Four new tirucallane triterpenoids, (21S,23R,24R)-21,23-epoxy-21,24-dihydroxy-25-methoxytirucall-7-en-3-one (2), (3S,21S,23R,24S)-21,23-epoxy-21,25-dimethoxytirucall-7-ene-3,24-diol (8), (21S,23R,24R)-21,23-epoxy-24-hydroxy-21-methoxytirucalla-7,25-dien-3-one (11), and (21S,23R,24R)-21,23-epoxy-21,24-dihydroxytirucalla-7,25-dien-3-one (12), along with 16 known analogues, 1, 3 - 7, 9 - 10, and 13 - 20, were isolated from the fruits of Melia azedarach. Their structures were elucidated by spectroscopic methods including 1D- and 2D-NMR techniques and mass spectrometry. These compounds were evaluated for their cytotoxicities against HepG2 (liver), SGC7901 (stomach), K562 (leukemia), and HL60 (leukemia) cancer cell lines. Compound 20 exhibited potent cytotoxicity against HepG2 and SGC7901 cancer cells with the IC values of 6.9 and 6.9 μm, respectively.

Three new phomalone derivatives, phomalichenones E-G (1-3), and seven known analogues (4-10) were isolated from the cultures of a deep-sea-derived fungus Alternaria sp. MCCC 3A00467. Their structures were elucidated by spectroscopic methods, including the 1 D and 2 D NMR, and ECD spectrum. Among the compounds isolated, phomalichenone F (2) presented cytotoxic activity against human myeloma cancer U266 cells with IC 50 value of 24.99 μg/mL. The most active compound, 10, showed cytotoxicity against U266, HepG2 and A549 cells with IC 50 values of 13.26, 14.69, 24.39 μg/mL, respectively.

Salmonella can resist various stresses and survive during food processing, storage, and distribution, resulting in potential health risks to consumers. Therefore, evaluation of bacterial survival profiles under various environmental stresses is necessary. In this study, the resistance profiles of five Salmonella isolates [serotypes with Agona, Infantis, Typhimurium, Enteritidis, and a standard strain (ATCC 13076, Enteritidis serotype)] to acidic, hyperosmotic, and oxidative stresses were examined, and the relative expressions of non-coding small RNAs were also evaluated, including CyaR, MicC, MicA, InvR, RybB, and DsrA, induced by specific stresses. The results indicated that although all tested strains displayed a certain resistance to stresses, there was great diversity in stress resistance among the strains. According to the reduction numbers of cells exposed to stress for 3 h, S. Enteritidis showed the highest resistance to acidic and hyperosmotic stresses, whereas ATCC 13076 showed the greatest resistance to oxidative stress, with less than 0.1 Log CFU/ml of cell reduction. Greater resistance of cells to acidic, hyperosmotic, and oxidative stresses was observed within 1 h, after 2 h, and from 1 to 2 h, respectively. The relative expression of sRNAs depended on the isolate for each stress; acidic exposure for the tested isolates induced high expression levels of DsrA, MicC, InvR, RybB, MicA, and CyaR. The sRNA RybB, associated with sigma E and outer membrane protein in bacteria, showed a fold change of greater than 7 in S. Enteritidis exposed to the tested stresses. CyaR and InvR involved in general stress responses and stress adaptation were also induced to show high expression levels of Salmonella exposed to hyperosmotic stress. Overall, these findings demonstrated that the behaviors of Salmonella under specific stresses varied according to strain and were likely not related to other profiles. The finding also provided insights into the survival of Salmonella subjected to short-term stresses and for controlling Salmonella in the food industry.