Phytochemical study of Psychotria schlechtendaliana (Rubiaceae) aerial parts resulted in the isolation of alkaloids 4 N oxide harmane (1) and strictosidinic acid (2), and the terpenoids sitosterol, estigmasterol, α-amyrin, β-amyrin and betulinic acid. The crude extract (CE), its fractions (hexane FH, chloroform FC, ethyl acetate FEA, hydromethanolic FHM, alkaloidal chloroform FCOH, alkaloidal aqueous FAq) and majority alkaloid (1) were investigated for their antiproliferative potential against nine human tumor cells lines and one non-tumoral human cell line (HaCat). CE, FH and FEA fractions exhibited strong growth inhibition for ovary cells (OVCAR-3, GI50 = 5.89; 1.36 and 6.59 μg mL-1, respectively) and FC, FH and FAq fractions showed potent activity on the growth of leukemia cell lines (K562, GI50 = 1.92; 7.23 and 8.81 μg mL-1, respectively). Compound 1 exhibited selective antiproliferative activity to breast cancer (MCF-7, GI50 = 32.7 μg mL-1) and was non-toxic to HaCat cells. To evaluate the anti-inflammatory effect, models of ear edema induced by croton oil and the enzyme myeloperoxidase (MPO) were used. FH and FC fractions exhibited anti-inflammatory effect and reduce ear edema compared to the control group. These fractions showed results superior to those exhibited by indomethacin (75.1%), FH (97.5%) and FC (95.5%) fractions. Rubiaceae (Rubiaceae (1 2, 2 , (2) sitosterol estigmasterol αamyrin, αamyrin α amyrin, amyrin α-amyrin βamyrin β CE (CE) hexane FHM FCOH nontumoral non tumoral HaCat. . (HaCat) OVCAR3, OVCAR3 OVCAR 3, 3 (OVCAR-3 GI GI5 5.89 589 5 89 136 36 1.3 659 6 59 6.5 mL1, mL1 mL 1, mL-1 respectively K562, K562 K (K562 1.92 192 92 723 7 23 7.2 881 8 81 8.8 respectively. MCF7, MCF7 MCF 7, (MCF-7 327 32 32. nontoxic toxic antiinflammatory anti inflammatory MPO (MPO used group 75.1%, 751 75.1% 75 (75.1%) 97.5% 975 97 (97.5% 95.5% 955 95 (95.5% ( (2 (CE (HaCat (OVCAR- 5.8 58 13 1. 65 6. mL- K56 (K56 1.9 19 9 72 7. 88 8. (MCF- 75.1 (75.1% 97.5 (97.5 95.5 (95.5 (OVCAR 5. K5 (K5 (MCF 75. (75.1 97. (97. 95. (95. (K (75. (97 (95 (75 (9 (7

A new bis-iridoid glucoside minutifloroside (1) was isolated from Palicourea minutiflora, together with asperuloside, (-)-epicatechin, catechin, quercetin, rutin, ursolic acid, oleanolic acid, daucosterol and two monoterpenic indole alkaloids strictosidinic acid and vincosamine. Structural characterization of the compounds was established on their spectral data basis, mainly mass spectrometry (MS) and 1D and 2D nuclear magnetic resonance (NMR). The bis-iridoid showed high activity against Candida albicans strain and antioxidant activity.

ABSTRACT The cultivation of sugarcane hybrids (X Saccharum officinarum L.) is an important revenue source for the Brazilian economy. Herein it is reported the evaluation of the cytotoxic activity of mid-polarity sugarcane extracts against human cancer cell lines, as well as the isolation of steroids sitosterol, stigmasterol and campesterol, phenolic acids p-hydroxybenzoic, p-hydroxycinnamic, vanillic and ferulic acid, terpenoids α-tocopherol and β-carotene and a novel substance in sugarcane, the flavonoid aglycone tricin (5,7,4-trihydroxy-3,5-dimethoxyflavone). The presence of large amounts of phenolic acids and the flavonoid tricin may explain the cytostatic activity observed for the mid-polarity crude extract and filtrates.

The isolation and structure determination of new cyclic peptide alkaloid ixorine, along with five known constituents frangulanine, syringaresinol, cinnamtannin B-1, daucosterol and mannitol from the branches of Ixora brevifolia are described. The cyclic peptide frangulanine is being described for the first time in the Rubiaceae family. The structures were elucidated on their spectral data basis, mainly one- (1H, 13C, DEPT) and two-dimensional (COSY, NOESY, HSQC and HMBC) nuclear magnetic resonance (NMR) and by comparison with data from the literature. The mixture of two cyclopeptide alkaloids showed weak activity against Leishmania amazonensis.

The chemical study of the orchid Maxillaria picta resulted in the isolation of the bioactive stilbenes phoyunbene B and phoyunbene C, in addition to four phenolic acids, one xanthone, steroidal compounds and two triterpenes. Crude extract, fractions, subfractions and the isolated xanthone were evaluated for anticancer activity against human tumor cell lines and against evolutionary forms of T. cruzi and L. amazonensis. The structures of the compounds were determined by GC-MS, and ¹H NMR, 13C NMR spectral methods as well as bidimensional techniques.

Bacteria from the genus Methylobacterium interact symbiotically (endophytically and epiphytically) with different plant species. These interactions can promote plant growth or induce systemic resistance, increasing plant fitness. The plant colonization is guided by molecular communication between bacteria-bacteria and bacteria-plants, where the bacteria recognize specific exuded compounds by other bacteria (e.g. homoserine molecules) and/or by the plant roots (e.g. flavonoids, ethanol and methanol), respectively. In this context, the aim of this study was to evaluate the effect of quorum sensing molecules (N-acyl-homoserine lactones) and plant exudates (including ethanol) in the expression of a series of bacterial genes involved in Methylobacterium-plant interaction. The selected genes are related to bacterial metabolism (mxaF), adaptation to stressful environment (crtI, phoU and sss), to interactions with plant metabolism compounds (acdS) and pathogenicity (patatin and phoU). Under in vitro conditions, our results showed the differential expression of some important genes related to metabolism, stress and pathogenesis, thereby AHL molecules up-regulate all tested genes, except phoU, while plant exudates induce only mxaF gene expression. In the presence of plant exudates there is a lower bacterial density (due the endophytic and epiphytic colonization), which produce less AHL, leading to down regulation of genes when compared to the control. Therefore, bacterial density, more than plant exudate, influences the expression of genes related to plant-bacteria interaction.