Guaianolide

 SL guaianolide (11,13-dehydrocompressanolide). 





DEPT spectrum (CDCl 3 , 75.5 MHz) of the guaianolide. 


 Mass spectra recorded in the positive MS E mode for guaianolide and parthenolide (500.0 μg mL -1 ) of the dichloromethane fraction of the





COSY spectrum (CDCl 3 , 300 MHz) of the guaianolide







HMBC correlation spectrum (CDCl 3 , 300 MHz) of the guaianolide. 






HMQC correlation spectrum (CDCl 3 , 300 MHz) of the guaianolide.





 13 C NMR spectrum (75.5 MHz, CDCl 3 ) of the guaianolide. 





1 H NMR spectrum (CDCl 3 , 300 MHz) of the guaianolide.

Journal of the Brazilian Chemical Society

Print version ISSN 0103-5053
On-line version ISSN 1678-4790

J. Braz. Chem. Soc. vol.14 no.5 São Paulo Sept./Oct. 2003

http://dx.doi.org/10.1590/S0103-50532003000500006 

Sesquiterpene lactones and other chemical constituents of Mikania hoehnei R.

Juliana S. Chaves; Dionéia C. R. de Oliveira^*

Departamento de Física e Química. Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Via do Café s/n, 14040 903, Ribeirão Preto-SP, Brazil

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532003000500006

8b-hydroxyzaluzanin D (1). Colorless gum; C₁₇H₂₀O₅; IR n_max/cm^-1 (NaCl film): 3494 (OH alcohol), 1750 (g-lactone), 1730 (acetyl group), 1664 and 1641 (c=c double bonds); EI-MS, m/z (relative intensity in %): 262 [M⁺- ketene] (14), 91 (24), 43 [CH₃CO]⁺ (100); ¹H NMR (300 MHz, CDCl₃), see Table 1. ¹³C NMR, DEPT 135⁰ and HMQC (75 MHz, CDCl₃): 45.0 (d, C-1), 36.5 (t, C-2), 74.5 (d, C-3), 147.7 (s, C-4), 50.4 (d, C-5), 77.6 (d, C-6), 50.1 (d, C-7), 65.7 (d, C-8), 41.8 (t, C-9), 142.8 (s, C-10), 136.0 (s, C-11), 170.8 (s, C-12), 121.6 (t, C-13), 117.4 (t, C-14), 114.2 (t, C-15), 169.4 (s, C-1'), 21.2 (q, C-2').

Results and Discussion

The chromatographic fractionation of hexane, ethyl acetate and ethanol extracts yielded stigmasterol, b-sitosterol and campesterol, lupeyl acetate,²¹ b-sitosteryl and stigmasteryl glucopyranosides,²² benzil 2,6-dimethoxybenzoate,²³ luteolin,²⁴ kaempferol²⁴ and dehydrocostuslactone.^13,14 The structures were established by comparison of their spectroscopic properties (mainly IR, ¹H and ¹³C NMR) with those reported in the literature and in some cases by direct comparison with authentic samples.

Structure of the guaianolide 1 was deduced from the IR, MS, ¹³C and ¹H NMR spectra data and the stereochemistry was defined from the coupling constants' value J and nOe difference correlations. This lactone has been previously reported as a synthetic compound obtained in the controlled acetylation of the natural guaianolide Integrifolin (8-epi-desacylcynaropicrin).¹² The IR spectrum displayed bands at 1750 cm^–1 (g-lactone), at 1730 cm^–1 (acetyl group), at 3494 cm^-1 (hydroxyl group) and weak bands at 1664, 1641 cm^–1 (c=c double bonds).

Inspection of the ¹H NMR spectrum of compound 1 indicated several signals very close to those observed in Zaluzanin D¹⁵. The position and the stereochemistry (b-orientation) of hydroxyl group at C-8 were determined by nOe correlation (Figure 1). nOe's were observed between the H-8 (d 4.37) and H-13a (d 5.62), H-7 (d 2.98) and H-9b (d 2.61). In the same way, correlation of the H-3 (d 5.50) with H-2b (d 2.45) and H-15a (d 5.32) in the nOe spectrum confirmed the a-orientation of H-3 which was attached to the carbon atom which is linked to the acetate group, as previously defined as Zaluzanin D (compound 2).

