We studied and compared genetic variation of Korean pine (Pinus koraiensis Sieb. et Zucc.) from 12 natural populations in Korea, China, and Russian Far East using allozymes and random amplified polymorphic DNAs (RAPDs). Eighteen polymorphic allozyme loci and 38 polymorphic RAPD fragments were analyzed. The level of allozyme diversity (A = 1.95, P95= 46.8%, Ho= 0.158, He= 0.169) and the degree of genetic differentiation (FST= 0.069) were comparable to those of other pines with similar life histories and ecological traits. Allozyme (He) as well as RAPD (Shannon’s index) variation decreased from south (Korea) to north (Russia), providing an evidence for the hypothesis of Korean pine’s northward migration. Differentiations among three different regions (Korea, China, and Russia) as well as among populations within regions were small. Substantial gene flow (Nm= 3.4) may be a partial explanation to this result. Clustering algorithms using various genetic distance measures showed some decisive geographic patterns at allozyme and RAPD level: the geographically close populations tended to be clustered together. On the other hand, two Chinese populations, Xobukho and Wangging, were grouped with the Russian populations rather than with the other Chinese populations. The Xiaoxing’anling and other mountains extended from north to south seemed to function as a barrier against gene flow between the Xobukho and Wangging (located east of the mountains) and the other Chinese P. koraiensis populations (located west of the mountains). The genetic diversities and differentiation estimated from RAPD data in Korean pine were congruent with those of allozymes.

Megadenia Maxim. is a small genus of the Brassicaceae endemic to East Asia with three disjunct areas of distribution: the eastern edge of the Qinghai-Tibetan Plateau, the Eastern Sayan Mountains in southern Siberia, and Chandalaz Ridge in the southern Sikhote-Alin Mountains. Although distinct species (M. pygmaea Maxim., M. bardunovii Popov, and M. speluncarum Vorob., Vorosch. and Gorovoj) have been described from each area, they have lately been reduced to synonymy with M. pygmaea due to high morphological similarity. Here, we present the first molecular study of Megadenia. Using the sequences of 11 noncoding regions from the cytoplasmic (chloroplast and mitochondrial) and nuclear genomes, we assessed divergence within the genus and explored the relationships between Megadenia and Biscutella L. Although M. bardunovii, M. speluncarum, and M. pygmaea were found to be indiscernible with regard to the nuclear and mitochondrial markers studied, our data on the plastid genome revealed their distinctness and a clear subdivision of the genus into three lineages matching the three described species. All of the phylogenetic analyses of the chloroplast DNA sequences provide strong support for the inclusion of Megadenia and Biscutella in the tribe Biscutelleae. A dating analysis shows that the genus Megadenia is of Miocene origin and diversification within the genus, which has led to the three extant lineages, most likely occurred during the Early-Middle Pleistocene, in agreement with the vicariance pattern. Given the present-day distribution, differences in habitat preferences and in some anatomical traits, and lack of a direct genealogical relationship, M. pygmaea, M. bardunovii, and M. speluncarum should be treated as distinct species or at least subspecies.

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From a root bark of Lespedeza bicolor Turch we isolated two new (7 and 8) and six previously known compounds (1-6) belonging to the group of prenylated polyphenols. Their structures were elucidated using mass spectrometry, nuclear magnetic resonance and circular dichroism spectroscopy. These natural compounds selectively inhibited human drug-resistant prostate cancer in vitro. Prenylated pterocarpans 1-3 prevented the cell cycle progression of human cancer cells in S-phase. This was accompanied by a reduced expression of mRNA corresponding to several human cyclin-dependent kinases (CDKs). In contrast, compounds 4-8 induced a G1-phase cell cycle arrest without any pronounced effect on CDKs mRNA expression. Interestingly, a non-substituted hydroxy group at C-8 of ring D of the pterocarpan skeleton of compounds 1-3 seems to be important for the CDKs inhibitory activity.