An experiment was conducted to ascertain the effects of irradiation and various concentrations of an aqueous solution of ortho-chlorophenoxyacetic acid on growth rate, abscission layer formation, fruit set, yield, time of maturity, ascorbic acidj dry weight, total nitrogen, total phosphorous, titratable acidity, reducing sugars, total carbohydrates, roughage, ash weight, sodium, potassium, calcium, magnesium, copper, iron, zinc and manganese of tomatoes. Supplementary illumination beyond that of the normal day length resulted in significant increases in weekly growth rate and iron content, with slight increases in fruit set, titratable acidity, total nitrogen, ash weight and magnesium content of tomatoes. The xylem area of the abscission layer was increased as a result of the supplementary illumination. Supplementary illumination also resulted in significant decreases in ascorbic acid, total carbohydrates, sodium and potassium. There were also slight decreases in yield, reducing sugars and calcium of tomatoes. Under normal day length the ortho-chlorophenoxy-acetic acid was more effective in inducing fruit set than where supplementary light was used. The most effective concentration was 75 p.p.m. The trends of the effects of the treatments are discussed, as well as the significant findings. / Science, Faculty of / Botany, Department of / Graduate

A dialyzing technique was developed to concentrate an estrogen hormone fraction suitable for separation by paper partition chromatography and spectrophotometry assay. Estrogens were not found in sexually differentiating salmon embryos. Small amounts of estriol, estradiol-17β and estrone added to the tissue could not be recovered. However, horse testes assayed by the same technique showed the presence of estradiol-17 β and estrone in concentrations of .097 and .143 mg./kg., respectively. The assay of horse testes was carried out on.90 gram lots, whereas the one previous chemical assay was done on 28,000 grams. It is concluded that this technique is very satisfactory for extraction of estrogens from animal gonads, but that hormone added to whole salmon embryos is inactivated by-some unknown system. A partition technique recently developed by F. Mitchell and R. Davies for the extraction of estrogens from human placentae was slightly modified for use with salmon embryos. This method confirmed the negative findings obtained by the dialyzing technique. On the basis of these experiments, there is no evidence to support the hormonal theory of sex differentiation in fishes. / Science, Faculty of / Zoology, Department of / Graduate

The neurohypophysial hormones of Pacific chinook salmon (Oncorhynchus tschawytscha) were purified and the amino acid sequence of both hormones determined. The extraction and purification procedure was developed in an effort to maximize the yields of pure hormones. Pituitary glands were extracted at 4°C using 0.2 M acetic acid. Purification consisted of gel filtration, ultrafiltration, and ion exchange. Gel filtration on Sephadex G-15 columns was used to separate neurohypophysial peptides from high molecular weight material. Separation of the two hormones was accomplished on one of three cation exchangers: carboxymethylcellulose, phosphocellulose or sulfoethyl-Sephadex. The hormones were eluted from cation exchange columns using a sodium or ammonium ion concentration gradient at constant pH; pH 5 was used for chromatography on carboxymethylcellulose and on phosphocellulose; pH 2.45 was used for chromatography on sulfoethyl-Sephadex. The two hormones were purified further by rechromatography of individual hormones on another cation exchange medium. The material obtained by rechromatography was pure as determined by amino acid analyses. The yields of pure hormones at the end of purification procedure was 48% of the starting material. The specific activities of the two purified hormones were 145 and 229 oxytocic units per milligram for Hormone I and Hormone II respectively. The amino acid sequence of Hormone I was determined by a combination of three methods: subtractive Edman degradation, partial acid hydrolysis, and Dansyl-Edman technique. The amino acid sequence of Hormone I was found to be that of 4-serine, 8-isoleucine oxytocin. The amino acid sequence of Hormone II was determined by the Edman subtractive method, the Dansyl-Edman technique, and the mobility of the C-terminal residue on high voltage electrophoresis. The amino acid sequence of Hormone II was found to be that of 8-arginine oxytocin. The two neurohypophysial hormones described from salmon have amino acid sequences identical with those described from four species of Gadiformes and one species of Cypriniformes by other workers. The position of Salmoniformes on the evolutionary tree of teleost fishes suggests that these structures are characteristic of a wide range of teleosts. / Science, Faculty of / Zoology, Department of / Graduate

