Optimization of Three Extraction Methods and Their Effect on the Structure and Antioxidant Activity of Polysaccharides in Dendrobium huoshanense.

Dendrobium huoshanense is a famous edible and medicinal herb, and polysaccharides are the main bioactive component in it. In this study, response surface methodology (RSM) combined with a Box-Behnken design (BBD) was used to optimize the enzyme-assisted extraction (EAE), ultrasound-microwave-assisted extraction (UMAE), and hot water extraction (HWE) conditions and obtain the polysaccharides named DHP-E, DHP-UM, and DHP-H. The effects of different extraction methods on the physicochemical properties, structure characteristics, and bioactivity of polysaccharides were compared. The differential thermogravimetric curves indicated that DHP-E showed a broader temperature range during thermal degradation compared with DHP-UM and DHP-H. The SEM results showed that DHP-E displayed an irregular granular structure, but DHP-UM and DHP-H were sponge-like. The results of absolute molecular weight indicated that polysaccharides with higher molecular weight detected in DHP-H and DHP-UM did not appear in DHP-E due to enzymatic degradation. The monosaccharide composition showed that DHPs were all composed of Man, Glc, and Gal but with different proportions. Finally, the glycosidic bond types, which have a significant effect on bioactivity, were decoded with methylation analysis. The results showed that DHPs contained four glycosidic bond types, including Glcp-(1→, →4)-Manp-(1→, →4)-Glcp-(1→, and →4,6)-Manp-(1→ with different ratios. Furthermore, DHP-E exhibited better DPPH and ABTS radical scavenging activities. These findings could provide scientific foundations for selecting appropriate extraction methods to obtain desired bioactivities for applications in the pharmaceutical and functional food industries.

The mitochondrial genome of Platencyrtus parkeri Feriere (Hymenoptera: Encyrtidae).

The mitochondrial genome of the Platencyrtus parkeri Feriere (Hymenoptera: Encyrtidae) was obtained via next-generation sequencing. The assembled mitogenome is 13,393 bp in length, which contains 33 classical eukaryotic mitochondrial genes with three tRNA genes and rrnS gene missing. All the 13 PCGs begin with typical ATN codons. The 19 detected tRNAs range from 58 to 70 bp in length with typical cloverleaf structure except for trnS1, whose dihydrouridine (DHU) arm forms a simple loop. Meanwhile, they have six tRNAs inserted between nad2 and nad3 compared with Encyrtus infelix. Phylogenetic analysis highly supported the monophyly of Pteromalidae. Eupelmidae and Encyrtidae have a close relationship. Within Encyrtidae, Platencyrtus parkeri Feriere and Encyrtus infelix are close to each other.

[The analysis of the eugenic culture in ancient China].

There was a centuries-old culture of eugenics in ancient China. We should have comprehensive and objective cognition of this tradition. The ancient people did not generally advocate marrying at a mature age as do people of modern times. They not only considered the prepotency, but also were influenced by other complicated social factors on the problem of mate selection. Although advocates of coition techniques claimed the purpose of prepotency, the eugenic effect of coition techniques deserved to be suspect. Regarding the aspect of embryo conservation and care, the most significant thing was not so-called "prenatal education", but various antenatal care methods which were proposed by TCM scholars. By making a comparison with modern eugenics, the ancient eugenics had the characteristics of valuing the male child only, commiserating with deformity and being based on familial values.