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1.
Res Sq ; 2024 Jul 30.
Article in English | MEDLINE | ID: mdl-39149481

ABSTRACT

Cross-individual variability is considered the essence of biology, preventing precise mathematical descriptions of biological motion1-7 like the physics law of motion. Here we report that the cerebellum shapes motor kinematics by encoding dynamic motor frequencies with remarkable numerical precision and cross-individual uniformity. Using in-vivo electrophysiology and optogenetics in mice, we confirmed that deep cerebellar neurons encoded frequencies via populational tuning of neuronal firing probabilities, creating cerebellar oscillations and motions with matched frequencies. The mechanism was consistently presented in self-generated rhythmic and non-rhythmic motions triggered by a vibrational platform, or skilled tongue movements of licking in all tested mice with cross-individual uniformity. The precision and uniformity allowed us to engineer complex motor kinematics with designed frequencies. We further validated the frequency-coding function of the human cerebellum using cerebellar electroencephalography recordings and alternating-current stimulation during voluntary tapping tasks. Our findings reveal a cerebellar algorithm for motor kinematics with precision and uniformity, the mathematical foundation for brain-computer interface for motor control.

2.
Sci Transl Med ; 16(747): eadl1408, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38748772

ABSTRACT

Essential tremor (ET) is the most prevalent movement disorder, characterized primarily by action tremor, an involuntary rhythmic movement with a specific frequency. However, the neuronal mechanism underlying the coding of tremor frequency remains unexplored. Here, we used in vivo electrophysiology, optogenetics, and simultaneous motion tracking in the Grid2dupE3 mouse model to investigate whether and how neuronal activity in the olivocerebellum determines the frequency of essential tremor. We report that tremor frequency was encoded by the temporal coherence of population neuronal firing within the olivocerebellums of these mice, leading to frequency-dependent cerebellar oscillations and tremors. This mechanism was precise and generalizable, enabling us to use optogenetic stimulation of the deep cerebellar nuclei to induce frequency-specific tremors in wild-type mice or alter tremor frequencies in tremor mice. In patients with ET, we showed that deep brain stimulation of the thalamus suppressed tremor symptoms but did not eliminate cerebellar oscillations measured by electroencephalgraphy, indicating that tremor-related oscillations in the cerebellum do not require the reciprocal interactions with the thalamus. Frequency-disrupting transcranial alternating current stimulation of the cerebellum could suppress tremor amplitudes, confirming the frequency modulatory role of the cerebellum in patients with ET. These findings offer a neurodynamic basis for the frequency-dependent stimulation of the cerebellum to treat essential tremor.


Subject(s)
Cerebellum , Essential Tremor , Neurons , Olivary Nucleus , Essential Tremor/physiopathology , Animals , Humans , Olivary Nucleus/physiopathology , Cerebellum/physiopathology , Mice , Male , Optogenetics , Female , Deep Brain Stimulation , Middle Aged , Electroencephalography , Aged
3.
Molecules ; 21(9)2016 Sep 02.
Article in English | MEDLINE | ID: mdl-27598114

ABSTRACT

Phytochemical investigation of the acetone extract from the roots of Aphanamixis polystachya resulted in isolation of four new tetranortriterpenes (1-4) in addition to one protolimonoid (methyl-1ξ,7R-diacetoxy-23R,25-dihydroxy-20S,24R-21,24-epoxy-3,4-seco-apotirucall-4(28),14(15)-diene-3-oate (5)), five known limonoids (rohituka 3 (6), rohituka 7 (7), nymania 1 (8), rubrin G (9), prieurianin (10)) and a steroid (2,3-dihydroxy-5-pregnan-16-one (11)). Their structures were determined by spectroscopic analyses, including 2D-NMR (COSY, HMQC, HMBC, and NOESY) and high-resolution electrospray ionization mass spectrometry (HRESIMS). Cytotoxic and anti-inflammatory activities of these compounds were evaluated. Compounds 4 and 5 showed significant inhibition against superoxide generation and elastase release by human neutrophils in response to (formyl-l-methionyl-l-leucyl-l-phenylalanine/cytochalasin B) (FMLP/CB).


