118495-99-1Relevant academic research and scientific papers
Chemical identification of 18-hydroxycarlactonoic acid as an LjMAX1 product and in planta conversion of its methyl ester to canonical and non-canonical strigolactones in Lotus japonicus
Akiyama, Kohki,Asami, Kei,Mori, Narumi,Nomura, Takahito,Sado, Aika,Seto, Yoshiya,Xie, Xiaonan,Yamaguchi, Shinjiro,Yoneyama, Kaori,Yoneyama, Koichi
, (2020)
Strigolactones (SLs) are a group of plant apocarotenoids that act as rhizosphere signaling molecules for both arbuscular mycorrhizal fungi and root parasitic plants. They also regulate plant architecture as phytohormones. The model legume Lotus japonicus (synonym of Lotus corniculatus) produces canonical 5-deoxystrigol (5DS) and non-canonical lotuslactone (LL). The biosynthesis pathways of the two SLs remain elusive. In this study, we characterized the L. japonicus MAX1 homolog, LjMAX1, found in the Lotus japonicus genome assembly build 2.5. The L. japonicus max1 LORE1 insertion mutant was deficient in 5DS and LL production. A recombinant LjMAX1 protein expressed in yeast microsomes converted carlactone (CL) to 18-hydroxycarlactonoic acid (18-OH-CLA) via carlactonoic acid (CLA). Identity of 18-OH-CLA was confirmed by comparison of the methyl ester derivative of the MAX1 product with chemically synthesized methyl 18-hydroycarlactonoate (18-OH-MeCLA) using LC-MS/MS. (11R)-CL was detected as an endogenous compound in the root of L. japonicus. 13C-labeled CL, CLA, and 18-OH-MeCLA were converted to [13C]-5DS and LL in plant feeding experiments using L. japonicus WT. These results showed that LjMAX1 is the crucial enzyme in the biosynthesis of Lotus SLs and that 18-hydroxylated carlactonoates are possible precursors for SL biosynthesis in L. japonicus.
Asymmetric Total Synthesis of Sarpagine and Koumine Alkaloids
He, Ling,Jiang, Yan,Qiao, Zhen,Qiu, Hanyue,Su, Xiaojiao,Tan, Qiuyuan,Yang, Jiaojiao,Yang, Zhao,Zhang, Min,Zhou, Wenqiang
supporting information, p. 13105 - 13111 (2021/05/10)
We report here a concise, collective, and asymmetric total synthesis of sarpagine alkaloids and biogenetically related koumine alkaloids, which structurally feature a rigid cage scaffold, with L-tryptophan as the starting material. Two key bridged skeleton-forming reactions, namely tandem sequential oxidative cyclopropanol ring-opening cyclization and ketone α-allenylation, ensure concurrent assembly of the caged sarpagine scaffold and installation of requisite derivative handles. With a common caged intermediate as the branch point, by taking advantage of ketone and allene groups therein, total synthesis of five sarpagine alkaloids (affinisine, normacusine B, trinervine, Na-methyl-16-epipericyclivine, and vellosimine) with various substituents and three koumine alkaloids (koumine, koumimine, and N-demethylkoumine) with more complex cage scaffolds has been accomplished.
Formal synthesis of actinoranone using a one-pot semipinacol rearrangement/Wittig reaction
Menger, Martina,Christmann, Mathias
, p. 10 - 16 (2018/11/30)
Here, we report a formal synthesis of the marine cytotoxic meroterpenoid actinoranone. Key steps include a semipinacol rearrangement/Wittig reaction sequence and a chiral pool approach for the syntheses of the tetralone and the ocatalin fragments, respectively. The presented route provides access to the natural product in 14 steps in the longest linear sequence.
