SynopsisFour phytogeographical regions of Pakistan are recognised in an analysis of the phanerogams of Pakistan. Among the uniregionals, the most common element is Irano-Turanian (45.6%) followed by Sino-Japancse (10.6%), Saharo-Sindian (9.1%) and Indian (4.5%). Though in terms of the area, the Saharo-Sindian region occupies by far the biggest territory, the density of uniregional elements is lowest in this region. Overall there are only 6 endemic genera and an estimated 372 endemic species in Pakistan out of 4882 species. Highest numbers of uniregional endemics per unit area are met with in the Sino-Japanese region, followed by the Irano-Turanian and Saharo-Sindian region. Most of the endemics (78.22%) are confined to mountainous regions (c. 1200 m or above). Four areas, i.e. Sino-Japanese region of Kashmir (10.21% endemics), N Baluchistan (Irano-Turanian; 9.4% endemics) and Chitral (9.1% endemics), may be recognised as centres of radiation in Pakistan.
The herbicidal potential of culture filtrates of four Trichoderma spp., namely Trichoderma harzianum Rifai, Trichoderma pseudokoningii Rifai, Trichoderma reesei Simmons and Trichoderma viride Pers., was evaluated against two problematic weeds of wheat, Phalaris minor L. and Rumex dentatus L. In laboratory bioassays, generally, metabolites of all four Trichoderma species significantly reduced various root and shoot growth parameters of the two target weed species. The original concentrations of the culture filtrates of all Trichoderma spp., except T. harzianum, significantly reduced various parameters of root and shoot growth of wheat seedlings. In a foliar spray bioassay, the culture filtrates of all four Trichoderma spp. significantly diminished root and shoot biomass of R. dentatus. The effect of these filtrates on the shoot growth of P. minor and wheat was not significant. Culture filtrates of the four Trichoderma species were successively extracted with butanol, n-hexane, chloroform and ethyl acetate. In detached leaf injection bioassays, n-hexane fractions (3 mg mL(-1)) of T. pseudokoningii, T. reesei and T. viride, and ethyl acetate fractions of T. horzianum and T. pseudokoningii were found to be toxic against R. dentatus. This study concludes that the culture filtrates of Trichoderma species have herbicidal potential in the control of R. dentatus.
Tamarix nilotica (Tamaricaceae) has been used in traditional Egyptian medicine as antiseptic agent. The polyphenolic compounds and flavonoids of T. nilotica have been previously investigated. [1][2][3][4][5] In our efforts to discover new drugs from medicinal plants, antioxidant activity of a selection of commonly occurring wild plants growing in Beni-Sueif governorate, Upper Egypt, has been tested.6) The in vitro antioxidant assays used were 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity, superoxide anion scavenging activity and iron chelating activity. Extracts prepared from the leaves and flowers of T. nilotica have shown the highest antioxidant activity in the three kinds of assay. In this report, phytochemical investigation on the leaves of T. nilotica was carried out. A new derivative of ferulic acid (1) and five known compounds 2-6 were isolated. The structures of the isolated compounds were elucidated on the basis of spectroscopic data and their DPPH radical scavenging activity were evaluated. Results and DiscussionCompound 1 was isolated from the n-butanol soluble fraction of the extract as a white amorphous solid. The UV spectrum showed absorptions at 205, 230, 299 and 314 nm. The 1 H-and 13 C-NMR spectra (including distortionless enhancement by polarization transfer (DEPT), heteronuclear multiple quantum coherence (HMQC), heteronuclear multiple bond connectivity (HMBC), correlation spectroscopy (COSY) and nuclear Overhauser effect spectroscopy (NOESY) experiments) have shown that compound 1 is a trans-ferulic acid derivative. Two 1H doublets at d 7.60 and 6.37 (Jϭ15.9 Hz) represented the trans-substituted olefinic H-1Ј and H-2Ј. The 1 H-NMR signals of two 3H singlets at d 3.86 and 3.75 represented two methoxy methyls. The singlet signal at d 3.86, that showed a correlation with signal at d C 52.0 in the HMQC spectrum, has shown a correlation with the carboxyl carbon signal at d C 169.4 in the HMBC spectrum. Therefore, the signal at d C 52.0 is assigned to the methoxy carbon esterifying the carboxyl group. The other signal at d C 56.7 is assigned to the methoxy carbon attached to C-3 on the aromatic ring. This latter signal showed a HMQC correlation with the signal at d 3.75 in the 1 H-NMR spectrum. A correlation in the HMBC spectrum between the signals at d 3.75 and d C 155.2 confirms the assignment of the latter signal to C-3. The 1 H-NMR spectrum has shown signals for three coupled aromatic protons. The coupling constants of these signals indicated that two of these protons are in ortho positions while the third one is in meta position to one of the former protons. The broad singlet signal at d 7.73 was assigned to proton attached to C-2. This signal showed a correlation in the HMQC spectrum with carbon signal at d C 122.6. Therefore, this signal was assigned to C-2. The signal at d C 155.2 (C-3) showed a HMBC correlations with d 3.75 (methoxy group attached to C-3) and d 7.73. This confirms the assignment of the latter signal to the proton attached to C-2. The HMBC correlation be...
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