Subject(s)
Leukocyte Elastase/metabolism , Limonins , Meliaceae/chemistry , Neutrophils/metabolism , Plant Extracts/chemistry , Plant Roots/chemistry , Superoxides/metabolism , Humans , Limonins/chemistry , Limonins/isolation & purification , Limonins/pharmacology , Neutrophils/cytology
4.
Plant Physiol Biochem ; 94: 165-73, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26094157

ABSTRACT

Breaking of seed dormancy by moist cold stratification involves complex interactions in cells. To assess the effect of moist cold stratification on dormancy break in seeds of Acer morrisonense, we monitored percentages and rates of germination and changes in plant growth regulators, sugars, amino acids and embryo ultrastructure after various periods of cold stratification. Fresh seeds incubated at 25/15 °C for 24 weeks germinated to 61%, while those cold stratified at 5 °C for 12 weeks germinated to 87% in 1 week. Neither exogenous GA3 nor GA4 pretreatment significantly increased final seed germination percentage. Total ABA content of seeds cold stratified for 12 weeks was reduced about 3.3-fold, to a concentration similar to that in germinated seeds (radicle emergence). Endogenous GA3 and GA7 were detected in 8-week and 12-week cold stratified seeds but not in fresh seeds. Numerous protein and lipid bodies were present in the plumule, first true leaves and cotyledons of fresh seeds. Protein and lipid bodies decreased greatly during cold stratification, and concentrations of total soluble sugars and amino acids increased. The major non-polar sugars in fresh seeds were sucrose and fructose, but sucrose increased and fructose decreased significantly during cold stratification. The major free amino acids were proline and tryptophan in fresh seeds, and proline increased and tryptophan decreased during cold stratification. Thus, as dormancy break occurs during cold stratification seeds of A. morrisonense undergo changes in plant growth regulators, proteins, lipids, sugars, amino acids and cell ultrastructure.


Subject(s)
Acer , Cold Temperature , Germination , Plant Growth Regulators/metabolism , Seeds , Acer/metabolism , Acer/ultrastructure , Seeds/metabolism , Seeds/ultrastructure , Time Factors
5.
Photodiagnosis Photodyn Ther ; 11(4): 498-509, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25461963

ABSTRACT

OBJECTIVE: To evaluate the outcomes of the combination of red light or intense pulsed laser (IPL) with 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) in the treatment of photodamaged neck skin. METHODS: The anterior of the neck was divided into four 2 cm × 2 cm sections and randomly assigned to red-light, red-light-PDT, IPL or IPL-PDT group. ALA cream of 5% was applied to PDT regions for 2h prior to light irradiation. Treatment was repeated once. The stratum corneum (SC) hydration, transepidermal water loss (TEWL), L(*), a(*), b(*) values, melanin index (MI), erythema index (EI), skin elasticity and skin thickness were examined by a blinded investigator. The function and volume of thyroid were also measured. RESULTS: After red-light-PDT, IPL-PDT and IPL treatment, the appearance of photoaging lesion was improved. The SC hydration, L(*) value, elasticity and thickness increased, whereas the TEWL and MI value decreased. These changes in red-light-PDT and IPL-PDT group were more obvious than IPL group. The a(*) and EI value increased in red-light-PDT group. No significant change was noticed in red-light group. Partial irradiation of the thyroid did not affect the function and volume of the thyroid. CONCLUSION: IPL-PDT and red-light-PDT showed better rejuvenation effect than IPL or red light alone on the neck skin.


