The synergic effect of iron plus blue light on the peroxidation of membrane lipid was investigated, using liposomes made of phospholipid. While strong irradiation did not affect Fe$^{+2}$-promoted lipid peroxidation that turned out to be O$_2$-dependent, ferric iron in bright light exerted a pronounced effect on the initiation of lipid peroxidation: this combined action of light and Fe$^{+3}$ on liposomal membranes was apparently independent of O$_2$. When liposomal samples containing Fe$^{+3}$ were subjected to irradiation, some portions of Fe$^{+3}$ were converted into Fe$^{+2}$. The extent of the Fe$^{+3}$-Fe$^{+2}$ conversion increased with increasing time of irradiation, which resembled the dependence of Fe$^{+3}$-promoted lipid peroxidation on irradiation. Further, it was observed that the effect of irradiation in liposomal samples containing Fe$^{+2}$ was strikingly mimicked by that of Fe$^{+2}$ addition to the same samples. The obligatory requirement of a suitable Fe$^{+3}$/Fe$^{+2}$ ratio for the genesis of iron-dependent lipid peroxidation, a controversial proposition, was also confirmed by the observation that lipid peroxidation was substantially enhanced by the addition of a mixture of Fe$^{+3}$ and Fe$^{+2}$, as compared to the addition of Fe$^{+3}$ or Fe$^{+2}$ alone. The results obtained in this study not only suggest that light acts as an effector for initiating lipid peroxidation, when Fe$^{+3}$ is present in membrane systems, but also imply that any chemical or physical factor that influences the redox states of iron in membranes can play a role in lipid peroxidation reactions.

The reaction of decaborane with trimethylsilyldiazomethane gives 1, 2-bis (trimethylsilyl)-1, 2-carba-closo-dodecaborane(12). This compound is similar to the icosahedral cage structure of o-carborane. This formation of the first adduct proceeds through deprotonation of the acidic center of B(9) and B(6) by intermolecular attack by the lone electron pair of the carbene, : CHSiMe$_3$. The yield of product is influenced by irradiation and thermal conditions.

Experiments were carried out to investigate whether P, deficiency in detached 25 mM mannose-feeding led to a decline of the photosynthetic electron transport rates through acidification of the thylakoid lumen. With increasing mannose-feeding time, the maximal CO2 exchange rates and the maximal quantum yields of photosynthesis decreased rapidly up to 6 h by 73% then with little decrease up to 12 h. The ATP/ADP ratio declined by 54% 6 h after the treatment and then recovered to the control level at 12 h. However, the NADPH/NADP~ ratio was not significantly altered by mannose treatment. Electron transport rates of thylakoid membranes isolated from 6 h treated leaves did not change, but they decreased by 30% in 12 h treated leaves. The quenching analysis of Chl fluorescence in mannose-treated leaves revealed that both the fraction of reduced plastoquinone and the degree of acidification of thylakoid lumen remained higher than those of the control. The reduction of PSI in mannose fed leaves was inhibited due to acidification of thylakoid lumen (high qE). The reduction of primary quinone acceptor of PSII was inhibited by mannose feeding. Mannose treatment decreased the efficiency of excitation energy capture by PSII. Fo quenching was induced when treated with mannose more than 6 h, and had a reverse linear correlation with (Fv)m/Fm ratio. These results suggest that Pi deficiency in Chinese cabbage leaves reduce photosynthetic electron transport rates by diminishing both PSII function and electron transfer from PSII to PSI through acidification ofthylakoid lumen, which in turn induce the modification of photosynthetic apparatus probably through protein (de)phosphorylation.

Photocatalytic ($\lambda$$_{ex}$ > 300 nm) reaction at room temperature by platinized titanium (IV) oxide particles produced 1-methyl-1, 2, 3, 4-tetrahydroisoquinolines (MIQ's) from phenethylamines in aqueous ethanol suspension under deaerated atmosphere. Among the phenethylamines, dopamine (2-(3, 4-dihydroxyphenyl) ethylamine) showed the highest reactivity to give MIQ almost selectively under the neutralized conditions. The other phenethylamines gave predominantly N-alkylated and N, N-dialkylated products in the methanol or ethanol solutions. The reaction mechanism includes a Schiff base intermediate to undergo either nucleophilic attack leading to MIQ or reduction to N-alkylated products.

