共查询到20条相似文献，搜索用时 15 毫秒
1.
The mechanism that controls the proportion of cannabichromene (CBC), a potential pharmaceutical, in the cannabinoid fraction
of Cannabis sativa L. is explored. As with tetrahydrocannabinol (THC) and cannabidiol (CBD), CBC is an enzymatic conversion product of the precursor
cannabigerol (CBG). CBC is reported to dominate the cannabinoid fraction of juveniles and to decline with maturation. This
ontogeny was confirmed in inbred lines with different mature chemotypes. A consistent CBC presence was found in early leaves
from a diverse clone collection, suggesting that CBC synthase is encoded by a fixed locus. Morphological variants possessing
a ‘prolonged juvenile chemotype’ (PJC), a substantial proportion of CBC persisting up to maturity, are presented. PJC is associated
with a reduced presence of floral bracts, bracteoles, and capitate-stalked trichomes. Genetic factors causing these features
were independent of the allelic chemotype locus B that was previously postulated and regulates THC and CBD synthesis and CBG accumulation. In contrast to previously described
Cannabis chemotypes, the cannabinoid composition of PJCs showed plasticity in that reduced light levels increased the CBC proportion.
The ability of PJC plants to enable the production of pharmaceutical raw material with high CBC purity is demonstrated. 相似文献
2.
The time course of cannabinoid accumulation in the leaves of individual plants of three Cannabis accessions was determined by gas-chromatographic analysis in greenhouse-grown plants. The total amounts and the concentration
ratios of CBD, THC and CBG were determined; two accessions (an experimental hybrid, (21R × 15R) × NL, and plants from a seized
seed lot) were found chemotypically uniform, with all plants belonging to chemotpe II (mixed) and I (high THC) respectively.
The Carmagnola accession showed chemotypic heterogeneity, with a majority of plants belonging to chemotype III. The CBD/THC
and CBG/CBD ratios were shown to be largely constant in the leaves, since 28 and until 103 days after sowing, and consistent
with the ratios determined on mature inflorescences. CBD and THC maximum amounts in the leaves showed a peak in the leaves
around 80 days from sowing, and were shown to be simultaneous during the growth period, irrespective of the chemotypes. Callus
cultures were obtained from all the five different chemotypes (I, II, III, IV, V), and GC analyses were performed. Independently
of the type and amount of cannabinoids in the mother plants, it was confirmed that callus cultures of Cannabis were not able to produce detectable amounts of any cannabinoids. 相似文献
3.
Characterisation of Cannabis accessions with regard to cannabinoid content in relation to other plant characters 总被引：1，自引：0，他引：1
Summary Ninety seven Cannabis accessions were evaluated for cannabinoid content and non-chemical plant characters. Variation within populations for cannabinoid content, and consistency of chemical characters at the population level were investigated. The relationship between chemical and other plant characters was very limited. Leaflet width and phenological data can be used for a rough prediction of the chemical phenotype on a population level. Various combinations of cannabinoid content and other economic plant characters were observed, thus a breeding programme will not be hampered by strict linkage. For a selection programme a direct analysis of cannabinoids will be inevitable. 相似文献
4.
Sebastiaan Hennink 《Euphytica》1994,78(1-2):69-76
Summary In the framework of a comprehensive Dutch research project the feasibility of hemp cultivation for paper pulp production is being investigated. This project also includes a hemp breeding programme which was initiated at CPRO-DLO in 1990. Hemp breeding is primarily aimed at improving bast fibre production since bast fibre is qualitatively superior to woody core fibre for paper pulp production. The progress of the ongoing breeding programme is hampered by the lack of knowledge on the inheritance of agronomic traits.The following traits were examined on 252 parental plants in 1991 and subsequently on their progenies in 1992: fibre content, plant height, date of flowering, stem diameter and cannabinoid contents. For each trait heritabilities were estimated and direct and indirect effects of artificial selection were studied.The heritability of bast fibre content was high and mass selection proved to be an efficient method causing no undesirable influence on other characters. Characters not directly related to bast fibre yield such as date of flowering, plant height and stem diameter were shown to have disadvantages as selection criteria for the improvement of bast fibre yield.The cannabinoids THC and CBD were studied, as the acceptance of hemp cultivation requires a low level. The content of THC, the psychoactive component can be successfully reduced by mass selection, but it is not certain that mass selection is the most efficient method. 相似文献
5.
