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Essential oils from the leaves of Vernonia patula (Dryand.) Merr. and Grangea maderaspatana (L.) Poir. collected from Pu Hoat Nature Reserve, Nghe An Province were studied for their chemical consti...

Herein, we report the results of our investigation on essential oils obtained by hydrodistilation of the leaves and fruits of Manglietia dandyi (Gagnep.) Dandy. The constituents of the oils were analyzed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The yields of the oils were 0.25% and 0.21% (v/w, leaf and fruit respectively), calculated on a dry weight basis. The main constituents of the leaf oils were (E)-nerolidol (18.4%) and α-selinene (11.0%) while the fruit oils contained abundance of β-caryophylene (27.7%), d-cadinene (13.7%), α-humulene (13.2%) and α-copaene (11.6%). The results indicated that M. dandyi leaf oil exhibited 96% and 100% mortality towards the fourth-instant larvae of Aedes albopictus at 24 h at tested concentrations of 50 µg/mL and 100 µg/mL. The oil only displayed 100% mortality at concentrations of 50 and 100 µg/mL and under 48 h. The minimum lethal concentrations, LC50, were 29.57 mg/mL (24 h) and 29.02 mg/mL (48 h); while the LC90 values of 46.21 mg/mL and 42.29 mg/mL were obtained respectively at 24 h and 48 h mg/mL. The chemical constituents and larvicidal action of M. dandyi essential oils are being reported for the first time.

The study result of Myrtaceae family in Ha Tinh province reported, 61 species of 13 genera. In of them 36 species and 6 genera have been added to the list of Ha Tinh province (2021). The family myrtaceae in Ha Tinh province has many different uses: 61 species for essential oils, 46 species for timber plants, 30 species for medicinal plants, 24 species for edible, 11 species for ornamental plants, 7 species for different uses and 4 species for tannin plants. In the stems form, the large groups of trees with 10 species, followed by average groups of trees with 15 species; small of trees dominated with 26 species and groups of shrubs 10 species. There are 4 major habitats: forest with 35 species (57.38%), light forest with 35 species (57.38%), subforest with 50 species (81.97%), along streams and beside the road with 35 species (57.38%).

There are very few reports on the phytochemistry of Anoectochilus setaceus Blume, Codonopsis javanica (Blume) Hook. f. and Aristolochia kwangsiensis Chun & F.C.How ex S.Yun Liang species in the literature. Here we present essential oil compositions of the three endemic plants from Vietnam. The analysis of the chemical constituents of the hydrodistilled essential oils was achieved by using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The essential oils of A. setaceus, C. javanica and A. kwangsiensis afforded very low oil yields: 0.12%, 0.31% and 0.10% (v/w), respectively, calculated on a dry weight basis. The result indicated that the major components of the leaf oil of A. setaceus consist mainly of α-cadinol (17.1%), (E,E)-farnesol (14.0%) and terpinen-4-ol (11.0%) while β-pinene (20.8%) and α-pinene (15.4%) were the main compounds identified in C. javanica. However, the significant compounds of A. kwangsiensis were sabinene (34.8%), β-caryophyllene (8.8%) and terpinen-4-ol (8.6%). To the best of our knowledge this is the first report on the essential oil compositions of these species.

Chemical composition of essential oils obtained from the leaf of Syzygium bullockii and Syzygium tsoongii were reported, corresponding oil content 0,36% and 0,27%. The analysis was performed by means of gas chromatography-flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). Twenty-seven components were identified in leaf oil of Syzygium bullockii, which represented about 76,75% of the total composition of the oil and six components were not identified, which represented 15,72%. The major constituents of the essential oil were (E)-caryophyllene (49,65%), spathulenol (4,29%), caryophyllene oxide (4,14%), bicyclogermacrene (3,35%), 2-tridecanone (3,25%). Fourty-six components were identified in leaf oil of Syzygium tsoongii, which presented about 99.71% of the total composition of the oil. The major constituents of the essential oil were E-caryophyllene (23,40%), bicyclogermacrene (21,23%), (Z)-β-ocimene (10,61%), α-humulene (6,33%), (E)-β-ocimene (4,99%). For the first time, the chemical compositions of the essential oils of Syzygium bullockii and Syzygium tsoongii from Vietnam were being reported.

