stolonifera, it is better to select plots with sufficient light.

[Comparison of growth and quality of wild and cultivated Artemisia stolonifera].

This paper aims to compare the difference of growth and quality between wild and cultivated Artemisia stolonifera, thereby providing references for further development and utilization of A. stolonifera. The wild and cultivated A. stolonifera from different altitudes were collected, and the agronomic characters, moxa yield, volatile components, flavonoids, and phenolic acids were determined. The results showed that the cultivated species were taller and stronger, with more leaves and branches, than the wild species. The moxa yield and combustion quality of wild products were higher than those of cultivated products. The content of main volatile components in cultivated products was higher than that in wild products. The content of flavonoids and phenolic acids in wild products was higher than that in cultivated products. At high altitude, the ignition performance, combustion persistence, comprehensive combustion performance, and heat release during combustion of the wild and cultivated A. stolonifera. were optimal. At middle altitude, the content of main characteristic volatile components and flavone phenolic acids in the leaves of the cultivated and wild A. stolonifera were the highest. At low altitude, the combustion quality and the content of the above components of the cultivated A. stolonifera decrease significantly. Considering the combustion quality and the content of the internal components of the leaf lint, the middle and high altitude areas are suitable for the artificial cultivation of A. stolonifera.

[Distinguishing between Artemisia stolonifera and A. argyi by specific PCR of leaves and non-glandular trichomes].

Artemisia stolonifera is a relative of A. argyi. The two species are difficult to be distinguished due to the similarity in leaf shape and have even less distinctive features after processing. This study aims to establish a method to quickly distinguish between them. At the same time, we examined the reasonability and applicability of the specific polymerase chain reaction(PCR) method. The C/T single nucleotide polymorphism was detected at the position 202 of the sequence, based on which specific primers were designed to identify these two species. The PCR with the specific primer JNC-F and the universal primer ITS3R produced a specific band at 218 bp for A. argyi and no band for A. stolonifera, which can be used to detect at least 3% of A. argyi samples mixed in A. stolonifera samples. The PCR with the specific primer KY-F and the universal primer ITS3R produced a specific band at 218 bp for A. stolonifera and no band for A. argyi, which can be used to detect at least 5% of A. stolonifera samples mixed with A. argyi. The limit of detection of the established method was 5 ng DNA. The established PCR method can accurately distinguish between A. stolonifera and A. argyi, which provides an experimental basis for the quality control of A. stolonifera and determines whether the herbs are adulterated.

The Miharamycins and Amipurimycin: their Structural Revision and the Total Synthesis of the Latter.

The structural puzzle of amipurimycin, a peptidyl nucleoside antibiotic, is solved by total synthesis and X-ray diffraction analysis, with the originally proposed configurations at C3' and C8' inverted and those at C6', C2'', and C3'' corrected. A similar structural revision of the relevant miharamycins is proposed via chemical transformations and then validated by X-ray diffraction analysis. The miharamycins bear an unusual trans-fused dioxabicyclo[4.3.0]nonane sugar scaffold, which was previously assigned as being in the cis configuration.

Amipurimycin: Total Synthesis of the Proposed Structures and Diastereoisomers.

The proposed diastereoisomers (1 a-d) together with their C8'-epimers (1 e-h) of amipurimycin, a unique antifungal peptidyl nucleoside antibiotic, have been synthesized for the first time. The synthetic approach is efficient and stereodivergent, and features a stereoselective aldol condensation to build the branched C9 sugar amino acid skeleton and a regio- and stereocontrolled gold(I)-catalyzed N-glycosylation to furnish the purine nucleoside. Analysis of the NMR data suggests that the previously assigned configuration of the tertiary C3' in amipurimycin should be of opposite configuration.

Dimerization of aldosuloses and aldonolactones into branched higher carbon sugars.

Homo-dimerizations of a variety of aldosulose and aldonolactone derivatives via aldol and Claisen reactions have been achieved, leading to novel branched higher carbon sugars in a highly stereoselective manner.