Just as the NMR spectrum of 2, the NMR spectrum of guaianolide 1 exhibited two characteristic doublets at d 6.42 and 5.62 (J 3.8 and 3.2 Hz respectively) corresponding to hydrogens of H - 13a and H - 13b of an exocyclic methylene group conjugated with a g-lactone. The exocyclic methylene groups attached to C-10 and C-4 were characterized by two singlets at d 4.99 (H-14a), 5.10 (H-14b) and a pair of triplets (J 2.0 Hz) at d 5.32 (H-15a) and 5.52 (H-15b), respectively.

The stereochemistry cis of the ring junction at C-1 and C-5 was established by the coupling constant (J 8.3 Hz) between H-1 and H-5. In the case of 1b, 5a-trans- guaianolide, a value of 10.0 Hz or greater is expected according to that reported in the literature.^25,26 The lactone ring junction was confirmed to be trans (6b H, 7aH) by the large coupling constant (J ~ 3.0 Hz) of the H -13-a-methylene protons this is due to H-6/H-7 (J 8.9 Hz) coupling constant.¹⁶

All other signals were in agreement with the proposed structure of the guaianolide 1 (Table 1). Heteronuclear multiple quantum correlation ¹H – ¹³C (HMQC) allowed us to assign unambiguously the signals of all carbons.

Besides the importance chemosystematic,²⁷ sesquiterpene lactone posseses a wide spectrum of biological activity.²⁸ Zaluzanin C, Zaluzanin D and its derivatives have shown several biological activities, such as activity against the P 388 lymphocytic leukemia in vitro,^29,30 antifungal activity,^31,32 inhibitory activity on nitric oxide production and nuclear fator KB,³³ inhibitory activity on ethanol absorption.³⁴

///////////





PORT LOUIS, port louis FOOD, MAURITIUS

.

 

 

 

 

 
 

 
 

/////////

Alkylidene Phthalides

.

http://pubs.acs.org/doi/suppl/10.1021/acs.orglett.6b01203

The N,O-diacylhydroxylamine derivative 4 has been prepared and its reactivity with nucleophiles investigated. On reaction with lithium enolates of cyclic or acyclic ketones, 4 is converted stereoselectively to the corresponding alkylidene phthalide. The stereochemical outcome of the transformation can be modified by changing the polarity of the reaction medium and the products isomerized under acidic conditions.

Stereoselective Synthesis of Alkylidene Phthalides

Andrei Dragan, D. Heulyn Jones, Alan R. Kennedy, and Nicholas C. O. Tomkinson^*

WestCHEM, Department of Pure and Applied Chemistry, Thomas Graham Building, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, U.K.

Org. Lett., Article ASAP

http://pubs.acs.org/doi/abs/10.1021/acs.orglett.6b01203

//////////// 

• Supporting Info

Mauritius

 

Mauritius

Country in East Africa

Mauritius, a volcanic island nation in the Indian Ocean, is known for its beaches, lagoons and reefs. The mountainous interior encompasses Black River Gorges National Park, with rainforests, waterfalls, hiking trails and native fauna like the flying fox. The capital, Port Louis, blends foreign influences and offers sites such as the Champs de Mars horse track, colonial Eureka plantation and 18th-century botanical garden.

Capital: Port Louis

Dialing code: +230

Currency: Mauritian rupee

President: Ameenah Gurib

Prime minister: Anerood Jugnauth

Continent: Africa

 

 

 

 

 

 

 

10 free things to do in Mauritius

If you’re staying in one of our luxury Mauritius hotels, or a private villa, we appreciate how hard it can be to drag yourself away from such peaceful surroundings. But with so much to see and do on the island, it would be a shame not to venture beyond the gates of your resort. Follow our guide to the best free things to do in Mauritius and go beyond the hotel – without spending a Mauritian rupee.
1. Wander through Port Louis market

