Apparatus for Countercurrent Distribution

Craig, Lyman C.; Post, Otto W.

doi:10.1021/ac60028a013

Cited by 220 publications

(71 citation statements)

References 9 publications

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“…each) of a GO-tube Craig countercurrent machine (18) and partitioned through 60 transfers between chloroform and citrate-phosphate buffer, pH 5.2 (40 ml. in each phase).…”

Section: Isolation Of Lycodinementioning

confidence: 99%

Lycodine, a New Alkaloid of Lycopodium Annotinum

Anet¹,

Eves²

1958

Can. J. Chem.

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LYCODINE, A NEW ALKALOID O F LYCOPODIUM ANNOTINUM1r \ new allcaloid, lycocline, CliHYINd, m.p. llSO, has been isolated fro111 Lycopodizr?rt a n -?~o t i n z~n l .Lycodine is a tetracyclic diaciclic base containi~lg a secontlary nitrogen atom, a 2,3-disubstit~ited pyridine ring, and a C-methyl group. T h e 2,3-dis~ibstit~1tion is in the form of a saturatecl sis-niemberecl ring.The all;aloids of Lycopodiu7n nnnokinz~m L. have been sti~died by several groups of worlters in Canada and in Europe (1, 2, 3, 4, 5 ) . The structure of annotinine, C1SH2103N, which is the main alkaloid of this species, is now known (6, 7) and is of a quite novel type. I t therefore becomes of interest to study the chemical structure of the minor alkaloids of this plant.During the process of developing suitable methods for the separation of the many minor alkaloids which have been reported to occur in this Lycopodium species, we noticed that certain fractions possessed ultraviolet absorption characteristic of a pyridine chromophore, inore or less submerged behind general absorption. This paper describes the isolation, characterization, and partial cletermination of the structure of a new alkaloid, lycodine, which was responsible for this characteristic Absorption.Lycodine was concentrated by countercurrent distribution of the allcaloid mother liquors from the crystallization of annotinine. Two successive countercurrent distributions were carried out, first in six large separatory funnels \vith the system chloroform-buffer of pH 6 and then in a 60-tube Craig machine with the system chloroforn~-buffer of pH 5.2.From these countercurrent distributions an all;aloid fraction was obtained which hacl the correct ultraviolet absorption. By chron~atography of this fraction on activatecl alumina pure crystalline lycodine was obtained.Lycodine, m.p. l l S O , [a],, -lo0, had the fornlula C17H2.LN? and gave a characteristic dipicrate, m.p. 229'-233' (decomp.), which was sparingly soluble in methanol. Titration of the base in 50% methanol showed that the pK,'s of the base were 3.97 and 8.08. One C-methyl group was found to be present by the Kuhn-Roth method. The ultraviolet spectra of the base in neutral and in acid solutions are shown in Fig. I , and correspond to an unconjugated pyridine chromophore in the base and salt forms respectively. A fuller discussion of these spectra will be left till after consideration of other results (see below).The infrared spectrum of the base (in Nujol) is shown in Fig. 2 ; the sharp band a t 3270 cm.-I must be due to a N-H group (8). As often happens (8) this band is of very low intensity in the spectrum (Fig. 2) of the carbon tetrachloride solution of the compound. The presence of a pyridine ring is confirmed by the band (9) a t 1580 cm.-I (in Nujol) and that of a C-methyl group by a band (10) a t 1382 cm.-I (in CC14). Acetylation of lycodine with acetic anhydride gave a N-acetyl clerivative, isolated as the monopicrate. Titration of the picrate showed that the acetylated base hacl only one basic center (pK, 4.95). H...

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“…each) of a GO-tube Craig countercurrent machine (18) and partitioned through 60 transfers between chloroform and citrate-phosphate buffer, pH 5.2 (40 ml. in each phase).…”

Section: Isolation Of Lycodinementioning

confidence: 99%

Lycodine, a New Alkaloid of Lycopodium Annotinum

Anet¹,

Eves²

1958

Can. J. Chem.

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“…Intermittent flow extractors include those in which there is a flow of liquid only during a portion of each cycle which includes contacting, mixing, settling and separation of the two phases repeatedly through a series of stages. This type of operation is exemplified by extractors such as those of Compere and Ryland (19), Craig (20)(21)(22), Lathe and Ruthen (23), Fenske and Tegge (24), Nadel and Highhouse (25) and a series of separatory funnels.…”

Section: Isc-458mentioning

confidence: 99%

“…Some extractors employ ''limited-feed" in the sense that essentially only a limited amount of feed such as a single batch addition can be processed without completely reloading the equipment. The Craig machine (20)(21)(22) and the apparatus of Lathe and Ruthen (23) both employing "limited-feed" have applications in scientific investigations but are not directly adaptable to problems requiring continued output. Large scale single batch extractors can be employed essentially only on the simpler separations.…”

Section: Isc-458mentioning

confidence: 99%

“…The term "countercurrent distribution" employed by Craig (21) does not refer to an actual countercurrent flow of liquids through the equipment but merely to a method of operation which permits direct application of the binomial expansion to interpret the results . In describing the extractor presented in this article the term "countercurrent" has the meaning indicated by K. A. Vorteressian and M. R. Fenske (26) whereby the flow of the immiscible liquid ~hases in opposing directions through the equipment actually occurs.…”

Section: Isc-458mentioning

confidence: 99%

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Countercurrent Liquid-Liquid Extractor

Wilhelm¹,

Foos²

1959

Ind. Eng. Chem.

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A novel countercurrent liquid-liquid extractor is presented and illustrated with applications. The apparatus consists essentially of an assembly of mixer-settlers, feeders, reservoirs, and flow lines that are made of glass or other chemical resistant materials. In operation this multistage assembly rotates intermittently in one direction on a horizontal axis causing the immiscible phases to progress to opposite ends of the unit. Details for the construction of the extractor and its principles of operation are given. Extractors of this design are applicable to experimental work and to the preparation of pure compounds in quantity.

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“…Among many types of aqueous-aqueous polymer phase systems available, polyethylene glycol (PEG)-dextran and PEG-potassium phosphate systems have been most commonly used for the partition of biological samples. Using these solvent systems, several different approaches have been made for performing purification of biological samples, such as single step partitioning, repetitive batch extraction, counter-current distribution (CCD) [2,3] and counter-current chromatography (CCC) [4].…”

Section: Introductionmentioning

confidence: 99%