The naphthoquinone 7-methyljuglone (5-hydroxy-7-methyl-1,4-naphthoquinone) has previously been isolated and identified as an active component of root extracts of Euclea natalensis which displays antitubercular activity. Herein, a series of synthetic and plantderived naphthoquinone derivates of the 7-methyljuglone scaffold have been prepared and evaluated for antibacterial activity against Mycobacterium tuberculosis. Several of these compounds have been shown to operate as subversive substrates with mycothiol disulfide reductase. The absence of a direct correlation between antitubercular activity and subversive substrate efficiency with mycothiol disulfide reductase, might be a consequence of their non-specific reactivity with multiple biological targets (e.g. other disulfide reductases). openUP (December 2007) Graphical abstractArticle Outline

The pentacyclic triterpenes of ursane and oleanane skeletons found to accumulate in a number of terrestrial plants in free or glycosidic form.1) Some of these metabolites such as amyrins and ursolic acid have been reported as the bioactive constituents from a number of plants used in traditional and folk medicine.2,3) Amyrins were found to exhibit interesting pharmacological activities such as anti-inflammatory, 4,5) antiproteolytic, 6) antifungal 7) etc. whereas, ursolic acid was found to exhibit significant activities such as hepatoprotective, anti-inflammatory, antiviral and anti-tumor etc.8) Ursolic acid was identified as one of the active components in rosemary (Rosmarinus officinalis) to inhibit the growth of some of the food associated bacteria and yeast. 9) Ursolic acid and its 3-keto and 11-keto derivatives have been shown to inhibit the growth of Staphylococcus aureus.10) It was also reported that ursolic acid decreases the cytopatholic effects in vitro cells exposed to Herpes simplex virus.11) Interestingly a-amyrin palmitate isolated from Santalum album found to exhibit insect (Atteva fabriciella, Eligama norcissu, Eupterote geminata) growth inhibiting and chemosterilant activities.12) The low acute toxicity and structure activity studies of these skeletons suggest that defined substituents on the lipophilic 5-ring backbone can increase selectivity and potency of a desired action 13) and are identified as the potent natural lead compounds for drug development.In connection with our chemical screening on Diospyros melanoxylon leaves, we have isolated large quantities of amyrins (0.94%) as an inseparable mixture of a-and b-and ursolic acid (0.56%), which prompted us to screen for antimicrobial activity along with their synthesized lipophilic fatty acid ester chains. The common functionality in these compounds is the hydroxyl at C 3 . In case of ursolic acid it has got an additional carboxylic acid functionality at C 17 . It was reported in literature that the acid moiety at C 17 and ester functionality at C 3 are highly essential for enhanced pharmacological activities of pentacyclic triterpenes. 14,15) In view of these observations, the C 3 -OH can be exploited to synthesize highly lipophilic ester chains. Interestingly some of the higher fatty acid esters (C 16 , C 18 ) of pentacyclic triterpenes have been reported from natural sources. 12) Lipophilicity is an important parameter in the development of antimicrobial agents. It increases with increase of the carbon chain. Molecules with carbon chains above C-10 are fairly lipophilic and good candidates for pharmacological evaluation. Further the partition coefficient (log P), which is well known as an index of lipophilicity, is an important physicochemical parameter in the development of antibacterial agent because it is known to be closely related to the permeation through a lipid coat of bacteria.16) In view of the above, we have now prepared the highly lipophilic 3-O-fatty acid ester chains (C 12 -C 18 ) of amyrins and ursolic acid and screened for ...

In this first-ever, double-blind, randomized, placebo-controlled pilot study comparing Ayurveda, MTX, and their combination, all 3 treatments were approximately equivalent in efficacy, within the limits of a pilot study. Adverse events were numerically fewer in the Ayurveda-only group. This study demonstrates that double-blind, placebo-controlled, randomized studies are possible when testing individualized classic Ayurvedic versus allopathic treatment in ways acceptable to western standards and to Ayurvedic physicians. It also justifies the need for larger studies.

The 3-O-fatty acid ester derivatives (C(12)-C(18)) of two pentacyclic triterpenic acids, ursolic acid and oleanolic acid, were synthesized under mild esterification conditions in excellent yields (80-85%) and screened for their antifeedant activity, together with the parent acids, against the agricultural pest tobacco caterpillar larvae (Spodoptera litura F) in a no-choice laboratory study. The Urs-12-ene-28-carboxy-3beta-octadecanoate and olean-12-ene-28-carboxy-3beta-hexadecanoate were found to exhibit exceptionally potent antifeedant activities at 50 microg/cm(2) concentration, even after 48 h.