A genetic factor that blocks the cannabinoid biosynthesis in Cannabis
sativa has been investigated. Crosses between cannabinoid-free material and high content, pharmaceutical clones were performed.
F1s were uniform and had cannabinoid contents much lower than the mean parental value. Inbred F2 progenies segregated into discrete groups: a cannabinoid-free chemotype, a chemotype with relatively low cannabinoid content
and one with relatively high content, in a monogenic 1:2:1 ratio. In our model the cannabinoid knockout factor is indicated
as a recessive allele o, situated at locus O, which segregates independently from previously presented chemotype loci. The genotype o/o underlies the cannabinoid-free chemotype, O/o is expressed as an intermediate, low content chemotype, and O/O is the genotype of the high content chemotype. The data suggests that locus O governs a reaction in the pathway towards the phenolic cannabinoid precursors. The composition of terpenoids and various
other compound classes of cannabinoid-free segregants remains unaffected. Backcrossing produced cannabinoid-free homologues
of pharmaceutical production clones with potential applications in pharmacological research. A new variant of the previously
presented allele ‘B
0’, that almost completely obstructs the conversion of CBG into CBD, was also selected from the source population of the cannabinoid
knockout factor. 相似文献
6.
This paper aims to clarify the genetic mechanism that is responsible for the accumulation of cannabigerol (CBG) in certain
phenotypes of Cannabis sativa L. CBG is the direct precursor of the cannabinoids CBD, THC and CBC. Plants strongly predominant in CBG have been found in
different fibre hemp accessions. Inbred offspring derived from one such individual were crossed with true breeding THC predominant-
and CBD predominant plants, respectively. The segregations in the cross progenies indicate that CBG accumulation is due to
the homozygous presence of a minimally functional allele, tentatively called B0, at the single locus B that normally controls the conversion of CBG into THC (allele BT) and/or CBD (allele BD). The fact that CBG accumulating plants have so far been found in European fibre hemp populations that are generally composed
of BD/BD plants, and the observation that the here investigated B0 allele possesses a residual ability to convert small amounts of CBG into CBD, make it plausible that this B0 is a mutation of normally functional BD. Therefore, B0 is considered as a member of the BD allelic series encoding a CBD synthase isoform with greatly weakened substrate affinity and/or catalytic capacity. 相似文献
7.
Roger G. Pertwee 《Euphytica》2004,140(1-2):73-82
Summary Cannabis is the unique source of a set of at least 66 compounds known collectively as cannabinoids. Of these, most is known about the pharmacology of 9-tetrahydrocannabinol (9-THC), the main psychoactive constituent of cannabis, and about cannabidiol (CBD), which lacks psychoactivity. Accordingly, this paper focuses on the pharmacological and therapeutic targets of these two cannabinoids. Many of the effects of 9-THC are mediated by cannabinoid receptors of which at least two types, CB1 and CB2, are present in mammalian tissues. Endogenous agonists for cannabinoid receptors have also been discovered. CB1 receptors are present at the terminals of central and peripheral neurones, where they modulate transmitter release. They also exist in some non-neuronal cells. CB2 receptors are expressed mainly by immune cells, one of their roles being to alter cytokine release. 9-THC also appears to have non-CB1, non-CB2 pharmacological targets. It is already licensed for clinical use in the U.S.A. as an anti-emetic and appetite stimulant and both 9-THC and 9-THC-rich cannabis extracts show therapeutic potential as neuroprotective and anticancer agents and for the management of glaucoma, pain and various kinds of motor dysfunction associated, for example, with multiple sclerosis and spinal cord injury. CBD has much less affinity for CB1 and CB2 receptors than 9-THC and its pharmacological actions have been less well characterized. Potential clinical applications of CBD and CBD-rich cannabis extracts include the production of anti-inflammatory and neuroprotective effects, the management of epilepsy, anxiety disorders, glaucoma and nausea, and the modulation of some effects of 9-THC. 相似文献
8.
萜类化合物的化感功能及其开发应用前景 总被引：2，自引：0，他引：2
萜类化合物在植物生命活动中扮演着重要角色,在天然产物中所占比重最大,其中很多是植物化感作用的关键物质,并广泛应用于农业、工业、医药生产等领域。鉴于此,本文就萜类化感物质的类型、分布、环境影响、生理生态功能以及应用前景进行总结,以期为萜类化感物质研究与开发应用提供参考。 相似文献
9.