Carlactone-type strigolactones and their synthetic analogues as inducers of hyphal branching in arbuscular mycorrhizal fungi
Mori, Narumi,Nishiuma, Kenta,Sugiyama, Takuya,Hayashi, Hideo,Akiyama, Kohki
, p. 90 - 98 (2016/11/23)
Hyphal branching in the vicinity of host roots is a host recognition response of arbuscular mycorrhizal fungi. This morphological event is elicited by strigolactones. Strigolactones are carotenoid-derived terpenoids that are synthesized from carlactone and its oxidized derivatives. To test the possibility that carlactone and its oxidized derivatives might act as host-derived precolonization signals in arbuscular mycorrhizal symbiosis, carlactone, carlactonoic acid, and methyl carlactonoate as well as monohydroxycarlactones, 4-, 18-, and 19-hydroxycarlactones, were synthesized chemically and evaluated for hyphal branching-inducing activity in germinating spores of the arbuscular mycorrhizal fungus Gigaspora margarita. Hyphal branching activity was found to correlate with the degree of oxidation at C-19 methyl. Carlactone was only weakly active (100?ng/disc), whereas carlactonoic acid showed comparable activity to the natural canonical strigolactones such as strigol and sorgomol (100?pg/disc). Hydroxylation at either C-4 or C-18 did not significantly affect the activity. A series of carlactone analogues, named AD ester and AA'D diester, was synthesized by reacting formyl Meldrum's acid with benzyl, cyclohexylmethyl, and cyclogeranyl alcohols (the A-ring part), followed by coupling of the potassium enolates of the resulting formylacetic esters with the D-ring butenolide. AD ester analogues exhibited moderate activity (1?ng–100?pg/disc), while AA'D diester analogues having cyclohexylmethyl and cyclogeranyl groups were highly active on the AM fungus (10?pg/disc). These results indicate that the oxidation of methyl to carboxyl at C-19 in carlactone is a prerequisite but BC-ring formation is not essential to show hyphal branching activity comparable to that of canonical strigolactones.
Synthesis toward the lindenane-type sesquiterpenoid monomer of Chlorahololide A
Zhang, Haizhen,Nan, Fajun
, p. 84 - 92 (2013/08/24)
An investigation toward the synthesis of the lindenane-type sesquiterpenoid monomer of Chlorahololide A using a Yamamoto rearrangement, intramolecular cyclopropanation reaction, 1,3-dipolar cyclization, and an intramolecular Heck reaction gave the pivotal intermediate 20. This gives a practical synthetic route that could generate further natural products of the Chloranthaceae family. Starting from alcohol (2), and on the basis of Yamamoto rearrangement, intramolecular cyclopropanation reaction, 1,3-dipolar cyclization, and intramolecular Heck reaction, the Lindenane-type sesquiterpenoid fragement (20) of Chlorahololide A (1) has been synthesized in a linear sequence of 21 steps and an overall yield of 1.8%. The flexible synthetic route could generate further natural products of the Chloranthaceae family. Copyright
On the Mechanism of Organoaluminum-Promoted Claisen Rearrangement of Allylic Vinyl Ethers
Nonoshita, Katsumasa,Maruoka, Keiji,Yamamoto, Hisashi
, p. 541 - 545 (2007/10/02)
The organoaluminum-promoted Claisen rearrangement of allylic vinyl ethers has been mechanistically studied by two sets of experiments and the observed Z and E selectivity is best accounted for by two possible chair-like structures with R substituents axial and equatorial, respectively.
Organoaluiminum-promoted claisen rearrangement of allyl vinyl ethers
Nonshita, Katsumasa,Banno, Hiroshi,Maruoka, Keiji,Yamamoto, Hishashi
, p. 316 - 322 (2007/10/02)
Unprecedentad stereochemical control has achieved in the Claisen of allyl vinyl of type 4 with certain bulky organoaluminum Thus, methylaluminum bis(4-bromo-2,6-di-tert-butylphenoxide) (reagent A) can be utilized for obtaining the (Z) isomer, (Z)-6, whereas the (E) isomer, (E)-6 was produced with methylaluminum bis(2,6-diphenylphenoxide) (reagent B). This organoaluminum-promoted Claisen rearrangement proceeds under very mild conditions with very good E and Z selectlvities. On the basis of the Claisen rearrangement of optically active substrate 7 with reagent A, the Z selectivity would be interpreted by the intervention of the chairlike transition-state conformation with the isobutyl substituent axial. The present organoalunminum-promoted Claisen rearrangement has successfully applied to the synthesis of (4E,7Z)-4,7-tridecadienyl acetate (15), a component of the sex of tuberworm moth, in stereoselective fashion. Furthermore, the Claisen rearrangement of bisallyl vinyi ether16 with reagent A or B has been found to involve the more substituted allylic system to furnish dienal 18 preferentially, not obtainable in the ordinary thermal rearrangement. This chemistry been further extended to the ionic rearrangement of dienyl vinyl ether 28 by using reagent A in a polar solvent the previously unknown, remote transfer of the vinyloxy moiety by [3,5]-sigmatropic rearrangement via ionic intermediate 29 has observed.