Subject(s)
Aminolevulinic Acid/administration & dosage , Photochemotherapy/methods , Skin Aging/drug effects , Skin Aging/radiation effects , Skin/drug effects , Skin/radiation effects , Adult , Double-Blind Method , Female , Humans , Light , Male , Middle Aged , Neck/radiation effects , Photosensitizing Agents/administration & dosage , Rejuvenation/physiology , Skin Physiological Phenomena/drug effects , Skin Physiological Phenomena/radiation effects , Treatment Outcome
6.
Nat Prod Res ; 27(8): 727-34, 2013 Apr.
Article in English | MEDLINE | ID: mdl-22690946

ABSTRACT

Phytochemical investigation of Hypericum nakamurai (Masamune) Robson has led to the isolation of three phloroglucinol derivatives 1-3. The structures of these compounds were determined by the analysis of their spectroscopic data (IR, mass and UV), and by the application of 1-D and 2-D-NMR techniques. Hyperinakin (1) is a new compound. The anti-inflammatory activities of compounds 1-3 were also tested and evaluated. A biogenetic pathway for compounds 1-3 was also proposed.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/isolation & purification , Hypericum/chemistry , Phloroglucinol/analogs & derivatives , Animals , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Cell Line , Mice , Molecular Structure , Phloroglucinol/chemistry , Phloroglucinol/isolation & purification , Plants, Medicinal/chemistry
7.
Food Chem ; 136(2): 1095-9, 2013 Jan 15.
Article in English | MEDLINE | ID: mdl-23122167

ABSTRACT

Two novel highly oxygenated nortriterpenoids, schisarisanlactones A (1) and B (2), have been isolated from the fruits of Schisandra arisanensis, an endemic plant of Taiwan. Compounds 1 and 2 possess an unprecedented 5/5/7/5/5-fused pentacyclic ring system. The structures of both compounds were determined on the basis of spectroscopic analyses, especially 2D NMR and MS. A plausible biogenetic pathway of 1 was proposed. Schisarisanlactone A (1) showed significant anti-HIV activity.


Subject(s)
Fruit/chemistry , Plant Extracts/chemistry , Schisandra/chemistry , Triterpenes/chemistry , Anti-HIV Agents/chemistry , Anti-HIV Agents/isolation & purification , Anti-HIV Agents/pharmacology , HIV/drug effects , Molecular Structure , Plant Extracts/isolation & purification , Plant Extracts/pharmacology , Taiwan , Triterpenes/isolation & purification , Triterpenes/pharmacology
8.
Bioorg Med Chem Lett ; 23(3): 880-5, 2013 Feb 01.
Article in English | MEDLINE | ID: mdl-23265871

ABSTRACT

Three new polyoxygenated C(18)-dibenzocyclooctadiene lignans, arisanschinins M and N (1 and 2) and schisphenin A (3), together with eight related metabolites (4-11), were isolated from the fruits of Schisandra arisanensis and Schisandra sphenanthera, respectively. The structures of 1-3 were elucidated on the basis of extensive spectroscopic and 2D NMR (HSQC, HMBC, and NOESY) analyses. The configuration of the biphenyl moiety in the octadiene ring was determined by circular dichroism (CD). Compound 1 possessed an unprecedented 3-(1-hydroxypropan-2-yl)-3-methyl-1,4-dioxo-2-one lactonide ring system attaching at C-6/C-14. Pharmacological studies revealed that compounds 3, 4, 6, 7, and 10 exhibited significant anti-hepatic fibrosis activity, while 9 and 11 showed cytotoxicity against HSC-T6 cells. The biogenetic pathway for compound 1 was also proposed.


Subject(s)
Cyclooctanes/chemistry , Fruit/chemistry , Lignans/chemistry , Plant Extracts/chemistry , Schisandra/chemistry , Cell Line , Cell Survival/drug effects , Circular Dichroism , Cyclooctanes/pharmacology , Humans , Lignans/pharmacology , Liver/drug effects , Liver Cirrhosis/drug therapy , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Plant Extracts/pharmacology
9.
Ann Bot ; 108(1): 13-22, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21562028