Treatment of cedar leaf oil with aqueous potassium permanganate resulted in the oxidative ring opening of thujone (XXIV) to yield the crystalline α-thujaketonic acid (XXV).⁷⁰ This material, because of its availability and interesting structure, represented an attractive starting material for the synthesis of analogues of insect juvenile hormone. Therefore, to achieve this aim, α-thujaketonic acid (XXV) was converted to form two products (or 'half-molecules') which were then coupled together and transformed to the analogues. In the initial study Grignard treatment of (XXV) produced an intermediate tertiary alcohol (LVIII) which cyclized spontaneously to a lactone (XXVI). The latter compound resisted further transformation and this approach was abandoned. On the other hand, (XXV) was refluxed in water to give β-thujaketonic acid (XXIX). This ring-opened acid was hydrogenated to give the ketoacid (XXX) which reacted with excess methylmagnesiurn iodide to yield the alcohol acid (XXXI). In the last reaction of this sequence some carboxylic acid was found to be converted to an alcohol ketone. This product (XXXII) was apparently formed via attack of the excess Grignard reagent (on to the salt of the acid) to yield the ketone from the acid. This alcohol ketone (XXXII) was reduced to a diol (XXXIII) and the latter converted to an acetate derivative (XXIV) 1n order to investigate its structure. Next, the desired alcohol acid (XXXI) was pyrolyzed to give the olefin acids (XXVII) and (XXVIII) which were separated via silver nitrate impregnated silica gel column chromatography. The required intermediate (XXVII) afforded one of the necessary products or 'half molecules'. In order to improve the overall yield of the required synthon (XXVII), α-thujaketonic acid was quantitatively converted to the methylene derivative (LIX) via reaction with two equivalents of methyl triphenyphosphorane.⁵⁹ Pyrolytic ring opening of the cyclopropane ring system in (LIX) afforded a good yield of the dienoic acid (XXXV). Reduction of the desired acid (XXXV) with potassium in liquid ammonia gave an 85% yield of the key intermediate (XXVII). The second required intermediate was synthesized via the esterification of β-thujaketonic acid (XXIX) with diazomethane in ether. This yielded the ketoester (XXXVII) which was used in the following coupling reaction sequence. Thus the key intermediate (XXVII) was treated with lithium diisopropylamide (LDA) in tetrahydrofuran (THF) to form the carboxylic acid dianion which was reacted with the keto ester (XXXVII) in THF to give a mixture of β-hydroxy carboxylic acids (XXXIX) and (XL). This product mixture was dissolved in dry pyridine and excess benzene-sulfonyl chloride was added 1n order to achieve the required cyclization to the expected olefinic β-lactones (XLI) and (XLII). Epoxidation of this mixture with metachloroperbenzoic acid (MCPBA) in methylene chloride yielded the corresponding epoxy β-lactones (XLIII) and (XLIV). The final step in the synthetic strategy was to utilize the pyrolytic decomposition of the intermediate β-lactone function to the central double bond inherent in the juvenile hormone systems. Therefore, the epoxy lactones (XLIII) and (XLIV) were subjected to such pyrolytic conditions but only decomposition products resulted. For this reason further studies with (XLIII) and (XLIV) were abandoned. The olefin acid (XXVII) was reacted with mercuric acetate in dry alcohol and the mercury intermediate thus derived was converted with sodium borohydride in methanol or ethanol to yield respectively the methoxy (IL) or the ethoxy acids (XLVIII). The ethoxy acid (XLVIII) was reacted with LDA in THF to give the expected carboxylic acid dianion, the latter upon addition of the ketoester (XXXVII) yielded a mixture of the β-hydroxycarboxylic acids (L) and (LI). This mixture was lactonized with benzenesulfonyl chloride in pyridine as described above to yield the ethoxy β-lactones (L11) and (LI 11). These were pyrolyzed and separated to give the juvenile hormone analogues (LIV) and (LV). Analogous investigations on the methoxy acid (IL) yielded the analogous β-hydroxy carboxylic acids (LVI) and (LVII). Time constraints precluded the conversion of these to the hormone analogues. / Science, Faculty of / Chemistry, Department of / Graduate

