Rational design and efficient synthesis of a fluorescent-labeled jasmonate

A fluorescent-labeled jasmonate was rationally designed based on examination of the model of interaction between the jasmonate and its receptor. An efficient synthetic route has been developed for this molecule. The biological activity of this fluorescent probe was retained which was similar to that of the methyl jasmonate as examined by root growth inhibition bioassay. This fluorescent probe will greatly facilitate biological studies of jasmonates through fluorescent imaging.     

Direct observation of the target cell for jasmonate-type leaf-closing factor: genus-specific binding of leaf-movement factors to the plant motor cell

We report the synthesis of the novel fluorescence-labeled jasmonate glycoside 2 based on β-d-glucopyranosyl 12-hydroxyjasmonate 1, which is a leaf-closing substance of Albizzia julibrissin Durazz. The fluorescence study using 2 revealed that the target cell for 1 is a motor cell. Probe 2 bound to the motor cells of two plants belonging to genus Albizzia. This result suggested that a receptor for 2, which is common among genus Albizzia would be involved in the nyctinastic leaf movement.     

Further Explorations into the Synthesis of Dehydro‐Hedione®

Dehydrohedione (DHH) 1 may be obtained in 20% overall yield by a Reformatsky reaction with enone methyl ether 3b , followed by acidic workup of the crude reaction mixture. Alternatively, epoxidation (3‐chloroperbenzoic acid, CH₂Cl₂, 84% yield) of the tertiary allyl alcohol derivative 4 affords a 1 : 2 mixture of 8a and 8b . The latter epoxy ester 8b may also be obtained stereoselectively either from 4 (^tBuO₂H, [Mo(CO)₆], 1,2‐dichloroethane, 70°, 62% yield; or ^tBuO₂H, [VO(acac)₂], decane, 20°, 92% yield), or from 5 (AcOMe, LiN(SiMe₃)₂, THF, ?78°, 84–87%). BF₃?Et₂O‐Catalyzed cascade rearrangement and OH elimination of 8a afford selectively DHH 1 in 88% yield. The cis disposition of the side chains of the weakly odoriferous hedione‐like analogues 2b and 2c was maintained by means of either an epoxy or a cyclopropane moiety.     

Derivatives of benzothiadiazole-7-carboxylates: synthesis and biological activity

Salicylic acid (SA) and methyl jasmonate (MJ) are important plant signal molecules to cause systemic acquired resistance (SAR), while it’s reported that they also have wide spectrum antitumor activities. Benzothiadiazole-7-carboxylates are plant activators which can cause SAR just like SA and MJ. To investigate whether the benzothiadiazole-7-carboxylate family is endowed with anticancer activities, several benzothiadiazole-7-carboxylate derivatives are synthesized and their inhibition to P388 murine leukemia cell and A549 human lung cancer cell compared with MJ are evaluated. The data indicated that benzo-1,2,3-thiadiazole-7-carboxylic acid 2-benzoyloxyethyl ester has a higher inhibition ability to the cancer cell P388 and A549, compared with MJ. Correspondence: Yufang Xu, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China.     

An Expeditious Synthesis of Methyl Jasmonate

We present an efficient three‐step, two‐pot synthesis of methyl jasmonate (trans‐ 1 ) based on Diels–Alder cycloaddition of cyclopent‐2‐enone ( 2 ) and chloroprene (= 2‐chlorobuta‐1,3‐diene; 3d ) in either CHCl₃ or CH₂Cl₂, catalyzed by SnCl₄ (0.2 mol‐equiv.) at 20° (75% yield). Subsequent ozonolysis of a cis/trans 55 : 45 mixture of the cycloadduct 4d in either CH₂Cl₂ or AcOEt at ? 78°, followed by addition of Me₂S and MeOH in the presence of NaHCO₃, afforded, in 64% yield, a cis/trans 40 : 60 mixture of the known aldehyde 5c . The latter was reacted at ? 50° under salt‐free conditions with the propyl Wittig reactant to furnish 1 as a cis/trans 20 : 80 mixture ((E/Z) 3 : 97). Alternatively, a cis/trans 7 : 93 mixture ((E/Z) 4 : 96) was obtained in 88% yield from epimerized 5c (AcOH, H₂O, 40°; 99%) under usual Wittig conditions at ? 20°.