ABSTRACT

BACKGROUND AND AIMS: In seeds with deep simple epicotyl morphophysiological dormancy, warm and cold stratification are required to break dormancy of the radicle and shoot, respectively. Although the shoot remains inside the seed all winter, little is known about its growth and morphological development prior to emergence in spring. The aims of the present study were to determine the temperature requirements for radicle and shoot emergence in seeds of Viburnum betulifolium and V. parvifolium and to monitor growth of the epicotyl, plumule and cotyledons in root-emerged seeds. METHODS: Fresh and pre-treated seeds of V. betulifolium and V. parvifolium were incubated under various temperature regimes and monitored for radicle and shoot emergence. Growth of the epicotyl and cotyledons at different stages was observed with dissecting and scanning electron microscopes. KEY RESULTS: The optimum temperature for radicle emergence of seeds of both species, either kept continuously at a single regime or exposed to a sequence of regimes, was 20/10 °C. GA(3) had no effect on radicle emergence. Cold stratification (5 °C) was required for shoot emergence. The shoot apical meristem in fresh seeds did not form a bulge until the embryo had grown to the critical length for radicle emergence. After radicle emergence, the epicotyl--plumule and cotyledons grew slowly at 5 and 20/10 °C, and the first pair of true leaves was initiated. However, the shoot emerged only from seeds that received cold stratification. CONCLUSIONS: Seeds of V. betulifolium and V. parvifolium have deep simple epicotyl morphophysiological dormancy, C(1b)B (root)-C(3) (epicotyl). Warm stratification was required to break the first part of physiological dormancy (PD), thereby allowing embryo growth and subsequently radicle emergence. Although cold stratification was not required for differentiation of the epicotyl--plumule, it was required to break the second part of PD, thereby allowing the shoot to emerge in spring.


Subject(s)
Plant Dormancy/physiology , Plant Shoots/growth & development , Seeds/physiology , Viburnum/physiology , Plant Leaves/growth & development , Seasons , Seeds/growth & development , Temperature , Time Factors , Viburnum/embryology , Viburnum/growth & development
10.
Org Lett ; 13(3): 446-9, 2011 Feb 04.
Article in English | MEDLINE | ID: mdl-21175150

ABSTRACT

A novel triterpenoid, schinarisanlactone A (1), was isolated from the fruits of Schisandra arisanensis. Compound 1 possesses an unprecedented skeleton having a 5/7/7/5/7/5/6/5-fused octacyclic ring system. The structure of 1 was determined by 2D NMR techniques (COSY, HMQC, HMBC, and NOESY) and was confirmed by X-ray crystallographic analysis. Schinarisanlactone A (1) exhibited significant anti-HIV activity.


Subject(s)
Anti-HIV Agents/isolation & purification , Schisandra/chemistry , Triterpenes/isolation & purification , Anti-HIV Agents/chemistry , Anti-HIV Agents/pharmacology , Crystallography, X-Ray , Fruit/chemistry , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Taiwan , Triterpenes/chemistry , Triterpenes/pharmacology
11.
J Nat Prod ; 73(7): 1228-33, 2010 Jul 23.
Article in English | MEDLINE | ID: mdl-20536188

ABSTRACT

Fractionation of an acetone extract from the fruits of Schisandra arisanensis afforded five new nortriterpene lactones, compounds 1-5, together with four known compounds, schindilactones D and E (6 and 7) and preschisanartanins A and B (8 and 9). Compound 1, a wuweiziartane-type nortriterpenoid, possesses a new type of fused ring system with a gamma-lactone ring between C-15 and C-17. Compounds 2, 6, and 7 may be categorized as schisanartane-type nortriterpenoids and compounds 3-5, 8, and 9 as preschisanartane-type nortriterpenoids. The structures of the new compounds were elucidated by 1D and 2D NMR spectroscopic data interpretation. The structure and relative configuration of 3 were supported by single-crystal X-ray diffraction analysis. The antiviral activity against HSV-1 and inhibitory effects on superoxide anion generation and elastase release by human neutrophils in response to FMLP/CB of compounds 1-9 were evaluated.