In this paper, we reported Zingiber neotruncatum as a new record for Vietnam. Voucher specimens were collected in Nghe An province (Pu Hoat Nature Reserve: Dong Van Commune), deposited in the Herbarium of the Biology, Vinh University. A detailed description and illustration are provided along with data on distribution, ecology, phenology and notices to the related species.

The aim of this research was to determine for the first the chemical constituents of essential oils derived from the leaves, pseudostems and rhizomes of Alpinia strobiliformis T. L. Wu & S....

The compositions of essential oils from the leaf, stem and fruit of Neolitsea buisanensis Yamam. & Kamik. from Vietnam were reported. The essential oils were analysed by gas chromatography (GC) and...

The essential oils obtained from the hydrodistillation of the leaves and stems of Piper laosanum C. DC. and Piper acre Blume (Piperaceae) were analysed by gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS). The main compounds in the leaf oil of P. laosanum were α-curcumene (12.0 %), germacrene D (6.3 %), sabinene (6.1 %) and spathulenol (5.1 %), while the stem oil was dominated sabinene (14.9 %), benzyl salicylate (14.3 %) and (E)-nerolidol (9.3 %). On the other hand, (E)-nerolidol (22.7 % and 15.6 %), sabinene (19.5 % and 19.9 %) and δ-cadinene (12.4 % and 13.5 %) respectively were the main constituents of the leaf and stem oils of P. acre. This is the first report on the volatile compositions of P. laosanum and P. acre.

A. annamensis and A. roxburghii belong to Orchidaceae family that has medicinal and ornamental plant value. They are in extinct endangered plants in wild due to the over- collected and loss of the suitable habitats. Using the LED lighting source for culture these species in in vitro condition to optimize the culture conditions, reduction of the production cost, especially electric bill for air-corditionning, lighting. In recent years, the trial applied LED which has the feature of energy saving, small size and a longer operating life, for plant production has started. In this study, LED illumination sources are in four different wavelengths of λ= 430- 470 nm; λ= 470-510 nm; λ= 510-560 nm; λ= 560-600 nm and white fluorescent lamp as control with light intensity photosynthetic photon flux density (PPFD) of 40 µmol/m2/s photon used to study their effects on the growth and development of A. annamensis and A. roxburghii species. After 8 weeks of implementing, the results showed that the LEDs of λ= 470-510 nm were suitable for the growth and development for A. roxburghii shoots while for A. annamensis, λ = 430- 470 nm were most suitable for budding and λ= 470-510 nm for shoot growth. Citation: Phan Xuan Binh Minh, Bui Thi Thanh Phuong, Pham Huong Son, Tran Minh Hoi, Nguyen Thi Phuong Lan, Vu Thi Thao, 2018. The effects of linght emitting diode lighting on growth and development of A. annanesis and A. roxburghii in vitro cultured shoots. Tap chi Sinh hoc, 40(1): x-xx. DOI: 10.15625/0866-7160/v40n1.10636. *Corresponding author: pxbminh@gmail.com Received 23 August 2017, accepted 2 December 2017

In this paper, compounds identified in the essential oils obtained by hydrodistillation of the leaves of Cinnamomum glaucescens (Nees) Hand.-Mazz and Cinnamomum verum J.S. Presl (Lauraceae family) of Vietnam origin are reported. The chemical analyses were performed using gas chromatography-flame ionisation detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). The significant compounds of C. glaucescens were geraniol (36.2%) and terpinen-4-ol (19.7%). On the other hand, C. verum comprised of linalool (22.0%) and bicyclogermacrene (11.2%). The present results may represent new chemotypes of the essential oils of C. verum and C. glaucescens.

