Nitric oxide (NO) is a free radical synthesized from L-arginine by nitric oxide synthase (NOS). It is believed that NO is an important mediator in numerous physiological and inflammatory responses. Particularly, a large amount of NO released from the inducible nitric oxide synthase (iNOS) is mostly associated with inflammatory processes. Overproduction of NO in these processes including sepsis and autoimmune diseases can have deleterious consequences and pathophysiologic relevance. Therefore, for the discovery of new inhibitory agents against iNOS activity, we have evaluated about 100 kinds of natural products after partition into three layers (n-hexane, ethyl acetate and aqueous) from 100% methanol extracts to study inhibitory effects on iNOS activity induced by lipopolysaccharide (LPS) in RAW264.7 cells culture system. As a positive control, curcumin, which is known as an anti-tumor promoter, anti-inflammatory agent as an iNOS inhibitor, was used and showed the dose-dependent inhibitory effect $(IC_{50},\;2.5\;{\mu}g/ml)$. Among tested fractions, the n-hexane fraction of Cimicifuga heracleifolia $(IC_{50}:\;9.65\;{\mu}g/ml)$, Forsythiae fructus $(IC_{50}:\;6.36\;{\mu}g/ml)$, Saposhnikovia divaricata $(IC_{50}:\;5.92\;{\mu}g/ml)$, and the ethyl acetate fraction of Chrysanthemum sibiricum $(IC_{50}:\;2.56\;{\mu}g/ml)$, Gastrodia elata $(IC_{50}:\;3.46\;{\mu}g/ml)$, and the aqueous fraction of Dianthus chinensis $(IC_{50}:\;6.73\;{\mu}g/ml)$, Euonymus alatus $(IC_{50}:\;6.78\;{\mu}g/ml)$, Mechania urticifoloria $(IC_{50}:\;8.01\;{\mu}g/ml)$ showed strong inhibitory activity against LPS-stimulated iNOS. Especially, the ethyl acetate fraction of Chrysanthemum sibiricum $(IC_{50}:\;2.56\;{\mu}g/ml)$, which exhibited the strongest inhibition against iNOS, was fractionated with silica-gel column chromatography. These subfractions exhibited dose-dependent inhibition against iNOS activity in the range of $2.59-5.6\;{\mu}g/ml$ except for fraction No. 3, 4, 5, 6, 8, 9, and 16. Our study shows that Chrysanthemum sibiricum has the strongest inhibitory effect against iNOS activity and has similar effect to curcumin. Therefore, further studies for the identification of active principles from Chrysanthemum sibiricum and investigation for the mechanism of the inhibition of iNOS by active principles will be performed.

Twelve species of Ipomoea were investigated for allelopathic behavior. Seed extracts of I. quamoclit, I. nil and I. pes-tigridis showed significant allelopathy over germination of other seeds. Investigation on seed extracts of I. quamoclit, revealed the presence of several phytochemical components viz., n-triacontanol, sitosterol, stigmasterol, ${\alpha}-amyrin$, taraxerone, taraxerol, erythrodiol, cucurbitacin-G. Seed fat of twelve species were also analyzed.

A new natural product $stigmast-5-en-3-O-{\beta}-D-glucopyranoside$ tetraacetate (1) along with known compounds $stigmast-5-en-3-O-{\beta}-D-glucopyranoside$ (2), stigmast-5-en-3-yl-cetate (3) and ${\beta}-sitosterol$ (4) have been isolated from the stems of Cuscuta reflexa. Their structures were elucidated on the basis of chemical and spectroscopic evidence.