10.
In these years, medicine value and clinical treatment value of extracts of the gmkgo biloba leares are studied deeply on home and abroad. With the growing development in the chemical inspect and chinical application, there are so many reports in domestic and abroad about the preparation technics, constituents analyse, pharmacological effects, toxicological experiments and clinical trials of ginkgo biloba leaves. There are kinds of flavonoids and terpenoids lactone in it, which have obrione protection and sechrity allepted by people in the world. A extensire prospect for application is manifested. The research progress of pharmacological effects of extracts of gmkgo bilobal. is summarized. 相似文献
11.
植物生长调节剂在中药材栽培上的应用 总被引：1，自引：0，他引：1
植物生长调节剂是人工合成的具有植物激素活性的一类化学物质,一般分为植物生长促进剂、植物生长延缓剂和植物生长抑制剂3类。笔者总结了植物生长调节剂在中药材栽培上的应用,归纳为促进生长发育、矮化植株并提高抗逆性、增加中药材产量、提高有效成分含量4个方面,进而简要分析了植物生长调节剂的作用机理;探讨了植物生长调节剂施用不当可能降低中药材活性成分含量、导致残留危害、影响中药材栽培环境等问题。并提出,从对药材质量的影响、检测方法与技术的开发、使用规范和残留限量标准的完善等方面开展进一步的研究,以期为科学使用植物生长调节剂提供依据,为促进中药材种植产业健康发展、保障中药用药安全提供参考。 相似文献
12.
13.
枇杷是国内大部分地区均可种植的一种植物。枇杷果实富含糖类、维生素和微量元素等营养成分,是一种营养价值高、经济价值高的水果;枇杷叶、花含有皂苷类、萜类、酚类和黄酮类生物活性的成分,具有抗肿瘤、抗癌、抗炎、降血糖、抗氧化、止咳平喘等功效。就枇杷的营养价值、功能价值和食品加工方面的应用研究进行论述,并讨论当前枇杷资源应用中存在的问题,以期为枇杷的综合资源利用提供参考依据。 相似文献
14.
Marcel A. J. Toonen Chris Maliepaard Theo H. Reijmers Hilko van der Voet H. Dick Mastebroek Hetty C. van den Broeck Michel J. M. Ebskamp Waltraud Kessler Rudolf W. Kessler 《Euphytica》2004,140(1-2):39-45
Summary Fibre formation in hemp (Cannabis sativa L.) is a dynamic process. In order to follow this process, the chemical composition of the hemp stem was studied during plant development using the acid and neutral detergent fibre and lignin methods. Additionally, near infra-red spectroscopy was carried out. To predict the chemical composition of the stem samples partial least square (PLS) analysis was carried out. The developed PLS models can predict the level of %ADF and %NDF in the hemp bast and core samples. For %ADL, the models are only suited for either core or bast tissues and can not be used for both tissues simultaneously. 相似文献
15.
为了高效利用汉麻黄酮类成分及系统开展汉麻黄酮类化合物的研究,本文综述了汉麻黄酮类化合物的结构、合成途径、生物活性及分析方法。归纳总结出汉麻中共含有26种黄酮类化合物,其主要结构类型以黄酮和黄酮醇为主;此外,在黄酮类化合物经典合成途径的基础上,明确了2种特征性汉麻黄酮成分-大麻黄素A和大麻黄素B的生物合成途径;同时,也总结了汉麻黄酮类化合物具有抗肿瘤、神经保护、抗抑郁等生物活性,并针对其结构特点和活性作用,建立了汉麻黄酮类化合物高效、快速的分析方法为LC-MS等功效。上述归纳可为开展汉麻黄酮类化合物的研究及应用提供参考。 相似文献
16.
西北干旱荒漠区植物化感作用研究进展 总被引：1，自引：0，他引：1
为探明荒漠生态系统中植物之间的化感作用,首次对近年来该领域所取得的研究成果、已报道的化感植物、化感物质以及化感物质释放途径等进行总结,认为：（1）中国有关荒漠植物化感作用的研究才刚刚起步,在该区菊科、豆科、蔷薇科、玄参科、禾本科等科属中发现具有化感潜势的植物。（2）荒漠植物化感物质释放的途径以自然挥发为主,这主要与其生长环境有关,鉴定出的化感物质有生物碱、黄酮类、萜类等化合物。（3）最后指出荒漠生态系统中化感植物研究存在的关键问题,对确定合理的荒漠植物保护措施及荒漠化综合治理提供理论依据和实践价值。 相似文献
17.
