Search

The photoreaction of 2,3,4',5-tetrahydroxystilbene-2- O -β-d-glucoside (TSG) has been investigated. Water-assisted/water-accelerated photodimerization of trans -TSG favored the formation of syn -head-to-tail [2 + 2] photocyclobutane under 365 nm irradiation as a result of hydrophobic association and a fluorescent solute-solute aggregate from their excited singlet states. In contrast, irradiation with 254 nm led to [2 + 2] photocycloreversion. The two cyclobutane dimers were first obtained through straightforward photoreaction and identified as multiflorumiside A and multiflorumiside C through the detailed analysis of high-resolution electrospray ionization mass spectrometry and one- and two-dimensional nuclear magnetic resonance. Therefore, trans -TSG should be protected from light and water.

Introduced freshwater fishes considerably influence the ecology and populations of native species. Previous research has revealed that introduced Zacco platypus may hybridize with chubs that are sister but distinct genera. However, we have little knowledge of Z. platypus ' mate choice or its impact on Taiwanese chubs. Therefore, this study identified the interspecific mating behavior between introduced Z. platypus and native Opsariichthys evolans and evaluated the former's invasive impact on cohabitants. Our observations showed that interspecific mating pairs do occur between Z. platypus male(s) and O. evolans female(s). Fifty-three percent of spawning events were interspecific mating and only 43% were between native O. evolans mating pairs. This study showed that Z. platypus male satellites might prefer to engage with Z. platypus , while O. evolans might engage by chance. However, introduced males of Z. platypus may be unable to recognize conspecific females. Meanwhile, introduced females of Z. platypus also have a mate choice preference for males of Z. platypus . Therefore, Z. platypus male hybridization might significantly reduce the successful mating ratio of O. evolans , leading to a dramatic reduction in native O. evolans offspring in the future.