The Monocotyledone in Pu Hoat Natural Reserve, Nghe An province was surveyed and identified with 432 species, 173 genera and 37 families; new recorded list Pu Hoat (2013) was 8 families, 76 genera and 260 species. There are 22 threatened species listed in the Red Data Book of Viet Nam (2007) in Pu Hoat Natural Reserve. The number of useful plant species of the Pu Hoat Monocotyledone is categorized as follows: 197 species as medicinal plants, 48 species for food and food stuffs, 94 species for ornamental, 38 species for essential oil. The plant species of Monocotyledone in Pu Hoat are mainly comprised of the tropical elements (64.36%), of them, the endemic elements with 23.38%; temperate elements (6.90%), cultivated elements (3.24%), unknown elements (1.85%) and global elements (0.18). The Spectrum of Biology (SB) of the flora in Pu Hoat is summarized, as follows: SB = 41.90 Ph + 24.77 Ch + 8.33 Hm + 15.28 Cr + 8.56 Th + 1.16 Hy. Keywords Diversity, Monocotyledone, Pu Hoat, Natural, Plants, Nghe An References [1] Viện Điều tra Quy hoạch Rừng. Điều tra đa dạng sinh học Pù Hoạt làm cơ sở Thành lập Khu Bảo tồn Thiên nhiên, Vinh, 2013.[2] Lê Thị Hương, Đỗ Ngọc Đài, 2012. Đa dạng thực vật và bảo tồn ở Khu Bảo tồn Thiên nhiên Pù Hoạt, Nghệ An, Tạp chí Khoa học và Công nghệ, 50(3E) 1347-1352.[3] Hoàng Danh Trung, Phạm Hồng Ban, Đỗ Ngọc Đài, 2010. Đa dạng thực vật bậc cao có mạch ở vùng đệm Khu bảo tồn thiên nhiên Pù Hoạt, Nghệ An, Tạp chí Nông nghiệp và Phát triển Nông thôn, 16, 90-94.[4] Sở Khoa học và Công nghệ Nghệ An, 2016. Nghiên cứu đa dạng sinh học Khu Bảo tồn Thiên nhiên Pù Hoạt, Nghệ An đề xuất biện pháp bảo vệ, Vinh.[5] Nguyễn Nghĩa Thìn, 2007. Các phương pháp nghiên cứu thực vật, Nxb Đại học Quốc gia, Hà Nội.[6] Nguyễn Tiến Bân, 1997. Cẩm nang tra cứu và nhận biết các họ thực vật hạt kín ở Việt Nam. Nhà xuất bản Khoa học và kỹ thuật, Hà Nội.[7] Phạm Hoàng Hộ, 2000. Cây cỏ Việt Nam, Quyển III, Nhà xuất bản Trẻ, TP HCM.[8] Wu P., P. Raven (Eds.) et al., 2002. Flora of China, Vol. 1-25. Beijing & St. Louis.[9] Brummitt RK, 1992. Vascular plant families and genera, Royal Botanic Gardens, Kew.[10] Nguyễn Tiến Bân (Chủ biên) et al., 2005. Danh lục các loài Thực vật Việt Nam, Tập III, Nhà xuất bản Nông nghiệp, Hà Nội.[11] Raunkiaer C, 1934. Plant life forms, Claredon, Oxford.[12] Nguyễn Tiến Bân (Chủ biên) et al., 2007. Sách Đỏ Việt Nam (Phần II: Thực vật). Nxb. Khoa học tự nhiên và Công nghệ, Hà Nội.[13] Ly Ngoc Sam, Dang Van Son, Do Dang Giap, Truong Ba Vuong, Do Ngoc Dai, Nguyen D. Hung, 2017. ¬¬Zingiber nudicarpum D. Fang (Zingiberaceae) a new record for Vietnam, Bioscience Discovery, 8(1): 01-05.[14] Nguyễn Thanh Nhàn, 2017. Nghiên cứu đa dạng thực vật VQG Pù Mát và đề xuất các giải pháp bảo tồn, Luận án Tiến sĩ Sinh học, Vinh.[15] Đặng Quốc Vũ, 2016. Nghiên cứu tính đa dạng thực vật làm cơ sở cho công tác bảo tồn tại Khu Bảo tồn thiên nhiên Xuân Liên, Thanh Hóa, Luận án Tiến sĩ Sinh học, Hà Nội.[16] Võ Văn Chi, 2012. Từ điển cây thuốc Việt Nam, Tập I-II. Nxb Y học, Hà Nội.Triệu Văn Hùng (chủ biên), 2007. Lâm sản ngoài gỗ ở Việt Nam, Nxb Bản đồ, Hà Nội.

