Search

Two undescribed triterpenoid saponins (1 and 3) along with six known saponins (2 , 4 - 8) were isolated from the flower buds of Lonicera macranthoides by an LC-MS guided fractionation method. Natural products 1 , 3 , 5 and 7 are the monodesmosidic saponins of ambradiolic acid, 23-hydroxybetulinic acid, hederagenin and oleanolic acid, respectively, sharing the same single sugar chain at C-3 of each aglycone. Furthermore, compounds 2 , 4 , 6 and 8 are their bisdesmosidic saponins with a further identical sugar chain at C-28 of the aglycone. All structures were identified by interpretation of their spectroscopic data. Compounds 1 - 8 were evaluated for in vitro cytotoxicity against the HeLa, HTC-116, B16 and MDA-MB-468 cell lines. Results showed that all monodesmosidic saponins exhibited moderate activity with compound 7 showing the most pronounced cytotoxicity against the four human cancer cell lines, with IC 50 values of 1.9–13.5 μM. The preliminary structure-activity relationships of the natural products are also discussed. [Display omitted] • LC–MS guided isolation for saponins containing the same sugar chain was proposed and validated. • Two new and six known saponins (1 - 8) were isolated from the flowers of Lonicera macranthoides. • Their structures were elucidated by NMR and HR-ESI-MS experiments. • Saponin 7 exhibited appreciable cytotoxicity against the HeLa, HTC-116, B16 and MDA-MB-468 cell lines. [ABSTRACT FROM AUTHOR]

Lagerstroemia × 'Xiaoxiang Huaxiu' (an F 1 hybrid of Lagerstroemia speciosa and Lagerstroemia indica 'Ebony Embers') exhibits significant sterility. Cytological studies have revealed numerous abnormal chromosomal behaviors during the meiotic division of pollen mother cells in L. × 'Xiaoxiang Huaxiu'. Transcriptome sequencing identified that LiDMC1 and LiASY1 were expressed at very low levels in 'Xiaoxiang Huaxiu'. To further verify whether the abnormal expression of LiDMC1 and LiASY1 was the fundamental cause of sterility in 'Xiaoxiang Huaxiu', we cloned the full-length gene sequences of LiDMC1 and LiASY1 from 'Ebony Embers'. Using VIGS (virus-induced gene silencing) technology, pTRV1 and pTRV2 gene silencing vectors were employed to silence LiDMC1 and LiASY1 in the paternal parent 'Ebony Embers'. The results indicated that in the double-silenced lines of 'Ebony Embers', the cytoplasm sizes of different tetrads during the tetrad stage varied significantly. There was a notable proportion of polyads, binucleate cells with micronuclei, and pentads. Additionally, pollen diameter varied significantly, closely resembling the sterility observed in 'Xiaoxiang Huaxiu'. Pollen viability in the double-silenced 'Ebony Embers' decreased by 22.8%. This study demonstrates that the low expression of LiDMC1 and LiASY1 leads to abnormal microspore development in 'Ebony Embers', and their low expression is the cause of sterility in 'Xiaoxiang Huaxiu'. • The F1 hybrid 'Xiaoxiang Huaxiu' exhibits significant sterility. • Transcriptome data reveals low expression levels of the meiotic genes LiDMC1 and LiASY1. • Double-silenced 'Ebony Embers' show a 22.8% decrease in pollen viability. • The abnormal expression of LiDMC1 and LiASY1 is the primary cause of sterility in "Xiaoxiang Huaxiu". [ABSTRACT FROM AUTHOR]

A novel processing technology for interlocking and joining three sheets of two copper foils and a perforated stainless steel sheet by laser shock forming is presented in this paper. In this forming process, two layers of ductile copper foils are positioned above a perforated stainless steel sheet, a shock pressure induced by pulsed laser is applied on the upper foil, both foils are indented downwards through the hole of the perforated sheet, and impact on the rigid bottom support, then spread radially to produce a double interlock, thus to join the three sheets together. Finite element analysis as well as practical experiments were conducted to verify the feasibility of making interlocks by laser shock forming. The numerical simulation reveals the deformation mechanism of interlocks based on the analysis of plastic flow and shape evolution during the process. These results point to the practicality of clinching and joining three sheets by laser induced plastic deformation, namely laser shock joining or laser shock clinching. [ABSTRACT FROM AUTHOR]