Natural pigments and colorants are widely used in the world in many industries such as textile dying, food processing or cosmetic manufacturing. Among the natural products of interest are various compounds belonging to carotenoids, anthocyanins, chlorophylls, melanins, betalains… The review emphasizes pigments with anthraquinoid skeleton and gives an overview on hydroxyanthraquinoids described in Nature, the first one ever published. Trends in consumption, production and regulation of natural food grade colorants are given, in the current global market. The second part focuses on the description of the chemical structures of the main anthraquinoid colouring compounds, their properties and their biosynthetic pathways. Main natural sources of such pigments are summarized, followed by discussion about toxicity and carcinogenicity observed in some cases. As a conclusion, current industrial applications of natural hydroxyanthraquinoids are described with two examples, carminic acid from an insect and Arpink red^TM from a filamentous fungus.

An efficient protocol for maintaining the artemisinin content in tissue culture and high frequency of in vitro direct and indirect regenerations of multiple shoots of high artemisinin yielding genotypes of Artemisia annua has been developed and their comparison with field grown mother plant has been carried out. The eleven elite genotypes(containing more than 1% artemisinin) were tested on seven different modified media formulations. Modified half MS(Murashige and Skoog's) media containing 100 mg L^-1 myo-inositol, 0.5 g L^-1 casine hydrolysate, 5 mg L^-1 biotin, 2 mL L^-1 RT(Revised Tobacco) vitamin stock, 0.5 mg L^-1 BAP and 0.01 mg L^-1 NAA showed best regeneration while, above modified MS medium containing 0.2 mg L^-1 BAP and 0.2 mg L^-1 NAA showed maximum shoot multiplication with maintained artemisinin content. Based on the chemical profiles of both the systems, minor difference was observed in their artemisinin content. A large scale culture of these plants maintained the normal growth index along with the artemisinin content and could be a better alternative to maintain the high artemisinin yielding genotypes with their genetic constraint in specific media combinations and also used as base material for further genetic improvement.

Seven cadinane sesquiterpenoids, named boreovibrins A-G(1-7), three dihydrobenzofurans(8-10), and two lactones(11 and 12), together with one known compound(13), were isolated from cultures of the basidiomycete Boreostereum vibrans. The new structures were elucidated by means of spectroscopic methods. Compounds 5, 6, and 11 showed weak inhibitory activities against isozymes of 11β-hydroxysteroid dehydrogenases(11β-HSD).

Direct Analysis in Real Time Mass Spectrometry(DART-MS) was applied to identify and study the distribution profile of piperidine alkaloids in different parts of Prosopis juliflora, without isolation and separation of the compounds by standard chromatographic techniques. With the help of DART-MS, chemical fingerprint of raw plant parts were generated, which revealed the presence of piperidine alkaloids in leaf, pod and flower. A comparative study of the distribution pattern, showed variation in the presence and distribution of these alkaloids in various parts of P. juliflora. The leaves and pod displayed the largest alkaloid pattern with a total of 12 different alkaloids in each part, whereas only 4 alkaloids were present in flower. Alkaloids:julifloridine, prosopine, prosopinine and prosafrinine were ubiquitously distributed in all the alkaloid rich plant parts. Juliprosopine was pre-eminet alkaloid in leaf, whereas pod and flower displayed copious amounts of julifloridine.

A potential strategy for drug lead identification and in-active natural products re-discovery is elaborated. Starting from fifteen structurally diverse natural products, a focused library featured by Michael acceptors is constructed with IBX mediated oxidation. Biological assay on five tumor cell lines indicates that four Michael acceptors, 8a, 11a, 12a, 14a, are with improved cytotoxicity(3-10 folds more potent than the parent compounds), which merit further investigations. Further thiol-sensitive assay of the active hit 8a revealed that it was an irreversible Michael acceptor. The results suggest that the strategy is not only effective and relatively high discovery rate(28%), but also resource saving.

Chemical study on the roots of Gentiana crassicaulis Duthie ex Burk(Gentianaceae) afforded 15 compounds, including two new iridoid glycosides, qinjiaosides B(1) and C(2). Their structures were elucidated by spectroscopic methods and chemical evidence. The isolated iridoid glycosides 1, 4-6 and 8-11 were tested for their anti-inflammatory activity by the inhibitory effects on LPS-induced NO and TNF-α production in macrophage RAW264.7 cells. All of them showed inhibitory effects on inflammatory mediators NO at a concentration of 15 μM, while 5 and 9 displayed the most potential inhibitory effects on TNF-α with IC₅₀ of 0.06 and 0.05 μM, respectively. The structure-activity relationships(SARs) of these iridoid derivatives were discussed.

Two new tirucallane triterpenoids, 2α-ethoxy-2, 3-secotirucalla-2, 29-epoxy-7-ene-23-oxo-3-oic acid(1) and(23E)-2α-hydroxytirucalla-7, 23, 25-triene-3-one(2), along with the known 2, 3-secotirucalla-2, 3; 2, 29-diepoxy-7-ene-3, 23-dione(3), were isolated from the leaves and twigs of Aphanamixis grandifolia. Their structures were elucidated by extensive NMR and MS data, and compound 3 was further confirmed by X-ray crystal diffraction analysis. Antimicrobial activities and insecticidal activities of these three compounds were also evaluated. Compound 1 showed good antimicrobial activity against Staphylococcus aureus with the MIC value of 1.56 μg/mL, while compounds 1 and 2 showed insecticidal activity at 100 ppm, with the corrected mortality 79.1% and 60.6%, respectively.

Two new neolignans, manneoinsigins A(1) and B(2), together with four known lignans, were isolated from the leaves and stems of Manglietia insignis. The new compounds were established on the basis of extensive spectroscopic analyses. All compounds except 2 were tested for their cytotoxic activity. Compound 3 showed weak cytotoxic activity against the HL-60 human tumor cell line with the IC₅₀ value of 23.5 μM.