The occurrence and biological activity of ecdysterone (insect moulting hormone) was examined in a number of plant species. A simple method was developed for the semiquantitative analysis of ecdysterone in plant extracts. The procedure consists of repeated washing of an aqueous methanolic extract of the plant with petroleum ether, followed by gradient elution of the freeze-dried aqueous extract on a SepPak (CIS reverse-phase cartridge), and high-performance liquid chromatography. Crude extract was purified on Sephadex LH20 for spectral analysis. Twelve species of ferns, three species of gymnosperms, and five species of angiosperms were examined for the presence of ecdysterone. Ecdysterone was found in a number of plant species, the chemistry of which has not previously been examined with respect to phytoecdysteroids. These include four species of ferns (Aspidotis densa (Brackenr.) Lellinger., Cryptogramma crispa (L.) R.Br., Blechnum spicant (L.) Roth, Polypodium glycyrrhiza D.C. Eat); two species of gymnosperms {Taxus brevifolia Nutt., Taxus canadensis Marsh.); and two species of angiosperms (Trillium cernuum L, Trillium ovatum Pursh.). Applied ecdysterone had no effect in a cytokinin bioassay, but elicited a slight increase in elongation of mung bean epicotyls (GA₃ bioassay) and elongation of excised dwarf pea hypocotyl hooks (auxin bioassay). / Science, Faculty of / Botany, Department of / Graduate

No description available.

In 1971 Schally and co-workers (Schally et al., 1971) isolated gonadotropin-releasing hormone (now called luteinizing hormone-releasing hormone (LH-RH)) from sheep hypothalami and established that the hormone was a decapeptide with the amino acid sequence: pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH₂. The peptide was subsequently synthesised (Matsuo et al., 1971b) and shown to stimulate the release of gonadotropins (luteinizing hormone and follicle-stimulating hormone) in a wide range of mammalian species (Schally et al., 1973, 1976). With the exception of amphibians, nonmammalian vertebrates have a poor gonadotropin response to synthetic mammalian LH-RH (for reviews, see Ball, 1981; Jackson, 1981; King and Millar, 1981a). Since there is considerable molecular heterogeneity in the related neurohypophysial nonapeptide hormones (oxytocin-vasopressin) amongst vertebrates (Acher et al., 1972), we postulated that differences might exist in the structure of hypothalamic LH-RH in different vertebrate classes, Utilising a combination of regionspecific antisera and chromatographic techniques, we established that amphibian hypothalamic LH-RH is identical to the mammalian peptide while avian, reptilian, and piscine hypothalamic LH-RHs differ structurally in the region Gly⁶-Leu⁷-Arg⁸ (King and Millar, 1979a, 1980), We have now conducted further studies on avian hypothalamic LH-RH, which indicate that the arginine residue in position eight of mammalian LH-RH is substituted by glutamine in this vertebrate class. Purification of LH-RH from chicken hypothalami and determination of the amino acid composition have confirmed that the structure of avian LH-RH is: pGlu-His-Trp-Ser-Tyr-Gly-Leu-Gln-Pro-Gly-NH₂.

The current interest in the secretions of the adrenal cortex is shared by physiologist, physician and pharmacologists alike. such attention is not surprising in the case of a gland which is immediately essential to life, which can produce syndromes as varied as precocious puberty, virilisation; Addison's disease; Cushing's syndrome, and the newly described hyperaldosteronism syndrome of Conn (1955), a gland which has been implicated in the parthenogenesis of diabetes (Hoet and Lukens, 195; Jackson, 1955), hypertension (Sepeika, 1948, 1955), pre-eclampsia, and atherosclerosis, and which profoundly effects so many of the metabolic processes of the body. The need for accurate measurement of adrenocortical function has therefore been accentuated in recent years. The purpose of this study was to find out as direct a method as possible for determining the rate of secretion of this gland and to define with this method the norms and normal variations.

Some three years ago I availed myself of an opportunity of pursuing a research project in the Department of Medicine at this Medical School. At that time, a long established interest in the study of plasma albumin metabolism was given fresh impetus by the development of techniques which overcame the problem of measuring rates of albumin synthesis and catabolism under conditions of metabolic chonge. Interest in the Department had centred mainly upon the nature of the adaptive changes occurring in albumin metabolism in response to altered dietary protein intake, and by the time I was due to take up my appointment many of these adaptive changes had been clearly defined. The factors mediating these changes however remained unknown.

Some three years ago I availed myself of an opportunity of pursuing a research project in the Department of Medicine at this Medical School. At that time, a long established interest in the study of plasma albumin metabolism was given fresh impetus by the development of techniques which overcame the problem of measuring rates of albumin synthesis and catabolism under conditions of metabolic chonge. Interest in the Department had centred mainly upon the nature of the adaptive changes occurring in albumin metabolism in response to altered dietary protein intake, and by the time I was due to take up my appointment many of these adaptive changes had been clearly defined. The factors mediating these changes however remained unknown.