'Gunja' is attributable to the plant Abrus precatorius L. (Leguminosae). Three forms with red, brown and another with white seeds are known to occur in this species and are employed for different therapeutic uses viz. as purgative, emetic, aphrodisiac, tonic and also as an abortifacient. According to some Ayurvedic literature the seeds are poisonous and should be given to the patients after proper processing ('Shodhan'). A comparative study of various phytochemical parameters, namely, percentage of successive extractives, total proteins, tannins, total ash and acid insoluble ash of these three forms of the processed (with cow's milk and Kanji) and unprocessed seeds was done. TLC and densitometric scanning of successive extractives was also carried out to serve as markers for processed and unprocessed seeds. The percentage of proteins, tannins, alcohol and water soluble extractives decreased in the processed material. Besides, their acute toxicity, CNS activity were also studied in albino mice and it was found that white seeds are more toxic as compared to the red and brown. The toxic effect was reduced with the processing. Further, the 'Kanji' processed seeds are less toxic than the milk processed one.

The chloroform extract of Pulicaria gnaphalodes yielded flavonoids (1-2), sesquiterpenoid (3), sterol (4), benzoic acid derivative (5) and fatty acids (6-7). Their structures were elucidated with the aid of NMR spectroscopy. The described compounds have not been reported so far from this source.

The effects of Eurycoma longifolia Jack were studied in maintaining mating behavior of sexually experienced castrated male rats after dosing them with 500 mg/kg daily of E. longifolia Jack for 10 days prior to test and later continued for two weeks where the rats were then castrated. The similar dosage was then continued for 12 weeks post-castration. However, $400\;{\mu}g/day$ of testosterone was administered subcutaneously on the day of castration and lasted for 6 weeks post-castration but later raised to $800\;{\mu}g/day$ until 12 week post-castration. Tests were conducted weekly from 2-6 weeks and 8-12 weeks post-castration. Results showed that all the experimental male rats exhibited mating behavior before castration. Further results also indicated that E. longifolia Jack successfully maintained mating behavior but less than precastration level from 2-6 weeks and later increased from 8-12 weeks post-castration. Similarly, $400\;{\mu}g/day$ of testosterone was effective in maintaining mating behavior from 2-6 weeks post-castration. However, $800\;{\mu}g/day$ of testosterone managed to return the male rats to the precastration level with all male rats exhibited mating behavior from 8-12 weeks post-castration. Further results also indicated that testosterone significantly increased the penis weights (p < 0.05) as compared to the E. longifolia Jack. In conclusion, this study shows that E. longifolia Jack continued to maintain mating behavior of sexually experienced castrated male rats, giving further evidence of the folkuse of this plant as aphrodisiac.

Tiliacora racemosa Colebr. belonging to the family Menispermaceae is the biggest store-house of diphenyl bisbenzylisoquinoline (DBBI) alkaloids. Exhaustive chemical processing of the root of T. racemosa by the application of modern separation techniques yielded a DBBI alkaloid which was identified as tiliacorine using sophisticated spectroscopic methods (UV, IR, $1^H-NMR$, Mass). Tiliacorine potentiated the sleeping time induced by standard hypnotics viz. chlorpromazine (CPZ), pentobarbitone (PB) and diazepam (DZ) in a dose dependent manner. Tiliacorine potentiated the analgesic action of standard analgesic agents viz., morphine and meperidine. It was also found to possess anti convulsive activity in the strychnine induced convulsion model.

Seed lipids and proteins of Crotalaria juncea L were analyzed for fatty acids and amino acids respectively. Gas chromatographic analysis of the oil gave palmitic acid (16.01%), stearic acid (7.29%), oleic acid (14.41%), linoleic acid (54.44%) and linolenic acid (7.86%). The defatted seed cake contained all the essential amino acids except methionine and six non-essential amino acids.

(+)-Hernandulcin is a sweet bisabolane-type sesquiterpene first isolated from Lippia dulcis Trev. (Verbenaceae). This oily compound is 1000-1500 times sweeter than sucrose but with poor solubility in water. Microbial transformation was employed to improve its water solubility, and a variety of microorganisms were screened for their ability to convert (+)-hernandulcin to more polar metabolites. Scale-up fermentation with Glomerella cinguiata, a fungal strain, has resulted in the isolation of a more polar metabolite (2).