Santaloïdes afzelii (R.Br. ex Planch.) Schellenb (Connaraceae) is used in Africa as an analgesic, aphrodisiac and in the treatment of stomachaches, muscular pains and in medico magic rites. The present study aims to identify the bioactive organic compounds from the bark and seeds of Santaloïdes afzelii collected in Korhogo in the north of Côte d’Ivoire. Microbiological testing againts Staphylococcus aureus of the hydro ethanolic crude extracts of the bark and seeds showed low activities compared to the activities of oxacillin and cefoxitin. The chemical investigations of these extracts led to the identification of gallic acid, epi-catechin and dimers of procyanidin.

Withania coagulans (Stocks) Dunal (family: Solanaceae) is a rigid undershrub found in Iran, Afghani­stan, Pakistan, northern India and Nepal. Its fruits are used to treat asthma, biliousness, flatulent colic, cough, diabetes, dyspepsia, liver complaints, intestinal infections, skin rashes, stomachache, strangury and wounds. The air-dried fruits of W. coagulans were exhaustively extracted with methanol in a Soxhlet apparatus. The concentrated methanol extract was adsorbed on silica gel to be chromatographed on a silica gel column. The column was eluted with dichloromethane, ethyl acetate and methanol suc­cessively to isolate ten new phytoconstituents characterized as (3R,4R)-dihydroxyadipic-?,?’-dilactone (n-hexa-1(3),4(5)-diolide, 2), (20S,22R)-1-oxo-witha-2,24-dienolide (withacoagulanide A, 3), (20S,22R)- 1-oxo-witha-24-enolide (withacoagulanide B, 4), (20S,22R)-1-oxo-witha-6ß-ol-2,24-dienolide (witha­coagulanide C, 5), (20S,22R)-1-oxo-witha-3ß,5ß-diol-24-enolide (withacoagulanide D, 6), (20S,22R)-1- oxo-witha-6ß-ol-2,24-dienolide-6ß-D-arabinopyranosyl-2'-(2''-methoxy)-benzoate (withacoagunalide C 6-arabinosyl 2'-O-anisate, 7), (20S,22R)-1-oxo-witha-3ß-ol-24-enolide-3ß-O-D-galactoyranosyl- (2'?1'')-ß-O-D-galactopyranoside (3-O-digalactosyl withacoagulanide B, 8), 1-oxo-3-seco-witha-21, 27, 28-trioic acid-24-ene-6ß-ol-19(8), 18(11)-diolide-6ß-O-D-galacuronopyranoside (3-secowithacoag­ulanolide 6ß-olyl galactourinoside, 10), (20S,22R)-1-oxo-witha-6ß-ol-2,24-enolide-6ß-O-D-(4'-acetoxy arabinopyranosyl-(2'?1'')-(3'',4''-diacetoxy arabinopyranosyl)-2''-(2'''-methoxy)-benzoate (withacoag­ulanide C 6ß-olyl diarabinosyl 2''-(O)-anisate, 11) and n-hexanoyl-ß-O-D-xylopyranosyl-(2'?1'')-ß-O-D-xylopyranosyl-(2''?1''')-ß-O-D-xylopyrano- side (caproyl trixyloside, 12) along with the known rare chemical compounds identified as cetyl palmitate (hexadecyl hexadecanoate, 1) and glyceryl-1,2-di­hexadecanoate-3-phosphate (glyceryl-1,2-dipalmityl 3-phosphate, 9). The structures of isolated phyto­constituents were established on the basis of analysis of spectral data and chemical means.

