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By the method of artificial water contamination, and using transmission electron microscope (TEM) and flow cytometer (FCM), this paper studied the effects of cadmium on the germ cell apoptosis in testis and the quality of mature spermatozoa in epididymis of mice. Compared with that in control group, the amount of the germ cells under apoptosis in experimental groups was remarkably higher, and the ultrastructure of the germ cells showed the phenomena such as mitochondrion vacuole, karyotheca invagination, chromatin margination, and karyopyknosis, indicating that cadmium could easily cause testis spermatocyte apoptosis of mice. The proportion of the germ cells with early apoptosis was significantly higher in experimental groups than in control group, while that of active germ cells was in reverse (P<0.05). In high dosage group (0.10 mmol CdCl2·L-1), the survival rate of germ cells (75.1%) was significantly lower than that in control group and other experimental groups, and the early apoptosis rate of the germ cells (22.6%) was significantly higher than that of the control. The DNA breakage rates of the germ cells in testis and epididymis were significantly higher in high dosage group (18.2% and 26.5%) than in control group (3.3% and 5.6%) (P <0.05), and the amounts of testis germ cells with DNA breakage in experimental groups were lower than those of the epididymis germ cells with DNA breakage. The apoptosis rates of the germ cells in testis and epididymis increased gradually with the increase of cadmium dosage. It was concluded that the dosage of cadmium had definite effects on the apoptosis and DNA damage of mice germ cells. [ABSTRACT FROM AUTHOR]

Understanding the mechanism of the negative differential resistance (NDR) in transition metal dichalcogenides is essential for fundamental science and the development of electronic devices. Here, the NDR of the current-voltage characteristics was observed based on the glutamine-functionalized WS 2 quantum dots (QDs). The NDR effect can be adjusted by varying the applied voltage range, air pressure, surrounding gases, and relative humidity. A peak-to-valley current ratio as high as 6.3 has been achieved at room temperature. Carrier trapping induced by water molecules was suggested to be responsible for the mechanism of the NDR in the glutamine-functionalized WS 2 QDs. Investigating the NDR of WS 2 QDs may promote the development of memory applications and emerging devices., (© 2021 IOP Publishing Ltd.)

Xerophilusin A (1), xerophilusin B (2), longikaurin B (3), and xerophilusin F (4) from Isodon xerophylus inhibit LPS-induced NO production in RAW 264.7 macrophages, with IC(50) values of 0.60, 0.23, 0.44, and 0.67 muM, respectively, and they all inhibited mRNA production in these same cells. They decreased the luciferase activity in RAW 264.7 cells transiently transfected with the NF-kappaB-dependent luciferase reporter, with IC(50) values of 1.8, 0.7, 1.2, and 1.6 muM, respectively. Compounds 1-3 reduced NF-kappaB activation, with compound 4 showing no effect, but p65 translocation from the cytoplasm to the nucleus and the LPS-induced degradation of IkappaB were inhibited by all four test compounds. These findings indicate that ent-kauranes are potential anti-inflammatory agents, with a specific mechanism in which both the inhibition of NF-kappaB translocation and the consequent decrease of pro-inflammatory mediators are implicated.

Chromatographic fractionation of the extract of Isodon henryi resulted in the isolation of seven new ENT-kaurane diterpenoids, named minheryins A-G (1-7), together with the six known ENT-kaurane diterpenoids leukamenin F (8), excisoidesin (9), leukamenin E (10), wangzaozin A (11), pseurata A (12), and racemosin A (13), which were elucidated by spectroscopic analysis. Compounds 7-13 were tested for their cytotoxicity against K562 and HepG2 cell lines, and they all exhibited significant activities with IC50 values<0.50 microg/mL. Isolates 1-5 were evaluated against the K562 cell line, and only 3 showed weak activity.

Isodon xerophilus has been used as a herbal cold tea for the prevention and treatment of sore throat and inflammation in southernwestern China. A phytochemical study on the ethyl acetate (EtOAc) soluble fraction of I. xerophilus leaves led to the isolation of two new ent-kauranoids, xerophinoids A (1) and B (2), together with 14 known diterpenoids. The structures of xerophinoids A (1) and B (2) were illustrated using spectroscopic methods including 1D and 2D NMR analyses. To study their biological activities, the effects of xerophinoids A (1) and B (2) on nitrite production, tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta were examined. In addition, xerophinoids A (1) and B (2) also exhibited potent cytotoxicity against several human tumor cell lines (IC50 < 11 microM), but they had no toxicity on human T-lymphocyte (C8166).

A phytochemical study of secondary metabolites produced by Schisandra chinensis has led to the isolation of six novel highly oxygenated nortriterpenoids, wuweizidilactones A-F (1-6). Compounds 3-6 possess an unprecedented 3,4-seco-18(13-->14)-abeo-artane skeleton. Interestingly, structures 3-6 have a beta-oriented methyl group at the C-14 position. This structural feature corroborates the biogenetic pathway proposed for the formation of 18-norschiartane-type compounds 1 and 2. The structures of these novel metabolites were established on the basis of their detailed spectroscopic analysis. The structure of 1 was also confirmed by single-crystal X-ray diffraction analysis. For the first time, the absolute configuration of these nortriterpenoids was determined by using a modified Mosher method.