Five crystalline substances, which are positive to$L_{IEBERMAN}-B_{URCHARD}$ reaction, were isolated from the unsaponifiable fraction of the fresh leaves of Betula latifolia $K_{OMAROV}$ (Betulaceae)by silica gel column chromatographic purification. Compound $A\;(C_{29}H_{50}O,\;mp\;136^{\circ}), \;B\;(C_{30}H_{52}O_3,\;mp\;165^{\circ}), \;C\;(C_{30}H_{52}O_4,\;mp\;237^{\circ}), \;D\;(C_{30}H_{52}O_3,\;mp\;196^{\circ})\;and\; E\;(C_{30}H_{52}O_4,\;mp\;121^{\circ})$ were isolated. Compound B was characterized as a new tetracyclic triterpenoid. Compounds A, C and D were identified as ${\beta}-sitosterol$, betulatriterpene C, and betulafolienetriol, respectively.

Tobacco, which has nicotine for its main component, has been in medical use for a long time and in great demand for smoking throughout the world. The purpose of this study is to control nicotine amount and to increase yield more efficiently by the method of systematic variations. Nutrient solutions for tobacco culture were designed and prepared in 10 kinds with mineral ions: $NO_{3^-},\;SO_{4^{--},\;PO_4{^{-3},\;K,{^+}\;Ca,{^{++}\;Mg,{^{++}$, Mn, B, Cu, Zn, Mo, and Fe. Nicotiana tabacum L. Yellow Special A, grown for 50days from sowing, was replanted in plastic pot and cultured for 65 days supplying with prepared nutrient solutions. After harvest, their nicotine amount was determined by means of acid-base titrimetry and gas chromatography. The tobacco plants in KCa 4 and KMg 9 groups demonstrated the highest yield in total leaves weight and KMg 7 group in average nicotine amount. They have shown the increase of nicotine amount from lower leaf to 16th leaf, and thereafter decreased gradually. The author also pursued the optimum ionic proportions for the absolute nicotine amount in tobacco by means of systematic variations method.

In the light of quality comparison the ratio of panaxadiol and panaxatriol contents was assayed in the extract of various ginseng products, whose origin of production and species of the original plants are different. Aglycone compositions of other ginsengs were not comparable with Korean ginseng in their ratio of panaxadiol and panaxatriol contents of dammarane glycosides.

In Cnidium officinale $M_{AKINO}$ and Platycodon grandiflorum A. $D_E\;C_{ANDOLE}$, chlorogenic acid was identified by Rf values, color reactions on paper chromatograms and UV-absorption spectra of the eluate of phenolic spots. And isochlorogeni acid-like substance was also found in the former. $1-Phenylalanine-U-C^{14}$ and sodium $acetate-2-C^{14}$ werse fed to both plants and their incorporation ratio to chlorogenic acid and isochlorogenic acid-like substance was compared. Phenylalanine was better precursor for chlorogenic acid in both plants than acetate. But acetate showed higher incorporation ratio to isochlorogenic acid-like substance in Cnidium officinale than that of phenylalanine.

Silica gel column chromatography on the ether extract from the fruits of Angelica gigas $M_{AKAI}$ gave two kinds of crystalline constituents. The following derivatives of coumarins were identified by IR, NMR spectra, elemental analysis and physico-chemical tests: iso-imperatorin $(mp\;108{\sim}109^{\circ},\;C_{16}H_{14}O_4)$ and decursidin $(mp\;60{\sim}61^{\circ},\;C_{24}H_{26}O_7)$.

Silica gel column chromatography of the ether extract of the root of Angelica decursiva $F_{RANCHET}\;et\;S_{AVATIER}$ form. albiflora $N_{AKAI}$ (Umbelliferae) gave four kinds of crystalline products of pyranocoumarin and furocoumarin: decursidin $(mp\;60{\sim}61^{\circ},\;C_{24}H_{26}O_7)$, decursin$(mp\;110{\sim}111^{\circ},\;C_{19}H_{20}O_5)$, umbelliferone $(mp\;227{\sim}228^{\circ},\;C_{9}H_{6}O_3)$, and nodakenetin $(mp\;187{\sim}189^{\circ},\;C_{14}H_{14}O_4)$. Besides, the methanol extract of the root was found to contain sucrose.

The saponins of two- and four-year-old American ginseng plants (Panax quinquefolium L.) (Araliaceae) collected in July and September were studied. American ginseng saponins (panaquilins) differ from Korean ginseng $(Panax ginseng\;C.A.\;M_{EYER})$ saponins (ginsenosides). The American ginseng saponins separated and named were panaquilins A, B, C, D, E-1, E-2, E-3, G-1, G-2, (c) and (d). One-dimensional thin-layer chromatography did not completely separate panaquilin mixture and was subject to misinterpretation. The panaquilins were more accurately separated and identified by the two-dimensional thin-layer method established. Some differences in American ginseng saponins were dependent upon the plant age, time of collection, and part extracted. The American ginseng sapogenin components are panaxadiol (panaquilins B and C), oleanolic acid (panaquilin D) and panaxatriol (panaquilin G-1). The panaquilins E-1, E-2 and E-3 mixture contained both panaxadiol and panaxatriol. The genins of panaquilins A, (c), (d) and G-2 were not identified. In addition, ${\beta}-sitosterol$ and stigmasterol were identified from the root ether extracts.

A component $F,\;C_{20}H_{30}O_4,\;M^+\;(m/e)\;334,\;mp\;258{\sim}260^{\circ},\;[{\alpha}]D=-133.25^{\circ}\;(C=0.2,\;EtOH)$, was isolated from Siegesbeckia pubescens $M_{AKINO}$. This compound was identified as $16{\beta}-(-)-kauran-17$, 19-dioic acid, using spectroscopies and synthesizing various derivatives of the compound F.

The pericarpia of Xanthoxylum piperitum D.C., X. coreanum $N_{AKAI}$ and Fagara mandshurica are used as an identical botanical drug in Korea. Although it is difficult to differentiate these three drugs on the basis of morphological characteristics, they can be easily identified by applying ethyl ether extracts of them on a silica gel thin-layer plate, using several developing solvent systems and color reagents, and comparing the component spots. The pericarpium of F. mandshurica gave the most spots and that of X. piperitum the least, which is also different from that of X. coreanum.