The genus Piper has about 1.500 species mainly distributed in tropical, there were 43 Piper species recorded in Vietnam. In this paper, we reported Piper minutistigmum C. DC. newly recorded for the flora of Vietnam. Voucher specimens were collected in Thanh Hoa province (Ben En National park), Nghe An province (Pu Mat National Park: Khe Kem), Ha Tinh province (Vu Quang National park: Doc De) deposited in the Herbarium of the Faculty of Biology, Vinh University and Herbarium of the Institute of Ecology and Biological Resources (HN) Ha Noi, Vietnam. Woody clember, 3-12 m high. Petiole 3-8 mm, glabrous or sometimes sparsely pubescent; leaf simple, alternate, ovate, 6-11 × 3-7 cm, leaf blade toward apex aute, glabrous or sometimes sparsely pubescent, base oblique, 1 side rounded, other side tapered and acute, bilateral difference 3-4 mm, apex acute to long acuminate; veins 3-4, usually 1 more lateral vein on wider side, apical pair arising along midvein. Male spikes is smilar to female spikes, 5-10 x 1-1,5 cm., peduncle 1-1,2 cm, bracts 1-1,5 cm. Fruit a drupe, globose, 1-2 mm, often red. Keywords Piper minutistigmum, Piperaceae, Ben En, Pu Mat, Vu Quang, National Park References [1] Chaveerach A., P.Mokkamul, R. Sudmoon, T. Tanee (2006), Ethnobotany of the genus Piper (Piperaceae) in Thailand, Ethnobotany Research & Applications, 4: 223-231.[2] Chaveerach A., R. Sudmoon T. Tanee, P. Mokkamul (2006), Three new species of Piperaceae from Thaila[3] nd, Acta Phytotaxonomica Sinica, 44: 447-453. [4] Cheng Y., N. Xia & M.G. Gilbert (1999), Piperaceae, Pp 110-129 in Flora of China Vol. 4. Edited by Z. Wu & P.H. Raven. Missouri Botanical Garden, St.Louis, Missouri.[5] Lê Thị Hương, Lê Đông Hiếu, Trần Minh Hợi, Đỗ Ngọc Đài (2018), Piperboehmeriaefolium (Piperaceae) loài bổ sung cho hệ thực vật Việt Nam, Báo cáo Khoa học về Nghiên cứu và Giảng dạy Sinh học ở Việt Nam, Hội nghị Khoa học Quốc gia lần thứ 3, Nxb Nông nghiệp Hà Nội, Quy Nhơn, 20/5/2018; 529-531[6] Nguyễn Kim Đào (2003), Họ Piperaceae trong Nguyễn Tiến Bân (Chủ biên), Danh lục các loài thực vật Việt Nam, tập 2, Nxb. Nông nghiệp, Hà Nội, 115-122.[7] Lê Đông Hiếu, Đỗ Ngọc Đài, Trần Minh Hợi (2017), Đa dạng họ Hồ tiêu (Piperaceae) ở Bắc Trung Bộ, Tạp chí Nông nghiệp và Phát triển Nông thôn, [8] Phạm Hoàng Hộ (1999), Piperaceae - Họ Hồ tiêu, Cây cỏ Việt Nam, 1: 228-301. Nxb Trẻ, Tp Hồ Chí Minh.

