555-10-2Relevant academic research and scientific papers
Primary attraction of the fir engraver, Scolytus ventralis
MacIas-Samano,Borden,Gries,Pierce Jr.,Gries,King
, p. 1049 - 1075 (1998)
In laboratory bioassays, Porapak Q-captured and steam-distilled volatiles from the bark of host trees, Abies grandis, particularly from rootrot-infected trees, attracted 50-70% of male and female fir engravers, Scolytus ventralis. Gas chromatographic-elec
Total syntheses of (+)-adunctins C and D: Assignment of their absolute configurations
Luo, Gan,Peng, Yu,Wang, Ya-Wen,Xiao, Jian,Zhao, Jun
, p. 9840 - 9843 (2021/12/07)
The first total synthesis of (+)-adunctin C (ent-1) and (+)-adunctin D (2), two monoterpene-substitued dihydrochalcones isolated from Piper aduncum (Piperaceae), was achieved. A regioselective oxidative [3 + 2] cycloaddition of acylphloroglucinol with (-)-β-phellandrene was developed to construct their unique spirobenzofuran skeleton. The absolute configurations of natural adunctins 1 and 2 were thus assigned through these endeavors. This journal is
Preparation method of spirobenzofuran compounds
-
Paragraph 0009; 0032-0034, (2020/11/12)
The invention discloses a preparation method of spirobenzofuran compounds. The method comprises the steps: taking commercially available phloroglucinol and 4-isopropyl cyclohexanone as raw materials;dihydrochalcone and beta-phellandrene with an extracyclic double bond are respectively synthesized through a Friedel-Crafts reaction and a Wittig reaction; after two fragment compounds of the hydrochalcone and the beta-phellandrene are obtained, with oxidized cycloaddition reactions, connecting the two fragment compounds, constructing a spirobenzofuran core skeleton, and thus preparing natural products adunctin C and adunctin D. According to the invention, an organic chemical synthesis means is adopted, synthesis of the target natural products adunctin C and adunctin D is used as guidance, anda new method for constructing the structural units is developed; meanwhile, the method is applied to synthesis and preparation of the natural products adunctin C and D with important physiological and pharmacological activities, the preparation yield is high, the cost is low, and the limitation of sources of the natural products is greatly broken through.
Converting S-limonene synthase to pinene or phellandrene synthases reveals the plasticity of the active site
Xu, Jinkun,Ai, Ying,Wang, Jianhui,Xu, Jingwei,Zhang, Yongkang,Yang, Dong
, p. 34 - 41 (2017/03/27)
S-limonene synthase is a model monoterpene synthase that cyclizes geranyl pyrophosphate (GPP) to form S-limonene. It is a relatively specific enzyme as the majority of its products are composed of limonene. In this study, we converted it to pinene or phellandrene synthases after introducing N345A/L423A/S454A or N345I mutations. Further studies on N345 suggest the polarity of this residue plays a critical role in limonene production by stabilizing the terpinyl cation intermediate. If it is mutated to a non-polar residue, further cyclization or hydride shifts occurs so the carbocation migrates towards the pyrophosphate, leading to the production of pinene or phellandrene. On the other hand, mutant enzymes that still possess a polar residue at this position produce limonene as the major product. N345 is not the only polar residue that may stabilize the terpinyl cation because it is not strictly conserved among limonene synthases across species and there are also several other polar residues in this area. These residues could form a “polar pocket” that may collectively play this stabilizing role. Our study provides important insights into the catalytic mechanism of limonene synthases. Furthermore, it also has wider implications on the evolution of terpene synthases.
Novel route to a fruitful mixture of terpene fragrances in particular phellandrene starting from natural feedstock geraniol using weak acidic boron based catalyst
Eisenacher, Matthias,Beschnitt, Stefan,H?lderich, Wolfgang
experimental part, p. 214 - 217 (2012/09/08)
Myrcene, ocimene and in particular phellandrene were selectively generated as products by dehydration of the natural feedstock geraniol over a weak acidic boron pentasil zeolite catalyst in a gas phase reaction. Additionally linalool was formed by rearrangement reaction. The total selectivity of these 4 terpenes is up to 99%.
