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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Comparison of some chemical constituents of the lycopods

McMullan, Eleanor Elizabeth January 1966 (has links)
A survey of some chemical constituents of the lycopods was carried out in order to determine whether the chemistry of these plants is correlated with their taxonomy. One approach to this problem was to study the products of photosynthesis of species of Lycopodium. Selaginella and Isoetes. Radioactive C¹⁴O₂ was to fed these plants and the distribution of radioactivity in sugars and amino acids was examined by means of paper chromatography. The distribution of radioactivity in sugars was characteristic for each genus, but the distribution of radioactivity in amino acids was not. In Selaginella 80% or more of the radioactivity was incorporated into trehalose while most of the rest of the radioactivity was found in sucrose. There was one exception to this: in S. kraussiana 40% of radioactivity was incorporated into trehalose while most of the rest was incorporated into an unidentified sugar. In Isoetes 4% to 8% of the radioactivity was found in trehalose with most of the rest in sucrose. In Lycopodiurn 95% or more of the radioactivity was found in sucrose and none was found in trehalose. Radioactive trehalose was administered to species of these genera and it was shown that they are all able to metabolize trehalose to some degree. Species of Selaginella, Isoetes and Phylloglossum were examined to determine whether they contain alkaloids. Phylloglossum extracts contained compounds with the chromatographic properties of Lycopodiurn alkaloids, but Selaginella and Isoetes species did not contain detectable amounts of these compounds. / Science, Faculty of / Botany, Department of / Graduate
22

Occurrence of Sorbito (D-glucitol) and related carbohydrate in Malus fruits.

Chan, Willard Wing Lap. January 1970 (has links)
No description available.
23

A Quantitative study of sorbitol and related carbohydrates in Malus.

Chong, Calvin January 1970 (has links)
No description available.
24

Sorbitol in malus.

Liu, Phyllis Shih-Kiang. January 1967 (has links)
No description available.
25

Flavonoid and triterpenoid constituents of the Ericaceae of Hong Kong (with a note on the essential oils of the Hong Kong Rutaceae)

Tam, Shang-wai, Arthur, Henry Richard, 譚尚渭 January 1961 (has links)
published_or_final_version / Chemistry / Master / Master of Science
26

The structure of avicennin: a coumarin from the bark of Zanthoxylum avicennae DC

Lee, Cheuk-man., 李卓民 January 1957 (has links)
toc / Chemistry / Master / Master of Science
27

Phytochemical study of codonopsis tangshen: Tien Shui tangshen.

January 1980 (has links)
Wong Man-po. / Thesis (M. Phil.)--Chinese University of Hong Kong, 1980. / Bibliography: leaves 88-91.
28

Phytochemical studies on medicinal plants: alisma orientale and desmodium styracifolium. / CUHK electronic theses & dissertations collection

January 2005 (has links)
Forty-six constituents have been identified from an ethanol extract prepared from the aerial parts of Desmodium styracifolium, including seven triterpenes: lupeol (15), lupeone (16), olean-12-ene-3beta, 22beta-diol (sophoradiol) (19), olean-12-ene-3beta, 22beta, 24-triol (soyasapogenol B) (20), (23Z)-9, 19-cycloart-23-ene-3beta, 25-diol (21), (24R)-cycloart-25-ene-3beta, 24-diol (24a), and (24S)-cycloart-25-ene-3beta, 24-diol (24b); one triterpene saponin: 3-O-[alpha-rhamnopyranosyl (1→2)-beta-galactopyranosyl (1→2)-beta-glucuronopyranosyl] soyasapogenol B (soyasaponin I) (53); three phytosterols: beta-sitosterol (17), stigmasterol (18), and daucosterol (47); sixteen isoflavanones and O-glycosides: 5, 7-dihydroxy-2', 4'-dimethoxy-isofavanone (homoferreirin) (22), 5, 7, 4'-trihydroxy-2'-methoxy-isofavanone (isoferreirin) (23), (3R)-5, 7-dihydroxy-2', 3', 4'-trimethoxy-isoflavanone (25a), (3S)-5, 7-dihydroxy-2', 3', 4'-trimethoxy-isoflavanone (25b), (3R)-5, 7-dihydroxy-2'-methoxy-3', 4'-methylenedioxy-isoflavanone (26a), (3S)-5, 7-dihydroxy-2'-methoxy-3, 4'-methylenedioxy-isoflavanone (26b), 5, 7, 3'-trihydroxy-2', 4'-dimethoxy-isoflavanone (secundiflorol H) (40), 5, 7, 2', 4'-tetrahydroxy-isoflavanone (dalbergiodin) (41), 3, 5, 7, 4'-tetrahydroxy-2, 2'-epoxyisoflavanone (42), (3R)-5, 7-dihydroxy-2', 3', 4'-trimethoxy-isoflavanone 7-O-beta-glucopyranoside (48a), (3S)-5, 7-dihydroxy-2, 3', 4'-trimethoxy-isoflavanone 7-O-beta-glucopyranoside (48b), (3R)-5, 7-dihydroxy-2'-methoxy-3', 4'-methylenedioxy-isofavanone 7-O-beta-(glucopyranoside (49a). (Abstract shortened by UMI.) / In the present study, two medicinal plants were investigated for their organic constituents. Plant samples were extracted and purified by chromatographic separation using a combination of methods. Each compound isolated was characterized by spectroscopic and physical data. A number of new chemical structures were found. / The investigation has led to the isolation and structural elucidation of fourteen pure compounds from an ethanol extract prepared from the dried rhizomes of Alisa orientale, including three types of skeletons: protostane triterpene, guaiane sesquiterpene and phytosterol. They were identified to be beta-sitosterol (1), (17S)-3, 11-dioxo-23-nor protost-12-en-23 (17)-olide (2), alisol B 23-acetate (3), alismol ( 4), alismoxide (5), alisol B (6), alisol A (7), 25-O-methylalisol A (8), 25-anhydroalisol A 24-acetate (9), 25-anhydroalisol A (10), alisol E 23-acetate (11), daucosterol 6'-stearate (12), (20R, 23S, 24R)-23, 24, 25-trihydroxy-2, 3-seco protost-13 (17)-en-3-oic acid 2, 11beta-lactone (13), and 13beta, 17beta-epoxyalisol A (14). Among them, compound 2 was a new naturally occurring skeleton of 23-nor protostane triterpene, and compound 13 a new 2, 3-seco-protostane triterpene. / Zhao Ming. / "September 2005." / Adviser: Chun-Tao Che. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3812. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 179-187). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.
29

Semisynthetic pyrrolizidine alkaloid antitumor agents and the toxic component of eupatorium rugosum

Fleischmann, Thomas John 08 1900 (has links)
No description available.
30

The chemistry of West African plants

Wragg, Keith January 1967 (has links)
No description available.

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