The chemistry of essential oil obtained by hydrodistillation of the leaf of Euodia meliaefolia (Hance) Benth., grown in Vietnam were being reported. The oil was analyzed by means of gas chromatography-flame ionisation detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS) techniques. The constituents of the essential oils were identified by comparison of their retention indices and mass spectra with authentic compounds. Sixty compounds representing 93.4 % of the total content were identified in the essential oil of E. meliaefolia. Monoterpene hydrocarbons (25.8 %), oxygenated monoterpenes (39.3 %) and aliphatic compounds (14.7 %) represent the main classes of compounds present in the oil. The main constituents of the oil which are mainly monoterpene compounds were linalool (17.1 %), β-phellandrene (12.4%), geranial (11.2%) and α-pinene (7.4%). The present study may represent the first report on the chemical composition of volatile oil of E. meliaefolia.

Leaves of Actinodaphne pilosa were collected at 2 different seasons from the Pù Hoạt Nature Reserve, Vietnam. The leaf samples were hydrodistilled to give essential oils, which were analyzed by gas chromatography (GC)–mass spectrometry and GC-flame ionization detection. The major components in the essential oils were α-pinene, ( Z)-β-ocimene, ( E)-β-ocimene, β-caryophyllene, germacrene D, bicyclogermacrene, and spathulenol. The essential oils were screened for antimicrobial activity against Enterococcus faecalis, Staphylococcus aureus, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans, as well as mosquito larvicidal activity against Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus. Actinodaphne pilosa leaf essential oils showed broad antimicrobial activity (minimum inhibitory concentration = 32, 64, 64, 16, and 16 μg/mL against E. faecalis, S. aureus, B. cereus, P. aeruginosa, and C. albicans, respectively) and excellent larvicidal activity (24-hour 50% lethal concentration = 19.0, 24.7, and 48.1 μg/mL against A. aegypti, A. albopictus, and C. quinquefasciatus, respectively).

This article reports the compounds identified in the leaf oils of five Clauseana species growing in Vietnam. The hydrodistilled oils were analysed for their chemical constituents by using gas chromatography-flame ionisation detector and gas chromatography coupled with mass spectrometry. The major compounds identified in Clausena dentata (Willd.) M. Roem. were α-pinene (21.7%), sabinene (18.3%) and β-myrcene (14.3%). Clausena dimidiata Tanaka comprised mainly of safrole (56.9%) and α-terpinolene (22.1%). However, 1-menthone (70.6%) and β-phellandrene (13.0%) were the most abundant compounds of Clausena indica (Dalz.) Oliver. Sesquiterpene compounds represented mainly by β-caryophyllene (16.7%), spathulenol (11.9%) and bicyclogermacrene (7.5%) were the major constituents of Clausena excavata Burm. f., while those of Clausena engleri Tanaka include bicycloelemene (12.1%), bicyclogermacrene (11.0%) and (E)-nerolidol (6.6%). This is the first report on the chemical analysis of essential oils of C. dimidiata and C. engleri.

Six known compounds including α-amyrin 3-acetate (1), β-sitosterol (2), betulinic acid (3), friedelan-3-one (4), artochamin B (5), and 2-C-methyl-d-erythritol 4-O-α-d-glucopyranoside (6) were isolated from the stem barks and leaves of Artocarpus nigrifolius (Moraceae) for the first time. Their structures were identified by spectroscopic methods as well as comparison with literatures. Cytotoxicity and antibacterial activity of 1–6 were evaluated. Results showed that artochamin B (5) possessed the highest cytotoxicity towards MCF7, Lu, HepG2, and KB cell lines with IC50 values of 4.59, 20.00, 3.60, and 1.18 μg/mL, respectively. It also inhibited the growth of Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus), whereas inactive on the growth of both Gram-negative bacteria and yeast.

The leaf oils of some genus of Annonaceae collected from Vietnam in December 2009 were analyzed by capillary gas chromatography (GC) and GC coupled with mass spectrometry (GC/MS). The major compounds identified in the oil of Artabotrys pallens Ast. were α-gurjunene (21.9%), α-phellandrene (20.1%) and bicycloelemene (9.6%). The oil of Goniothalamus tamirensis Pierre ex Finet & Gagnep. contained β-selinene (12.3%), bicyclogermacrene (10.9%), caryophyllene oxide (10.4%) and bicycloelemene (5.6%) in abundance. However, β-pinene (33.4%), α-pinene (32.3%) and β-caryophyllene (10.5%) were the most quantitative significant constituents of Dasymaschalon rostratum Merr. & Chun. From the oil of Uvaria pierrei Finet & Gagnep. we could identified bicycloelemene (18.3%), germacrene D (30.2%), bicyclogermacrene (26.4%) and β-bisabolene (7.7%) as the major compounds, while γ-elemene (54.0%) was the most singly abundant constituent of Uvaria dac Pierre ex Finet & Gagnep oil. All the other compounds were identified in amou...