The quantum yields of fluorescence ($\Phi$$_f$) and trans $\to$ cis photoisomerization ($\Phi$$_{t$\to$ c}$), trans-4-(2-(9-anthryl)vinyl)pyridine, an aza analogue of 1-(9-anthryl)-2-phenylethylene, were measured in several solvents at room temperature. $\Phi$$_f$ and $\Phi$$_{t$\to$ c}$ are 0.38 and < 0.01 in hexane and 0.02 and 0.38 in acetonitrile, respectively. As solvent polarity decreases, $\Phi$$_{t$\to$ c}$ strongly reduced, whereas $\Phi$$_f$ strongly increased. A singlet mechanism of trans $\to$ cis photoisomerization is suggested since $\Phi$$_{t$\to$ c}$ and $\Phi$$_f$ change in opposite direction.

$PdCI_2(PPh_3)_2$-catalyzed photolysis of 1-phenyl-4-(pentamethyldisilanyl)buta-1,3-diyne (1) in dry benzene gives 1,4-disilacyclohexa-2,5-diene type dimerization products(3-6) via silacyclopropene. The silacyclopropene is formed from the singlet excited state of 1 and this silacyclopropene reacts with $(PPh_3)_2Pd^0$to form palladasilacyclobutene. In this reaction, the silylene-palladium complex is generated and reacts with 1 to give another silacyclopropene. $PdCI_2(PPh_3)_2$catalyzed photolysis of 1 with other alkynes supports the involvement of this silylene complex.

Irradiation of aromatic $\alpha$-diketones, such as benzil, 4,4'-dimethylbenzil, 4-chlorobenzil, 4,4'-diisopropylbenzil, 3,3,'-dimethylbenzil, in methanol gives rise to xanthone derivatives, in addition to $\alpha$-hydroxyketones. Irradiation of 4,4'-dibromobenzil, 2,2'-pyridil, 2,2'-naphthil and 9,9'-anthril yields only $\alpha$-hydroxyketones, whereas 4,4'-dimethoxybenzil yields methyl 4-methoxybenzoate.

Singlet oxygen-mediated photooxidation and subsequent triplet oxygen insertion of 11-hydro-13-(methyloxy)carbonylartemisinate (4) yielded a diketo compound 5 as the major product instead of the expected 11-hydro-13-(methyloxy)carbonylartemisinin (6). The formation of the unexpected product was in part consistent with the mechanism proposed by Acton and Roth and is the first isolation of the diketo compound from the photooxidation of artemisinate.

Optical spectra of 5-amino-2H-1, 2, 4-thiadiazoline-3-one (AT) and some 2-aroyl-5-aroylamino derivatives are reported. Absorption spectra of 2-aroyl-5-aroylamino derivatives show bathochromic shift due to AT group and other substituents of phenyi ring. Weak emission is observed for some derivatives.

Elevated near-UV radiation, containing a large amount of UV-B and a small amount of UV-C, inhibited the development of leaves and tillers, the increase in biomass production, the elongation of plant height, the photosynthetic rate and the chlorophyll content in rice plants in a phytotron. Elevated UV-B radiation filtered through cellulose diacetate film or UV-31 cut filter (transmission down to 290 nm) similarly suppressed each growth component above. Near-UV radiation-caused injuries were alleviated either by elevated CO$_2$ atmosphere or by exposure to high irradiance-visible radiation. On the basis of these findings, we examined cultivar differences in the resistance to UV radiation-caused injuries among 198 rice cultivars belonging to 5 Asian rice ecotypes ( aus, aman, boro, bulu and tjeleh) from the Bengal region and Indonesia and to Japanese lowland and upland rice groups. It was shown that .various cultivars having different sensitivities to the effects of near-UV radiation were involved in the same ecotype and the same group, and that the Japanese lowland rice group and the boro ecotype were more resistant. Among Japanese lowland rice cultivars, Sasanishiki (one of the leading varieties in Japan) exhibited more resistance to near-UV radiation, while Norin 1 showed less resistance, although these two cultivars are closely related. It was thus indicated that the resistance to the inhibitory effects of near-UV radiation of rice cultivars is not simply due to the difference in the geographical situation where rice cultivars are cultivated. From the genetic analysis of resistance to the inhibitory effects of UV radiation on growth of rice using F$_2$ plants generated by reciprocally crossing Sasanishiki and Norin 1 and F$_3$ lines generated by self-fertilizing F$_2$ plants, it was evident that the resistance to the inhibitory effects of elevated near-UV radiation in these rice plants was controlled by recessive polygenes.