This study aims to evaluate the effect of freeze-drying and spray-drying on total phenolics con­tents and antioxidant capacity from aqueous extract of Justicia secunda leaves. Total pheno­lic compounds extraction procedure consists of using an extraction-concentration procedure performed at three-step process, including ultrasound-assisted water extraction followed by cross-flow microfiltration of the crude extract and its concentration by reverse osmosis. After final step of extraction procedure, a concentrated extract, namely RO extract was obtained. In order to convert RO extract to powder form, two drying methods are used; freeze-drying and spray-drying. The powder obtained by freeze drying, namely P1, presented the higher content of polyphenols (9542 ± 38 µmol.g-1 GAE) and antioxidant capacity (4256 ± 15 µmol.g-1 TE) than that obtained by spray drying and namely P2. The freeze-drying technology could be a good outcome to preserve polyphenols structure and consequently their antioxidant capacity in aqueous extract of J. secunda leaves. Moreover, seven minor phenolic compounds of RO extract were characterized by HPLC coupled to UV/Vis diode array detection and mass spectrometry with electrospray ionization (LC/DAD/ESI-MS). There were kaempferol-3-O-coumaroyl gluco­side (10), justiflorinol (14), luteolin-7-O-rutinoside (18), apigenin 6-C-glucoside-7-O-rhamno­syl-hexoside (19), quercetin-7-O-glucoside-3-O-rutinoside (20), apigenin-7-O-neohesperido­side (23), and naringenin-7-O-rutinoside (25) among the characterized compounds.

Malaria which is caused by the Plasmodium parasite and transmitted through bites of infected female Anopheles mosquitoes is an important public health concern in Africa. Insect repellents are commercially available but most of the synthetic repellents have adverse effects to the user as well as the environment. Previous studies have shown that Nigella sativa L. seed extracts have insecticidal and insect repelling activity. The objective of the present study was to evaluate the repellence efficacy of essential oil of Nigella sativa L. seeds on Anopheles gambiae sensu stricto and to determine the chemical composition of the essential oil. The repellence activity of the essential oil was dose-dependent and comparable to that of DEET (N,N-diethyl-m-toluamide). The repellence of the oil was 98.81 and 100% at concentrations of 0.01 and 0.1 g/mL, respectively. GC-MS analysis showed the major components of the essential oil to be p-cymene (34.67%), a-thujene (11.55%), trans-4-methoxythujane (5.81%), ß-pinene (4.66%), methylcyclohexane (3.11%), a-pinene (2.82) and longifolene (2.55%). The repellence activity of N. sativa seed oil against An. gambiae can be attributed to the presence of a-pinene, p-cymene and longifolene. These findings have confirmed that the essential oil of N. sativa seeds contains compounds that repel An. gambiae and therefore can be used to control spread of malaria through prevention of mosquito bites.

Davana (Artemisia pallens Bess), belonging to Asteraceae family, is an important aromatic crop of South India. The field experiment was laid out in randomized randomized complete block design (RCBD) with 6 replication during winter season 2018-2019. The 35 days old seedling were transplanting to the main field with spacing of 30 cm × 30 cm in order to investigate the influence of different growth stages on the essential oil content and major chemical composition of davana. The essential oil content found to be varied from vegetative stage (0.12%) to full blooming stage (0.25%). The major component davanone was found to be higher at before anthesis followed by anthesis stage (full blooming stage) and gradually decreased from early initiation of seed set stage to seed maturing stage. However, the amounts of other major constituent of davana oil like (E)-ethyl cinnamate and bicyclo germacrene increased from the vegetative stage to the seed maturing stage. Significant interaction effect observed between chemical content and different stages. Based on the experimental results full blooming stage is ideal for harvesting and it was also confirmed with the normal practice of farmers harvesting the crop.

In this paper, chemical constituents and antimicrobial activity of essential oil from the pseudo-stem of Zingiber castaneum Škornick. & Q.B. (Zingiberaceae) Nguy?n growing in Vietnam havw been reported. Essential oils were obtained by hydrodistillation using the Clevenger-type apparatus. Chemical components of the essential oil were analyzed by gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC/MS). The minimum inhibitory concentrations (MIC) were evaluated by the method of microdilution broth susceptibility assay. The main constituents of the oil were bicyclo­germacrene (28, 15.8%), cis-ß-elemene (18, 9.8%) and germacrene D (26, 9.2%). The pseudo-stem oil of Z. castaneum displayed antimicrobial activity against Pseudomonas aeruginosa (ATCC 25923), Aspergillus niger (ATCC 9763) and Fusarium oxysporum (ATCC 48112) with MIC values of 12.5 ± 0.57 µg/mL, 50 ± 1.00 µg/mL and 50 ± 0.50 µg/mL, respectively. The results indicate the potential of Z. castaneum essential oil as a source of antimicrobial agent.