One new flavonol diglycoside, 4′,5-dihydroxy-3,3′,7-trimethoxyflavone 4′- O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (1), and two known compounds (2–3) were isolated from the methanol extract of Anoectochilus annamensis Aver. aerial parts. The effects were evaluated of all isolated compounds (1–3) on LPS-induced production of the inflammatory mediator nitric oxide (NO) by RAW264.7 cells. 4′,5-Dihydroxy-3,3′,7-trimethoxyflavone (2) was the most active while the addition of a rutinoside at C-4′ (compound 1) decreased the inhibitory activity. This is the first report on the chemical composition and biological activity of A annamensis.

The chemical composition and the antimicrobial activity of the essential oil isolated from aerial parts of Acronychia pedunculata (L.) Miq. from Vietnam are reported. Analysis was carried out by GC (RI), GC-MS and 13C NMR. Thirty-four compounds were identified, accounting for 92.8% of the oil. The major constituents were alpha-pinene (57.4%) and (E)-beta-caryophyllene (13.6%). The essential oil of A. pedunculata was shown to possess a broad spectrum of antimicrobial activity against various bacteria, particularly Salmonella enterica and Staphylococcus epidermidis.

The chemical composition of the volatile oil extracted from aerial parts (twigs, leaves and flowers) of Michelia foveolata growing wild in Vietnam was investigated by combination of column chromatography, GC (retention indices), GC–MS and 13C-NMR spectroscopy. Fifty-eight components were identified, with sabinene (32.4%) and terpinen-4-ol (13.7%) as the main constituents. The essential oil was tested against 11 bacteria using the agar disc diffusion method, and exhibited a significant antibacterial activity against Salmonella enterica, Staphylococcus epidermidis, Staphylococcus aureus and Bacillus cereus (MICs = 2–4 µl/ml). Copyright © 2007 John Wiley & Sons, Ltd.

Essential oils produced from a population of Artemisia vulgaris of Vietnamese origin cultivated near Hanoi were subjected to analysis by GC, GC/MS and 13C-NMR. The oils were found to contain oxygenated monoterpenes as major components (1,8-cineole, camphor and α-terpineol). The composition of these oils differed from that previously reported for Vietnamese A. vulgaris oil. Only slight differences in the composition of the oil were observed along the vegetative life of the plant. No significant difference was observed between compositions of leaf and flower oils. In addition, the combination of retention indices, GC/MS and 13C-NMR spectroscopy allowed the identification of unusual sesquiterpenes such as presilphiperfolan-9α-ol as a minor component.

Bursera tonkinensis leaf and fruit oil was analysed by GC/RI, GC/MS and 13C-NMR. The main constituents were α-phellandrene (70.1%), β-phellandrene (8.4%) and α-pinene (7.6%). This oil is different to those produced from the majority of Bursera species.

The chemical composition of Vietnamese oil samples of the aerial parts of Clausena indica (Dalz.) Oliver and C. anisum-olens (Blanco) Merryll have been investigated using a combination of chromatographic and spectroscopic techniques. C. indica essential oil contained mainly terpinolene (53.9 and 56.1%), and myristicin (17.9 and 7.3%), whereas the major components of C. anisun-olens essential were citronellal (22.8%), geranial (21.4%) and neral (16.8%). The compositions of the investigated samples have been compared with those of essential oils from various origins.

