The effect of age on enolase turnover in the free-living nematode, Turbatrix aceti.

The rates of synthesis and degradation of enolase and total soluble proteins slow with age in the free-living nematode, Turbatrix aceti. The half-lives are 73 and 58 h for soluble protein and enolase, respectively, in young organisms (5 days old). The respective figures are 163 and 161 h for old organisms (22–30 days old). Similar slowing of protein turnover occurs when the organisms are aged by a repeated screening procedure which avoids the use of fluorodeoxyuridine, an inhibitor of DNA synthesis normally added to aging cultures to obtain synchrony. The results support the idea that slowed protein turnover may be responsible for the formation of altered enzymes in old organisms.     

Progesterone antagonism of androgen-dependent marking in gerbils

The role of progesterone (P) as an androgen antagonist in Mongolian gerbil territorial marking was assessed in the present investigation. Twenty-seven mature males were observed for two consecutive weeks in a marking apparatus. On the basis of the average of the two sessions, subjects were matched and assigned to one of three groups. All animals were orchidectomized and tested three weeks after surgery. Three days after a single postoperative session a schedule of hormonal replacement was initiated. Group 1 was administered 640 μg testosterone propionate (TP). Group 2 received 640 μg TP followed immediately by 3 mg P. A third group received 640 μg TP followed by a 1 mg injection of P. Subjects were tested for marking 24 hr after the injection for a cumulative period of 6 wk.Results indicated that (a) castration drastically reduced marking; (b) TP alone and TP + 1 mg P restored the behavior; (c) TP + 3 mg P inhibited its restoration; and (d) a significant interaction was present between hormonal therapy and the 6-wk testing interval. However, all three hormonal treatments restored sebaceous gland dimensions. Results are discussed in terms of a model of hormone-gene action.     

Echitoserpidine: A new alkaloid of the fruits of Alstonia venenata

The structure of echitoserpidine, a new alkaloid of the fruits of Alstonia venenata has been established as (1) on the basis of spectral and chemical evidence.     

Alcaloïdes steroidiques du Malouetia Brachyloba et du M. Heudelotii

Malouetine and funtumafrine C have been isolated from the leaves of Malouetia brachyloba, indicating that this species is not very different from M. bequaertiana. Five conanine derivatives have been extracted from the leaves of M. heudelotii, a species which does not contain any alkaloid with a quaternary ammonium function.     

OCCURRENCE OF PHYIWATED CHLOROPHYLL c IN ISOCHRYSIS GALBANA AND ISOCHRYSIS SP. (CLONE T-ISO) (PRYMNESIOPHYCEAE)1

The pigment composition of two clones of Isochrysis galbana Parke (CCMP 1323 and CCAP 927/1), and Isochrysis sp. (clone T-ISO) was analyzed by high-performance liquid chromatography using a polymeric octadecylsilica column. Fluorescent peaks with retention times higher than chlorophyll a were detected for all three clones. The corresponding pigments were isolated and characterized in terms of their visible absorbance and fluorescence spectra. The pigments were similar to phytol-substituted chlorophyll c, previously isolated from Emiliania huxleyi (Lohm.) Hay and Mohler and other species containing chlmophyll c₃. The presence of phytol-substituted chlorophyll c in I. galbana which lacked chlorophyll c₃, increases the diversity of chlorophyll patterns for the Haptophyta, which can be grouped, at present, into six different pigment types. This is the jrst observation of a haptophyte containing the apolar phytylated chlorophyll c-like pigment but lacking chlorophyll c₃.     

DEUCALION GEN. NOV. AND ANISOSCHIZUS GEN. NOV. (CERAMIACEAE,CERAMIALES), TWO NEW PROPAGULE-FORMING RED ALGAE FROM SOUTHERN AUSTRALIA1

Two new propagule-farming red algae from southern Australia, Deucalion levringii (Lindauer) gen. et comb. nov. and Anisoschizus propaguli gen. et sp. nov., are described and defined largely on their development in laboratory culture. Deucalion is included in the tribe Compsothamnieae on the basis of its subapical procarp and alternate distichous branching. It differs from the other genera included in that tribe in that it produces 3-celled propagules, polysporangia, a subapical cell of the fertile axis which bears 3 pericentral cells, and an apparently post-fertilization involucre which develops from the hypogenous and sub-hypogenous cells of the fertile axis. Its gametophyte morphology has been elucidated in culture, as only sporophytes are known from the field. Gametophytes do not appear to produce propagules. Anisoschizus is provisionally included in the tribe Spermothamnieae on the basis of its subdichotomous branching, possession of a prostrate system and the production of polysporangia. It differs from the other genera of the tribe in the production of 2-celled propagules. Observations on the germination of the “monosporangia” of Mazoyerella arachnoidea and Monosporus spp. indicate that they are analagous to the propagules of Deucalion and Anisoschizus. The nature of these propagules and their role in recycling the parent plant are discussed and contrasted with true monosporangia. It is recommended that Monosporus be maintained as a form genus containing representatives from more than one tribe, as exemplified by plants from Lord Howe I. provisionally identified as M. indicus Boergesen which have both prostrate and erect, as opposed to only erect, axes.     

Factors affecting the extraction and the relative proportions of multiple forms of plant α-galactosidases

The extractability of α-galactosidase activity from mature Vicia faba seeds and the conversion of the low molecular weight form II to the larger oligomer I, was examined over a range of salt concentrations. Specific and total activities of the preparations were high when strong salt solutions were used. Extraction of α-galactosidase I, in comparison with II, requires solutions with a high ionic strength (e.g. 0.5 M NaCl). Interpretation of gel filtration patterns are, however, complicated by conversion of II to I which occurs under these conditions. This conversion is also enhanced by routine procedures used for enzyme purification, such as citric acid precipitation.     

A trypsin and chymotrypsin inhibitor from seeds of Bauhenia purpurea

A trypsin and chymotrypsin inhibitor was partially purified from Bauhenia purpurea seeds and separated from a second inhibitor by Ecteola cellulose chromatography. The factor inhibited bovine trypsin and chymotrypsin as well as pronase trypsin and elastase. It formed a complex with trypsin and with chymotrypsin, but a ternary complex could not be detected. Differences were detected in the effect on trypsin and on chymotrypsin, although one enzyme interfered with the inhibition of the other. The results obtained point to two active centers on the inhibitor for the trypsin and chymotrypsin inhibition such that the one cannot complex with the inhibitor after this inhibitor had complexed with the other.     

Novanin: A germacranolide from Artemisia nova

A new germacranolide, novanin (I), has been isolated from Artemisia nova and its structure determined. The compound is also present in small amount in A. tripartite Rydb. ssp. rupicola Beetle.