Mating Behavior of Rosalia batesi (Coleoptera: Cerambycidae) Is Mediated by Male-Produced Sex Pheromones.

Rosalia batesi Harold (Cerambycidae) is a hardwood boring species endemic to Japan. We investigated the adult mating behavior of this species in the field and laboratory. Most males appeared on mating sites before noon, significantly earlier than females did, in field observations. The female approached and contacted the male; the male responded and started the successive mating sequence, comprising mounting, copulation, and appeasement behavior. Before the encounter, the male raised its fore and mid legs and bent the abdominal tip ventrally. Next, a peculiarly structured bifurcate tip was exposed with opening and closing motion, which can be observed in the entire family Cerambycidae and is thought to be associated with the emission of volatile male sex pheromones. Male and female orientation toward conspecifics was examined using T-shaped olfactometers in four combinations (male⁻male, female⁻male, female⁻female, male⁻female). Males exclusively attracted females, indicating the existence of male-produced sex pheromones. A laboratory bioassay with three temperature regimes revealed the temperature dependence of this calling behavior. The calling behavior occurred only when the air temperature and male body surface temperature, which are associated with light intensity, were within the range of 26⁻33 °C and 26⁻28 °C, respectively.

New isomeric azine-bridged dinuclear platinum(II) complexes circumvent cross-resistance to cisplatin.

Four new isomeric azine-bridged complexes ([(cis-Pt(NH(3))(2)Cl)(2)(mu-pzn)]Cl(2) (1a) (pzn = pyrazine) and its corresponding nitrate salt (1b), [(cis-Pt(NH(3))(2)Cl)(2)(mu-pmn)]Cl(2) (2) (pmn = pyrimidine), and [(cis-Pt(NH(3))(2)Cl)(2)(mu-pdn)](NO(3))(2) (3) (pdn = pyridazine) have been newly synthesized as potential anticancer compounds. These complexes have been characterized by (1)H and (195)Pt NMR spectroscopy, and also the X-ray crystal structure of 1b has been determined. The reactions of 1a, 2, and 3 with guanosine-5'-monophosphate (GMP) have been monitored and kinetically investigated in D(2)O solutions at 310 K using (1)H NMR spectroscopy. Both 1a and 2 react with 2 equiv of GMP to form 1:2 complexes. The reactions involve a stepwise direct substitution of chloride ligands by GMP, with similar reaction rates for both complexes. On the other hand, the reaction of 3 with GMP results in the cleavage of one of the Pt-N(pyridazine) bonds to form an N7,O6-platinated polymer. The reaction products have been separated and have been characterized by (1)H and (195)Pt NMR spectroscopy. A cytotoxicity assay of the azine-bridged complexes (1a, 1b, 2, and 3) has been performed on human tumor cell lines and two L1210 murine leukemia cell lines (one sensitive to and one resistant to cisplatin). In general, the complexes show lower cytotoxicity than cisplatin for the human tumor cell lines except for the IGROV cell line. Their cytotoxicity for the mouse cell lines is comparable to or higher than that of cisplatin. Furthermore, these complexes appeared to largely or partly overcome the cross-resistance to cisplatin. Implications of these findings are discussed in the context of a structure-activity relationship for this class of compounds.

A novel isomerization on interaction of antitumor-active azole-bridged dinuclear platinum(II) complexes with 9-ethylguanine. Platinum(II) atom migration from N2 to N3 on 1,2,3-triazole.

The reactions of the dinuclear platinum(II) complexes, [[cis-Pt(NH(3))(2)](2)(mu-OH)(mu-pz)](NO(3))(2) (1, pz = pyrazolate), [[cis-Pt(NH(3))(2)](2)(mu-OH)(mu-1,2,3-ta-N1,N2)](NO(3))(2) (2, 1,2,3-ta = 1,2,3-triazolate), and a newly prepared [[cis-Pt(NH(3))(2)](2)(mu-OH)(mu-4-phe-1,2,3-ta-N1,N2)](NO(3))(2) (3, 4-phe-1,2,3-ta = 4-phenyl-1,2,3-triazolate), whose crystal structure was determined, with 9-ethylguanine (9EtG) have been monitored in aqueous solution at 310 K by means of (1)H NMR spectroscopy. The dinuclear platinum(II) complexes 1-3 each react with 9EtG in a bifunctional way to form 1:2 complexes, [[cis-Pt(NH(3))(2)(9EtG-N7)](2)(mu-pz)](3+) (4), [[cis-Pt(NH(3))(2)(9EtG-N7)](2)(mu-1,2,3-ta-N1,N3)](3+) (5), and [[cis-Pt(NH(3))(2)(9EtG-N7)](2)(mu-4-phe-1,2,3-ta-N1,N3)](3+) (6). The reactions of 2 and 3 involve a novel isomerization, in which the Pt atom, initially bound to N2 on the 1,2,3-ta, migrates to N3 after the first substitution by N7 of 9EtG. This isomerization reaction has been unambiguously characterized by 1D and 2D NMR spectroscopy and pH titration. The reactions of 2 and 3 with 9EtG show faster kinetics, and the second-order rate constants (k) for the reactions of 1-3are 1.57 x 10(-4), 2.53 x 10(-4), and 2.56 x 10(-4) M(-1) s(-1), respectively. The pK(a) values at the N1H site of 9EtG were determined for 4-6 from the pH titration curves. Cytotoxicity assays of 1-3 were performed in L1210 murine leukemia cell lines, respectively sensitive and resistant to cisplatin. In the parent cell line, 2 and 3 exhibit higher cytotoxicity compared to cisplatin, especially, 2 is 10 times as active as cisplatin. 1 was found to be less cytotoxic than cisplatin, but still in the active range and more active than cisplatin in a cisplatin-resistant cell line.