Yoshisuke Tsuda

New class of steroidal alkaloids from Fritillaria imperialis

Two members of a new class of C-nor-D-homo steroidal alkaloids, impranine (1). and dihydroimpranine (2). along with a new pyridyl-pregnane-type steroidal alkaloid, fetisinine (3). and a known base, korsevine (4). were isolated from the bulbs of Fritillaria imperialis. The structures of the compounds were established on the basis of spectroscopic techniques and some chemical transformations. Compounds 1 and 2 form a new class of steroidal alkaloids, named as impranane.

Biological Activities of Indian Celery, Seseli diffusum (Roxb. ex Sm.) Sant. & Wagh

In continuation of our work on Indian celery (Seseli diffusum (Roxb. ex Sm.) Santapau & Wagh; Umbelliferae), the fractionation of the 80% MeOH–H2O extract of the seeds was performed to identify the principles responsible for its folk use as an antispasmodic and diuretic. Several compounds were isolated as active components: seselin (1) and anthriscinol methyl ether (4) showed a selective cytotoxicity to some yeast strains. Compound 1 also showed spasmolytic activity. On the other hand, isopimpinellin (3) and isorutarin (5) exhibited a spasmogenic effect on the smooth muscle preparations. Compound 5 was also found to have antioxidant activity. Among them, compound 4 was isolated for the first time from this plant. Copyright

New diterpene isopimara-7,15-dien-19-oic acid and its prolyl endopeptidase inhibitory activity

The ethanolic extract of the bulbs of Fritillaria imperialis was subjected to fractionation by solvent–solvent extraction. The nonpolar fraction showed inhibitory activity against prolyl endopeptidase (PEP) (EC.3.4.21.26), a large intracellular enzyme that preferentially hydrolyze proline-containing oligopeptidase at the carboxylic side of a prolyl residue. We have isolated a diterpenoid isopimara-7,15-dien-19-oic acid (1) from the nonpolar fraction of F. imperialis, and on methylation of compound 1, a methylester 2 was obtained which is a known compound previously isolated from Fritillaria thunbergii. The present article describes the isolation and structural elucidation of isopimara-7,15-dien-19-oic acid (1) by single-crystal X-ray diffraction techniques along with its prolyl endopeptidase inhibitory activity.

Survey of Ephedra resources in the Northern Areas of Pakistan and their genetic diversity

More than 400 species of medicinal plants grow in the Northern Areas of Pakistan, including Ephedra plants. To investigate the wild Ephedra plant resources in the area, we surveyed the medicinal plants and collected 71 specimens from 18 collecting sites to analyze their genetic variation. The DNA sequences of the internal transcribed spacers 1 and 2 (ITS 1 and 2) of nuclear ribosomal DNA and a noncoding sequence of chloroplast DNA (trn L/F) were analyzed. This DNA data analysis and external morphological features were used to confirm the species of the specimens, and it was found that E. intermedia was the major species in the area and that E. gerardiana and E. przewalskii were present sporadically. Although it inhabits a relatively small area in comparison with the northwestern Chinese provinces, the DNA sequence of E. intermedia in the Northern Areas of Pakistan was significantly more heterogeneous than the same species grown in those neighboring regions. Most of the E. intermedia specimens contained more than 0.7% ephedrine alkaloids, fulfilling the requirement of the Japanese Pharmacopoeia; thus, the Ephedra plants in the area are a genetic and medicinal resource of great importance.

Botanical origin of Indian celery seed (fruit).

In the course of our study on the traditional medicines and foodstuffs used in Pakistan, we investigated the origin of Indian celery by using the analysis of the internal transcribed spacer (ITS) sequence of nuclear rDNA and a phytochemical approach. We found that the source plant of the Indian celery containing coumarin derivatives such as seselin (1), bergapten (2) and isopimpinellin (3) was not common celery, Apium graveolens. Our results suggest the source plant is Seseli diffusum even though Indian workers reported that A. graveolens seeds contain the aforementioned compounds. In addition, a market survey of the Indian celery in Pakistan and related countries revealed that the Indian celery seeds in Pakistani markets are mainly composed of three species which have been confused in rural markets.

The Structure of a new Crystalline Cevane Alkaloid: its identity with Persicanidine B and Harepermine

The structure of a new crystalline base (melting point (mp) 167–169°C) obtained from Fritillaria imperialis was elucidated as (20R, 25R)-5α,17β-cevanine-3β,6β-diol, X-ray diffraction analysis of the mono-hydrate. The base was found to be identical with persicanidine B and also with harepermine.

Synthesis of some substituted adamantane-2,4-diones from 4, 4-disubstituted cyclohexanone enamines and methacryloyl chloride

The reaction of methacryloyl chloride with the morpholine enamine 4a derived from 4-acetyl-4-isopropenylcyclo-hexanone 3a gave 4,6-anti-6-hydroxy-5,6-dimethyl-7-isopropenyladamantane-2,4-dione 6a and 4,6-syn-6-hydroxy-5,6-dimethyl-7-isopropenyladamantane-2, 4-dione 7a as racemates epimeric at 6-C. Comparable results were found for the corresponding phenyl and benzyl substituted cyclohexanones 3b and 3c. In the case of the methyl-substituted cyclohexanone 3d 4,6- anti-alcohol 7d was isolated in pure form.