Tip growth is a common strategy for the rapid elongation of cells to forage the environment and/or to target to long-distance destinations. In the model tip growth system of Arabidopsis pollen tubes, several small- mo...Tip growth is a common strategy for the rapid elongation of cells to forage the environment and/or to target to long-distance destinations. In the model tip growth system of Arabidopsis pollen tubes, several small- molecule hormones regulate their elongation, but how these rapidly diffusing molecules control extremely localized growth remains mysterious. Here we show that the interconvertible salicylic acid （SA） and meth- ylated SA （MESA）, well characterized for their roles in plant defense, oppositely regulate Arabidopsis pollen tip growth with SA being inhibitory and MeSA stimulatory. The effect of SA and MeSA was independent of known NPR3/NPR4 SA receptor-mediated signaling pathways. SA inhibited clathrin-mediated endocytosis in pollen tubes associated with an increased accumulation of less stretchable demethylated pectin in the apical wall, whereas MeSA did the opposite. Furthermore, SA and MeSA alter the apical activation of ROP1 GTPase, a key regulator of tip growth in pollen tubes, in an opposite manner. Interestingly, both MeSA methylesterase and SA methyltransferase, which catalyze the interconversion between SA and MESA, are localized at the apical region of pollen tubes, indicating of the tip-localized production of SA and MeSA and consistent with their effects on the apical cellular activities. These findings suggest that local generation of a highly diffusible signal can regulate polarized cell growth, providing a novel mechanism of cell polarity control apart from the one involving protein and mRNA polarization.展开更多
目的三氟柳合成工艺的优选。方法通过试验考察不同酰化试剂、催化剂、反应温度、反应时间对合成工艺的影响。结果以乙酸酐为酰化试剂和多聚磷酸为催化剂在50℃下反应30 m in制得了高产率且高纯度的三氟柳。结论该工艺简单,易于控制,产率...目的三氟柳合成工艺的优选。方法通过试验考察不同酰化试剂、催化剂、反应温度、反应时间对合成工艺的影响。结果以乙酸酐为酰化试剂和多聚磷酸为催化剂在50℃下反应30 m in制得了高产率且高纯度的三氟柳。结论该工艺简单,易于控制,产率高,为89.5%。展开更多
Fluvoxamine maleate is an excellent antidepressive drug. In the literatures, it was synthesized by the use of 4-（trifluoromethyl） aniline or 4-（trifluoromethyl） benzonitrile as starting materials and 5-methoxy-4＇...Fluvoxamine maleate is an excellent antidepressive drug. In the literatures, it was synthesized by the use of 4-（trifluoromethyl） aniline or 4-（trifluoromethyl） benzonitrile as starting materials and 5-methoxy-4＇-（trifluoromethyl-phenyl） valerophenone as a key intermediate. However, the methods in literatures have some disadvantages, such as the use of expensive materials, heavy pollution of environment, long reaction time and low yield of the product （only 30-40% overall yield）. We herein report an environmentally friendly synthetic method of fluvoxamine maleate, which used 4-（trifluoromethyl） benzoic acid and tetrahydrofuran as starting materials and FeCI3 as catalyst for the coupling of acid chloride with Grignard reagent. The fluvoxamine maleate was synthesized in 46% overall yield, through the oximation, etheration and salification of the intermediate successively.This method has some advantages, such as the use of commercially available materials, low cost, short production period （12-14 h）, high yield and light pollution.展开更多
文摘Tip growth is a common strategy for the rapid elongation of cells to forage the environment and/or to target to long-distance destinations. In the model tip growth system of Arabidopsis pollen tubes, several small- molecule hormones regulate their elongation, but how these rapidly diffusing molecules control extremely localized growth remains mysterious. Here we show that the interconvertible salicylic acid （SA） and meth- ylated SA （MESA）, well characterized for their roles in plant defense, oppositely regulate Arabidopsis pollen tip growth with SA being inhibitory and MeSA stimulatory. The effect of SA and MeSA was independent of known NPR3/NPR4 SA receptor-mediated signaling pathways. SA inhibited clathrin-mediated endocytosis in pollen tubes associated with an increased accumulation of less stretchable demethylated pectin in the apical wall, whereas MeSA did the opposite. Furthermore, SA and MeSA alter the apical activation of ROP1 GTPase, a key regulator of tip growth in pollen tubes, in an opposite manner. Interestingly, both MeSA methylesterase and SA methyltransferase, which catalyze the interconversion between SA and MESA, are localized at the apical region of pollen tubes, indicating of the tip-localized production of SA and MeSA and consistent with their effects on the apical cellular activities. These findings suggest that local generation of a highly diffusible signal can regulate polarized cell growth, providing a novel mechanism of cell polarity control apart from the one involving protein and mRNA polarization.
文摘Fluvoxamine maleate is an excellent antidepressive drug. In the literatures, it was synthesized by the use of 4-（trifluoromethyl） aniline or 4-（trifluoromethyl） benzonitrile as starting materials and 5-methoxy-4＇-（trifluoromethyl-phenyl） valerophenone as a key intermediate. However, the methods in literatures have some disadvantages, such as the use of expensive materials, heavy pollution of environment, long reaction time and low yield of the product （only 30-40% overall yield）. We herein report an environmentally friendly synthetic method of fluvoxamine maleate, which used 4-（trifluoromethyl） benzoic acid and tetrahydrofuran as starting materials and FeCI3 as catalyst for the coupling of acid chloride with Grignard reagent. The fluvoxamine maleate was synthesized in 46% overall yield, through the oximation, etheration and salification of the intermediate successively.This method has some advantages, such as the use of commercially available materials, low cost, short production period （12-14 h）, high yield and light pollution.
