Haplophyllum buxbaumii has yielded three new lignan type A glucosides: majidine [2], qudsine [3], and arabelline [4], Cleistanthin B [1] is also reported for the first time from this family. Temperature-dependent nmr studies have provided insight into the conformational equilibria existing in 1, 2, and 4.In continuation of our systematic phytochemical investigation of Haplophyllum buxbaumii A. Juss. (Rutaceae) (1), we now report the isolation and structure elucidation of four diphyllin glucosides, three of which (2-4) are new. These are cleistanthin B [1], 4-The bluish fluorescence of the four lignan glucosides under uv light as well as their similar uv spectra (X max 261.6 nm) indicated that all these compounds bear an arylnaphthalene nucleus (2). The acid hydrolysis of the four lignan glucosides afforded the same aglycone, which was identified by spectral data as diphyllin [11] (12). The sugar residues, identified by tic comparison with authentic samples, were found to be glucose of compound 1, apiose and xylose of compound 2, apiose, arabinose, and glucose of compound 3, and arabinose and glucose of compound 4.The uv, ir, ms, and 'H-nmr spectra were reported for cleistanthin B (3). As the 'Hnmr assignments were not fully made, we present in Table 1 the 'H-nmr spectrum with the assignments of the individual aromatic protons. The 13C-nmr chemical shifts and multiplicity assignments of cleistanthin B are shown in Table 2.Compound 2 was assigned the molecular formula C31H32015) positive fabms m!z 645 [M + H]+). The 'H-nmr spectrum of the acetylated derivative 6 of compound 2showed five 3 H singlets in the region between 2.02 and 2.14, corresponding to the aliphatic acetoxy groups, indicating the presence of five aliphatic hydroxyl groups. The 13C-nmr spectrum (DMSO-

Phytochemical analysis of the ground aerial parts of Artemisia arborescens resulted in the isolation from the ethanolic extract of the known compounds: artemitin, arborescin, sesamin, (+)-lirioresinol beta-dimethyl ether, chrysoeriol, apigenin, beta-sitosteryl glucoside, dihydroridentin, and chrysoeriol 4-glucoside. The last six compounds are isolated from this plant for the first time. The same fraction also yielded the new eudesmanolide jordanolide (1). The effect of an aqueous extract of the plant was studied on rat isolated ileum, uterus, and urinary bladder. The aqueous extract (AE) caused a concentration-dependent reduction in the amplitude of the phasic contractions and in the tone of the ileum. On the other hand, AE caused a significant increase in the frequency as well as the amplitude of the phasic contractions and increased the tone of the isolated uterus and the urinary bladder strips. On the uterus, quinacrine, an inhibitor of the release of arachidonic acid and its metabolites, and indomethacin, a cyclooxygenase inhibitor, potentiated rather than inhibited the effects of AE on this tissue. These observations are discussed in relation to the use of the plant extract in folk medicine.

No abstract

No abstract

The effects of the flavone 3,3'-di-O-methylquercetin (DOMQ) have been examined and compared with those of quercetin, on guinea-pig isolated ileum, trachea, and main pulmonary artery (MPA). Except for transient contractions induced by low concentrations (10(-8)-3 x 10(-6) M), DOMQ and quercetin (up to 3 x 10(-4) M) caused reduction of the tone and the phasic contractions of the ileum. A23187 reversed the inhibitory effects of quercetin but not those of DOMQ. DOMQ and quercetin caused concentration-dependent relaxation of the trachea and the adrenaline-contracted MPA. DOMQ shifted to the right the concentration-effect curves induced by acetylcholine on the ileum and the trachea, and by adrenaline on MPA and those induced by CaCl2 on ileum, trachea and MPA. DOMQ also inhibited the contractions induced, in Ca2+-free EGTA-containing buffer, by histamine on ileum and by adrenaline on MPA. These observations suggest that DOMQ inhibits Ca2+ influx, Ca2+ release from intracellular stores and, more likely, Ca2+ binding to intracellular receptor proteins.

The effects of the flavone luteolin, extracted from Cokhkum richii, on guinea-pig isolated ileum, pulmonary artery, trachea, atrium, perfused heart, and on blood pressure and blood flow of anaesthetized guinea-pigs were studied. Luteolin (10-'-3 X M) caused concentration-dependent relaxation of the tone of ileum, epinephrineprecontracted pulmonary artery and only mild relaxation of acetylcholme-precontracted trachea. These effects were not affected by pretreatment with 1 m M theophylline except in the ileum where theophylline shifted to the left the luteolin concentration-effect curve. Luteolin (3 X 10-6-3 X M) caused an increase in the beating rate and the contractility of the spontaneously beating atrium and of the isolated perfused heart. Theophylline (1 mM) significantly inhibited the effects of luteolin on the atrium and the perfused heart. Luteolin, in doses of 0.3, 1.0, 1.5 and 5 mg/kg body weight had no effect on heart rate of anaesthetized guinea-pigs but caused depression of systolic and diastolic blood pressure except at the lowest dose used where there was a small increase in both parameters. Also, only the lowest dose (0.3 mg/kg) caused a small increase in blood flow. Larger doses of luteolin caused dose-related inhibition of blood flow. The effects of luteolin on blood pressure and blood flow were not affected by theophyllme pretreatment (5 mg/kg). These observations suggest that the effects of luteolin may be tissue-specific and in the isolated heart they may be attributed to inhibition of cyclic AMP phosphodiesterase. The data further demonstrate that luteolin has potential cardiovascular effects that merit further investigation.

No abstract

No abstract