ABSTRACT
Both enantiomers of lavandulol (1), an important constituent of lavender oil, were prepared by enzymatic optical resolution, and the odor quality of the single antipodes were evaluated. The fragrance of the nature-identical (R)-enantiomer ('weak floral, herbal odor with slightly lemon-like, fresh citrus fruity nuance') was superior to those of both the unnatural (S)-enantiomer ('very weak odor') and the racemate ('weak floral, herbal odor').
Subject(s)
Enzymes/metabolism , Monoterpenes/chemistry , Monoterpenes/metabolism , Odorants/analysis , Oils, Volatile/chemistry , Plant Oils/chemistry , Acyclic Monoterpenes , Lavandula , Molecular Structure , StereoisomerismABSTRACT
Enacyloxin IIa methyl ester in non-protic solvent gave rearranged product in acidic conditions such as surface of TLC plate of silica gel or by treatment with a catalytic amount of p-toluenesulfonic acid. On the other hand, such a rearrangement did not occur in polar protic solvent. The structure of the rearranged product was elucidated as 4-acyl analog of the cyclohexane ring.
Subject(s)
Polyenes/chemistry , Chromatography, Thin Layer , SolventsABSTRACT
[structure: see text] A convergent total synthesis of cis-solamin and its diastereomer was accomplished using VO(acac)2-catalyzed diastereoselective epoxidation followed by cyclization of bis-homoallylic alcohol as the key step. By comparison of the optical rotation of two possible diastereomers, it is suggested that the absolute configuration of natural cis-solamin is 1a.
Subject(s)
Annonaceae/chemistry , Benzethonium/chemical synthesis , Cyclization , Epoxy Compounds/chemical synthesis , Indicators and Reagents , Magnetic Resonance Spectroscopy , Optical Rotation , StereoisomerismABSTRACT
To investigate the transformation from (2E,6E)-farnesyl pyrophosphate to (2Z,4E)-γ-ionylideneethanol in the abscisic acid-producing fungi, Cercospora cruenta, plausible [2-14C]-C15 intermediates were prepared and fed. Substrates such as (2E,6E)-farnesyl pyrophosphate, (2Z,4E)-γ-ionylideneethanol and its pyrophosphate were incorporated into ABA and its known biosynthetic precursors. It is suggested that (2E,6E>farnesyl pyrophosphate is converted to (2Z,4E)-γ-ionylideneethanol in four consecutive steps: dehydrogenation, isomerization, cyclization and hydrolysis.
ABSTRACT
This review describes research on the chemistry (biosynthesis, metabolism and synthetic analogs) of a plant hormone, abscisic acid (ABA), covering 1970 to 2002 with 123 references
Subject(s)
Abscisic Acid , Plant Growth Regulators , Abscisic Acid/biosynthesis , Abscisic Acid/chemistry , Abscisic Acid/metabolism , Carotenoids/chemistry , Carotenoids/metabolism , Molecular Structure , Plant Growth Regulators/biosynthesis , Plant Growth Regulators/chemistry , Plant Growth Regulators/metabolism , Plants/chemistry , Plants/genetics , Plants/metabolism , Structure-Activity RelationshipABSTRACT
A new drimane sesquiterpenoid was isolated from the heartwood of the Japanese yew, Taxus cuspidata Sieb. et Zucc. Its structure was established as 1beta-acetoxyisodrimeninol (1beta-acetoxy-11,12-epoxy-7-drimen-11-ol, 1). This compound was gradually oxidized to give y-lactone (1beta-acetoxy-8-drimeno-11,12-lactone, 4).
Subject(s)
Plants, Medicinal/chemistry , Sesquiterpenes/isolation & purification , Taxus/chemistry , Chromatography, Liquid , Japan , Lactones/chemistry , Lactones/isolation & purification , Molecular Conformation , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Sesquiterpenes/chemistry , Spectrometry, Mass, Electrospray Ionization , Spectrophotometry, InfraredABSTRACT
Four new polyoxygenated cyclohexenes, 2-O-acetyl-6-O-methylzeylenol (2), 2-O-benzoyl-3-O-debenzoylzeylenone (5), 3-O-debenzoylzeylenone (6) and 3-O-debenzoylgrandiflorone (8), were isolated from the leaves of Uvaria purpurea. 2-O-acetyl-6-O-benzoylzeylenol (3) was also isolated for the first time as a natural product. Compounds 5-7 each showed inhibitory activity against the root growth of Lactuca sativa. Their structures were established by spectroscopic and chemical methods.
Subject(s)
Annonaceae/chemistry , Cyclohexanes/chemistry , Plants, Medicinal/chemistry , Chemical Phenomena , Chemistry, Physical , China , Circular Dichroism , Indicators and Reagents , Magnetic Resonance Spectroscopy , Mass Spectrometry , Molecular Conformation , Plant Development , Plant Leaves/chemistry , Plants/drug effects , Spectrometry, Mass, Fast Atom Bombardment , Spectrophotometry, InfraredABSTRACT
A series of N-substituted aryl and alkyl carbamates (RNHCOOR'; R: aryl, alkyl; R': aryl, alkyl) was prepared and screened for inhibitory activity toward the germination of oat seeds. The activity of each compound was compared with that of chlorpropham (isopropyl 3-chlorocarbanilate). Some of the synthetic carbamates possessing the N-(phenylthio)methyl group, PhSCH2NHCOOR', showed inhibitory activity close or comparable to that of chlorpropham.
Subject(s)
Avena/embryology , Carbamates/chemical synthesis , Carbamates/pharmacology , Germination/drug effects , Seeds/drug effects , Spectrum AnalysisABSTRACT
Three novel 4-deacetoxy-1,7-dideoxy azetidine paclitaxel analogues were synthesized through a convenient route that employed hydroboration-amination and intramolecular S(N)2-type substitution reaction from a natural taxoid taxinine. All analogues have been tested for cytotoxicity against three human tumor cell lines. None of them showed remarkable cytotoxicity compared to paclitaxel against tested tumor cell lines.
Subject(s)
Antineoplastic Agents, Phytogenic/chemical synthesis , Azetidines/chemical synthesis , Paclitaxel/analogs & derivatives , Paclitaxel/chemical synthesis , Antineoplastic Agents, Phytogenic/pharmacology , Azetidines/pharmacology , Drug Screening Assays, Antitumor , Humans , Indicators and Reagents , Paclitaxel/pharmacology , Structure-Activity Relationship , Tumor Cells, CulturedABSTRACT
Two new taxoid metabolites, 2alpha,7beta,10beta-triacetoxy-5alpha,13alpha-dihydroxy-2(3-->20)abeotaxa-4(20),11-dien-9-one (1) and 2alpha-acetoxy-5alpha-cinnamoyloxy-9alpha,10beta-dihydroxy-3,11-cyclotax-4(20)-en-13-one (2), were isolated from the methanol extract of needles of the Japanese yew, Taxus cuspidata.