The sexual differentiation of Cannabis sativa L.: A morphological and molecular study 总被引：1，自引：0，他引：1
V. M. Cristiana Moliterni Luigi Cattivelli P. Ranalli Giuseppe Mandolino 《Euphytica》2004,140(1-2):95-106
Summary Cannabis sativa L. is a dioecious species with sexual dimorphism occurring in a late stage of plant development. Sex is determined by heteromorphic chromosomes (X and Y): male is the heterogametic sex (XY) and female is the homogametic one (XX). The sexual phenotype of Cannabis often shows some flexibility leading to the differentiation of hermaphrodite flowers or bisexual inflorescences (monoecious phenotype). Sex is considered an important trait for hemp genetic improvement; therefore, the study of the mechanism of sexual differentiation is of paramount interest in hemp research. A morphological and molecular study of Cannabis sativa sexual differentiation has been carried out in the Italian dioecious cultivar Fibranova.Microscopic analysis of male and female apices revealed that their reproductive commitment may occur as soon as the leaves of the fourth node emerge; the genetic expression of male and female apices at this stage has been compared by cDNA-AFLP. A rapid method for the early sex discrimination has been developed, based on the PCR amplification of a male-specific SCAR marker directly from a tissue fragment.Five of the several cDNA-AFLP polymorphic fragments identified have been confirmed to be differentially expressed in male and female apices at the fourth node. Cloning and sequencing revealed that they belong to nine different mRNAs that were all induced in the female apices at this stage. Four out of them showed a high degree of similarity with known sequences: a putative permease, a SMT3-like protein, a putative kinesin and a RAC-GTP binding protein. 相似文献
18.
Paolo Ranalli 《Euphytica》2004,140(1-2):121-131
Summary Hemp is a multi-use crop, able to provide fiber, cellulose, seeds and seed oil, cannabinoid, and biomass. Integrating many agroindustrial chains, Cannabis is considered a crop model in which insights into specific metabolic pathways and biosynthetic processes are valuable for improvement of the plant for all sets of industrial derivatives. In this review the hemp breeding status is elucidated and many aspects are focused: (i) recovering, maintenance and characterization of genetic resources; (ii) widening of germplasm and genetic variability; (iii) marker-assisted selection and development of breeding programs; (iv) sexual differentiation; (v) monitoring of THC content. Modern hemp varieties for fiber and other specific end uses have been developed and new varieties are entering production. The scenario for the breeding advances in hemp relies on basic and applied research which provides insights to identify a strategy for the design of modified plants with enhanced performance. This is accounted by the dissection of traits into components and the modification of single steps of the related metabolic pathways. These advances are provided by genomic techniques and are able: (i) to identify key genes encoding enzymes and regulatory factors participating in cannabinoid, fiber and oil biosynthesis; (ii) to identify the mode of regulation of these genes; (iii) to characterize the function of the selected genes through higher, lower or specific expression incited by specific promoters. The identification of molecular markers for specific traits, gathered in a saturated linkage map, will have a remarkable impact on hemp breeding. The advances in basic and applied research make it possible to design methods for the identification of superior parents and cross combinations and the development of selection schemes that rely on less labour-intensive and time-consuming methods. 相似文献
19.
黄酮类化合物的研究进展 总被引：5，自引：0，他引：5
黄酮类化合物具有广泛的生理和药理活性。这类化合物已成为国内外医药界研究的热点,是一类极具有广阔开发前景的天然药物。综述了近几年黄酮类化合物在提取、含量测定、分离纯化、结构鉴定等方面的研究进展。 相似文献
20.
蕨类植物内生菌研究进展 总被引：3，自引：1，他引：2
植物内生菌是一种新的微生物资源,具有潜在和良好的应用前景。有关蕨类植物内生菌报道少。综述了蕨类植物内生菌的多样性、活性成分与功能研究进展。对植物内生菌作为重要天然药物新来源的前景及存在的问题进行了讨论。 相似文献