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-H(2) O 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.

COMPARISON OF DIFFERENT PHENOTYPIC METHODS OF DETECTION OF METHICILLIN RESISTANCE IN Staphylococcus aureus WITH THE MOLECULAR DETECTION OF mec-A GENE.

OBJECTIVE: To evaluate accuracy, cost-effectiveness and ease to perform different phenotypic methods i.e. Cefoxitin 30 microg disc, Oxacillin 1microg disc and Oxacillin agar screening plate (6microg/ml ) for early and accurate identification of MRSA by comparing with the detection of mec-A gene in our clinical isolates. DESIGN: A comparative study. PLACE AND DURATION OF STUDY: Clinical samples submitted in the Clinical Microbiology Laboratory at Aga Khan University Hospital, Karachi, from 1st August to 31st October 2006. MATERIAL AND METHODS: Out of 200 clinical samples, conventional Polymerase chain reaction (PCR) was done on 62 pure biochemically identified S. aureus isolates for mec-A gene detection. Phenotypic methods for detecting methicillin sensitivity (Cefoxitin 30 microg disc, Oxacillin 1 microg disc and Oxacillin agar screening plate) were also used according to the recommended incubation time, duration and temperature on the same isolates. RESULTS: Out of 62 isolates of S. aureus, mec-A gene were detected (MRSA) in 32, whereas 30 were mec-A gene negative (MSSA). Cefoxitin disc and agar screening plate correctly identify all MRSA isolates with the sensitivity and specificity of 100%. Single isolate was false, positively detected as sensitive with Oxacillin 1microg disc, due to which, the sensitivity and negative predictive value of this method were reduced to 96.9% and 96.8% respectively, while positive predictive value and specificity remained 100%. CONCLUSION: Comparing different phenotypic methods for MRSA screening in routine microbiology laboratory, Cefoxitin disc and Oxacillin agar screening has better sensitivity and specificity comparative to Oxacillin disc. However, Cefoxitin disc can be preferred especially for small laboratories because it is easy to perform, do not require special technique and media preparation is consequently more cost-effective.

Novel diterpene lactones from Suregada multiflora.

Two new diterpene lactones, suregadolides A (1) and B (2), were isolated from a dichloromethane extract of Suregada multiflora bark. These compounds possess a novel skeleton, which contains a cyclopropane ring bridging C-3 and C-4 of the abietane skeleton. The structures were established on the basis of one- and two-dimensional NMR and other spectroscopic studies. Compound 1 showed moderate inhibitory activity in a mutant yeast strain bioassay.

A new diepoxy-ent-kauranoid, rugosinin, from Isodon rugosus.

A new diterpenoid, rugosinin (1), isolated from Isodon rugosus, with absolute configuration was proved by single-crystal X-ray diffraction analysis, to be the member of a rare class of C-20/C-7 and C-20/C-14 diepoxy- ent-kauranoids. Effusanin A (2), effusanin B (3), effusanin E (4), lasiokaurin (5) and oridonin (6) were found as known constituents of the genus Isodon with C-20/C-7 epoxy function. These compounds have exhibited DNA-damaging activity in assay which employed DNA-repair deficient (RAD 52Y) and repair proficient (RAD +) yeast strains.