Subject(s)
Antiviral Agents/isolation & purification , Drugs, Chinese Herbal/isolation & purification , Herpesvirus 1, Human/drug effects , Lactones/isolation & purification , Schisandra/chemistry , Triterpenes/isolation & purification , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Crystallography, X-Ray , Drugs, Chinese Herbal/chemistry , Drugs, Chinese Herbal/pharmacology , Fruit/chemistry , Humans , Lactones/chemistry , Lactones/pharmacology , Molecular Conformation , Molecular Structure , Neutrophils/drug effects , Neutrophils/enzymology , Nuclear Magnetic Resonance, Biomolecular , Triterpenes/chemistry , Triterpenes/pharmacology
12.
Org Lett ; 12(5): 1016-9, 2010 Mar 05.
Article in English | MEDLINE | ID: mdl-20108936

ABSTRACT

A phytochemical investigation of the fruits of Schisandra arisanensis has yielded a novel triterpenoid, arisandilactone A (1). Compound 1 has an unprecedented skeleton having a 5/5/7/5/8/5-fused hexacyclic ring system. The structure of 1 was elucidated by spectroscopic methods, especially 2D NMR techniques (COSY, HMQC, HMBC, and NOESY) and was confirmed by X-ray crystallographic analysis. A plausible biosynthetic pathway for 1 is also discussed.


Subject(s)
Fruit/chemistry , Schisandra/chemistry , Triterpenes/chemistry , Triterpenes/isolation & purification , Chromatography , Heterocyclic Compounds/chemistry , Magnetic Resonance Spectroscopy
13.
Tree Physiol ; 30(2): 275-84, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20008838

ABSTRACT

The medicinal Asian plant genus Phellodendron is known to contain several very important compounds that have biological action. The main purpose of this study was to determine whether seeds of Phellodendron amurense var. wilsonii can be stored and to characterize their dormancy. Seeds of this taxon stored at -20 and -80 degrees C and in liquid nitrogen retained their high germinability, indicating that they have orthodox storage behavior. Intact seeds from freshly collected fruits were dormant and required 12 weeks of cold stratification at 4 degrees C for complete germination. Scarifying the seed coat was partially effective in breaking seed dormancy. Exogenous gibberellins (GA(3), GA(4) and GA(4+7)) promoted germination of scarified seeds, GA(4) and GA(4+7) being more effective than GA(3). Fluridone, an abscisic acid (ABA) biosynthesis inhibitor, was efficient in breaking dormancy, but it was less effective than GA(4) or GA(4+7) alone. Paclobutrazol, a GA biosynthesis inhibitor, inhibited seed germination, and the inhibitory effect was reversed completely by GA(4) and by GA(4+7). ABA content of seeds subjected to cold stratification or to incubation at 35/10 degrees C, which enhanced seed germination, was reduced about four- to sixfold compared to that of fresh seeds. Higher concentrations of GA(3), GA(4) and GA(7) were detected in nondormant seeds and in seeds with an emerged radicle than in fresh seeds. Present results seem to indicate that dormancy in P. amurense var. wilsonii seeds is imposed partially by the seed coat and partially by high ABA content. ABA content decreased and GA(3), GA(4) and GA(7) content increased during germination.


Subject(s)
Abscisic Acid/metabolism , Germination , Gibberellins/metabolism , Phellodendron/metabolism , Seeds/growth & development , Cold Temperature , Cryopreservation , Seeds/metabolism
14.
J Nat Prod ; 72(9): 1663-8, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19673515

ABSTRACT

An acetone extract of the fruits of the Taiwanese medicinal plant Schisandra arisanensis has yielded 11 new oxygenated lignans. Four of these, named arisantetralones A-D (1-4), possess the aryltetralone skeleton, while the other seven, named arisanschinins F-L (5-11), are polyoxygenated C(18)-dibenzocyclooctadiene lignans. Structures were determined on the basis of spectroscopic analyses, especially 2D-NMR techniques. The structure of compound 1 was confirmed by X-ray crystallographic analysis. Immunomodulatory activity of the isolated lignans was tested and evaluated.