Take a stroll through the daily Port Louis market for a real insight into the people, produce and culture of Mauritius. Take time to absorb all the different sights and sounds, and experience the sweet scent of exotic fruits, herbs, spices and street food.
2. Visit Cap Malheureux

Spend an afternoon ambling through this atmospheric fishing village just north of Grand Baie on the island’s northernmost tip. Due to a history of shipwrecks, the name translates as ‘Cape Misfortune’ but there’s nothing sad about this secluded beauty spot with views out to the offshore islands of Ile Ronde, Ile Plate and Coin de Mire.
3. Discover the Mauritius art scene

Mauritian artists have much inspiration to draw on, with a vast cultural heritage derived from Africa, Asia and Europe, and an incredible natural landscape on the doorstep. You can see their work, and that of other international artists, at some of the many art galleries on the island, including Galerie du Moulin Cassé, Seebaluck Art Gallery and 3A The Excellence of Art
4. Admire the surfing action at Le Morne

Surfing and kitesurfing can be challenging to master, but they both make excellent spectator sports if your sense of balance is less than stellar. One of the best places to watch these daredevils in action is down at Le Morne in the island’s south west, where the favoured position and large flat lagoon makes for excellent watersport conditions.
5. Watch the fishermen’s catch arrive at Grande Gaube

The little north eastern fishing village of Grande Gaube is a great place to get a feel for one of the island’s longstanding traditions – fishing. The village is home to many families whose livelihood depends on the sea, and if you don’t mind a very early start you can watch the men return to shore in their wooden pirogues and unload their overnight catch.
6. Explore Chinatown

When large numbers of Chinese traders arrived in the 1940s, they settled in the area around Royal Road in the Mauritian capital of Port Louis, and a thriving Chinatown was born. Shopfronts burst at the seams with all kinds of goods: paper lanterns, crockery, hand-held fans, toys, spices, dried vegetables, musical instruments. Wander the streets for a glimpse of this fascinating neighbourhood.
7. Walk around Ganga Talao

Considered by many to be the most sacred Hindu place in Mauritius, Ganga Talao, otherwise known as Grand Bassin, is a secluded lake which lies within the crater of an extinct volcano about 550 metres above sea level. A popular spot for locals and tourists alike, the site is also home to a temple dedicated to Shiva and other Hindu gods.
8. Learn about the island’s past at Aapravasi Ghat

One of two World Heritage Sites in Mauritius, Aapravasi Ghat is the original immigration depot which saw more than half a million indentured labourers arrive between 1834 and the 1920s to work in the sugar plantations. Most Mauritians are able to trace their ancestry back to this site.
9. Watch the sun go down at Trou aux Biches

It’s the Mauritian beach that everyone’s heard of, and for good reason. If you’re looking for the perfect location to watch the sky do its thing in glorious technicolor, the sunsets here are legendary. And if a proposal is on the cards, it might just be the ultimate spot.
10. Discover Black River Gorges National Park

Much of the forested mountain range in the island’s south west corner belongs to Black River Gorges National Park. This protected haven for endangered species of flora and fauna is full of hiking trails and viewpoints, and is one of the best places in Mauritius to feel at one with nature. The deep green views across this remote volcanic landscape are spectacular.

/////////

2,4,6-Tris(2-chloropropan-2-yl)-1,3,5-trioxane

2,4,6-Tris(2-chloropropan-2-yl)-1,3,5-trioxane 


mp 106–108 °C (Lit.(1) 106–107 °C);  

¹H NMR (CDCl₃, 300 MHz) δ = 1.54–1.63 (m, 18 H), 4.86–4.90 (m, 3 H) ppm;  

¹³C NMR (CDCl₃, 75 MHz) δ = 26.7, 67.2, 103.0 ppm;

IR ν_max (solid) 1154, 1122, 1107 cm^–1.

 


ref 1
Stevens, C. L.; Gillis, B. T. J. Am. Chem. Soc. 1957, 79, 3448– 3451, DOI: 10.1021/ja01570a036



/////////



Al Shifa College of Pharmacy
Poonthavanam Post, Kizhattur Village
Perinthalmanna, Malappuram Dist
Kerala-679 325, India