38142-45-9Relevant academic research and scientific papers
Two new monoterpene glycosides and trypanocidal terpenoids from Dracocephalum kotschyi
Saeidnia, Soodabeh,Gohari, Ahmad Reza,Uchiyama, Nahoko,Ito, Michiho,Honda, Gisho,Kiuchi, Fumiyuki
, p. 1249 - 1250 (2004)
From the whole plant of Dracocephalum kotschyi BOISS., two new monoterpene glycosides (9, 10), together with seven known terpenoids and a phytosterol (1-8), were isolated. Their structures were determined to be limonen-10-al (1), geranial (2), neral (3), β-sitosterol (4), oleanolic acid (5), ursolic acid (6), p-mentha-8-en-1,2-diol (7), colosolic acid (8), limonen-10-ol 10-O-β-D-glucopyranoside (9), and limonen-10-ol 10-O-β-D- glucopyranosyl-(1→2)-β-D-glucopyranoside (10). Compounds 1 (3.1 μM), 2 (3.1 μM), 3 (3.1 μM), 5 (6.2 μM), 6 (6.2 μM), and 8 (6.2 μM) were effective against epimastigotes of Trypanosoma cruzi.
Stereoselective Synthesis of Limonene-Based Chiral 1,3-Amino Alcohols and Aminodiols
Le Minh, Tam,Fül?p, Ferenc,Szakonyi, Zsolt
, p. 6708 - 6713 (2017/12/07)
An unexpected ring-closing reaction of an α,β-unsaturated carboxylic acid, derived from (R)- and -(S)-limonene, in the presence of trifluoroacetic anhydride (TFAA) resulted in bicyclic α-methylene ketones and their hydroxylated analogues in a stereoselective intramolecular acylation reaction. The reaction was studied in detail, and was optimised for both compounds. The addition of secondary and primary amines to both keto alkenes followed by in-situ reduction of the resulting aminoketones with sodium borohydride gave new bicyclic terpenoid secondary and tertiary 1,3-amino alcohols and aminodiols with excellent diastereoselectivities. Regioisomeric aminodiols were prepared stereoselectively from the unsaturated 1,3-amino alcohols by hydroboration with Me2S·BH3/H2O2.
Engineering Rieske Non-Heme Iron Oxygenases for the Asymmetric Dihydroxylation of Alkenes
Gally, Christine,Nestl, Bettina M.,Hauer, Bernhard
supporting information, p. 12952 - 12956 (2015/11/02)
The asymmetric dihydroxylation of olefins is of special interest due to the facile transformation of the chiral diol products into valuable derivatives. Rieske non-heme iron oxygenases (ROs) represent promising biocatalysts for this reaction as they can be engineered to efficiently catalyze the selective mono- and dihydroxylation of various olefins. The introduction of a single point mutation improved selectivities (≥95 %) and conversions (>99 %) towards selected alkenes. By modifying the size of one active site amino acid side chain, we were able to modulate the regio- and stereoselectivity of these enzymes. For distinct substrates, mutants displayed altered regioselectivities or even favored opposite enantiomers compared to the wild-type ROs, offering a sustainable approach for the oxyfunctionalization of a wide variety of structurally different olefins. Modulation by mutation: Rieske non-heme iron oxygenases can be used as efficient biocatalysts for the selective oxyfunctionalization of various olefins yielding vicinal cis-diols and allylic alcohols. Introduction of a single amino acid substitution in the active sites of two selected oxygenases resulted in variants with improved stereoselectivities and product formations.
A chemoenzymatic, preparative synthesis of the isomeric forms of p-menth-1-en-9-ol: Application to the synthesis of the isomeric forms of the cooling agent 1-hydroxy-2,9-cineole
Serra, Stefano,Fuganti, Claudio,Gatti, Francesco G.
experimental part, p. 1031 - 1037 (2009/04/05)
A preparative-scale synthesis of the four p-menth-1-en-9-ol isomers 2a-5a has been achieved by means of two chemoenzymatic processes. Both synthetic pathways start from the enantiomeric forms of limonene that are converted into p-mentha-1,8-dien-9-al isomers 12 and 15. The baker's yeast mediated reduction of the latter aldehydes afforded compounds 3a and 5a, respectively, with very high enantioselectivity. Moreover, chemical reduction of 12 and 15 gives the mixtures of enantiopure diastereoisomers 2a/3a and 4a/5a, respectively. PPL (Porcine pancreas lipase) mediated resolution of the latter mixtures followed by fractionating crystallization of derivatives 2b-5b allowed the enantio- and diastereoisomerically pure alcohols 2a-5a to be obtained. Compounds 2a-5a have then been used as starting materials for the preparation of four isomers of the cooling agent 1-hydroxy-2,9-cineole (6-9). Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
9,10-Dihydroxy-1,8-cineole (1,3,3-Trimethyl-2-oxabicyclo[2.2.2]octane-10,11-diol)
Carman, Raymond M.,Handley, Paul N.
, p. 769 - 776 (2007/10/03)
The title compound (3) has been synthesized and its presence sought in the urinary metabolites of the brushtail possum.
The Synthesis of 9-Substituted p-Mentha-1,8(10)-diene Derivatives
Suemune, Hiroshi,Iwasaki, Genji,Ueno, Kohshi,Sakai, Kiyoshi
, p. 4632 - 4636 (2007/10/02)
The chemical conversion of (+)-limonene (1) and (-)-perillyl alcohol (10) into 9-substituted p-mentha-1,8(10)-diene derivatives is described.The lithiated species of 1 and 10 were easily obtained in good yields, by using sec-butyl lithium in N,N,N',N'-tetramethylethylenediamine.The reaction of the lithiated species (A and B) with various electrophiles was completed within 1-2h to give 9-substituted p-mentha-1,8(10)-diene derivatives.The stereochemistry of the chiral center of the starting material was retained in the products. 9-Hydroxy-p-mentha-1,8(10)-diene(8) was also obtained by another short sequence of steps.Oxidation of the phenylthio derivative (7) gave the sulfoxide (9).Treatment of 9 with trimethyl phosphite afforded 8.Keywords - synthesis; lithiation; limonene; perillyl alcohol; electrophile