The chemical composition of essential oils from four Piper species, Piper retrofractum Vahl., P. boehmeriaefolium (Miq.) C. DC., P. sarmentosum Roxb., and P. maclurei Merr., were analysed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Nineteen to sixty-four compounds representing 92.0%-98.4% of the total contents were identified in the oil samples. The major constituents identified in P. retrofractum leaf oil were benzyl benzoate (14.4%), myrcene (14.4%), bicycloelemene (9.9%), bicyclogermacrene (7.0%) and β-caryophyllene (5.3%). On the other hand, the main constituents of P. boehmeriaefolium were α-copaene (28.3%), α-pinene (7.4%) and 1, 8-cineole (5.7%). P. sarmentosum showed a very different chemical profile characterized mainly by aromatic compounds and devoid of monoterpene hydrocarbons. The major constituents were benzyl benzoate (49.1%), benzyl alcohol (17.9%), 2-hydroxy-benzoic acid phenylmethyl ester (10.0%) and 2-butenyl-benzene (7.9%). The leaf of P. maclurei was characterized by higher amount of (E)-cinnamic acid (37.4%) and (E)-nerolidol (19.4%). Moreover, (Z)-9-octadecanoic acid methyl ester (28.0%), (E)-cinnamyl acetate (17.2%), phytol (12.2%) and (E)-cinnamaldehyde (8.8%) were the major compounds identified in the stem oil.

The chemical composition of Enhydra fluctuans essential oil from Vietnam was investigated by GC/retention indices and carbon-13 NMR spectroscopy. Myrcene, limonene, trans- and cis-dihydroperillaldehydes were the major components. This is the first report of the two isomers in nature. Copyright © 2000 John Wiley & Sons, Ltd.

The chemical composition of the essential oil of Piper bavinum was investigated, using a combination of GC (RI), GC/MS and 13C-NMR. The main constituents were bicyclogermacrene (10.6%), globulol (5.7%), ledene (5.1%), α-pinene (4.4%), viridiforol (3.5%), terpinen-4-ol (3.2%) and α-gurjunene (3.0%).

The essential oil of Acanthopanax trifoliatus (L.) Merr. from Vietnam, was investigated using combination of capillary GC, GC–MS and carbon-13 NMR spectroscopy after fractionation by column chromatography. More than 60 compounds, representing 97.4% of the total amount were identified. The main components were α-pinene (23.9%), sabinene (14.9%), terpinen-4-ol (9.0%), β-pinene (7.7%) and p-cymene (5.8%). Carissone, an eudesmane derivative, was identified as a minor component by carbon-13 NMR. Copyright © 1999 John Wiley & Sons, Ltd.

The essential oils of ambrette (Hibiscus abelmoschus L., syn. Abelmoschus moschatus) were produced from seeds collected in the different provinces of Vietnam. Five samples were investigated and 35 components were identified by a combination of high resolution GC, GC/MS and 13C-NMR spectrometry. The major constituents were found to be (E)-2,3-dihydrofarnesyl acetate (32.9-67.3%), (E,E)- farnesyl acetate (14.9-35.5%), the macrocyclic lactone ambrettolide (3.0-5.5%) and (Z,E)-farnesyl acetate (0.9-5.1%). The oils consisted for more than 90% of acetates and aldehydes.

The essential oil isolated from Asarum cordifolium C. E. C. Fischer recently discovered in Vietnam, and A. glabrum Merr., an endangered species listed as vulnerable in the Red Data Book of Vietnam, have been analyzed by a combination of chromatographic and spectroscopic techniques including 13C NMR spectroscopy. The composition of A. cordifolium essential oil, investigated for the first time, was dominated by elemicin (82.5%). The essential oil isolated from A. glabrum contained safrole (41.9%) as its major component and was characterized by the diversity of phenylpropanoids contained in this oil (10 compounds).

International audience; Cupressus tonkinensis was treated for a long time as a synonym of Cupressus torulosa D. Don. and it was proposed as new species in 1994. The two species differed by morphological characters and they were distinct in their random amplified polymorphic DNAs (RAPDs). Leaves and stems of C. tonkinensis produce monoterpene-rich oils whose composition is investigated here for the first time by combination of chromatographic and spectroscopid techniques. a-pinene (23.1%), sabinene (21.0%) and terpinen-4-ol (14.4%) were the major components of the leaf oil that contained also b-elemol (4.2%). In contrast, a-pinene (42.5%) was by far the major component of the stem oil beside myrcene (10.2%) and cedrol (9.0%).