Subject(s)
Immunologic Factors/isolation & purification , Lignans/isolation & purification , Plants, Medicinal/chemistry , Schisandra/chemistry , Crystallography, X-Ray , Fruit/chemistry , Humans , Immunologic Factors/blood , Immunologic Factors/chemistry , Immunologic Factors/pharmacology , Lignans/blood , Lignans/chemistry , Lignans/pharmacology , Models, Molecular , Molecular Conformation , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Oxygen/chemistry , Taiwan
15.
Tree Physiol ; 28(9): 1431-9, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18595855

ABSTRACT

Intact seeds from freshly harvested fruits of Myrica rubra (Sieb et Zucc.) were dormant and required 8 weeks of warm stratification followed by 12 weeks of cold stratification for germination. Exogenous application of gibberellic acid (GA(3)) to intact fresh seeds was effective in breaking dormancy, with > 70% of seeds germinating when treated with 5.2 mM GA(3) and incubated at a day/night temperature of 30/20 degrees C for 20 weeks. Removing the hard endocarp or endocarp plus seed coat of fresh seeds promoted germination, and addition of GA(3) to the embryo accelerated germination. The gibberellins GA(1) and GA(4) were more effective than GA(3) in promoting germination of seeds with the endocarp removed. Endogenous contents of GA(1), GA(3), GA(4), GA(7) and GA(20) were quantified by gas chromatography-mass spectrometry-selected ion monitoring in the endocarps, seed coats and embryos of fresh seeds treated with 5.2 mM GA(3). The content of GA(3) decreased in the endocarp during incubation, whereas GA(1) contents increased in the endocarp and seed coat. A high GA(1) content was detected in the endocarps and embryos of newly germinated seeds. We speculate that GA(3) was converted to GA(1) during incubation and that GA(1) is involved in seed germination. Endogenous abscisic acid (ABA) contents were measured in fresh seeds and in warm and cold stratified seeds. The ABA content in fresh seeds was distributed in the order endocarp > seed coat > embryo, with the content in the endocarp being about 132-fold higher than in the seed coat and embryo. Total ABA content of seeds subjected to warm or cold stratification, or both, was 8.7- to 14.0-fold lower than that of fresh seeds. Low contents of endogenous GA(1), GA(3), GA(7) and GA(20), but elevated contents of GA(4), were found in the seed coats and endocarps of warm plus cold stratified seeds and in the seed coats and embryos of newly germinated seeds. These observations, coupled with the finding that GA stimulated germination of dormant Myrica seeds, provide evidence that endogenous ABA inhibited release of dormancy and that endogenous gibberellins, especially GA(4) or GA(1), or both, are involved in germination.


Subject(s)
Abscisic Acid/metabolism , Germination , Gibberellins/metabolism , Myrica/physiology , Seeds/physiology , Abscisic Acid/antagonists & inhibitors , Cold Temperature , Gibberellins/antagonists & inhibitors , Gibberellins/pharmacology , Hot Temperature , Plant Growth Regulators/pharmacology , Pyridones/pharmacology , Triazoles/pharmacology
16.
Chem Biodivers ; 5(1): 162-7, 2008 Jan.
Article in English | MEDLINE | ID: mdl-18205119

ABSTRACT

Bioassay-guided fractionation of the acetone extract of the roots of Casearia membranacea furnished three new clerodane diterpenes, caseamembrins S-U (1-3) and the known caseamembrin Q (4). Their structures were established by extensive spectroscopic analyses, especially 2D-NMR. Compounds 1-4 were tested against human tumor cells, including HeLa (cervical epitheloid carcinoma), DLD-1 (colon carcinoma), Daoy (medulloblastoma), and KB (oral epidermoid carcinoma) cell lines. Caseamembrin T (2) exhibited the most potent activity against Daoy cells (ED(50)=10 ng/ml), superior to that of the standard drug mitomycin.


Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Casearia/chemistry , Diterpenes, Clerodane/chemistry , Diterpenes, Clerodane/pharmacology , Plant Roots/chemistry , Antineoplastic Agents/isolation & purification , Cell Line, Tumor , Cell Proliferation/drug effects , Diterpenes, Clerodane/isolation & purification , Drug Screening Assays, Antitumor , HeLa Cells , Humans , Magnetic Resonance Spectroscopy/methods , Magnetic Resonance Spectroscopy/standards , Molecular Conformation , Reference Standards , Stereoisomerism , Structure-Activity Relationship
17.
J Nat Prod ; 68(11): 1665-8, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16309320

ABSTRACT

Bioassay-guided fractionation of the EtOAc extract of Casearia membranacea leaves and twigs afforded three new clerodane diterpenes, caseamembrins M-O (1-3), and the known rel-(2S,5R,6R,8S,9S,10R,18S,19R)-2-(2-methylbutyryloxy)-6-hydroxy-18,19-di-O-acetyl-18,19-epoxycleroda-3,13(16),14-triene (4) and caseamembrin D (5). The structures of 1-3, including the relative configurations, were established by extensive NMR spectroscopic analyses. The cytotoxic activities of the isolated diterpenoids against human oral epidermoid (KB), medulla (Med), and colon (DLD-1) cancer cell lines were evaluated.


Subject(s)
Antineoplastic Agents, Phytogenic/isolation & purification , Casearia/chemistry , Diterpenes, Clerodane/isolation & purification , Plants, Medicinal/chemistry , Antineoplastic Agents, Phytogenic/chemistry , Antineoplastic Agents, Phytogenic/pharmacology , Diterpenes, Clerodane/chemistry , Diterpenes, Clerodane/pharmacology , Drug Screening Assays, Antitumor , Humans , Molecular Structure , Plant Leaves/chemistry , Plant Stems/chemistry , Stereoisomerism , Taiwan , Tumor Cells, Cultured
18.
Plant Cell Physiol ; 45(9): 1158-67, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15509838

ABSTRACT

Studies on seed storage of Chionanthus retusus Lindl. & Paxt. revealed an orthodox behavior, one which showed both desiccation and freezing tolerance. An epicotyl after-ripening dormancy was expressed in C. retusus seeds by slow growth of the shoot apex relative to more rapid growth of the radicle when seeds were germinated at 30/20 degrees C. Although these seeds exhibit radicle protrusion, they must be after-ripened for another 8-10 weeks at 30/20 degrees C in order to obtain normal shoot growth. Removal of the endosperm, however, quickly stimulated cotyledon and shoot emergence without the additional after-ripening. Water-soluble glucoside phenolics, GL-3, Nuzhenide, ligustroside and oleoside dimethyl ester are present at relatively high levels in endosperm of freshly harvested seeds. These glucoside phenolics are excreted from the endosperm during subsequent after-ripening. Embryo and endosperm tissue from seed germinating at 30/20 degrees C (germination being defined by protrusion of the radicle) had a 10 times lower abscisic acid (ABA) content than similar tissues from freshly harvested mature seed. However, no shoot growth occurred even with the 10-fold reduction in ABA and a concomitant increase in endogenous gibberellins A1, A4 and A20. Thus, epicotyl dormancy during the first 8 weeks of after-ripening at 30/20 degrees C may be controlled by factors other than high ABA, i.e., the slow development of the shoot apex following radicle protrusion may be controlled more by high levels of glucoside phenolics than by diminished ABA and elevated GA levels.


Subject(s)
Abscisic Acid/pharmacology , Germination/drug effects , Glucosides/pharmacology , Oleaceae/embryology , Phenols/chemistry , Plant Roots/growth & development , Seeds/physiology , Glucosides/chemistry , Magnetic Resonance Spectroscopy , Microscopy, Electron, Scanning , Oleaceae/physiology , Seeds/ultrastructure , Spectrometry, Mass, Fast Atom Bombardment
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