Conjugated dienes as prohaptens in contact allergy: In vivo and in vitro studies of structure-activity relationships, sensitizing capacity, and metabolic activation
Bergstroem, Moa Andresen,Luthman, Kristina,Nilsson, J. Lars G.,Karlberg, Ann-Therese
, p. 760 - 769 (2007/10/03)
There is a great interest in developing in vitro/in silico methods for the prediction of contact allergenic activity. However, many proposed methods do not take the activation of prohaptens to sensitizers by skin metabolism into account. As a consequence, consumer products containing potent sensitizers could be marketed. To identify prohaptens, studies regarding their structure-activity relationships and the mechanisms of their activation must be conducted. In the present investigation, we have studied the structure-activity relationships for alkene prohaptens. A series of seven alkenes (1-7), all of the same basic structure but with variation in the number and position(s) of the double bond(s), were designed and screened for sensitizing capacity using the murine local lymph node assay. Compounds 1-7 were also incubated with liver microsomes in the presence of glutathione to trap and identify reactive metabolites. The metabolic conversion of three alkenes (9-11) to epoxides (12-15) was also studied along with comparison of their sensitizing capacity. Our results show that conjugated dienes in or in conjunction with a six-membered ring are prohaptens that can be metabolically activated to epoxides and conjugated with GSH. Related alkenes containing isolated double bonds and an acyclic conjugated diene were shown to be weak or nonsensitizers. For the first time, the naturally occurring monoterpenes α-phellandrene, β-phellandrene, and α-terpinene were demonstrated to be prohaptens able to induce contact allergy. The difference in sensitizing capacity of conjugated dienes as compared to alkenes with isolated double bonds was found to be due to the high reactivity and sensitizing capacity of the allylic epoxides metabolically formed from conjugated dienes. We recommend that these structure-activity relationship rules are incorporated into in silico predictive databases and propose that the prediction of contact allergenic activity of suspected prohaptens is based on assessment of susceptibility to metabolic activation and chemical reactivity of potential metabolites.
The reaction of cyclic allylic alcohols with aliphatic alcohols in the presence of cerium(III) chloride
Uzarewicz,Dresler
, p. 181 - 195 (2007/10/03)
Cyclic secondary and tertiary allylic alcohols react with primary aliphatic alcohols in the presence of cerium(III) chloride heptahydrate to give alkyl allylic ethers. When secondary or tertiary aliphatic alcohols are used 1,3-dienes are obtained from allylic alcohols heaving the 3-methyl-2-en-1-ol moiety (3-8, 13-15).
Thermodynamics of the Isomerisation of the p-Menthadienes and the Additivity of the Properties of Cyclic Hydrocarbons
Kabo, G. Ya.,Roganov, G. N.,Filippenko, Z. A.
, p. 1521 - 1522 (2007/10/02)
We have studied the equilibria and obtained the thermodynamic parameters for the isomerisation of nine p-menthadienes in the range 225-350 deg C.An approach has been proposed and shown to be effective for the additive calculation of the properties of aliphatic hydrocarbons: this is based on the introduction of additional effective characteristics for an atom which take into account its participation in the ring system of the molecule.
ISOMERIZATION EQUILIBRIUM OF THE p-MENTHADIENES IN THE VAPOR PHASE
Filippenko, Z. A.,Baranov, O. M.,Roganov, G. N.,Kabo, G. Ya.
, p. 47 - 51 (2007/10/02)
The isomerization equilibrium between nine p-menthadienes has been studied in the vapor phase at 250 deg C and their equilibrium ratios have been determined.A method for the quantitative GLC analysis of mixtures of isomeric p-menthadienes has been developed.
Preparation of β-phellandrene
-
, (2008/06/13)
β-Phellandrene is prepared by pyrolyzing a para-menth-1-ene-7-sulfonate salt.