The volatile compounds identified from four species of Annona from Vietnam are being reported. The oils were obtained from aliquots of plant samples by steam distillation and subjected to GC and GC-MS analysis. The main compounds of Annona glabra L., were β-caryophyllene (21.5%) germacrene D (17.7%), α-cadinol (5.4%) and β-elemene (5.2%). Annona squamosa L., comprised mainly of α-pinene (1.0-11.9%), limonene (0.8-11.7%), β-cubebene (0.5-13.0%), β-caryophyllene (11.6-24.5%), spathulenol (0.8-9.0%), caryophyllene oxide (1.0-10.6%) and α-cadinol (3.3-7.8%). The significant constituents of Annona muricata L., were α-pinene (9.4%), β-pinene (20.6%), ρ-mentha-2,4(8)-diene (9.8%), β-elemene (9.1%) and germacrene D (18.1%). However, camphene (0.2-6.6%), α-copaene (2.0-7.3%), β-elemene (5.9-16.6%), β-caryophyllene (8.3-14.9%), β-bisabolene (0.4-10.2%), δ-cadinene (1.7-4.8%) and germacrene D (9.3-22.8%) were the main compounds common to samples of Annona reticulata L. There were significant amounts of sabinene (11.2% and 2.7%; leaf and stem bark) and bicycloelemene (9.6% and 6.1%; stem and bark).

The leaf essential oils of five Desmos species from Vietnam have been extracted by steam distillation and subjected to GC and GC-MS analyses. The plant samples were Desmos cochinchinensis Lour., D. penduculosus (A. DC.) Ban, D. penducolosus var. tonkinensis Ban, D. chinensis Lour., and D. dumosus (Roxb.) Saff. The oils were rich in sesquiterpene hydrocarbons (65.9%-88.9%) and monoterpene hydrocarbons (6.3%-30.9%). The oxygenated counterparts were less common. The quantitatively significant constituents of the oils were alpha-pinene (2.4%-12.1%), beta-elemene (2.2-39.5%), beta-caryophyllene (13.9-26.3%), germacrene D (9.9-15.5%), bicyclogermacrene (2.0-11.4%) and alpha-humulene (3.8-7.5%). The studied oils could be classified into two chemical forms: oils with abundance of beta-caryophyllene, germacrene D and alpha-pinene (D. cochinchinensis, D. penducolosus var. tonkinensis, D. chinensis and D. Dumosus) and oil with high amounts of beta-elemene, beta-caryophyllene and germacrene D (D. penduculosus).

The essential oils obtained by hydrodistillation from the leaves of five species of Annonaceace grown in Vietnam were analyzed by gas chromatography (GC) coupled with mass spectrometry (GC/MS). The main constituents of Artabotrys hongkongensis Hance were the sesquiterpenes spathulenol (13.1%), β-caryophyllene (6.6%), γ-elemene (6.3%) and δ-cadinene (6.3%). β-Caryophyllene (12.1%), bicycloelemene (11.2%) and bicyclogermacrene (11.6%) were the predominant components of the oil of Melodorum fruticosum Lour, whereas the oil of Polyalthia longifolia var. pendula Hort was comprised mainly of β-caryophyllene (30.0%), α-zingiberene (21.7%), aromadendrene (15.2%) and β-selinene (9.1%). The main constituents of Fissistigma maclurei Merr. were germacrene D (26.1%), α-terpinene (8.2%), spathulenol (10.0%), and bicyclogermacrene (6.6%), while α-santalene (14.3%), β-caryophyllene (6.3%), terpinen-4-ol (6.3%), caryophyllene oxide (5.7%), trans-α-bergamotene (5.3%) and allo-ocimene (5.3%) were identified in significant quantity from Fissistigma rufinerve (Hook.f. & Thomson) Merr.